Quoth an antivaxer: Vaccines are making dogs autistic! [Respectful Insolence]

If there’s one thing about antivaxers, it’s that they’re single-minded beyond belief. No matter what the chronic health problem, it’s always about the vaccines. To them, vaccines are always the cause. Autism? Vaccines must be the cause. Asthma? vaccines. Diabetes? Obviously vaccines. Sudden infant death syndrome (SIDS)? What else could it be but the vaccines? (Never mind that there’s plenty of evidence suggesting that vaccinated children have a lower risk of SIDS.) That’s how antivaxers think. Monomania doesn’t even begin to describe it.

I was reminded of this yesterday when I came across yet another article on yet another antivaccine website blaming vaccines for yet another health issue. What made the article stand out to me was that the health problem wasn’t in humans. Rather, it was in man’s best friend. After all, if antivaxers can confuse correlation with causation to blame an increased number of vaccinations in the recommended vaccine schedule for the “autism epidemic” in humans, they can damned well do it for dogs too:

Just as the incidence of Autism-Spectrum Disorders (ASDs) has risen alarmingly in children over the last half century, there is evidence that similar behavioral disorders have been observed in pets, most widely reported among pet dogs. It is too early for mainstream veterinary authorities to confidently confirm that dogs can develop autism, but there are numerous reports of behavior patterns in pets that mirror autism behavior in children. Studies are underway to evaluate the possibility that animals can become autistic.1

One thing I couldn’t help but notice about this article, which is credited to Kate Raines, is that there were basically no peer-reviewed studies cited. That first reference goes to a PetMD article entitled Can Dogs Have Autism? I read the article. The evidence presented wasn’t particularly convincing for reasons that I’ll explain later. In the meantime, let the hilarity continue. Take it away, Kate:

Though the appearance of autism-like behaviors has been observed in dogs since the mid 1960s, the first researcher to specifically relate some of those behaviors to autism was Nicholas Dodman, DVM, who initially set out in 2011 to look for a genetic cause of obsessive tail chasing in bull terriers. This behavioral characteristic has been observed in as many as 85 per cent of a bull terrier litter and often results in self-maiming.

Presenting the evidence from his study at the 2015 American College of Veterinary Behaviorists, Dr. Dodman reported an autism-like condition, noting that “the vast majority of affected dogs were males, and many had other strange behaviors or physical conditions that accompanied the tail chasing, such as explosive aggression, partial seizures, phobias, skin conditions, gastrointestinal issues, object fixation and a tendency to shy away from people and other dogs.”2 He and his associates were further able to establish that two biomarkers common to children with autism were also present in the affected dogs.3

What are “autism-like” behaviors in dogs? How does one recognize or even quantify such behaviors in canines? How does that analogy even work? Does tail chasing really correspond to stimming, which is what I think Raines is getting at? It’s a behavior that could be due to so many other different things. Ditto phobias and aggression, and we’re not even taking into account issues with training. Before we get to the question of whether canine autism even exists or not, I can’t help but point something out. Be it man or beast, if there’s anything that anyone can describe as looking autistic, no matter how tenuously, to antivaxers there can be only one cause. (Kind of like the other way there can be only one.)

What could that cause be….? Hmmm… I wonder…

Oh, hell, you know it just as well as I do: Vaccines. Raines talks about how vaccines for dogs are required at least every three years, depending on the vaccine, particularly the rabies vaccine, referring to dog vaccines as the “immune systems of pets” being “artificially manipulated with the rabies vaccine time and again throughout their lives.” She then goes on a tear, claiming that strange dog behaviors after the rabies vaccine, specifically the “rabies miasm,” behavioral changes claimed to mimic the symptoms of early rabies.

Having never heard of this phenomenon before, I did a bit of Googling. Not surprisingly the main sources I could find for rabies miasm were not exactly what I would call reliable ones. The number one source came from Dogs Naturally Magazine, which goes so far as to postulate a condition called “inherited rabies miasm” to describe a condition when an unvaccinated puppy “is overly timid, overly aggressive, or hyperactive.” Yep, vaccines are so evil to our pets that the evil can be passed on from mother to puppy. It didn’t take long for this particular article to invoke “the teachings of Samuel Hahnemann, the Father of Homeopathy.” Yes, when I see someone invoke The One Quackery To Rule Them All, it always sets my skeptical antennae a’twitchin’.

Let’s just put it this way. The Skeptvet took on another Dogs Naturally article on the same topic, referring to it as pseudoscientific fear mongering. He points out the paucity—the extreme paucity—of evidence supporting claims of serious changes in dog behavior after vaccination and points out that these claims are without basis in fact or evidence. None of this stops an antivaxer from leading with an appeal to big pharma greed:

Globally, the animal vaccine industry has been valued at $6.27 billion in 2015 and, at a calculated annual growth rate (CAGR) of 6.9 per cent, it is expected to rise to $11.40 billion by 2024.17 North America and, particularly, the United States remains the lead market for animal vaccines, accounting for 37 percent of the total. Much of that market is fueled by the human companion (pet) animal segment. There are more pets in the U.S. than anywhere else in the world and, coupled with strict regulations on vaccination of companion animals in this country, the pet vaccine market is not expected to decrease.

Given the current laws requiring annual or three-year repeat rabies vaccinations, and the routine veterinary practice of vaccinating pets annually, it may come as no surprise that we are seeing an increase of autoimmune disorders and autism-like behaviors in pets.

I can’t resist borrowing a legal term: Objection! Facts not in evidence. And they’re not, either. No support is given for either the claim that there is an increase in autoimmune disorders and autism-like behaviors in pets, and there really isn’t any evidence provided to demonstrate that vaccine have anything to do with such an increase, even if there is one. That’s even leaving aside the question of whether dogs can have autism.

The claim that dogs can get autism is largely based, for purposes of this article, on the work of Tufts University veterinarian and behaviorist Dr. Nicholas Dodman. It didn’t take me long to figure out that Dr. Dodman has published research articles and popular books about animal behavior. More problematically, he is known for making direct comparisons between clinical behavioral disorders in humans and similar patterns of behavior in animals. Yes, some behaviors in animals can strikingly resemble similar behaviors in humans, and it is quite possible that there are similar neurologic mechanisms in humans and animals underlying such behavior. On the other hand, there is a great danger in anthropomorphizing animal behaviors and applying human labels to them, especially when there are profound gross anatomic abnormalities associated with this behavior, including hydrocephalus (“water on the brain”).

As the Skeptvet points out, there are significant differences between humans and dogs. Specifically, the diagnosis of autism spectrum disorder involves observing abnormalities in language development. Language is an integral part of human behavior and development. It’s much less of an issue for dogs. Then there’s the issue of making direct analogies between animal behaviors and human behaviors. For example, Dr. Dodman identifies tail chasing in bull terriers as autism-like behavior, which strikes me as exaggerating the similarities between a dog behavior like this and human behavior. What, specifically, makes tail chasing an “autistic behavior”? It’s repetitiveness? Dogs exhibit other repetitive behaviors, such as licking or pacing or circling. Are these “autistic”? Right now, such behavior has been dubbed “canine dysfunctional behavior,” which is a mighty vague description that could encompass a broad range of behaviors.

None of this is to say that dogs can’t develop a neurodevelopmental disorder that resembles autism. After all, human and dog brains share a lot of anatomy and physiology, and dogs are very social animals. Disorders that affect their social behavior can be quite noticeable. It wouldn’t be at all surprising to learn that dogs might “get autism” (or a canine version of autism), but, as is the case with all animal models of human disease, how relevant comparisons with human disease is can be a big issue. As Skeptvet puts it:

There are behavioral disorders in dogs that share symptomatic and possibly causal features of behavioral disorders in humans. While the use of human diagnostic terminology in dogs is problematic, it is not unreasonable to suggest dogs may have behavioral syndromes similar in symptom pattern and causal factors to autism and other human disorders. Animal models of human disease are an established and useful element of medical research, and this can be reasonably applied to behavioral disorders if done judiciously. Dogs clearly do not get autism as it is defined and exhibited in humans, but they may well have related disorders that can provide insight into the causes and treatment of autism in humans.

Regardless of whether or not we choose to call similar or related disorders in dogs and humans by the same name, we can at least be confident of one key fact:

VACCINES DON’T CAUSE AUTISM!!!

Exactly. Longtime readers (or just people who have been paying attention to the vaccine-autism manufactroversy for a long time, whether they’ve ever encountered this blog or not) might remember Mady Hornig’s mouse model of autism that several bloggers mockingly dubbed “rain mouse.” Basically, she injected newborn mice of different strains with thimerosal in a way that supposedly simulated the human immunization schedule of the time. Hornig likened certain mouse behaviors observed in some of the mice injected with thimerosal to autism, including one mouse grooming another to death and another mouse biting its tail, both of which, according to her, were evidence that the mice had “become autistic.” You can see the problem with making analogies between mouse behavior and human behavior here. Admittedly, making analogies between dog behavior and human is not quite as much of a stretch, but it’s still something that should be done with extreme caution.

Whatever the neurodevelopmental or behavior disorder in dogs described by Dodman, they weren’t autism. They might in some ways resemble autism, but there are also significant difference. It’s possible that studying such dogs could shed some insight into human autism, but it’s an unjustifiable extrapolation to call what these dogs have “autism,” and it’s even more ridiculous to claim that the “vaccines done it.”

Ridiculous, of course, is pretty much every antivaxer’s middle name.