Sophia Yin

Sophia Yin, DVM, (recently deceasedwas an applied animal behaviorist. A long-time The Bark contributing editor, she was also the author of two behavior books.

Good Dog: Studies & Research
What Dogs are Saying with their Barks
Research explores animal sounds as a form of communication

A sleep-deprived gentleman once asked me, “How is it that dogs can bark so long? When I yell for hours on end, I lose my voice.” Then he went on to describe the dogs in his neighborhood, whose barking bouts lasted longer than all of the Wagner operas combined.

Anyone who’s experienced an epic canine oratorio has probably wondered, “What’s going on? Do dogs just like to hear the sound of their voices?” Until recently, some researchers thought this was the case, taking the position that because dogs bark at almost anything and everything and for hours on end with no apparent reply, dog barking must not be a specific form of communication. Rather, barking is just a loud and obnoxious way for them to say, “Hey! Look at me!” More specific information, it was postulated, comes from reading body expression and olfactory messages.

Given the sparse number of studies on vocal communication in dogs, this contention seemed reasonable until consideration of the ever-expanding research on songbirds, ground squirrels and monkeys provided a very different view.

For decades, while some looked at dogs and pooh-poohed their barks as nuisance noise, others—such as Dr. Peter Marler, professor emeritus at the University of California, Davis, and a pioneer in the field of vocal communication in birds—were taking a closer look at the sounds that animals, including the common chicken, make. Says Marler, “Chickens are an obvious case … to most people, the sounds are a kind of noise, or vicarious vocalizations that have little meaning. But this view could not be more wrong. In fact, many studies show that chickens have a very rich and elaborate vocal repertoire, and that different calls mean different things.”

These studies started with the finding that roosters have specific types of predator-alarm-calls, one for aerial predators such as hawks, and another for ground predators. Play-back studies—in which hens hear taped versions of these calls in the absence of both a predator and visual signals from the rooster—show that the calls deliver specific information. Hens duck for cover upon hearing a recording of the aerial call and extend their necks and look for the danger when they hear the ground-alarm-call. These responses to the respective calls tell us the calls have specific meanings to those who hear them.

And those aren’t the only interesting chicken calls. Roosters also make a particular call when they find a morsel to eat, and this sound, part of the rooster’s courtship routine, serves to attract hens. As with the alarm calls, recorded food calls played back from behind a barrier with a hen on the other side will cause the hen to approach when she hears them. What’s more, states Marler, “If the calls were recorded from a male who had a very choice food item, like a cricket, she’ll approach faster than if the calls are given [for] a piece of grain or peanut. So the calls convey some information about food quality.” And, like the alarm calls, these differential responses indicate the calls have meaning.

But what about those calls, like barking, that go on and on with no obvious response from other animals? Dr. Don Owings, professor of psychology and animal behavior at the University of California, Davis, says, “Call communication can be organized on different time frames, so that you don’t see an immediate response to each vocalization. You have to look at the effect of signaling in a time frame that is appropriate for the signaling behavior.”

This longer time frame reveals interesting things. For instance, California ground squirrels respond to mammalian predators by uttering a chatter vocalization. Other squirrels respond by running to their burrow or standing up and looking around. If the predator lingers, the calling ground squirrels move from an erratically spaced, episodic chatter to a highly rhythmic “deet-deet-deet.” Observation reveals that individuals who hear the vocalization don’t startle or respond to each vocalization, and often return to their feeding and previous activities. However, Owings’ student, Jim Loughry, looked more closely at the overall activity and body postures over a longer time period and found that squirrels listening to this rhythmic vocalization were more vigilant overall. Even if they were eating, they would eat while sitting upright as they scanned their surroundings.

So what possible functions could vocalizations that carry on for hours at a time have? Well, male songbirds sing for hours at a time to attract females and to defend their territory. Additionally, during breeding season, wolves howl for hours at a time with no detectable reply. This howling may function as a beacon to attract females from neighboring packs. Perhaps prolonged canine vocalizations have a long-term function as well?

In 2000, armed with the rich body of literature on vocal communication and the support of those already well-established in the field, I decided to pursue the question of barking in dogs. Yes, some dogs do bark incessantly and some seem to bark in any and every context, but was it possible that barks were slightly different in different contexts, so that dogs actually produced bark subtypes? If so, perhaps these vocalizations could be specific forms of communication.

With the advent of improved acoustic-analysis equipment, others had been able to test similar theories in other animals. As mentioned earlier, Owings found that squirrels emit chatters when they see mammalian predators and occasionally with avian predators; they also chatter when having aggressive interactions with another animal and immediately after copulating with a female. Though these findings might lead one to conclude that the vocalization is not functionally specific, modern sound equipment revealed that the chatter calls are structurally different in different contexts.

Similarly, Dr. Julia Fischer, a researcher at the Max–Planck Institute for Evolutionary Anthropology in Leipzig, Germany, found that Chacma baboons have different bark vocalizations for different contexts, including an alarm bark that is structurally different from a contact bark, which is uttered when mother and offspring are separated.

To test my hypothesis about bark subtypes, I found ten barking dogs and recorded them in three different situations. In situation one, the disturbance situation, the dog was recorded while barking at the sound of the doorbell. In situation two, the isolation situation, I recorded the dog when it was locked outside, isolated from its owner. And in situation three, the play situation, I recorded barks as the dog played with its owner or another dog. This sounds simple but surprisingly, even dogs dubbed excessive barkers often couldn’t be used because they only barked in two of the three contexts, which suggests that maybe dogs don’t really bark at any- and everything.

In order to ensure that I had enough barks to give a good idea of the average bark for each context for each specific dog, we set up the dogs in each situation many different times on many different days over a three-month period. Once I’d collected enough barks, more than 4,600 in all, I turned to my collaborator, Dr. Brenda McCowan, a researcher at the University of California, Davis, who specializes in acoustic communication in animals ranging from dolphins to cattle. Using a sound-analysis program that converts audio to a visual representation of pitch-over-time and amplitude- over-time and a computer macro (a set of instructions for the computer to follow) designed by McCowan, we took 60 sequential measurements over time for one bark, or along the visual representation of each bark.

The data yielded clear results. Dog barks were different in the different contexts and therefore, could be categorized into subtypes. The doorbell-disturbance barks were relatively harsh, low-pitched and with little pitch variation throughout. Dogs blurted these barks out full force and so fast that they were often fused into what I formally dubbed “superbarks.” Isolation barks, on the other hand, were higher pitched and more tonal, with more variation in both pitch and amplitude. Usually, they occurred as single barks, but some dogs definitely learned to bark more repetitively when doing so eventually reunited them with their owner. The play barks were similar to the isolation barks, except that they usually occurred in clusters rather than singly.

Not surprisingly, we also found that dogs could be identified by their barks. This basically means that as you lie in bed listening to the sound of the neighboring canid’s greatest hits, you should be able to identify exactly which neighboring canid is the offending artist.

So what do these findings mean? Well, we can’t tell whether dogs intentionally alter their barks to deliver a message to other dogs or people. The only way to determine this would be to teach the dog English so that he could tell us, “I am now intentionally changing my bark to deliver this message.” Most likely, the variation is a reflection of the internal motivational state the dog is in at the time that he barks.

What we can tell is that because there are specific bark subtypes, barks have the potential to play specific communicative rolls and provide specific information—intentional or unintentional—to the animals, including humans, who are listening. Not specific like, “Timmy’s stuck in the well! The one to the left of the big oak tree on the other side of the creek!” More like, “I’m separated from you! Come get me!” or “Intruder alert!” Furthermore, since bark subtypes occur in specific contexts, we can learn to tell what our dog is saying by listening to his barks and then examining the context. His “woof” for an unknown intruder may be different from his “ruff” when he alerts to a friend approaching the house. And his “huff” to come inside may be different when the desire is more urgent.

But is the barking actually communicative? Well, for a vocalization to be communication, the animal who hears the signal must respond in a specific way. As with the chicken food-call and alarm-call cases, this is usually tested through play-back studies, and such studies have not yet been performed on dogs. However, a study by David MacDonald and Geoff Carr on free-roaming dogs in Italy suggests that barks can have specific effects on other dogs, even when the “barkers” can’t be seen. The free-roaming dogs in this study lived in small groups and scavenged at local dump sites. When the largest group of dogs barked in a group prior to heading toward the dump site from up to one kilometer away, dogs in smaller groups consistently evacuated the site; they apparently knew that they were no match for the larger gang. And on a more familiar note, Marler points out that if we pay attention, it’s easy to notice that barking usually elicits a response from other dogs.

But this is only half the picture. Says Owings, “For the vocalization to be communicative, the vocalizers should be sensitive to social contexts and consequences.” That is, the animal producing the vocalization should adjust it based on the behavior of the listeners. While there is little research in this area, general observations indicate that this happens too. For instance, when one dog barks at the doorbell and another dog, or even the resident human, joins in a barky “No! No!”, the dog responds with louder and more prolonged bark behavior. Take away his back-up and suddenly, the initial barking bout abates. Or then there’s the dog who barks at you until you toss his toy, but barks harder and louder when you’re on the phone because that’s the time when you’re most likely to toss the toy quickly in order to get him to quiet down. These cases provoke the question: What exactly is the role of the human (the primary animal to whom many barks are directed) in the development of bark behavior in dogs?

Clearly, there are an infinite number of questions about barking and its communicative function for the dog, and there’s much catch-up needed to reach the same level of understanding that we have for chickens and squirrels. But it all starts with a simple study showing that dogs have different barks in different contexts, and plugs away, developing and answering one question at a time.

To test your own ability to interpret dog barks, or to read more about barks as communication or as a nuisance behavior, visit Dr. Yin’s “Nerdbook” website.



News: Guest Posts
Five Essential Tips for Training Dogs to Sit Politely Instead of Jumping

It’s that time of year when good doggy manners manner. Sophia Yin, DVM has these simple pointers for teaching how not to jump up on your guests, but how to be good hosts and greet them by sitting politely. Her techniques, like using high reinforcement rates, can be easily applied to other training essentials, like the “holy grail” of a solid recall. Give it a try! —Editor’s Note

Everyone knows that you should reward good behavior and ignore bad behaviors, right? So if your dog jumps on you, ignore the jumping and then reward with a treat when he sits, right? WRONG! This answer is wrong enough that if you're one of my interns and, after your first several sessions, you still think it’s right, you will not be an intern for much longer. Why? Because if this is the information you provide to clients, many will fail and turn to more punitive methods. The following are 5 essential tips for approaching problem behaviors such as jumping.

Tip 1: Don’t ignore the unwanted behavior. Remove the rewards for unwanted behavior instead. It turns out that if you ignore unwanted behavior, you may accidentally be rewarding it. You should instead remove rewards for unwanted behavior-which is very different. For instance, most clients complain that they are ignoring their dog when he jumps but they aren’t getting the results they want. They don't realize that the dog does not perceive their actions as removal of attention. Their hands are still dangling like tug toys or they are still walking around which makes them look interactive, see the video below. What owners should be told is to remove what their dog wants, attention in this case, within 0.5 seconds and do it in a way that the dog perceives that they have removed their attention. That may mean standing up completely straight and holding both arms folded against their body while they stand silent and stationary. Or it may just mean pulling their hands away and back to their body. If they remove their attention in a clear manner, they will see a quick and clear response from their dog.

Tip 2: Train the desired behavior first. It’s essential that the humans know to first train the good behavior—sitting politely—or it could take the dog forever to figure out what else will earn rewards besides jumping. A five or ten-minute training session where the dog earns 10-50 rewards is generally adequate.

Tip 3: Use a high reinforcement rate first. Then quickly and systematically reduce and vary the rate. Once the dog is sitting, the owners need to reward at a high reinforcement rate. Giving just one treat for sitting often won't hack it. The first treat you give is for sitting, but additional treats are for remaining seated so that Rover doesn’t just get up and try to jump again. At first, the treats should come rapidly—enough to keep Rover seated—but as soon as Rover is sitting stably at that treat interval, the interval should be increased and varied. This process should be repeated until Rover is sitting automatically and remaining stably seated. Then the focus should be on switching to other rewards such as petting and praise.

Tip 4: Use a flash lure to prevent Rover from getting the first jump in. If your dog tends to jump on you and then sit afterwards, you should change your strategy FAST so that you don't accidentally reward this chain of behaviors—jump then sit. You can add in what I call a flash lure before Rover has a chance to jump. As he’s running over to you but before he has a chance to jump (preferably when he’s about 2 steps away), suddenly flash a treat right to his nose level by just straightening your arm. This will cause him to stop will all four feet on the floor. When he's completely stationary, you can quickly bring the treat all the way back to your body and clearly out of his reach so he knows he doesn't get it yet. Once he sits, then he gets the treat.

Tip 5: Practice a lot in a short period of time. Because your goal is to develop a new greeting habit with your dog, it’s essential that you practice a lot over a short period of time. For instance, if you set up the situation where your dog is excited to see you five times a day and each time he earns 10-20 rewards and never has a chance to jump then by tomorrow he will probably be sitting automatically in this situation. By the end of the week, the good behavior should be a habit!

That's, of course, assuming that in between your practice sessions he didn't have a chance to get rewards for the opposite behavior!

These are some important subtleties that can help you get behavior changes quickly. It’s important to apply these principles to all training exercises to get the fastest progress.



Used with permission from Dr. Sophia Yin, visit her on drsophiayin.com


Good Dog: Studies & Research
For Dogs, What We Do is More Important Than What We Say
Research shows that for dogs, actions count

My suspicions were confirmed on December 26, 2002, while at the Metreon Theater in San Francisco. As the youngest in the family, my job was to wait in line for tickets, and, knowing this, I went prepared with a scientific article titled, “Do dogs respond to play signals given by humans?” The research, lead by Nicola Rooney at the Anthrozoology Institute in Southampton, UK, featured 21 dog/owner pairs playing—or at least, attempting to play. In what could surely have been billed as a comedy, owners patted the floor, barked, bowed, shuffled their feet, slapped their thighs, crawled on all fours—anything to get their dogs to romp with them.

The researchers videotaped the sessions and meticulously catalogued, recorded and identified common actions used by owners to solicit play. They then tested to see which signals actually worked. As expected, bowing in a human version of a dog play-bow, as well as lunging while verbally encouraging the dog, usually elicited play. Other gestures, such as tickling the dog as though she were a human infant, or stamping one’s feet as though dislodging last week’s dried mud from hiking boots, just earned blank looks. And surprisingly, patting the floor and clapping were less than 50 percent successful. What’s more, while barking at, kissing or picking up the little pooches probably brought on laughs from the researchers, most dogs failed to find these actions amusing.

As interesting as these findings were, the real message—one that stayed with me—was what came next. Upon analyzing the data, the researchers found that although some actions tended to instigate play while others resulted in silent stares, the frequency with which the owners used the signals was unrelated to their success. In other words, owners tended to use unsuccessful gestures even after they were demonstrated not to work. And there I had it, scientific proof: Dogs are smarter than humans. Well, at least in some ways. You see, dogs are champions at trial-and-error learning. They have all day to try things out and see what works.

For instance, want to play fetch when your people aren’t interested? Grab a tennis ball and drop it at your human’s feet, and then bark until he finally picks it up and tosses it. Getting the silent treatment? Bark longer and louder—you’ll eventually get a response. Or, choose the right time, like when your human’s on the phone; that’s when they’ll do anything to get you to shut up.

While dogs are masters of this style of learning, we humans are hindered by our much-vaunted cognitive abilities. Armed with the wonderful capacity to observe and imitate, we copy the behaviors we see, whether they work or not. Clouded by our preconceptions of the techniques we’re supposed to use, we forget to stop and evaluate whether our actions or methods actually work.

This might seem like fun and games when it’s just us dancing around trying to get our dogs to play. At worst, when our pooch refuses to romp, we attribute it to her not being in the mood. But when it comes to something more important, like coming when called or sitting on command, a dog’s failure to perform can result in her being labeled “stubborn” or “stupid.” Because what else could it be?

Well, according to a series of research studies by Daniel Mills (veterinarian and researcher in Behavioural Studies and Animal Welfare at the UK’s University of Lincoln), as with play signals, much poor performance could be attributed to dogs’ inability to decipher our signals. It turns out that even if our dog responds to our commands some of the time, she may not know what they mean as well as we think she does.

According to Mills, a number of factors determine how well our dogs perceive the message we intend to give. One is whether the signal is verbal or visual. While we humans are used to communicating by talking, Mills’ research indicates that this may not be the best mode of communication with dogs. In an experiment to test which signal type takes precedence, Mills and his colleagues trained dogs to respond to a verbal right and left cue as well as a visual pointing cue for the same behaviors. To guard against bias that could be created by the order of teaching, half of the dogs were initially trained using verbal cues and the other half, using visual cues

Then they tested the dogs by placing a treat-holding container on either side of the subject—one box on the right and one on the left. When they gave the “left” cue, the dog got the food reward if she ran to the box on the left. If she ran to the wrong box, she got no reward. Once dogs consistently responded correctly to verbal and visual cues alone, the cues were given together, with a twist. The researchers gave a verbal signal for one direction and a visual signal for the other to see which one the dogs would follow. For anyone whose dog competes seriously in agility, the results were a no-brainer: The dogs consistently followed the visual pointing cue and ignored the verbal cue. This dynamic plays out on every agility course—a dog will usually go where her handler’s body is pointing rather than where the handler might be verbally trying to send her.

This bias toward the visual as opposed to the verbal can pose problems for dogs even in everyday life, says Mills, “This simple example emphasizes that when training dogs, we have to realize that dogs may be reading signals we’re not aware of.” So when your voice tells the dog to do one thing but your body tells her to another, she’s not being stubborn—she may just be reading a different message than the one you think you’re sending.

Even when we’re purposefully sending visual commands to our dogs, such as in the obedience trial ring or field trials or other long-distance work, there’s more to the signal than we might think. Says Mills, “In a similar study, we looked at the dog’s response to different visual right-and-left cues. We compared eye movement and head movement to the right or left with pointing right or left, but keeping the eyes and head looking forward.” Using six dogs, they found that dogs found the hidden food source faster when the two signals were presented together which, Mills says, suggests that “Dogs are taking in the whole picture of what’s going on.” That is, they don’t look at our hands or our head, they look at our entire body. As a result, if all signals are not consistent, dog can become confused.

Do these studies mean we should scrap verbal commands altogether and focus on the visual signals? Obviously, dogs can learn verbal commands, because we use them all the time and some dogs respond correctly on a regular basis. But perhaps even those who respond don’t know the cues as well as we think. Mills and his colleagues performed a series of studies to test this, too. First, they tested slight variations in the commands to see if dogs recognized them as the same words. They taught dogs to stand and stay, and then, from five feet away, the trainer gave either a “come” command or a “sit” command.

Once the dogs were reliable about responding correctly, the researchers changed the command words slightly. In place of “sit,” they used “chit,” “sat” and “sik,” and in place of “come,” they used “tum,” “keem” and “kufe.” The results? In general, dogs did not respond as well to the similar-sounding words; or, taken from another viewpoint, they were able to recognize that the similar-sounding words were not the same as the commands they had learned. This sounds like no big deal, but, says Mills, “From a practical point of view, due to slight differences in how handlers pronounce words, obedient response to one handler’s commands won’t necessarily transfer to another unless the phonemic characteristics are mimicked.”

You might think you could get around this by tape-recording the command and just playing it back, but Mills found that dogs don’t respond to tape-recordings as though they were a real-time human voice. In yet another experiment, a “come” or “sit” command was given in one of four conditions: from a person sitting in a chair; from the same person wearing sunglasses to prevent visual cues; and both conditions, but the command issuing from a tape recorder behind the person. Says Mills, “Dogs made many more errors when the tape recorder was used.”

Such errors could be attributed to the dogs distinguishing a difference between the tape-recorded and live voice command, but another hypothesis is that dogs also rely on lip movement or some other indication that the human is speaking to them. In fact, in a fifth variation, the handler uttered the “come” or “sit” cue while looking away from the dogs, and they again made many errors, indicating that orientation of the handler is important.

By now, it should be clear: Be aware of visual signals, as they may override the verbal commands. Make sure all of your signals mean the same thing, or your message may look more like a dubbed version of Godzilla than a clear-cut cue. When you do use verbal cues, make sure everyone says them exactly the same way, or train your dog that slight variations mean the same thing. And if you plan on your dog responding correctly to your verbal commands when you’re out of sight or facing away, you’ll have to specifically train him to do so.

And that’s not the end of it. Turns out that the emotional content of your message is important too. Mills’ group trained dogs to reliably come or sit when a handler was standing five feet away behind a screen. Then they tested to see how dogs responded to different emotional contents. The commands were uttered in a neutral tone; a happy tone, with the inflection ascending; an angry version, with the tone descending; and a gloomy version, in which the handler sighed first. Dogs responded more predictably when the tone was positive, but when the command was said in an angry or gloomy manner, there was more variation in their responses.

So what’s the take-home message? The one your pooch is dying for you to learn? Here it is: Perhaps when your dog gives you a blank stare after you utter a command you think he knows, she has a good reason. Because when communicating with our pets, it’s not just what we say, it’s how we say it and whether our visual and verbal cues are sending the same message. Once we become more aware of the signals we send to our dogs and how they perceive them, we can cut down the number of everyday frustrations and open clearer lines of communication with our four-legged friends.



Wellness: Health Care
Vet Advice: Seizures in Dogs and Canine Epilepsy
Don’t delay—see the vet today for a thorough workup

Few events are as terrifying as witnessing your pet in the throes of a full seizure. One second, he looks perfectly normal, and the next, he’s on his side, eyes glazed, muscles twitching frenetically. He may even lose control of his bladder or bowels. A result of abnormal electrical activity in the brain, this episode may last only seconds, but when it happens, time seems to move in slow motion.

For some dogs, this is a one-time experience, but in most cases, seizures recur. If so, and if the abnormal electrical activity is caused by an underlying problem within the brain, the condition is termed epilepsy.

You might think that because epilepsy is fairly common, diagnosis and treatment are straightforward. Unfortunately, that’s not the case. Patients often show no signs; diagnostic tests are frequently negative; and, at least initially, the actual seizure events can be few and far between. These factors can contribute to a decision to take a wait-and-see approach, which can lead to problems later on.

As Dr. Michael Podell, a veterinary neurologist at the Animal Emergency and Critical Care Center in Northbrook, Ill., notes, “It’s important to identify—as much as possible—the underlying cause … Sometimes it’s easy to take the conservative approach … [but] unfortunately, it can often be a more serious problem.”

Consider, for example, one of Podell’s recent cases. “I saw an eight-year-old Shepherd mixed-breed who had her first seizure almost a year ago. The second one was several weeks later. Her regular veterinarian performed blood work and radiographs, and all was OK. She did not have another [seizure] until January. Then she had two more. Then the owners brought her to see us.” Though she looked normal, with no obvious neurological problems, says Podell, “she had a meningioma in her olfactory lobe the size of a golf ball.” Fortunately, these benign tumors, the most common type of brain tumor, can be treated with good success by veterinary neurologists.

Because there are so many potential underlying causes of seizures, the workup must be step-wise and thorough, a comprehensive attempt to parse the possible culprits: disorders originating within the brain (tumors; viral, bacterial or parasitic infections; strokes; head trauma) from those originating outside the brain. For instance, nutritional deficiencies as well as toxins like lead, insecticides, moldy foods and some human supplements can provoke brain changes that lead to seizures. Additionally, metabolic abnormalities such as liver or kidney disease can cause seizures, and some anesthetic agents and medications may also trigger them in sensitive animals.

The workup starts with a history, including information on vaccinations, diet, exposure to toxins, and the time relationship between seizures and other activities. In most cases, blood chemistry, a complete blood count and urinalysis will help systematically rule out many of the extracranial causes. If no underlying disease process is found and the animal is between one and five years of age, idiopathic (cause unknown) epilepsy may be diagnosed. If the dog is less than one year of age, he is more likely to have a congenital abnormality, and if he’s older than five to seven years of age, specific disorders of the brain are more common. In turn, these cases (as well as those with difficult-to-regulate idiopathic epilepsy) will require further workup, which may include an MRI and cerebral spinal fluid tap.

Regardless of age and the likelihood of finding idiopathic epilepsy, early treatment is important, because with each seizure, more nerve cells within the brain will begin to fire randomly. As Dr. Podell notes, “The brain’s threshold for seizure may lower on a constant basis.” In other words, each seizure makes it more likely that another one will occur. This in turn can make the seizures progressively more difficult to manage.

So, to the bottom line: In general, Dr. Podell suggests, “If a dog has had two seizure clusters [two or more seizures occurring over a short period of time, with the dog regaining consciousness in between] in a year, or two or more regular seizures within a six-month period,” he should receive appropriate diagnostic workup and treatment as soon as possible. Early diagnosis and treatment with anti-seizure medications where indicated are critical to a successful outcome.

To find out more about canine seizures and epilepsy, start with a visit to the Canine Epilepsy Network.


Good Dog: Studies & Research
Dog Training: Operant Conditioning
When operant conditioning clicked (and clucked)

On a warm and slightly overcast morning in 1967, a rusty, mustard-colored station wagon slowly approached the terminal at San Francisco International Airport. Wheels still rolling, a door opened and something gray jumped out. As the wagon continued on its way, an animal headed toward the terminal. It was a cat.

Straight five steps, then wait. The glass door opened and as a portly man in a business suit dragged his overnight bag through it, the cat darted in. Straight 10 paces and the cat was inside the terminal. It headed left 20 feet, then right 30 feet, then left two more feet. No one seemed to notice. The cat settled under a bench where two men sat, engaged in intense conversation. Ten minutes passed, then 20; the cat lay patiently, its tail occasionally twitching.

Then, abruptly, the cat stood up and retraced its steps. Two feet to the right, 30 feet to the left, 20 feet to the right and out the glass doors. Once again, the station wagon pulled up and without stopping, a door opened. The cat leaped in. Mission accomplished.

The project, commissioned by the CIA and run by Animal Behavior Enterprises, had been a success. The cat’s cochlear implant (a device agents used to listen to the cat’s environment) had proven reliable, and its months of training using the relatively new technology of operant conditioning had proven effective for this intelligence operation.

Does this sound preposterous? Would it sound less preposterous if the trained animal had been a dog? Thanks to the science of operant conditioning, European police and military teams have been able to train their working dogs to perform at a much higher and more reliable level than had been possible using traditional coercion- based methods.

This type of training is no small feat. In 1996, Simon Prins, co-author of K9 Behavior Basics: A Manual for Proven Success in Operational Service Dog Training (2010), was hired to lead an innovative project for the Canine Department of the Netherlands National Police Agency. A test project with a three-year timeline, it would continue if it were a success. The project included a detailed list of tasks for dogs to perform.

“This included normal operational tasks, such as tracking, and explosive and narcotics detection,” says Prins, “but also climbing, rappelling, traveling by helicopter and boat and, the most challenging, training dogs to work with cameras and to follow radio or laser guidance at long distances.”

Although Prins had been a patroldog handler in the regional police force for only a few years, he was selected for this project because he was seen as an innovator. “I had been questioning our traditional force techniques because I noticed that dogs would shut down and stop working, or my police dog would become aggressive to me and to the trainer. So I was already looking for new methods.”

Stepping Up
New methods were what the job was all about. “The other traditional [forcebased] trainers all said that radio or laser guidance was not possible,” according to Prins. But he was sure there must be a way; so, even though he would not be able to return to his old job if he failed, he accepted the challenge. Within three years, he had succeeded in completing all of the tasks set for him, as well as a few more.

At this point, you may be asking yourself — given the fact that people have been training dogs for more than 4,000 years — why did traditional trainers feel these new tasks were impossible? Also, if a guidance system had already been developed for cats in 1967 in the U.S., why did it take Prins three years to reinvent the wheel 30 years later?

Bob Bailey, who worked on the 1967 project and later became co-owner of Animal Behavior Enterprises after marrying its cofounder, Marian Breland, explains. According to Bailey, it was the advent of animal training and behavior as a science that allowed them to develop the system for dogs, cats and, later, dolphins. “Dog training has been practiced as an ancient craft,” says Bailey. “The science of training wasn’t developed until the 1940s with B.F. Skinner.”

What’s the difference between craft and science? According to Bailey, “Crafts generally develop over thousands of years and tend to preserve what’s old and what has been done before. Information is passed down in secret from master to apprentice, and the apprentice must never question the master.” As a result, when errors are introduced, they tend to be preserved. Another characteristic of a craft is that a change is usually designed only to solve an immediate problem. “Rarely do they look for general principles,” says Bailey.

Science, on the other hand, is a systematic way of asking questions, a process that eventually weeds out mistakes. It’s guided by principles and data, and researcher’s approaches change and are revised as new information comes to light. As a result, science advances quickly compared to craft.

Bailey backs up his description with an example: “For 1,000 years, the Chinese used gunpowder to build small rockets. Then the Turks decided to build bigger ones, which they used on the British. It took them 800 years to develop the technology.” Then, in the 1900s, science and technology stepped in. In 1926, American rocket pioneer Robert Goddard launched the first liquid- propellant rocket. In 1949, less than 25 years later, the U.S. sent a rocket to the moon.

“So it took 800 years of craft to send a six-foot rocket half a mile and less than 50 years of science to send a rocket to the moon,” Bailey summarizes.

From Puzzle Boxes to Bells and Whistles
Once the psychology of learning became a science, animal training made the same great strides. In 1898, scientist Edward Thorndike first described the principle of operant conditioning. Using cats and a small cage called a puzzle box, with food outside the box, he found that cats placed in the cage could learn how to get out, and that with each trial, they got faster at it. He theorized that the cats were learning by trial and error.

Others were making discoveries at the same time, but the one who really put things together was B.F. Skinner. Through many experiments, Skinner developed the principles of operant conditioning, which describes how animals cope with their environments.

Skinner found that animals learn to repeat behaviors with consequences they view as positive and to avoid behaviors with those they view as negative. They learn best when the positive or negative consequence is timed exactly to the behavior, and their learning rate is directly proportional to the rate at which the behavior is reinforced.

Research and technology advanced quickly, and within only eight years, operant conditioning had made its way out of the lab into an applied setting. During World War II, Skinner, who wanted to help with the war effort, set out to train pigeons to guide missiles by pecking at an image of the target site on a screen in a project called Project Pigeon. To demonstrate to the navy how it worked, Skinner took six pigeons and the apparatus in which they were trained to Washington, D.C. The demonstration was successful, but the navy turned him down; the admirals may have been taken aback when Skinner opened the chamber, which resembled a Pelican missile warhead, and they saw three pigeons pecking away.

Skinner’s two graduate students, Marian Breland and her husband, Keller Breland, had dropped out of their degree programs to help with Project Pigeon. They learned a lot while working with Skinner, more than they had learned in class, and became skilled at shaping — a process by which a goal behavior is taught in increments, systematically rewarding intermediate behaviors. They also learned about secondary reinforcers — unique tones such as a clicker or whistle that, when paired with food, could be used to tell the animal exactly when it had done something right.

The couple, who saw how powerful these nonforce techniques could be, decided that when the war was over, they would get into some kind of business where they would use operant technology to help solve problems for animals and, later, humans. In 1947, they founded Animal Behavior Enterprises (ABE), whose mission was to demonstrate a better, more scientific way of training animals in a humane manner using less aversives.

They started with dogs, but trainers shunned the new method, claiming that people had been successfully training for centuries and no new approaches were needed. Rebuffed on the canine front, the Brelands turned to other species. For 47 years, ABE trained animals for its own theme park, the IQ Zoo, in Hot Springs, Ark., as well as for shows across the country. At ABE’s height, the Brelands could have up to 1,000 animals in training at any given time, many for companies such as General Mills, who used them in commercials and at sales conferences. They also worked on animal behavior and training projects for the U.S. Navy and Purina, as well as for Marineland of Florida and Parrot Jungle, where they developed the first of the now-traditional dolphin and parrot shows. When they started, there was only one trained dolphin, whom it had taken trainers two years to get ready to perform. In six weeks, Keller trained two new dolphins to perform the same behaviors.

Bob Bailey met the Brelands when he was hired as director of dolphin training for the navy and Keller and Marian were contracted to help. “I spent six months at ABE learning to train many animals, including chickens.”

Three years later, the same year Keller passed away, Bailey joined ABE as assistant technical director and head of government programs. Later, he became research director too and then executive vice president and general manager. Eventually, he and Marian married.

Over the course of their career, the Baileys trained more than 140 species (or about 16,000 individual animals). In 1990, they retired and closed ABE. Then, in 1996, they received a series of calls from Simon Prins.

Inspired by Dolphins
“I’d spent a year traveling internationally and searching for training methods. I saw a dolphin show, and the girls were training the dolphins to perform incredible behaviors without shock collars or punishment devices. I did more research, and it all led back to Marian and Bob Bailey, so I contacted them,” Prins recalls. It took 20 emails and 10 phone calls before the couple agreed to help. “Bob was quite rude … he hung up on me many times.”

“We didn’t want to deal with police or military because in our experience, they are punishment-based,” says Bob. In the U.S., the Baileys had come to feel that force-based trainers could not make the change to operant technology because eventually, they fell back on the method with which they were most comfortable. “These trainers take what we say and modify it. They take good operant-conditioning principles and modify them, and then say they won’t work.”

Eventually, as Prins continued to meet Bob’s increasing demands, Bob agreed to help. Prins came with a few other trainers as well as his superiors to the Baileys’ Hot Springs headquarters to learn by training chickens.

Animal Behavior Enterprises had tested many animals for learning purposes and found that chickens provide by far the best training model (find out why). Prins and his bosses quickly learned that training is a technical skill rather than a mystical, inborn ability. A science, not a craft. They trained chickens to selectively peck just one type of object among a group of objects, and to perform tasks only on cue. They learned to train behaviors as a series of many little shaping steps, and to keep track of the outcome of each trial in order to determine whether they were having success or needed to fix their technique or plan. They did this all with positive reinforcement — without physically manipulating the chickens.

“Bob and Marian changed my whole perspective on animal training,” says Prins. As a result, he met all of the 1996 goals, and more. At first it was difficult. ABE had developed remote-guidance systems for cats, dogs and dolphins by 1967. In months, they could train dolphins to perform many behaviors, including traveling 12 hours on a circuitous eight-mile route with no reinforcement. It took Prins three years to work out the methods.

“I talked to Bob by mail and phone, but it was difficult, because I was the only one here using these techniques,” he recalls. The process required thinking about what he wanted, planning how he would get it and then implementing the plan and collecting data. This was followed by an evaluation of the data and revisions to the plan based on the results. This process defines the field of applied animal psychology that the Brelands had created based on Skinner’s work. It’s something that most dog trainers are ill-equipped to do.

Whenever Prins got stuck, he fell back on his old habit of blaming the dog instead of recognizing that he had signaled the wrong behavior with his body language or had poor timing or an inadequate shaping plan. According to Bob, the traditional method of training would advise, “Get a bigger stick and beat the dog harder.” He reminded Prins that he needed to stop blaming the dog and look more carefully at video evidence to see what was going wrong.

“He had been training under the eye of other trainers, who for many years [had taught] him it was the dog’s fault, and you must correct the dog,” says Bob. “If you’re the one making the errors, you should be beating yourself, not the dog.”

The three-year process was a challenge, but he kept at it because he felt that it was the only way they could get the consistency and reliability they needed. As Prins explains, “If you have a punishment-trained dog, in the new situation when they are not sure what to do, they are afraid they will receive punishment, even if it is mild. Dogs just stop performing, [and] learning slows down or stops.” He had already found that it was much more effective to condition an animal to see the world as an environment in which something positive could occur at any moment.

So he stuck with it until he had the techniques down. As a result, the program was even more successful than anticipated. “Our dogs often work far from our position, often in the dark and always in an area they have never seen before,” he says. While trainers prepare the dogs for many situations, they can never truly simulate real-time operations, which usually happen in unpredictable surroundings and are stressful for the human handlers. But once they are taught by teaching dogs that performing in many different situations is fun, dogs are able to perform reliably.

Training speed has also improved. “[With] the first dog, [it] took me eight months to train him to follow a laser. With operant-conditioning, it now takes me four weeks.”

The training is heavily weighted toward positive reinforcement, but both Bailey and Prins point out that rarely, aversives are also used. Aversives are not used until trainers understand operant conditioning well and have been training extensively in it for six months, and only when a dog exhibits behavior that puts himself, humans or the operation at risk. The aversive may range from verbal reprimands to low-level shock. Before trainers use an electronic collar, they must wear the collar around their own necks and see what it’s like to be trained this way. They find out what it feels like when a correction is given, and even worse, given at the wrong moment as commonly happens even with the most skilled trainers. “Then they understand how difficult it is, and they do not like to use it,” says Prins. Overall, aversive methods comprise about 1/1000 of the training.

Their success has led to other countries, including Belgium and Norway, adopting this approach. Despite the advantage of being able to learn from Prins’s mistakes, all the trainers in his group experience some of what he did during his first three years. To select new trainers, he sends potential candidates through four five-day chicken training camps in Sweden. “The punishment trainers fall hard. We give them four days to see if they can make the change. The process is grueling,” he observes.

The change is worth it. Trainers see the difference, and the proof is not just in their impressions. It’s in the hard data: shorter training times, more dogs trained for less money, behaviors they could never train before and more consistent, reliable dogs, which lead to more successful missions.

Bailey explains that while a handful of trainers may be motivated to improve the treatment of their dog, “the trainers who actually make the changes are those who want more success and recognize that simply beating their dog more will not get that additional success.” Once they understand and become skilled at the operant technology, an added benefit is that they can finally enjoy their work and so can the dog.

Good Dog: Activities & Sports
Recipe for a Great Canine Running Partner
The ABCs for your first runs together

You like to run, your dog likes to run. It seems like a no-brainer: How about the two of you running together? While you might be concerned about your dog’s ability to run a reasonable distance, the most common hindrance to sharing this passion is your dog’s ability to stay at your side.

First steps
Because you’ll want your dog’s front feet even with or slightly behind yours during a run, the first mission is to teach him to walk nicely on-leash at your side. For the purpose of this article, we’re choosing the left side.

Start with a hands-free set-up such as the Buddy System, or with a regular four- to six-foot leash that you hold while keeping your bent arm at your side in normal running position. You can also use a head halter or a harness with a front connection to help guide your dog. Whatever approach you choose, the leash should be long enough to hang in a U when you’re standing next to him. Have some kibble or small treats and, with your dog sitting at your side, give him several treats in a row until he’s in a stable sit/stay. Then, move forward at a power-walking pace so it’s clear you want him to come with you.

When he’s walking next to you and looking at you, reward him. If his feet get ahead of yours, stop before he gets to the end of the leash. If you’re holding the leash in your hand, be sure to keep your arm glued to your side rather than extending it forward. When he reaches the end of the leash, he’ll likely pull and pull. Stand stock still and wait him out. When he turns to look at you, lure him back into a sit in front of you. Give several treats in a row until he’s focused just on sitting and looking at you. When you’re ready, move forward again at a brisk pace. Repeat this every time he charges ahead, until he understands that getting in front of you causes the walk to stop, and sitting and looking at you causes the walk to resume.

Next, work on about-turns and U-turns to train him to stay by your side. For the about-turn, walk forward in a straight line, turn 180 degrees to your right so your dog is on the outside, then head back on the same line. Do this randomly when he gets even one foot ahead of yours. Make the turns more fun by jogging a few steps and then rewarding him when he catches up and looks at you.
The U-turn is like the about-turn, but in the opposite direction. You turn to your left in order to head back in the direction from which you started, which places your dog on the inside of the turn. Get slightly ahead of him and then cut him off as you make the U-turn. This teaches him that he should stay by your side so that you don’t keep cutting him off. If you have problems getting around your dog, hold a treat in front of his nose; when he stops to eat it, complete the U-turn while he’s stationary, then head in the new direction.
As you walk, alternate these three ways of training him to stay at your side, and reward him for sticking near you. Make sure to do this until it becomes a habit.

First run
Now, apply these techniques to your run. Your first runs should actually just be your dog’s regular walks interspersed with periods of jogging. (Because it’s important to stick to the training, don’t initially try this on your regular run.) Start by jogging a half-block at a time, and be prepared to stop or do about-turns. When he gets better at staying at your side, you can run for longer periods, adding distance gradually. Avoid feeding large meals to your dog right before the run. Small treats or kibble during the run are fine.

Rules of the road
Keep your dog near you so the two of you aren’t hogging the entire track or trail and the leash isn’t creating a tripping hazard for others. If you’re running with a group, make sure he doesn’t run up on others, as clipping their heels could cause a fall. In fact, it’s often best to run between the dog and other people, since dogs sometimes veer off. If you’re on a road, run facing traffic with your dog on your left. Always leash your dog when running on a street or road.

Keeping your dog hydrated
If you’re only running a few miles, your dog does not have breathing issues and the weather is cool, you probably don’t need to carry water. Conversely, if you’d need water during a run, you definitely want to provide the same number of water breaks for your dog.

Knowing when to stop
Dogs are less tolerant of heat than humans, and their main mode of cooling off is by panting. If your dog looks alert and is panting quietly with his mouth open but his tongue is just peeking out of his mouth, then he’s probably okay in terms of heat. If his tongue is hanging out of his mouth, his mouth is open wide and the commissures are pulled back, then it’s time to slow down, or stop for a rest. If his breathing doesn’t go back to normal within a few minutes, end the run. If you’re running at a decent clip, you’ll have other signs that he’s tired: he’ll slow down and start hanging behind you instead of trying to be slightly ahead or right next to you. And if he has to lie down to rest when you stop, then you’ve pushed him too far. Finally, avoid coaxing him to go faster than he wants; endorphins can mask dogs’ pain just as they can our own.

So, that’s the recipe for creating a great canine running partner: Start with training, maintain good manners, follow the rules of the road, stay alert to your dog’s condition and, when in doubt, take a break. Now, get out there and run!

News: Guest Posts
Strike this Book from your Gift List
Smooch Your Pooch—adorable story with dangerous advice

Every Christmas it seems like some child-safety watch group finds at least one or two toys that are dangerous for kids. This Christmas there is one gift that’s actually dangerous for both kids and pets. It’s an adorable book called Smooch Your Pooch, and its message is so dangerous that even the American Veterinary Society of Animal Behavior (AVSAB) is taking a stand against it. In a press release, they state, “[AVSAB] strongly advises that parents avoid purchasing the recently released children’s book Smooch Your Pooch for their kids. The book recommends that children ‘Smooch your pooch to show that you care. Give him a hug anytime, anywhere.’ This information can cause children to be bitten.


What’s the Problem? While this adorably illustrated book, with its sweet, catchy rhymes, is meant to foster affection for pets, the contents, as well as the cover illustration, teach kids to hug and kiss dogs; this can cause dogs to react aggressively. No one knows that better than Dr. Ilana Reisner, a veterinary behaviorist at the University of Pennsylvania School of Veterinary Medicine. Dr. Reisner and her colleagues published a study examining why children get bitten by dogs. Says Reisner, “The recommendations in this children’s book—and even the title of the book—are potentially dangerous.”   That’s because many dogs do not like being petted or hugged. They just tolerate it—at least temporarily.   Reisner elaborates, “Although some dogs are not reactive about being kissed and hugged, these types of interactions are potentially provocative, leading to bites. In a study we published in a journal called Injury Prevention, we looked at dogs that had bitten children and found that most children had been bitten by dogs that had no history of biting. Most important here, familiar children were bitten most often in the contexts of ‘nice’ interactions—such as kissing and hugging—with their own dogs or dogs that they knew.”   Because children are shorter than adults, the bites can be severe. “Sadly, small children are most often bitten in the face and head,” Reisner says.  “We assume this is because they are bringing their faces close to the dogs.”   Given this information, teaching kids to kiss and hug pooches is clearly not safe. But Smooch Your Pooch goes a step beyond and recommends, “Give him a hug, anytime, anywhere.”   While some dogs may tolerate or even enjoy an occasional kiss or hug, they may not tolerate incessant kissing or hugging indefinitely. To the dog who needs a break from kids or needs to know he has a safe location where he can choose to be free of constant attention and pestering, these unsolicited hugs can take him to the breaking point—the same way incessant pestering does for human adults and sibling. The difference is that a human sibling might get angry and hit or scream. Dogs growl, snarl and bite.   So, even dogs who are perfect most of the time can bite seemingly out of the blue.   Of course, to the skilled eye these bites are not random or even unexpected. Reisner’s study found, that in addition to biting when they are hugged, kissed, bent over or sometimes simply petted, dogs are reactive when they are approached/touched while resting, when they have anything they consider “high value” (food, toys, a favorite blanket or even the parent), and when they are hurt or frightened.   Based on these research findings, Reisner states emphatically, “I would not recommend that children take this book’s advice to kiss and hug their dogs. After all, dogs do not hug or kiss each other, and it is understandable that they might feel uncomfortable with such displays by children. In fact, bending over a dog and looking directly into its eyes can be seen as a ‘threat’ in dog language.”   Instead, she recommends more appropriate games and displays of affection, such as fetch, going for a walk together (with adult supervision), and even training new tricks. “Training simple tricks can be very rewarding for both the dog and for its young companion,” Reisner says. “Dogs like to be warm and comfortable and well fed, and most of all to be near us rather than isolated.”   Does this mean you should never hug your dog? Reisner suggests, “If a family dog is clearly unconcerned about being hugged and kissed, showing affection that way is probably fine.”   You can tell when a dog enjoys being hugged because he leans or rubs against you the way a human enjoying a hug would. Dogs who don’t enjoy hugs act aloof and may lean or look away, similar to the way a child reacts when you pinch their cheeks affectionately. Dogs who are not enjoying this kind of attention may also show other signs of anxiety, such as yawning, licking their lips, tensing up, or dropping their tail low or between their legs. When we ignore these signals of discomfort, they may try to warn us with a raised lip or a low growl.   Reisner does stress that children should never approach or interact with dogs who are lying down, resting or asleep. Instead, she recommends that children only pet the dog if the dog chooses to come to them. “Pick up a leash and a box of treats, and call the dog to you,” she says.   So the rule for kids is: Interact with the dog when the dog approaches willingly. Otherwise, kids should give the dog his own space.
Good Dog: Studies & Research
Spin Out
Canine compulsive disorder is no laughing matter

You've probably seen it on TV or on YouTube. Case One: A dog lies on the couch chewing a bone.His hind leg starts to twitch repetitively.He tenses up and stares back at it anxiously as though it’s an intruder sneaking up on his bone. His raises his lip, he growls. Then blam! He attacks his leg. Canned laughter. $100,000 prize winner, America’s Funniest Home Videos. Case Two: A Bull Terrier spins repetitively in the bathroom and then in the living room. “She loves to spin,” states the owner as she encourages the dog to spin more.“She’s spun around 40 times here.” Case Three: A long shadow of a human with outstretched arms fills empty white cement. In dives an Australian Cattle Dog, attacking the shadow’s hand as though it were the hoof of a lazy cow refusing to keep up with the herd.


Amusing? Perhaps. But if you are a veterinarian trained in behavior or an applied animal behaviorist, these descriptions fire up the warning sirens as they conjure images of similar cases in much more serious form.


“I had one client who had a Bull Terrier who would spin a little,” says Dr. Alice Moon-Fanelli, a clinical assistant professor at Tufts Cummings School of Veterinary Medicine. “The owner could easily stop the behavior by calling the dog and then redirecting him to a more appropriate behavior, so she didn’t really think much about it. She just let the dog spin unless it bothered her.” Unfortunately, when this owner went back to work after a number of years of being home, the dog started spinning more and more, and she could no longer stop him.“By this time, he was spinning several hours a day,” reports Moon-Fanelli. “He would spin until he collapsed. Then one night, she came home and the dog was a bleeding mess because he had chewed and ripped off parts of his tail.”


That is just one of many cases Moon- Fanelli has had. One of her earlier cases was even worse. “I saw a dog named Jake belonging to a young couple in New York City. The dog was spinning nonstop for 80 percent of his waking hours. His pads were raw and he was a rack of bones from not eating and then burning calories off. He would get aggressive if you tried to restrain him. They couldn’t even take him for walks because he would spin.He wasn’t a companion anymore.” She isn’t the only behaviorist who has seen such cases.


Dr. Mami Irimajiri, a lecturer at Kitasato University in Japan who studied the effects of drug therapy in treating these disorders while she was earning her PhD at Purdue University, describes one of her cases: “I had an interesting cat patient during my veterinary behavior residency at the University of Georgia. This cat would attack her tail whenever she saw it moving. She was about one year old and had been doing this for about four weeks when she presented to us. She would growl and then attack her tail and bite it. Then she would scream from the pain and run away.”


Dr. Andrew Luescher, director of Purdue’s Animal Behavior Clinic, describes yet another case. “I had one dog that fixated on objects to the point that he could not drink anymore.” Irimajiri, a former graduate student of Luescher’s, elaborates, “The dog would jump into any object he saw.He would see his food and then try to pounce on it or see his water bowl and try to pounce into it. The owner had to feed the dog by hand and give him water by water bottle.”


Dr. Nicholas Dodman, director of the Tufts University Animal Behavior Clinic, describes a similar case. “I saw one dog that was obsessed about his tin bowl.He would only eat if the little bowl was right next to his food. If you took it away he would not eat. It turns out he used to be a rock chewer and then moved to a new house with no rocks. The owners gave him a tin bowl to replace his rocks. The dog was so obsessed with the bowl that he would chew on the bowl whenever he wasn’t eating out of it.”


Some people might consider similar behavior in their own pets to be simply odd behaviors—stupid pet tricks, if you will. But if the signs were to progress to the life-disrupting or life-threatening stages described previously, a mental health disorder might pop up on the owner’s radar. In fact, in each of the previously described cases, the dogs were diagnosed with Canine Compulsive Disorder (CCD).


What Is CCD?

Compulsive disorders are characterized by repetitive or sustained behaviors performed out of context to the point that they seem abnormal.They are performed for excessive durations and can lead to physical injury. Moon-Fanelli observes that, “These behaviors are derivations of hard-wired behaviors necessary for survival, such as eating and grooming.” For instance, tail chasing or spinning, as well as cases where dogs chase lights or shadows, are forms of predatory behavior. Flank-sucking in Dobermans, during which the dog turns around and grabs and sucks on her flank, may be considered a form of eating or ingestive behavior. These dogs occasionally ingest blankets that their owners provide for them to suck on.Acral lick dermatitis, in which dogs spend hours licking the wrist area of their front legs, can be a form of over-grooming.


Unlike the repetitive spinning or pacing one might see in a zoo animal living in boring environments—those animals repeat the same movements over and over—with compulsive behaviors, it’s the goal that matters. That is, in some cases, compulsive spinners may spin in more than one direction, compulsive pacers wander around the house rather than in an unerring path, and light- or shadow-chasers follow the light or shadows rather than a particular footfall pattern. Some cases can be difficult to distinguish from stereotypes, but regardless of the form the compulsive disorder takes, the behaviors are virtually out of the animal’s control. Says Dodman, “It’s like a continuous loop circuit, and the behaviors are constantly recycling and repeated.”


Compulsive Disorder in Dogs vs. OCD in Humans

As suggested, compulsive disorders in animals are similar in appearance to obsessive-compulsive disorders (OCD) in humans; however, because animals cannot express their internal states in words,we don’t know whether they obsess. In humans, the behavior is driven by unreasonable obsessions.For instance, OCD sufferers may feel overly concerned for their safety or hygiene. The obsessions cause anxiety, which causes the sufferer to engage in compulsions in an attempt to alleviate the distress brought on by the obsession.Performing the compulsions, such as repeatedly checking that all of the doors are locked or repeatedly showering or hand-washing, provides relief. This relief is short-lived, though, and the compulsive symptoms actually worsen.


How does this differ in animals? According to Luescher, the same area of the brain may be affected in both dogs and people. People with OCD have changes in the prefrontal cortex of the brain, the area that animals use to reason or to interpret their environment. Luescher has performed brain-imaging studies on a Bull Terrier with compulsive fixation on objects and found that this dog’s prefrontal cortex was involved. According to Luescher, such findings don’t mean that the conditions are completely homologous; even if human OCD patients and canine compulsive disorder patients are physiologically similar, there is a difference. “People with OCD suffer partly because they know it does not make sense,” he states. “They feel ashamed and try to hide their symptoms. Dogs, on the other hand, perform their behaviors openly.” So they are not ashamed about the behavior; however, they may be anxious or distraught while they are performing the behavior.


Despite the differences, compulsive behaviors in humans and animals are related in that they are anxiety-based, and some animals carry a genetic predisposition. As Moon-Fanelli, whose research focuses on the inheritance of compulsive disorders in Bull Terriers, notes, “We think compulsive disorders are hereditary because we see some of these compulsive behaviors more frequently and almost exclusively in certain breeds.” For instance, German Shepherds, Australian Cattle Dogs and Bull Terriers spin or tail-chase; Wirehaired Terriers tend to shadow- or light-chase; and Dobermans flank-suck or blanketsuck. Additionally,Miniature Schnauzers compulsively check their rear ends. They may walk a few steps and then stop and look at their hind end, or get up and check the area where they were sitting or sniff it.


Thus far, research by Dodman and Moon-Fanelli strongly suggests that compulsive spinning is hereditary in Bull Terriers. Dodman and Moon-Fanelli’s work has even shown that the trait occurs more in some Bull Terrier families than others and is expressed in dogs who have never been with another tail-chasing dog, which suggests that the behavior is inherent, not learned.


Luckily, having a hereditary predisposition does not necessarily mean that the disorder will show up. Environmental stress increases the odds of a compulsive disorder being expressed, and it may wax and wane based on stress, which can take many forms. Some dogs have a strong genetic predisposition but no stressful event is seen prior to onset, whereas with others a clearly stressful event is associated with the onset.


Luescher gives an example.“I had one case, a 10-month-old German Shepherd puppy who used to show mild aggression to the owner. A traditional force-based trainer showed the owner how to give a ‘proper’ choke chain correction. The puppy temporarily acted less aggressive, but then two days later, he suddenly started chasing his tail for many hours a day.” The stress of the force-based training had precipitated the behavior.


In other cases, the stress may involve kenneling, traveling, a change in the owner’s schedule or the addition of a new person to the household.Moon-Fanelli considers that, for dogs with a strong genetic component, “the stress may be relatively mild. These dogs can’t cope with things that a normal dog can handle.” She has seen Bull Terriers who spontaneously started chasing the sound of running water or microwave bells— the owner can’t wash dishes, flush the toilet or use the microwave because these sounds trigger the dog’s spinning.


In some cases, the condition can progress quickly to the point where it completely disrupts the human-pet bond. Moon-Fanelli describes such a situation. “I had one case, a Bull Terrier named Fletcher, who began spinning suddenly at five months without an identifiable trigger. The first day, they thought it was puppy tail-chasing. Then the next day, he chased for an hour but could easily be distracted. Then, coinciding with this, they had to leave him with a pet sitter for the weekend.When they came back, he was spinning nonstop.” The owner, who was a veterinarian, tried temporary treatment with sedatives in the hopes of immediately controlling the intense spinning. This made the dog wobbly but didn’t stop his spinning.The usual treatments for compulsive disorders, such as Prozac®, a serotonin re-uptake inhibitor, combined with environmental enrichment, also had no effect. Says Moon- Fanelli,“They couldn’t get it under control so they had to euthanize. It was distressing to them and to the other dogs in the household.He did not have any quality of life.”


Most cases don’t progress this quickly. Rather, they may have a long history of being rewarded. Says Luescher, “A common case is that people start playing with lasers or flashlights and the dog chases the light. This is normal.But then, as the owners encourage the dog, it gets out of hand and the dog starts to go after lights reflecting off surfaces. So the behavior is no longer context-specific.” Says Moon-Fanelli, “With Doberman flank-sucking, most owners think it’s cute and give their dogs blankets.” The dogs ingest little portions of blanket regularly. It’s not irritating like spinning, and although the duration may be long, it occurs at night or other times when the dog is resting so it doesn’t noticeably disrupt the dog’s normal activity.As a result, owners equate it with thumb-sucking. Adds Fanelli,“Because it’s nondisruptive, owners don’t care until the dog ingests her blanket and has to have surgery.”


Diagnosis and Treatment

First, a veterinarian is needed to rule out potential medical look-alikes. For instance, some dogs have a neurological problem instead of a compulsive disorder. “We’ve had a number of cases where the dog that has been circling has a brain tumor diagnosed on MRI rather the compulsive disorder,” states Luescher. Similarly, Luescher recalls a horse with repetitive leg movements like those of the America’s Funniest Home Videos dog. “It turned out to be a partial seizure due to a brain tumor.”He adds, “In another case, a dog presented with possible compulsive disorder, and it was actually due to Ehrlichia, an infectious agent that attacks the nervous system.”


Other instances can be related to dermatologic conditions. Dodman in particular recalls one case.“We had a Golden Retriever with a lick granuloma…not responding to medications for compulsive disorders. A closer dermatologic examination and blood work revealed that [the dog] had a deep-seated skin infection in just that one region, plus low thyroid levels. Treatment with antibiotics and thyroid medications cured the dog.”


Once other causes are ruled out, compulsive disorders can often be treated successfully with a combination of drug therapy (Reconcile® or Clomicalm®) and behavior modification. Up to 70 percent of patients do well on the combination of drug therapy and behavior modification, says Luescher. “These dogs have far fewer compulsive bouts, and when they do have the bouts, they can easily be redirected toward other activities, and will stay with these new activities.” He adds,“Some are treated successfully with behavior modification alone, too. It usually takes longer, though.”


Despite the success with drug therapy, all of those interviewed emphasized the need for concomitant behavioral modification. As Luescher observes, “Drug therapy alone does not make sense, since the environmental cause is still there.” Moon-Fanelli adds, “If the cause is conflict or stress, then even with the neurochemistry changes brought about by medications, you need to teach the animal to cope with the stress.” Behavior modification involves a combination of tactics: maintaining a predictable schedule, increasing exercise, interrupting the compulsive behavior and redirecting it by rewarding alternative relaxed behaviors (such as performing tricks), and improving the bond by participating in reward-based sports such as agility. Occasionally, a complete change of environment can have a dramatic effect.With Jake, the New York City dog who spun so much he couldn’t eat or drink, “I treated him with medications for years,” says Dodman.“It only got better when the couple split up and the dog was taken to live on a farm upstate.”The new owners were a couple with children, and they were able to get Jake’s attention and redirect his behavior.


All four behaviorists interviewed warned strongly against punishment, which is sometimes recommended by traditional dog trainers such as Cesar Millan on Dog Whisperer. Says Dodman, “I saw Cesar Millan put a choke chain collar on a dog with compulsive disorder and pop it. This is about as sophisticated as electrifying the taps [faucets] with an OCD hand-washer. This would stop the behavior, but the anxiety would still be there and could erupt in a more anxious behavior.”


Moon-Fanelli gives an example of one such redirection of anxiety. “I had a client with a spinning Bull Terrier and we were working on a treatment plan. The owner called up and said she had enlisted the help of a trainer who recommended a shock collar. She happily reported the shock collar had worked. The dog was no longer spinning, but I could hear her yelling to her dog, ‘Suzie, stop that.’When I asked what Suzie was doing, she said that Suzie was pacing around the kitchen.” The consequence, as Moon-Fanelli points out, was that “the tail spinning had evolved into pacing.”


Luescher also recalls a particular Miniature Schnauzer who was both licking an inner thigh and staring at the ceiling. Owner punishment precipitated the behavior. The added difficulty with punishment is that when owners are inconsistent, it adds even more stress than when they are consistent. Says Luescher, “If you don’t have consistent rules, the dog can never figure the rules out.Everyone wants to be successful and control life, to bring about good things and avoid bad things. If they don’t have this ability, they can go into a state of learned helplessness.”


When Should You Be Concerned About Your Dog’s Behavior?

Both Moon-Fanelli and Luescher stress that dogs who exhibit spinning or other compulsive behaviors for short periods of time aren’t necessarily abnormal. But if a behavior such as spinning starts occurring outside of its original context, or for more than a minute per bout, or 3 to 10 minutes per day, then the dog should be evaluated for a compulsive disorder. This is especially so if the behavior occurs out of sight of the owner. If the behavior occurs primarily in the owner’s presence, it may be an attentionseeking activity rather than a compulsive disorder.


Unfortunately, most people wait until the behavior significantly disrupts family life—when the dog chases lights for hours, spins and can’t be interrupted, or chews his tail until he has a wound. This delay makes the disorder much more difficult and sometimes impossible to treat successfully.Consequently, it is better to err on the side of caution and consult with a veterinary behaviorist or applied animal behaviorist early on to determine whether your pet has a compulsive disorder and to rule out other disorders.An early diagnosis can prevent the owner from accidentally strengthening the behavior by rewarding it with attention or increasing the anxiety through punishment.Additionally, it’s best not to encourage repetitive spinning or chasing of laser-lights and shadows—the potential long-term consequences outweigh the momentary amusement.

Wellness: Healthy Living
Can Diet Overcome DNA?
Scientists investigate the new field of nutrigenomics.

Have you ever had problems losing weight and wondered if you’re just genetically fat and doomed to your pudgy fate? If so, you may be in luck. Scientists studying nutrition and genetics in dogs are helping to debunk the myth that your genes set your physiologic fate in stone.

“Your DNA tells you everything you could be. It doesn’t tell you everything you are going to be,” says Dr. Steven Hannah, Director of Molecular Nutrition at Nestlé Purina PetCare.“There are many factors that modify the ultimate expression of an animal.” One such factor is diet.

New studies are finding that diets can alter the expression of genes. In other words, they can determine which genes are active. In fact, there’s now a branch of nutrition called “nutrigenomics” dedicated to the study of how nutrients affect gene expression.

In an active gene, a segment of DNA is transcribed to RNA, which can then be translated into many copies of a single protein. Each gene codes for a different protein and each protein has a slightly different job. Some proteins provide structure, such as the protein in muscle or collagen.Other proteins, called enzymes, drive the chemical reactions that create the various hormones, neurotransmitters and products needed by the body, as well as creating products that serve as energy to power the body.

In humans, the study of nutrigenomics is slow because there are too many factors to consider in a person’s normal life—even in just their diet. But with dogs, researchers have already discovered diets that alter arthritis and obesity.

How does nutrigenomics come into play in developing these diets? First, the company or researcher identifies gene expression profiles in affected and normal dogs.Next, they figure out which ingredients they believe will change the gene expression profile from that of an affected dog to that of a healthy one. Then they formulate a mixture, feed it to the affected individuals and see if the gene expression profile changes in a positive way. For instance, in the case of arthritis or degenerative joint disease, researchers at Purina compared the gene expression profile of normal, healthy cartilage cells, called “chondrocytes,” to that of arthritic chondrocytes.

“We have constructed a gene expression array chip that has virtually every gene known in the dog,” states Hannah. “It has tens of thousands of genes on it. We took the chondrocyte cell’s RNA and applied it to the chip.” The chip, in turn, revealed every gene whose expression was affected.

“We were able to identify which genes in the tissue were up- and down-regulated in arthritis,” says Hannah.“Because those genes are codes for all of the proteins the cell was making, it’s a snapshot in time of what the cell is planning to do biochemically.” (“Up-regulation” and “down-regulation” are the processes by which cells increase or decrease, respectively, the quantity of a cellular component, such as RNA or protein, in response to an external variable.)

By examining the 325 up-regulated genes and the 25 down-regulated genes, Purina researchers were able to look at the biochemical decision of the arthritic cell compared to a healthy chondrocyte cell. What they found was that the arthritic cells were up-regulating specific enzymes that degrade the cartilage and down-regulating enzymes that inhibit the degradation process. That is, they were primed for cartilage destruction.

The next step was to determine what dietary changes might affect the joint. These tests started in petri dishes. First, the researchers grew chondrocytes in cell culture and added inflammatory mediators that would be seen with any joint injury. This made the chondrocytes look arthritic. Then they added nutrients at various concentrations to see which nutrients would help the cells repair.With that testing, they found that omega-3 fatty acids provided good results, and they were able to determine which levels worked best.

But, as Hannah points out, “We can’t feed the nutrient directly into an animal’s joint. There’s no cell culture dog food. Rather, we needed to next see if we could get the nutrient from the food in the same concentrations into the dogs’ joint.”They needed to know if the fish oil would be digested, absorbed and then the omega-3 fatty acids transported to the joint in concentrations shown to be effective in the cell culture.

“Luckily, at the time, Colorado State was conducting an arthritis study in dogs,” says Hannah.“We were able to put these dogs on test diets with different levels of omega-3 fatty acids and then analyze the joints.” They quickly found that they were indeed able to match the levels that they had gotten in the petri dish.

“That’s all nice,” says Hannah,“but the bigger question is whether the dog actually cares. Does it make a clinical difference?” That’s where force-plate analysis came in. This process determines whether a dog’s lameness has improved; researchers did find improvement in the dogs’ physical abilities.

“We were able to verify that the changes in the gene expression profile were accompanied by changes in the corresponding enzyme levels too,” says Hannah. “After the diet, the joints contained less metalloprotease, an enzyme that degrades the cartilage, and more protein that inhibited the metalloproteases. So the omega-3 down-regulated the enzymes that chew up cartilage and up-regulated factors that inhibit the degradation.”

Another major area of nutrigenomics research is in obesity. “We’ve looked at the gene expression profile in obese patients,” says Dr. Todd Towell of Hill’s Pet Nutrition.“We can see a huge difference in gene expression between dogs who are obese and those who are lean.”

What classes of genes are different? The short answer is that at the level of gene expression, obese dogs are up-regulated at systems that make them efficient at storing fat in adipose tissue. They are fat storers. Those who are lean are more efficient at burning fat for energy.

Armed with this information, researchers set out to answer the million-dollar question: Is it possible to design a diet that would both allow weight loss and change the gene profile? To find out, Hill’s researchers fed overweight animals a new weight-reduction diet and then looked at their gene expression profiles; they looked at percent of body fat and genomic analysis at the onset of the study and then again after four months on the diet. All the dogs went from overweight to lean, and those on the new diet showed a change in 254 genes—240 were down-regulated and 14 were upregulated. The diet had changed the dogs’ metabolisms from fat-storing to fat-burning.

Interestingly, in a similar study with dogs on a high-protein weight-loss diet, dogs also went from fat to lean, but their gene expression profiles remained those of metabolically obese dogs. So they were still fat-storers, which suggests they would gain weight back. Because it’s the gene expression in the fat cells that’s important, the downside to this study is that researchers tested the gene expression in blood cells but did not test it in the fat cells where fat is actually stored; their assumption was that gene expression was also changing in the fat cells.

Another researcher who has looked at gene-expression changes in fat is Dr. Kelly Swanson, adjunct assistant professor at the University of Illinois, Department of Veterinary Clinical Medicine. “We fed a fructooligosaccharide, which is a fiber-like substance that’s not digested by the host but preferentially stimulates the beneficial microbes in the gut.” In other words, the fructooligosaccharide hangs around in the gut, where it serves as food for beneficial microbes. As a result, it allows the beneficial microbes to flourish.

The results? The diet improved insulin sensitivity in fat cells of obese dogs. Several genes that coded for proteins important in lipid regulation and oxidation were up-regulated. These results suggest that a diet with fructooligosaccharides could be useful in diabetic patients.

These findings are just the start. Says Hannah,“Researchers are routinely using nutrigenomics to understand physiology and biology at a new level. Instead of just trying to find individual genes that predispose dogs to developing diseases such as diabetes or obesity, researchers are now asking, ‘What about all of the genes and corresponding pathways?’ It’s about understanding how a molecule or nutrient changes gene expression.”

Says Swanson, “With nutrigenomics, you often get to disease states you don’t understand. If you can identify the genes and pathways affected in the disease process and know the effect of nutrition on that same process, you can determine the biological mechanisms to target.”

Wellness: Healthy Living
Do Environmental Pollutants Cause Cancer in Dogs?
Do environmental pollutants cause canine cancer?

From the pesticides used in agriculture, insecticides and cleaners used in households, and solvents used in paints to toys made of synthetic products and artificial preservatives and additives in our food, man-made chemicals and pollutants are everywhere. With so many synthetic chemicals around us, could some of these products—as well as other aspects of our environment—be causing cancer in our canine companions?

Dr. Larry Glickman, veterinarian and epidemiologist at Purdue University, has no doubt that they do. “Of course. There are many chemicals and environmental factors known to cause cancer in people, and many may also cause cancer in pets. The problem,” he observes, “is that these are far better studied in humans than in pets.”

The dearth of study is a matter of both convenience and money. Says Glickman, “With humans, there are mandatory reporting systems for disease—such as death certificates, [which list the] immediate and underlying cause of death.” As a result, agencies can track how frequently certain diseases result in death, and thereby accumulate information as to whether there is an increase or decrease in specific cancers, for example. “With animals, we don’t have anything,” say Glickman. “We just have scattered pieces of data to look at frequency of diseases.” These include hospital records or, increasingly, insurance claim records. But, Glickman emphasizes, “This is way behind what has been done in humans.”

Clear Links Exist
Despite the scarcity of studies, some research has identified clear links between cancer in dogs and environmental factors. For instance, a 1983 study by Glickman and his colleagues revealed that dogs with a mesotheliomas (a rare tumor of the chest cavity) were more likely to have lived in households where owners had exposure to asbestos, or to have gone with their owners to workplaces in which asbestos materials were handled (e.g., shipbuilding and brake repair). Additionally, chrysolite asbestos fibers were found in significantly higher amounts in the lung tissue of these dogs than in dogs with other types of lung tumors and no history of exposure to asbestos.

In another example, Glickman notes that “exposure to cigarette smoke has been shown to increase nasal cancer in dogs.” Long-nosed dogs are two times more likely to develop nasal cancer if they live with a smoker than if they are not exposed to cigarette smoke, and the incidence of canine nasal cancer increases with the number of packs the human in the household smokes per day. Similarly, short-nosed dogs are twice as likely to develop lung cancer if they live in a house with cigarette smokers. In these dogs, cotinine levels (a metabolite of nicotine) in the urine are high compared to those of dogs in nonsmoking households. Taken together, these findings suggest that the longer air-filtration system of long-nosed dogs serves to protect them from lung cancer but also predisposes them to developing nasal cancer.

Glickman’s own research has revealed other environmental risks. As he reported in 1989 in the Journal of the American Veterinary Medical Association, female dogs exposed to insecticides in flea sprays and dips are at higher risk of developing bladder cancer than those on whom such products are not used. As with nicotine, the compounds in dips and sprays are absorbed into the bloodstream. The body gets rid of these products by excreting them into the urine. The risk is further enhanced in overweight females, most likely because the compounds, once absorbed, are retained in fat. Animals with more fat retain more of the chemicals. And finally, risk was also elevated in females who lived close to a second potential source of insecticides—a marsh that had been sprayed for control of mosquitoes, for example.


According to Glickman, “No one chemical type of flea and tick dip accounted for the increased risk; however, the active ingredients generally account for less than 5 percent of the total product. The remaining ingredients were labeled as ‘inert” and consisted of solvents such as benzene, toluene, xylene and petroleum distillates, many of which are themselves known carcinogens [in people and lab animals].” A second study in 2004 by Glickman also looked at the spot-on flea and tick products such as Advantage® and Frontline® but found no increase in cancer. These products are minimally absorbed into the dog’s bloodstream and consequently are not excreted via the bladder. [Ed. Note: For more about over-the-counter spot-on products, see our blog on the current  (2009) EPA investigation into their toxicity.]

Research also suggests a link between 2,4-D (marketed under many names, including Ded-Weed, Lawn-Keep, Weedone, Plantgard, Miracle and Demise), a phenoxyherbicide commonly used on lawns, and cancer. The findings, however, conflict. A 1991 study published in the Journal of the National Cancer Institute reported that pet dogs in homes where 2,4-D was applied to the lawn at least four times per year had twice the risk of developing lymphoma, compared to dogs who lived where lawns were not treated. These findings were challenged by the Chemical Industry Task Force, and the ensuing reanalysis of the original data found no significant relationship between the herbicide and lymphoma in dogs. (Kaneene, John B. and Miller, RoseAnn. “Re-analysis of 2,4-D use and the occurrence of canine malignant lymphoma.” Veterinary and Human Toxicology, 41, No. 3: 164–170. June 1999).
A subsequent 1994 study in the scientific journal Cancer, Epidemiology, Biomarkers and Prevention did, however, show that dogs living around residences recently treated with 2,4-D absorbed measurable amounts of the herbicide for several days after application. Dogs exposed to lawns within seven days of treatment were 50 times more likely to have high levels of the herbicide than those exposed to lawns treated more than seven days previously. The highest concentration of 2,4-D was found in dogs walking on lawns within two days after the lawn had been treated. Despite these higher herbicide concentrations, Dr. Antony Moore, veterinary oncologist at Veterinary Oncology Consultants in New South Wales, Australia, states, “This is not sufficient to say that use of the herbicides causes a high risk for cancer. However, if you’re an owner and have a dog, why use 2,4-D when there are other equally good herbicides available?”

The link between herbicides and cancer in the general dog population may be debatable, but when one considers a specific breed, the Scottish Terrier, the link is clear. Overall, Scottish Terriers are at 18 times increased risk of transitional cell carcinoma (bladder cancer) when compared to mixed-breed dogs. When exposed to lawns treated with phenoxyherbicides four or more times a year, Scottish Terriers had a four times higher risk of developing bladder cancer than those who were not exposed to herbicide. That risk increased to seven times if they were exposed to both herbicides and insecticides.

This suggests a question: If these chemicals are carcinogenic, why are they still around? Well, says Dr. Moore, “It’s very hard to show that a factor causes cancer. We can only show that it increases the risk of getting cancer. For example, a study out of Italy showed that dogs who lived with people who used paints and solvents were at 4.6 [percent] higher risk of developing lymphoma. This finding does not tell you that because you spill solvent on the ground and a dog walks through it one time, the individual dog’s risk is higher.”

Other studies have shown that area of residence can increase the cancer risk. “The same study out of Italy showed that dogs that lived in the industrial areas had an 8.5 times higher risk of developing lymphoma than those living in urban areas,” says Moore. Similarly, a study published in 1971 in Archives of Environmental Health found that tonsillar squamous cell carcinoma was 10 times more common in animals living in cities than in those living in more rural environments. Both findings imply that urban living exposes animals to more environmental pollutants; however, they do not quantify an amount of urbanization or industrialization that significantly increases risk, or which anatomical characteristics put some individual dogs at greater risk than others. As Moore explains, other factors come into play, including long-nosed vs. short-nosed, or Scottish Terrier vs. other breeds, amount of exposure, and obesity.

The Biology of Cancer
This interplay of factors can in part be explained by the mechanism of cancer. Normally, cells have a set lifespan. They die and are replaced by new cells. During the cells’ lifespan, mutations in their DNA commonly occur, and though many are repaired, others are not, which often leads to early programmed cell death (apoptosis). Some mutations, however, result in prolonged cell survival, because mutations in the cell repair mechanisms or in the mechanisms that normally lead to programmed cell death have already taken place. In other words, these cells avoid apoptosis and divide in an uncontrolled manner. As they do so, they form an enlarging mass of cells that can invade local tissues as well as spread to other locations. Thus, cancerous cells are the result of multiple mutations occurring in the right combinations.

Because of these interactions, it can be difficult to appreciate some cancer risks. “Everyone knows about a 90-year-old guy who smoked all his life,” Moore says. “While smoking increases the risk of cancer, it may be that this person just doesn’t have the changes in his cells that can combine with the mutations caused by smoking to result in cancer.” More information is necessary. “It’s possible that the genome project will help identify genes related to getting cancer or being more at risk for getting cancer, but the risk may not present until the animal is exposed to the right environmental factors, such as herbicides, or becomes obese.”

Genes Play a Role
Clearly there are genetic factors. Says Glickman, “In the average breed, 20 to 30 percent of dogs die of cancer, but in other breeds, such as Golden Retrievers, it is probably 60 percent.” In some animals, the very traits that make them desirable as pets or especially skilled at certain tasks make them prone to certain cancers. For instance, Irish Wolfhounds and other large sighthounds bred for exceptional speed and ability to capture agile prey such as deer or rabbits are also prone to developing osteosarcoma (bone cancer). In fact, in general, dogs with legs longer than 50 cm (or a little less than 20 inches) are at risk for this cancer of the leg bones. Similarly, as noted earlier, the same trait that protects long-nosed dogs against lung cancer predisposes them to cigarette-related nasal cancers.

Information on genetic predispositions can be used to help decrease cancer risk. In the case of Scottish Terriers, Glickman is working with the National Cancer Institute to identify those at highest risk for bladder cancer and to establish the genetic basis for that predisposition. Says Glickman, “The goal is to screen all Scottish Terriers as puppies and identify those with higher risk of bladder cancer. Those that [have this risk] can have twice-yearly evaluations of urine to look for early signs, or can have an ultrasound performed every six months.” If the cancer is detected early on, it might be possible to remove it. But even more valuable is that with these predisposed dogs, exposure to lawn chemicals can be eliminated and diet can be changed. Consumption of vegetables—specifically leafy greens and yellow-orange vegetables—three or more times a week was associated with a 70 to 90 percent reduction in risk of developing transitional cell carcinomas in Scottish Terriers.

Risks Not Limited to Chemicals
Clearly, another reason why just banning all carcinogens known to man would not solve the problem is that environmental risks of cancer are not limited to chemicals. A 1995 study in the American Journal of Epidemiology found that dogs living in houses with high magnetic fields, as measured by the current configuration wire code, were nearly seven times more likely to develop lymphosarcoma. This included both cables above and below ground. Interestingly, Moore states that these findings have never been shown in humans. Another non-chemical risk factor for cancer in dogs is the failure of the owner to have the dog spayed. This is one of the most common and well-documented risk factors for cancer in female dogs. Says Moore, “Female dogs who are intact are much more likely to develop mammary cancer than those who are spayed. Spaying before the first heat cycle reduces the risk to almost zero.” This risk steadily increases with each heat, up to about 6 to 8 percent risk of mammary cancer after the dog has gone through two to three cycles. Once the dog hits about two and a half years of age, 40 percent will develop mammary cancer. Says Moore, “This is a disease we can practically eliminate by spaying dogs early.”

Additionally, diet can further reduce the risk of mammary cancer. One research study looked at the diet of dogs the year before they had surgery for mammary cancer. For dogs on a low-fat diet, the level of protein (measured on a dry-matter basis, not based on the crude analysis number reported on the bag) was strongly predictive for how long they would live. Protein greater than 27 percent on a dry-matter basis correlated with survival past three years of age. Those dogs on a low-fat diet with less than 23 percent protein survived less than six months. Protein levels made no difference or had no effect if the dog was on a high-fat diet. In addition to diet composition, the researchers also found those dogs that were overweight at one year of age were three times as likely to develop mammary cancer.

More Studies May Provide Better Answers
So should you just avoid all possible carcinogens?

“That’s fine if you don’t drink or eat,” says Glickman, “but they are everywhere.” Even environmental factors as ubiquitous as sunlight can increase risk of cancer, especially in light-skinned pets. It’s a matter of exposure levels combined with genetics.

How high does the risk have to be to be important? Glickman recommends that we consider how likely the animal is to be exposed. A 20 percent increased risk may be important for dogs who are exposed a lot, whereas a twofold increased risk is less worrisome if the animal will not receive much exposure. Thus, for Scottish Terriers, a breed in which it is calculated that 75 percent of bladder cancers are related to chemical exposure, it is best to avoid phenoxyherbicides and insecticides, whereas a moderate exposure is much less likely to cause a problem for other dogs.

In defining “a lot” and “not much,” Glickman notes that “this speaks to the concept of attributable risk, which is the proportion of a specific type of cancer that can be attributed to a specific exposure such as insecticides. Attributable risk is a function of how many individuals in a population are exposed to insecticides plus the risk of cancer associated with insecticides. Thus, a chemical associated with a small increased risk of bladder cancer is important if a high proportion of dogs are exposed. In contrast, a chemical like asbestos is associated with a very high risk of mesothelioma, but very few dogs are exposed, and the attributable risk is thought to be low in people (about 5 percent of all lung cancers). In contrast, the attributable risk for lung cancer (90 percent) associated with smoking is very high even though the risk of lung cancer associated with smoking is relatively low, since so many people smoke.”

Both Glickman and Moore stress the need for more studies. It’s not accurate to assume that if an individual pet gets cancer, it must be due to some factor noticed to be different in the environment—many factors may change simultaneously. For instance, says Moore, “When people were first looking at causes of Down Syndrome in humans, they found that the sixth child was much more likely to have Down Syndrome. So that was thought to be a risk factor. But it was really the age of the mother at birth.”

Clearly, careful studies that take a myriad of potential risk factors into consideration are needed—for example, comparing dogs who develop a specific cancer to similar groups of cancer-free dogs, and even similar groups with other types of cancer—in order to identify potential correlations. This sort of research, which involves a multitude of animals who are followed throughout their lifetimes, is expensive, often running into millions of dollars. The adage “forewarned is forearmed” applies here, however; understanding the connections between genetic predispositions and environmental risk factors gives us the information we need to make better decisions about the dogs we love and care for—decisions that could potentially improve the quality and length of their lives. And that benefit is priceless.


In 2007, the Morris Animal Foundation launched “Canine Cancer Cure,” a $30 million effort to cure canine cancer. This effort involves fundraising and managing and administering research grants to veterinary colleges and research organizations. Check for updates on their progress.

Originally published under the title: “The Canine in the Coal Mine.”