The problem of venomous snake bites is significant. Snake bites kill or injure dogs, destroy skin and muscle, cause permanent liver, kidney, heart, neurological, and joint damage. It is estimated that about 150,000 dogs and cats are bitten annually in the United States by venomous snakes. Dogs are up to 500 times more likely to be bitten by a venomous snake than to get rabies. A snake bite is severely painful to the dog and can cost the owner thousands of dollars in veterinary bills. This rattlesnake vaccine is designed to reduce the likelihood of death, permanent injury, and severe pain caused by rattlesnake bites.
Initially, two doses are recommended, spaced one month apart. Typically, protection from boosters last about 6 months. Dogs should get at least one booster per year approximately one month before the beginning of rattlesnake exposure. Dogs exposed to rattlesnakes longer than about 6 months, or dogs at higher risk, should get a booster every 6 months. Dogs over 100 Lbs or under 25 Lbs should get an additional booster shot 30 days after the first booster shot in the initial vaccination sequence (three injections total) and then booster normally.
The vaccine has an excellent safety record. It is manufactured by Hygieia Biological Laboratories, which has been making veterinary vaccines since 1991. The vaccine was licensed by the State of California in 2003 and the USDA in 2004. It was listed as a non-core vaccine by AAHA in 2006. The vaccine has been used in over 4,700 clinics, by over 8,000 veterinarians. Over 1,000,000 doses have been used in well over 250,000 dogs. Anaphylactic reactions are rare and estimated at about 1 in 500,000 injections.
Fewer than 1% of dogs suffer any adverse side effects. The most common side effect is a small granuloma (lump) at the injection site. This lump typically doesn’t bother the dog and will usually self resolve in about two to six weeks; hot packing the area three times per day will speed resolution. In about 1 in 300 vaccinations, the dog will develop a sterile abscess at the injection site. The risk of site reactions can be significantly reduced by: 1) avoiding the intrascapular location; 2) using a 1″ needle and ensuring vaccine placement fully into the “dead space” between the subcutaneous fat and underlying muscle; and 3) not administering other vaccines at the same time. Systemic reactions similar to flu like symptoms (vomiting, diarrhea, lethargy) occur in fewer than 1 in 3,000 vaccinations.
This vaccine has limitations. Full antibody protection is not reached until 30 days following boosters. The vaccine protection can be overcome with enough venom and special circumstances. These circumstances include smaller dogs, large snakes, multiple bites, baby snake bites, the motive of the snake to bite, bites into or near vital organs, IV bites, how well the dog responds to the vaccine, and some snake species that this vaccine has little or no protection against. In such circumstances, antivenin may still be required. In addition, antibiotics may be necessary to treat infection following snake bites. The vaccine is not antivenin, and not a treatment for a snake bite.
The vaccine has shown significant snake species cross protection both in the laboratory and in the field. This will provide various levels of protection against the most common species of American rattlesnakes and Copperheads. The best protection has been reported from bites from the Western and Western Diamond back rattlesnakes. The vaccine has some protection against the Pygmy, Massasauga, Sidewinder, and Timber rattlesnakes. The vaccine has limited protection against the Eastern Diamondback rattlesnake. The vaccine will not protect against the Mojave rattlesnake, Coral snakes, or Cottonmouth snakes.
None of the typical treatments for snake bite are contraindicated with this vaccine. Veterinarians can still use antivenin, steroids, antihistamines, and fluids. Dogs will typically present with less severe symptoms and recover more quickly with little or no necrosis. We recommend that dogs be closely monitored for 24 hours post-bite.
Client education should include reminding dog owners that vaccine reduces but does not eliminate all effects from snake bites; snake bites will often appear as bug bites. Even vaccinated dogs bitten by rattlesnakes should be seen by veterinarians ASAP.