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.

 

 

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.

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.

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.”