Can Vaccinations Cause Autism in Dogs?

The anti-vaccination movement now seems to be impacting dogs.

Posted Sep 26, 2017

US Air Force -Yokota Air Base photo
Source: US Air Force -Yokota Air Base photo

I received an interesting note from an acquaintance which started me thinking, and ultimately started me worrying. The note read, in part:

"My sister lives in Brooklyn, in the Williamsburg area. In case you don't know this area, it is considered to be the hipster part of New York City. This is where the young and hip try to live a holistic and 'natural' lifestyle and tend to impose the same living conditions on their dogs.

"The reason why I'm writing to you is that my sister's group of dog owning friends have been telling her that she should not vaccinate her dog because vaccinations have been shown to trigger autism in children and they can do the same for dogs. I was wondering if you could tell me if there is any truth to these claims."

This note raises a whole lot of issues. I suppose the first is whether or not dogs can suffer from autism. This is a very active debate, with some researchers claiming that canine autism is a bona fide condition while others do not. The science is ambiguous. Researchers have mostly reached the conclusion that the autism is idiopathic, which simply means that its cause is unknown. However it has also been determined that the condition is congenital, which means that dogs are born with it and don't develop it over time. Other research suggests that there are genetic components to canine autism which may be inherited from the dog's parents, and these may affect the development of the so-called "mirror neurons" which appear to be associated with the behavioral symptoms of autism.

The most suggestive evidence for the possibility of canine autism comes from Nicolas Dodman, who is a veterinary behaviorist at Tufts University and one of the leading canine researchers in the world. He started out studying a sample of Bull Terriers who compulsively chased their tails and noted that some of them also showed behavioral symptoms which are typical of autism, such as being socially withdrawn and avoiding interactions with people and other animals. Further analysis showed that these Bull Terriers also have elevated levels of two types of blood chemicals —neurotensin and the corticotropin-releasing hormones. This is significant because humans with autism also show elevated levels of these substances. You can read more about his research by clicking here.

Other researchers have pointed out that the existing research that supports the idea of canine autism has been done on only one breed of dogs, namely the Bull Terrier, which has a relatively strange head shape and a unique genetic makeup. Furthermore the symptoms supposedly associated with canine autism are also found in other behavioral conditions, such as obsessive-compulsive disorders. Furthermore many of these symptoms are ambiguous, in much the same way that a cough can be a symptom of tuberculosis, pneumonia, congestive heart disease, or a simple cold. Emphasizing the difficulty in determining what autism might look like in a dog Brooklyn veterinarian Stephanie Liff said "We've never diagnosed autism in a dog. I don't think you could."

Even if we accept the fact that canine autism exists, the linkage between vaccination and autism has been scientifically rejected. The fear that vaccines might cause autism started in 1998 in a study conducted by a British physician, Dr. Andrew Wakefield. In it he claimed that he had evidence which showed a link between autism and the widely used measles-mumps-rubella vaccine. His study was later determined to be fraudulent and was retracted by the journal that published it. Furthermore, as a consequence of this, Wakefield was stripped of his right to practice medicine in the United Kingdom. Since that time, 17 studies in 7 different countries, resulted in the gathering data from hundreds of thousands of children. All of these studies have shown that those receiving such vaccines were not more likely to develop autism than those who haven't received them. Even if we can put aside the debate as to whether or not dogs actually can develop autism, dog owners should be reassured by this extensive research. However in our media dominated society the opinions of celebrities with no scientific training, such as Jenny McCarthy, Jim Carrey and Robert Kennedy, Jr., seem to carry more weight with the public than the actual scientific data.

Failing to vaccinate dogs has a number of potential consequences not only for the dogs themselves but for the population of humans. In the United States children receive vaccines to prevent 14 different diseases. Young dogs receive vaccines for four diseases: canine parvovirus, canine distemper, canine hepatitis and rabies. Notice that rabies is not preceded by "canine" because rabies can infect people as well — it's the same virus. That's why all states in the US require rabies vaccination for dogs.

You must understand that rabies is a killer which is contracted from the bite of a rabid animal. Once you show symptoms of the disease it is 100 percent fatal. The only saving possibility is that if you can treat a person who has been bitten by a rabid animal quickly enough (before they start showing symptoms), the series of shots can save their lives. The animals most likely to transmit the virus are bats, raccoons, skunks, and foxes (in that order). In the United States each year 1 to 3 people die from rabies, and 30,000 to 60,000 Americans are subjected to the series of four rabies vaccines because of bites from potentially rabid animals.

The situation in the United States is far better than that in the rest of the world where dogs are not required to be vaccinated. According to the World Health Organization, 55,000 people die from rabies each year. But in the rest of the world it isn't bats, raccoons, skunks, or foxes that are transmitting the diseases it is dogs. Dogs used to be a major cause of rabies in the United States, but the vaccination programs which began in the 1940s virtually wiped out dogs as a cause of this disease in people.

People who choose not to vaccinate their dogs for rabies don't recognize the risk that they are exposing their pets to, even if their pet does not contract the disease. Consider the World Health Organization's guidelines for the control and prevention of rabies (guidelines that have been accepted in whole or in part by most governmental animal control organizations). "If an unvaccinated dog or a cat bites a person or an animal, even if that bite does not appear to be medically significant, that animal should be immediately euthanized. If it is a person who has been bitten they should be immediately placed on the rabies vaccination regime. If it is another animal that has been bitten, that animal should also be euthanized." In other words, when you're overenthusiastic pet dog accidentally punctures your thumb when grabbing at a treat that you are offering him he is placing his life in danger should your physician ask you about the vaccination status of your pet. Not only may your dog be taken away from you but you may be subjected to the very unpleasant series of anti-rabies shots. Similarly if your dog is involved in a scuffle with another dog and has bitten or receives a bite your veterinarian is duty bound to report that if your dog is unvaccinated, thus exposing your pet and the other dog to euthanasia. This seems to me to be a pretty severe risk to take with your pet dog on the basis of a scientifically disproved association between vaccination and autism.

Stanley Coren is the author of many books including: Gods, Ghosts and Black Dogs; The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission