Did you know that the rattlesnake vaccine reduces the likelihood of death, permanent injury or severe pain if your dog is bitten? The vaccine does not prevent or eliminate the toxicity of snake bites, but it can improve the outcome after a bite. Veterinary treatment is still necessary for vaccinated dogs. The vaccine is approved for dogs older than 4 months and initially dogs need two doses one month apart. Vaccination is best done twice a year, in March for spring exposure and August for fall exposure.