Often, dogs are the first alert. Their willingness to swim in and drink slimy water makes them sentinels for some of the most powerful natural poisons on earth.

A Labrador Retriever enjoying a family outing in June collapsed after swimming in a Minnesota lake. He died that day at the vet’s office. Tests are pending but the vet suspects the dog was poisoned by cyanobacteria, also known as blue-green algae (BGA).

While most algae are harmless, some species of BGA produce toxins that can kill a dog within minutes. Those that survive, or dogs who are often exposed to low levels of toxins may develop health problems such as chronic liver disease, and possibly tumors; damage that may go unnoticed until it’s severe. Humans can be sickened, too, though deaths are rare.

Dog deaths are another matter.

As health agencies weigh the human risks that lie in recreational and drinking water from harmful algal blooms, they’ve been looking closely at animal deaths.

In New Mexico, 100 elk died last August after drinking water tainted with BGA. When it comes to pets, researchers suspect many deaths are missed because people don’t even realize their dogs were exposed. Vets may not recognize the symptoms, and tests to detect the toxins can be costly and complex.

A study published in 2013 found 368 cases of dogs that died or were sickened by BGA in the U.S. between the late 1920s and 2012. The authors say these “likely represent a small fraction of cases” in the U.S. each year. “The vast majority of BGA associated dog deaths remain unreported and often unrecognized by owners and veterinarians.”

And the cases have surged along with the number of toxic blooms fueled by nutrients such as phosphorous and nitrogen washed into waterways from agriculture, lawns and other sources—and by climate change.

Reports of canine poisonings were sporadic until the mid-1970s, when dog deaths attributed to BGA were reported “almost yearly,” the study notes.

In 2007, as drought plagued much of the country, the Minnesota lake region alone saw as many as 40 cases of canine algae poisoning, and at least four deaths. Since 2001, eleven dog deaths have been blamed on BGA in California’s Humboldt and Mendocino Counties.

The earliest known case in the U.S. was in the late 1920s when a dog swam in California’s Clear Lake during an algal bloom. The dog reportedly became ill after licking “a thick coating of algae” from its fur. In 2013, another dog sickened after playing in the lake was less fortunate... this dog did not survive.

Spotting Blue-Green Algae

There are plenty of clues for telling BGA— the most primitive group of algae—from harmless green, brown, and other kinds. But according to a fact sheet from the Humboldt County Health department, while most BGA blooms don’t produce toxins, only tests can tell. “All blooms should be considered potentially toxic.” Only “a few mouthfuls of algae-contaminated water may result in fatal poisoning.”

For one thing, its color isn’t always blue-green. It can also be reddish-purple or brown, and other hues. And not all blue-green species produce toxins, while the dozens that do are only toxic at certain times. Normally, algae are equally distributed throughout the water. But excess nutrients, heat and drought make for large blooms, followed by large die offs. As it decays, toxins are released. These can still taint the water after it looks clear. Blooms may last for a week; their toxins may last three weeks.

Even when BGA isn’t floating on the surface, it may lurk below, moving up and down with available light and nutrients. At night it often floats to the top, forming scum. So blooms can appear overnight.

Wind and waves can then concentrate toxic blooms in shallow areas or at the water’s edge—right where dogs like to splash, wade or drink. The water doesn’t taste bad, vets say, so dogs will lap it up. Some like to gobble down dried algae mats.

After the sudden death of a dog last July—hours after swimming in an Oregon reservoir—officials issued an alert, as they did in Minnesota. But toxic blooms and dog deaths were nothing new. According to Minnesota Department of Natural Resources, from 2004 through 2007, the state had reports of eight algae-related dog deaths, while toxic blooms are a familiar scourge at the Oregon reservoir.

At least 18 states have monitoring programs to detect harmful blooms. But sometimes, even advisories aren’t enough. After two dogs died within hours of drinking water from a private lake in Nebraska in 2004, state agencies acted quickly. Two weeks later, monitoring and notification networks were in place. But by the end of the recreation season there were reports of three more dog deaths, wildlife and livestock deaths, and more than 50 cases of human effects at Nebraska lakes.

The Environmental Protection Agency hasn’t set national standards for BGA toxins in recreational or drinking water, though scientists and some politicians are calling for them. This summer, the agency is promoting safety and public awareness to help protect dogs and kids.

While most algal blooms just make the water unappealing, an EPA information sheet says, “there are some real risks if dogs swim in, wade, or drink from water” with harmful algal blooms. The toxins “can sicken pets, causing everything from mild eye irritations and diarrhea to extreme health problems, including liver poisoning and even death.”

The EPA recommends that outings with pets to lakes, rivers and streams include an algae check. Dogs should not drink, swim or wade in water that is discolored, smells bad, or where there are mats of algae, foam or scum. If dogs do get into scummy water, rinse it off with tap water immediately, making sure they don’t lick algae from their fur. The toxins can also be absorbed through their skin. If a dog shows signs of poisoning, seek veterinary treatment right away. And report incidents to the Public Health Department. To avoid adding to the algae problem at home, the agency advises not over fertilizing.

According to the study of canine incidents, BGA toxins can be inhaled and ingested, and exposure can induce “acute, sub-acute or chronic poisoning” in animals and people.

Most reported dog deaths involved swimming in or drinking from lakes, rivers and other fresh waters where slime was visible. In California, BGA from freshwater tributaries drained into Monterey Bay, killing sea otters in 2010. Scientists were baffled by the deaths. They hadn’t known the toxins could reach the ocean. One major clue: suspicious dog deaths at a lake tainted with BGA that drains to the sea.

Other dog incidents may have involved beach outings. The study of canine cases says that between 2007 and 2010, at least 8 dogs developed serious or fatal liver disease after visiting Monterey-area beaches. Two of the dogs belonged to local veterinarians, but weren’t tested for the toxin that was killing sea otters.

Blue Green Algae Toxins & Treatment

Are water-loving breeds more at risk? Researchers warn that diagnosing algae poisoning is hard enough—such assumptions can lead to the wrong diagnosis. But the study did find that the most incidents involved Labrador Retrievers.

However, the “wide range” of affected dogs included Poodles, Dachshunds and toy breeds, which also encountered BGA in urban and residential water bodies. These waters, often shallow and stagnant in warmer months, can have high levels of nutrients escaped from nearby yards and gardens, “providing ideal conditions for toxic blooms.”

The belief that small dogs or urban-dwelling dogs don’t encounter algae may influence the diagnoses considered. Also adding to the problem of detection and treatment, the study claims: the tests are expensive and can take weeks, access to testing may be limited, and diagnosis may not be a priority for the owner after the dog has died.

According to an algae fact sheet from Humboldt County health department, the toxins of concern are nervous system poisons (neurotoxins) and liver poisons (hepatotoxins). The neurotoxins can kill animals within minutes by paralyzing respiratory muscles, while hepatotoxins can cause death within hours by causing blood to pool in the liver.

The canine study mentions the many reports of animals drinking algae-tainted water “and dying within hours from neurotoxicity or hepatotoxicity, or developing sublethal chronic liver disease.”

Another less dangerous compound causes allergic responses. But initial, low-level exposure to any of these toxins may cause skin irritation and stomach upset, the study says. So those symptoms alone may not help identify the toxin.

Both nervous system toxins and liver toxins can be fatal. Liver toxins cause weakness, vomiting, pale mucous membranes and diarrhea. Common signs of neurotoxins are muscle tremors, seizures, labored breathing and difficulty moving.

Often implicated in poisonings are anatoxins (neurotoxins) and microcystins (liver toxins, considered more common and possibly carcinogenic, research suggests). Dogs are especially susceptible to anatoxins, according to the North Carolina Department of Health’s website; these poisons can be fatal within minutes – or hours. Quick veterinary care with anti-seizure medication and oxygen may help.

The consensus is that there is no antidote for BGA toxins. But the review of dog poisonings says that most exposed animals aren’t given specific treatment, even though “simple, cost-effective treatments may improve their chances.” In the case of microcystin exposure, since many believe that no therapies exist, owners and vets “might euthanize suspect cases or provide limited supportive care.”

After several days of veterinary treatment, a Miniature Australian shepherd sickened by algae at a Montana lake was only getting worse. On the fifth day, her vets tried a new therapy not readily available. Last year, a report described what happened next as possibly the “first successful treatment of microcystin poisoning.”

Over the next few days the little Aussie made a surprising comeback.

After eight long days, that dog went home.

***

You gaze into your dog’s eyes. Your dog gazes back at you. It’s true love, right? Yes, absolutely! And it’s not just any kind of love, but perhaps one of the most powerful kinds of love that exists—the love between mother and child.

So says a new study published in the prestigious journal Science called ”Oxytocin-gaze positive loop and the co-evolution of human-dog bonds.” This research provides evidence that our feelings of love for dogs are mutual and are in part a result of looking into one another’s eyes, just like mothers and babies do to form their strong attachment.

In humans, it has been shown that mothers who spend more time in mutual gazing with their babies have higher levels of oxytocin. (Oxytocin is a hormone that plays a large role in the formation of social bonds as well as feelings of love.) Additionally, there is a positive feedback loop in humans. Mothers with higher oxytocin levels engage in more mothering behavior, which affects oxytocin levels in their babies. That in turn leads to higher levels of attachment, which increases oxytocin levels in mothers, leading to more maternal behavior, and so on.

The purpose of this new research was to investigate whether humans and dogs also have a positive-feedback loop in which oxytocin plays a role, and if so to learn whether gazing is a part of the process. In one part of the study, researchers measured levels of oxytocin in the urine of people and their dogs both before and after they interacted. They found that in pairs in which the dogs gazed at their guardians for a long time, levels of oxytocin rose in both the people and the dogs.

In the second part of the study, experimenters examined whether giving oxytocin to dogs affected their gazing behavior or the oxytocin levels of their guardians. Researchers gave oxytocin to dogs (intranasally) and observed that female dogs given this chemical gazed at their owners for longer periods of time than female dogs given saline as a control. (It didn’t affect male dogs the same way.) Even though they were not given oxytocin, guardians’ levels of this hormone increased after interacting with female dogs who had received it. Researchers are not sure why the behavior of female, but not male, dogs was affected by the oxytocin.

This research suggests that the bond we feel with our dogs is not only similar to the bond between mothers and children, but that the mechanism behind the connection is the same. This type of attachment between different species is rare and continues to interest scientists and dog lovers alike. It’s possible that the process of domestication of the dog was possible in part because dogs co-opted the social communication and social bonding process of babies.

Do you feel the love when you and your dog gaze into one another’s eyes?

Animal abuse happens all too often in oh so many situation and cultures, yet little research has been devoted to the problem. An interesting study in the Journal of Applied Animal Welfare Science (JAAWS) titled “Behavioral and Psychological Characteristics of Canine Victims of Abuse” compared dogs who have been (or have most likely been) abused with dogs who have not been abused.

Not surprisingly, behavioral differences were found between the abused dogs and other dogs. Dogs with a history of abuse were rated by their guardians as more excitable and performed more attachment and attention-seeking behavior than their counterparts. They also displayed more fear and aggression towards unfamiliar people and unfamiliar dogs. They rolled in feces more often, exhibited more fearfulness on stairs, showed higher levels of hyperactivity, were more persistent barkers and had a greater frequency of “bizarre, strange, or repetitive behaviors.” That last category includes actions such as hoarding shoes, digging deep holes, sucking on pillows and being unable to stop, and circling when anxious.

The researchers discuss possible interpretations of the results of their study. They point out that fearfulness towards strangers (dogs and people) and aggression towards them are highly correlated in a number of studies, suggesting that much of the aggression seen in the abused dogs could be motivated by fear. They also point out that abuse could cause fearfulness that leads to aggression through a conditioned response, but that aggression could also be a result of genetic predisposition, poor socialization, brain injury and other injuries that could cause aggression motivated by pain.

The researchers went through several steps to identify abused dogs for inclusion in their study. Magazines sent to members of Best Friends Animal Society included a notice requesting anyone who suspected their dog had been abused to consider participating in a study about canine abuse. Over 1100 respondents were given a link to SurveyMonkey, which asked about reasons for suspecting abuse. From that sample, 149 were chosen for the next phase of the study because the cases of those dogs were considered “more likely than not to involve substantiated abuse.”

Five experts were then given the dogs’ historical information and physical reports of injuries, but no behavioral information. (Behavioral information was not included because that was the subject of the study.) If at least four of the experts evaluated the information and concluded that it was probable that the dog had been abused, the dog was included in the study. Only dogs who were still alive at the time of the study were included in order to avoid problems with memory or biased recall.

Of the 149 selected in the first phase of the study, only 69 proceeded to the next stage. Their guardians were instructed to fill out the highly detailed Canine Behavioral Assessment and Research Questionnaire (C-BARQ), which was designed to measure a number of behavioral characteristics in dogs. The C-BARQ has become a standard research tool used to compare the behavior of different groups of dogs. In this study, the abused dogs were compared to 5239 dogs from the C-BARQ database who matched the abused dogs in age range now and at the time of acquisition and the source of the dogs.<

Studies of abuse, in both children and animals, have limitations because abuse is often done secretly, and because of incomplete information about the victims. Rarely is there much information about their personality and behavior before being abused. This study, as the researchers note, suffers from these limitations as well as others.

Another limitation of this study is that it correlates behavior with a history of abuse, but is unable to show whether that abuse plays a causal role in the behavior of abused animals. While it is hard to imagine that abuse does not affect behavior, correlational studies are not designed to elucidate any such claims. The researchers caution that the differences they found between abused dogs and other dogs does not mean that the abuse CAUSED these differences. It is also possible that some of these behavioral characteristics are risk factors for abuse, meaning that they made abuse more likely, or that the abusive environment, rather than the abuse itself, played a casual role.

The researchers recommend that future studies investigate which behavioral differences are caused by abuse, which are risk factors for abuse and which are both. (For example, aggression in human children is known to be both a risk factor for abuse and a result of abuse.) They would also like to investigate which types of abuse are the most damaging. Again comparisons to humans are inevitable, and it is known that emotional abuse is often more damaging and harder to recover from than physical abuse. Finally, they want to know more about how the age at which dogs are abused affects outcomes.

Like many people, it makes me physically ill when I think about abuse of people or of animals, but I’m grateful that it is being studied. The more we know about abuse—its causes and its effects—the better we are able to help those who have suffered and to prevent additional instances of abuse.

A new study in the journal Animal Cognition that reports that oxytocin increases canine responses to human social cues adds to the large number of known effects of this chemical. The more that oxytocin is studied, the more influential it seem to be.

All the articles that refer to oxytocin as “the love hormone” are simplifying to the point of distortion. Sure, levels of this chemical rise in the early stages of romantic love, but that’s just a small part of its role in our lives. Oxytocin is a biologically occurring molecule made of a short chain of nine amino acid acids that has strong effects on the body and on social behavior. Ever since a study roughly 20 years ago showed that it played a key role in the choice of a lifelong mate in the famously monogamous prairie vole, a series of studies have shown its key role in a number of species in trust and social interactions, including bonding. New human parents of babies show a rise in oxytocin, for example.

On the other hand, the moms out there experience other effects of oxytocin related to parenting, and those aren’t all so sweet and glorious. The same chemical that helps us love our babies also helps our babies enter the world and thrive in it. That’s because oxytocin is important for the production of contractions during childbirth and also for lactation to feed our infants.

>To make matters more complicated, oxytocin can make memories of negative social interactions more intense. So, again, “the love hormone” is really not a fair and complete way to describe its social function. Perhaps it’s more accurate to say that it focuses our attention on social information and gives us the ability to understand it at a deeper level. The recent study. “Oxytocin enhances the appropriate use of human social cues by the domestic dog (Canis familiaris) in an object choice task ” supports this view of this powerful biochemical.

The researchers who conducted this study investigated the effects of oxytocin on canine performance in an object choice test (OCT). In an OCT, a person gives a non-verbal, social cue to a dog to indicate the location of a piece of hidden food. Based on the dog’s response, it is possible to learn what cues are meaningful to dogs and which ones they can correctly interpret. Two common cues in OCT studies are pointing and gazing in the direction of the food. In this study, dogs and their guardians came to the test center twice, 5 to 15 days apart for a set of 40 OCT trials, 20 for each cue—gazing or pointing. On one visit, the dog was given an intranasal dose of oxytocin prior to the study and on the other visit, an intranasal saline control was given. The order of these two treatments varied between dogs.

The dogs who were given oxytocin first performed better in their first session than those dogs given saline during the first visit to the testing center. Effects were not as obvious in the trials involving gazing. In gazing trials, the dogs given oxytocin performed no better than if they guessed randomly where the food was hidden, while the dogs given saline first did even worse. Since previous studies have suggested that dogs actively choose to avoid locations that humans have gazed at, this research suggests the possibility that oxytocin counteracts that negative interpretation by dogs, and that they simply guess.

vious OCT studies, dogs have shown no improvement over time. Since learning occurred no matter which treatment dogs received first, it does not appear as though the oxytocin was responsible.

Maybe it’s the science geek in me who has always been fascinated by social behavior, but I’m just as thrilled with the idea of oxytocin as “the social information enhancer and clarifier chemical” as I ever was by the term “the love hormone.”