Pet Vaccinations Causing Pet Autism


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One offshoot of the anti-vaccination movement involves people who believe inoculations are causing their pets an animal version of autism.

A closer look at this belief reveals a series of correlations linking recent genetic research to a series of misguided assumptions and non-existent studies.

The Brooklyn Paper featured this story last week.

Not a shot! Anti-vax movement prompts Brooklynites to withhold inoculations from their pets, vets say

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Some Brooklynites are refusing to vaccinate their pets against virulent and potentially deadly illnesses — some of which could spread to humans — thanks to a growing movement against the life-saving inoculations, according to borough veterinarians.
A number of people refusing to vaccinate their pets are more specific:

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A Clinton Hill–based veterinarian said she has heard clients suggest the inoculations could give their pups autism, however, echoing the argument of those who oppose vaccinating kids. But even if pooches were susceptible to the condition, their owners probably wouldn’t notice, according to the doctor.

There wasn’t much more explaining the reasoning behind this belief, so I poked around a little and found the pet autism idea on a few websites, which offered more information on the trend.

One of them, The Vaccine Reaction, featured an article that attempted to make the correlation between pet vaccinations and pet autism.

Kate Raines wrote “Autism Symptoms in Pets Rise as Pet Vaccination Rates Rise,” for The Vaccine Reaction in April 2017 and it is a fairly subtle attempt (at least as far as these websites go).

I’ll stick to the main points:

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Autistic Behaviors Recognized in Dogs
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

Part of this is true. Bull terriers do have a notable tendency to chase their tails. And research has focused on potential genetic markers that may cause the behavior. I am including the Dodman article here.

But a couple of caveats seem to be in order. An “autism-like condition” covers a lot of ground and does not mean autism. Also, and I am not a scientist, but even if genetic markers are similar, I would have to say that human and canine brain physiology and chemistry are very different.

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“Canine Dysfunctional Behavior” May Be Autism
Though most animal behaviorists still prefer to categorize animals with these traits as having “canine dysfunctional behavior” rather than “autism,”9 those who concede the condition may in fact be autism describe the condition as both “idiopathic,” meaning the cause is unknown, and congenital,” meaning the puppies are born with autism behaviors rather than developing autism sometime after birth. Theorizing that the syndrome may be caused by a “lack of mirroring neurons in the brain,” studies also suggest that autism may appear in puppies as a result of parental exposure to toxins or unnecessary vaccines.

The last sentence comes from a very short article on dog autism symptoms from the website Vetinfo. It does not cite any studies that link pet vaccines and autism.

It is also interesting that the lack of evidence did not stop Kate Raines from moving from “autism-like” to straight out autism in her article.

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Adverse Reactions to Vaccines in Dogs
From paralysis to seizures, and from immune-mediated hemolytic anemia to injection-site fibrosarcomas, adverse reactions to vaccination are not uncommon in pets. Often attributable to annual vaccinations that some veterinarians consider totally unnecessary, vaccine reactions also may lead to allergies, skin problems, behavioral changes, and autoimmune diseases.

Behavioral Changes Following Vaccination
Some of the most common behavioral changes are associated with the rabies vaccine, which is the only vaccine federally mandated for pets and must be re-administered at least every three years if not annually, depending on how the vaccine is labeled. Usually the two vaccines are identical, but a vaccine labeled for one year must be given annually, even if it is exactly the same dosage and formulation as one labeled as a three-year vaccine.

The source cited for “adverse reactions” comes from the National Vaccine Information Center, which is a noted anti-vax organization.

In contrast, the American Medical Veterinary Association does not recognize behavioral changes as a possible adverse reaction to vaccination. It does offer a long list of physical problems that may result from getting your pet inoculated.

Lastly, the link between rabies and behavioral changes comes from another website, this time EnlightenMe. The article on the website makes no mention of any behavioral problems caused by the rabies vaccine.
Is the 3 Year Rabies Vaccine for Pets Different From the Yearly Vaccine?
But a couple of caveats seem to be in order. An “autism-like condition” covers a lot of ground and does not mean autism. Also, and I am not a scientist, but even if genetic markers are similar, I would have to say that human and canine brain physiology and chemistry are very different.

Some autism-like conditions in humans are personality disorders, which have to be considered first before any diagnosis for autism can be done.

ETS Policy Statement for Documentation of Autism Spectrum Disorder in Adolescents and Adults page 7
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To the extent possible, the evaluator should investigate and rule out other
potential diagnoses that may affect the expression of an autism spectrum
disorder. These diagnoses, such as bipolar disorder, social anxiety disorder,
reactive attachment disorder, generalized anxiety disorder, or obsessive-compulsive disorder should be identified and ruled out as appropriate.
Furthermore, 2 of the 20+ suspected genetic markers is not much.

I think someone just thought that title sounded more spectacular and others ran with it.

(edit:spelling corrected, source added)
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