Pictured above – Crotalus atrox, the Western diamondback rattlesnake
By Carole Milligan, A.C.A.N. graduate and Certified Carnivore Nutrition Health Coach
A recent post on my local community Facebook page shared a homeowner’s encounter with a rattlesnake in her backyard. In her post, she encouraged everyone reading the post to make sure their dogs get the rattlesnake vaccine. Most responses to her suggestion were from dog owners who said they were going to get their dogs vaccinated.
My first thought on reading this was, how can there be a “vaccine” for rattlesnake bite?
Vaccine theory posits that injecting a killed or weakened germ into the body will stimulate the immune system to produce antibodies, as if the body had been infected with a disease. The vaccine is supposed to mimic a natural infection, without actually causing an infection.
However, a rattlesnake bite is not an infection. A bite from a venomous snake puts a toxin into the body. How can there be a vaccine against a rattlesnake bite?
If you know me, you know that was all that was needed to get me going. Being the curious person that I am, I hoisted my sails and set off on a internet voyage of investigation and discovery.
Vaccines are supposed to stimulate the immune system to create antibodies against antigens. Antigens are defined as any substance that causes the immune system to produce antibodies against it. Using that definition, snake venom is considered an antigen, which is why the rattlesnake shot can be called a vaccine.
Screen shot 2015-04-20 at 8.50.39 PMThe rattlesnake vaccine is a toxin acclimatizator. The theory is that by injecting a little bit of rattlesnake venom into the dog, at periodic intervals, the dog will develop a tolerance for rattlesnake venom. The idea is that if your dog is bitten by a rattlesnake, the vaccine MAY give you more time to get your dog to a veterinarian.
The vaccine manufacturer recommends that the first injection should be boostered after the first month, and then again every four to six months after that. Cost for the shots vary anywhere from $20.00 to $40.00, plus the cost of the office visit. The rattlesnake vaccine manufacturer also recommends that the series of shots be repeated every year. (Does anyone else hear the old time cash register KA-CHING sound after reading that?)
The fear-based marketing for this product sounds reasonable at first, like something any responsible pet owner living in areas where rattlesnakes might live would want to do for their pets.
Ready for the kicker? The rattlesnake vaccine DOES NOT make a dog immune to rattlesnake venom. Even if your dog has received those shots, if your dog is bitten by a rattlesnake it is an emergency situation. You must get your dog into a vet’s office as soon as possible for treatment, just the same as if your pet had not received any rattlesnake vaccine shots.
No less an authority than UC Davis School of Veterinary Medicine states:
“…Although there may be circumstances where a rattlesnake vaccine may be potentially useful for dogs that frequently encounter rattlesnakes, there remains little fact-based data to support the efficacy of the vaccine to date.”
In fact, the vaccine is not currently stocked and is not advocated for animals seen at the UC Davis Veterinary Medical Teaching Hospital. 
“Potentially” useful? Weren’t any safety and efficacy studies on dogs performed by the manufacturer?
Drum roll, please….and the answer is…NO. According to the 2011 American Animal Hospital Association’s Canine Vaccine Guidelines:
“Field efficacy and experimental challenge data in dogs are not available at this time.” 
That was four years ago. Time to check for updated information about the vaccine. I went to the manufacturer’s website. A check of the rattlesnake vaccine manufacturer’s website has a FAQ page about the vaccine. There were no statistics or report findings. To address a question about how well the vaccine works, I found this statement:
“…Veterinarians typically report that vaccinated dogs bitten by rattlesnakes experience less swelling, less tissue damage and a faster recovery from snakebite than unvaccinated dogs. Several factors may influence antibody effectiveness against venomous snakebite. Snake-related factors include the snake species, age of the snake and amount of venom injected.”
Regarding the safety of the vaccine, the website states:
”… Safety data for this vaccine is similar to the available safety data of other pet vaccines currently in use. The vaccine is licensed by the United States Department of Agriculture and is recommended by thousands of veterinarians nationwide.”
According to noted veterinary immunologist Dr. Ron Schultz (DVM), no one knows very much about the vaccine, and in his opinion, it has not been adequately tested. Most of the tests were done with rabbits, mice, and other species, BUT NOT DOGS. There is not a lot of research available on the rattlesnake vaccine.  
So, let’s wrap our minds around this. What amounts to an opinion survey, from veterinary clinics that profit from selling the vaccine, is being used to promote the effectiveness of the vaccine. Vague wording from the manufacturer (without any links to test results), is supposed to be reassuring enough to make us want to go out and get those jabs for our dogs.
I found a heartfelt blog post from a dog owner whose dog developed AIHA, Auto Immune Hemolytic Anemia, after receiving one dose of the rattlesnake vaccine. Her veterinarian felt the AIHA was caused by the vaccine. The owners took the dog to a specialist, who advised that the rattlesnake vaccine caused the dog’s white blood cells to attack the red blood cells, killing the red blood cells, which caused the anemia. In an email discussion with her, she said that her dog has since died, and she has received emails from many dog owners about their dogs being sickened and killed after receiving the rattlesnake vaccine. Her dog’s illness and demise after receiving the rattlesnake vaccine is not an isolated case.
I found some information on the ingredients in the vaccine-aluminum hydroxide and thimerosal (mercury) are used as preservatives. It is noted that the vaccine is intended for use in healthy dogs, which means if your dog has any kind of chronic health condition, the vaccine should not be given to the dog.
Known side effects of aluminum hydroxide are severe stomach pain, constipation, bloody/black/tarry stools, coughing up blood, pain upon urination, extreme drowsiness, fatigue, loss of appetite, and muscle weakness. Thimerosal is a mercury containing organic compound used as a preservative in vaccine, and is known to induce neural damage in patients.  Thimerosal contains a mercury compound, ethyl mercury, which is a toxic metal that can cause immune, sensory, neurological, motor, and behavioral dysfunctions.
If my dogs encounter a rattlesnake, and IF one of them is bitten by a rattlesnake, the vaccine MAY be effective slowing the effects of the venom. The UC Davis School of Veterinary Medicine says there is little fact-based evidence, and does not stock the vaccine. Tests of the vaccine were not done on dogs. There are known adverse side effects from the ingredients in the vaccine.There are known cases of dogs becoming extremely ill and/or dying after receiving the vaccine. I have to ask this question: As there weren’t safety or efficacy studies done on dogs, are we paying for the privilege of OUR dogs being used as test subjects?
After investigating the rattlesnake vaccine, it is my opinion that it is not such a great product after all. If I lived in an area with rattlesnakes, I wouldn’t have the vaccine given to my dogs. I would find an accredited dog trainer, and have my dogs trained to leave snakes alone.
My suggestions? Keep your dog on a short leash in rattlesnake country. If you take your dog for hikes or walks where rattlesnake live, go in the early morning when snakes are less active. Walk in the middle of trails and pathways. Avoid rocky and/or grassy areas. The best idea, I think, is to teach your dog to become snake adverse. Invest in a behavioral training course for your dog that will teach your dog to avoid snakes. If your dog has received avoidance training, then he or she will know to stay away from rattlesnakes if they come onto your property.
The information on this blog is intended as educational only. It is not intended to replace your veterinarian. Please do your own research and use your own good judgment.
Carole Milligan is a graduate of ACAN, certified as a Carnivore Nutrition Consultant, that writes occasional articles on pet wellness, and has edited books on pet wellness.
© All original content copyright (Carole Milligan) (2015)