FAQs About Rattlesnake Bites

By: Celeste Treadway, DVM

TVMA Member
Austin, TX

Published October 2015

In certain parts of Texas, we see many rattlesnake bites, and we receive many questions about prevention and treatment. Below are some of the common questions we answer:

Q: What happens if my pet gets bitten by a rattlesnake?

A: Reactions to rattlesnake bites may vary from severe and fatal to no reaction at all in cases of “dry bites” (in which no venom is actually injected). Typical signs of a rattlesnake bite are rapid swelling, pain and dark fluid oozing from the skin. The venom may cause necrosis of tissues (skin may eventually slough off), blood clotting inadequacies, kidney failure and other complications in multiple parts of the body

Q: What is the treatment?

A: If you suspect your pet may have been bitten by a rattlesnake, take it to a veterinarian immediately. Assessment by the doctor will help determine what treatments your pet may need. Mild cases may only need pain medication and antibiotics to prevent infection. More severe cases will require hospitalization, anti-venom and close monitoring to assess clotting ability, kidney function and other critical blood parameters.

Q: How can I prevent this from happening to my pet?

A: Snake aversion training teaches your dog to AVOID a snake if it smells or hears one, which can help prevent a bite. Your dog’s avoidance behavior can also alert you that there is a snake in the vicinity. This is an affordable and highly effective way to teach your dog that snakes are best avoided (which dogs apparently don’t know instinctively).

Avoiding areas where snakes are more likely to be present will reduce risk, but each person has to decide how much fun (hiking, camping, etc.) they want to give up in exchange for safety. Avoiding “wild” areas is no guarantee. Many of the snakebite cases we see occur in the owner’s own yard! As our suburbs continue to expand into previously wild areas, snakebites will continue to be a problem.

Cats are not as likely as dogs to get bitten by a venomous snake, but when they do, it tends to be serious. Keeping your cat indoors eliminates this particular risk. There is not much, practically speaking, that you can do to prevent an outdoor cat from exposure to a snake. If your cat spends most of its outdoor time in your yard, then keeping your yard fairly short and not maintaining “hiding places” (woodpiles, boards on the ground, etc.) for snakes may help. There is no reliable way to protect a cat that wanders freely outdoors.

Q: Is there a vaccine for rattlesnake bites?

A: The Crotalus vaccine (or “rattlesnake vaccine”) is only approved for administration to dogs, not cats or other pets. This vaccine has received “conditional approval” from the FDA. Whether or not your dog should receive it will depend on your pet’s particular risk factors, health history and your comfort level with the uncertainties of the vaccine (see below). Lifestyle and temperament of the dog are important factors in deciding whether your dog should be vaccinated. A couch-potato lapdog is at much less risk of exposure to rattlesnakes than a young Labrador retriever or terrier that sticks its nose into everything.

Q: If my dog gets the Crotalus vaccine, is it then safe if it gets bitten by a snake?

A: NO. The vaccine has been found to reduce the severity of injury in most rattlesnake bite cases, but it is not a guarantee that a bitten dog will not develop problems. Some vaccinated dogs still become seriously ill and require extensive and expensive medical treatment. Some vaccinated dogs still die when bitten by a rattlesnake, while some are fine. Unfortunately, snakebite cases are so variable that there is not a good way to do controlled, scientific studies to exactly measure how much the vaccine helps. Anecdotally, veterinarians in South Texas, who tend to see many, many rattlesnake-bitten dogs, feel that the vaccine helps to reduce the overall injury and death rate from rattlesnake bites. The vaccine may also provide some protection against copperhead bites. However, it does not offer any protection against water moccasins or coral snakes, which are also found in Central Texas.

Q: Are there any bad side effects of the vaccine?

A: A small percentage of dogs will develop a sometimes-painful swelling at the injection site. Sometimes these swellings will abscess (fill with nasty fluid, which can sometimes get infected) and then need to be treated with antibiotics or drained. This can be an added expense for the pet owner and uncomfortable for the dog. Other than these swellings, which occur in approximately one percent of cases, the vaccine appears to be relatively safe. There are no reported deaths after administration of the vaccine.

Dr. Celeste Treadway practices veterinary medicine at Lakeline Animal Care in Austin, Texas.