A California company, Red Rock Biologics, is marketing a canine vaccine that has proved effective in protecting dogs against venomous snakebite.

According to company spokeswoman Janet Jones most veterinarians are selling the vaccine for $25 to $30 a dose.

Red Rock Biologics recommends two vaccinations, administered about 30 days apart. Annual booster shots will keep the dog’s immunity level high, said Jones.

“This vaccination is not a silver bullet that makes dogs impervious to snakebite,” Jones said. “The owner should still get the dog to a vet as quickly as possible.”

Jones said there’s been a huge response from Texas since Red Rock Biologics began a national campaign late last year. The abundance of aggressive western diamondback rattlesnakes in the majority of Texas, combined with mild weather and a longer active season for the reptiles, translates to thousands of canine snakebites each year.

Veterinarian Steve Bentsen of McAllen, Texas, treats five to 10 snakebites a year.

Last week, one of Bentsen’s clients brought in a large Labrador retriever that had been struck in the face three times by a big rattler. Though he received prompt medical attention, the dog died.

“It is my feeling that 80 percent of the dogs that are bitten survive, mostly without permanent damage,” Bentsen said. “The reaction that a dog has to a snakebite depends on where the dog is bitten and how much venom the snake injects. We strongly encourage our hunting dog owners to snake-proof their dogs with a shock collar.”

The snake-proofing clinics use live rattlesnakes with their fangs removed so they can’t bite the dog. Wearing a shock collar, the dog is introduced to the snake.

A dog’s usual reaction to the sounds and smells of a snake is to stick its head in for a closer examination. That’s why most canine snake-bite victims are bitten on the face or head.

When the dog shows interest in the snake, the trainer administers an unpleasant electrical shock. Some dogs require repeated shocks, but most dogs quickly learn the lesson that snakes are something to be avoided.

Working dogs are not the only canines at risk from snakes.

Pets that live in rural areas are often bitten in their own backyards. Rattlesnakes are not uncommon inside the city limits of cities such as Austin, San Antonio and Abilene, as well as dozens of smaller towns.