Rattlesnake Bites and the Rattlesnake Vaccine
A rattlesnake bite is an emergency, vaccinated or not. What a Southern California study found about the vaccine, and what the reviews say about treatment.
Written by thecanineledger
If a snake may have bitten your dog, go to a vet now, even if your dog has had the rattlesnake vaccine. Keep your dog calm and carry it if you can. Call ahead so the clinic can prepare.
Our note: This advice is ours. We found no source on first aid.
A 2014 study of 82 dogs treated for rattlesnake bites in Southern California found that “Vaccination status did not significantly affect the length of hospitalization ( P =0.8119) or the number of antivenin vials required for the treatment” (Leonard et al., Veterinary Medicine: Research and Reports 2014). Antivenin, or antivenom, is the treatment that neutralises venom.
While a vaccine sounds like protection, the evidence that it helps once a dog is bitten is thin. This page sets out what the studies found. It covers North American rattlesnakes. For adders, see our separate page.
1. What the vaccine study found
The dogs. “Five nonacademic emergency and referral veterinary hospitals in Southern California were involved in the study and contributed records regarding a total of 82 client-owned dogs”. “Fourteen dogs (17%) had a history of prior vaccination against crotalid venom.” Crotalids are pit vipers, including rattlesnakes.
The result. “This preliminary study did not demonstrate a statistically significant protective effect of the canine rattlesnake vaccine in dogs suffering from clinical signs of envenomation warranting treatment with antivenin.”
What it doesn’t show. It was small, with only 14 vaccinated dogs, and it looked only at dogs ill enough to need antivenom. Dogs with milder bites weren’t included. The authors say a better study would control how long ago each dog was vaccinated.
Funding. “The authors report no conflicts of interest in this work.”
2. What vet guidelines say
No position. The 2014 study notes that in the American Animal Hospital Association’s vaccine recommendations of the time, “no position is taken regarding use of this vaccine, due to limited experimental and field data.”
Other snakes. The study says the maker “does not claim cross-protection against venom of cottonmouth, Mojave, or coral snakes.”
AAHA’s current position. The 2022 AAHA vaccination guidelines still find no published evidence: “Veterinarians choosing to use this toxoid should be aware of the lack of peer-reviewed published data” (AAHA 2022, Rattlesnake toxoid).
→ Core and Non-Core Vaccines: What the 2024 WSAVA Guidelines Say
3. Treatment at the vet
Antivenom. A 2026 review says “benefits from the use of antivenom are consistently reported in companion animals, such as a quicker resolution of bite-site edema” (Migliorisi et al., Frontiers in Veterinary Science 2026). Oedema is swelling. The authors declared no conflicts of interest.
Cost. The review notes that intensive care, “multiple antivenom vials used, and mechanical ventilation all contribute to significant expenses in envenomated dogs and cats.”
Antibiotics. A 2023 evidence summary looked at seven case series. “The incidence of wound infection was low in the studies and overall antimicrobials seemed to have no significant effect on outcomes such as survival or wound infection.” Its strength of evidence was rated weak (Ballman and Messina, Veterinary Evidence 2023).
Our note: The 2026 review’s figure of survival that “approached 97%” comes from a study of 272 bitten dogs at five emergency centres in Arizona (Witsil et al., Toxicon 2015). We could read only the abstract. It says 8 of the 272 dogs died, and all of them were treated with antivenom. The abstract doesn’t say who funded the study.
4. If you live in rattlesnake country
- Know your nearest emergency vet before you need one.
- Keep your dog on a lead on trails in snake season.
- Ask your vet about the vaccine, and what the evidence does and doesn’t show.
Our note: These points are ours. We didn’t look for evidence on snake-avoidance training.
5. What we could not verify
| Commonly said | What we found |
|---|---|
| “A vaccinated dog doesn’t need the vet after a bite” | No. Every bite needs a vet. One study found no clear benefit in dogs needing antivenom. |
| “The vaccine protects against all snakes” | No. The maker doesn’t claim protection against several species. |
| “Bitten dogs always need antibiotics” | Not supported, in a 2023 evidence summary. The evidence is weak either way. |
| “Most bitten dogs die” | Not among treated dogs. A recent review reports about 97% survival with antivenom in North America and 98% in South Korea (review). |
Sources
- Leonard MJ, Bresee C, Cruikshank A. Effects of the canine rattlesnake vaccine in moderate to severe cases of canine crotalid envenomation. Vet Med (Auckl) 2014: retrospective study, 82 dogs, five Southern California hospitals. No conflicts declared
- Migliorisi A, Johnson T, Nelson T, et al. Snake envenomation in veterinary medicine: comparative insights and emerging therapies. Front Vet Sci 2026: narrative review. No conflicts declared
- Ballman M, Messina D. In dogs with snakebites does the use of antimicrobials compared to no antimicrobials reduce incidence of wound infection? Vet Evid 2023: knowledge summary of seven case series
- Witsil AJ, Wells RJ, Woods C, Rao S. 272 cases of rattlesnake envenomation in dogs: demographics and treatment including safety of F(ab’)2 antivenom use in 236 patients. Toxicon 2015: retrospective study, 272 dogs, five Arizona emergency centres. ⚠️ abstract read
Always confirm with your vet before acting on anything on this page.