As posted on Terrier-L.
Here's a summary of recent first aid recommendations for the treatment of snake bite in humans. One of them--keeping the bite victim inactive- may be difficult in the case of dogs; otherwise, the treatment should be the same. The recommendations against doing certain things apply equally in the case of both dogs and humans.
Treatment for the bite of venomous snakes is a subject of controversy and some treatments that were recommended only a few years ago are no longer thought to be effective. For example, making small incisions at the site of the wound and trying to extract the venom from the tissue by suction--for years a standard treatment in North America--is no longer recommended. Applying ice to, or otherwise cooling, the site of the wound ('cold therapy'), for a time encouraged is now known to inhibit the body's own defense mechanisms against the toxin (cooling decreases the action of the antibodies), without decreasing the action of the lecithinases, which are an important component of snake venom.
Fortunately, venomous snakes do not always inject venom when they bite; in roughly 25% of the bites from venomous snakes no venom is injected. When venom is injected the bite is by no means always fatal. (In the US, where we have three main varieties of venomous snakes, fewer than 3% of those bitten die--and even this figure is probably too high because although almost all fatal bites are reported, many nonfatal bites go unreported, even if the victim is hospitalized and treated.)
The seriousness of a bite depends on its location (bites on the head or trunk are more serious than bites on the extremities); on the amount of venom injected (snake venom is more concentrated in the spring if the snake has been hibernating, and of course multiple bites will inject more venom); and on the type of snake. Unless you are very far from veterinary help the application of a tourniquet (e.g. on a leg for a bite on the paw) is unnecessary, and, if you are unskilled in first aid, likely to do more harm than good. Keep the bite victim as quiet (inactive) as possible, and as calm as possible: talk soothingly and comfortingly to both dogs and humans. If necessary, treat for shock.
Even the bite of a non-venomous snake can carry tetanus, and snake bites should be disinfected as one would any other animal bite, and a tetanus booster should be given.
I've mostly said what not to do by way of first aid. What should be done is up to your vet. He or she may recommend the injection of antivenin. The antivenin used in the US is made from horse serum; many humans have serious (fatal) allergic reactions to horse serum. I would assume that the same is true of dogs. Antivenin should never be given to a person or an animal known to be sensitive to it.
What I've said applies to the bites of snakes common to North American and to Europe; the bites of some Asian and African species and of some tropical species elsewhere require more aggressive and intensive treatment.
- Keep calm. Keep the victim calm.
- Not every bite from a venomous snake injects venom.
- Even if venom is injected, a single bite from the one of the snakes common to North America is rarely fatal.
- Most of what you may read about treating snakebites that was written more than twenty years ago is probably wrong.
- Many vets/doctors have never seen an actual case of snakebite.
Mr. Paul (firstname.lastname@example.org) would be glad to answer general questions about venomous snakes in North America; the toxicity of their bites; and the generally accepted guidelines for treatment should your dog or other pet be bitten. He cannot provide emergency advice or diagnosis, nor can he identify a particular species of snake from a rough, verbal description of a wound. Should your dog be bitten (or should you even suspect that it has been bitten) by a venomous snake, contact your veterinarian, your local poison control center--or, in extreme cases your personal physician--immediately. Do not panic, but do not delay.