Venomous snake bite of equids occurs in certain areas of North America. The risk of rattlesnake envenomation may justify the use of Crotalus atrox (Western Diamondback Rattlesnake) toxoid vaccine in equids. Pre-exposure vaccination may be recommended for those animals in geographic areas or for those traveling to areas where exposure to venomous snakes justifies vaccine usage.
There is one conditionally licensed inactivated (Crotalus atrox Toxoid) vaccine for use in healthy horses 6 months of age or older as an aid in the reduction of morbidity and mortality due to intoxication with Crotalus atrox toxin.
The label claim for the vaccine is that it may also provide protection against the venoms of the Western Rattlesnake (including the Prairie, Great Basin, Northern and Southern Pacific varieties), Sidewinder, Timber Rattlesnake, Massasauga and the Copperhead. Partial protection may be obtained against Eastern Diamondback Rattlesnake venom. This vaccine does not provide protection against venom from the Water Moccasin (Cottonmouth), Mojave Rattlesnake or Coral Snake.
Use in healthy horses 6 months of age or older.
Adult horses: Administer a primary series of three doses at one month intervals. Booster doses are recommended at 6 month intervals.
Pregnant mares: Manufacturer information claims the product is safe for use in pregnant mares, however this information does not appear on the product label. It is recommended veterinarians contact the manufacturer with questions regarding use in pregnant mares.
Foals: (6 months of age and older) Administer a primary series of three doses at one month intervals. Booster doses are recommended at 6 month intervals. There is no specific information available regarding the vaccination of foals less than 6 months of age.