My dog has been bitten by a snake. Now what?
It depends on the species of snake. There are approximately three thousand species of snakes in the world with less than five hundred venomous species. In North America, there are about twenty-five species of venomous snakes. The most common venomous species of snakes in North America include:
Cottonmouths or water moccasins
Rattlesnakes account for most venomous snakebites and for almost all deaths. Most other venomous snakebites are by copperheads and, to a lesser extent, cottonmouths (water moccasins). Coral snakes account for less than one percent of all bites.
What are the signs of snakebite?
In dogs bitten by a non-venomous snake, swelling and bruising
around the bite are the most common clinical signs. In some cases,
it may still be possible to see the paired puncture wounds from the
fangs in the center of the wound. The bite may be very painful and
may become infected if not treated by a veterinarian. There will be
very little progression of the swelling unless infection develops.
Most swelling resolves within forty-eight hours in uncomplicated
The clinical signs associated with a venomous snakebite vary based on the species of snake. As a general rule, there is extensive swelling that often spreads rapidly. Bleeding or a bloody discharge often occurs at the site of the bite. The puncture wounds from the fangs may not be visible due to either the rapid swelling or the small mouth size of young or small snakes.
The venom of most North American pit vipers (crotalids) contains toxic protein components, which produce local and systemic effects. These effects may include local tissue and blood vessel damage, hemolysis or destruction of red blood cells, bleeding or clotting disorders and lung, heart, kidney, and neurologic defects. Crotalid venom can cause shock, hypotension (low blood pressure), and lactic acidemia (a disturbance in the pH of the blood). The venom of most North American pit vipers causes only minor neuromuscular disease, although Mojave and Eastern diamondback rattlesnake venom may cause serious neurologic deficits.
Coral snake (elapid) venom contains primarily neurotoxic components (components that are toxic to the neurologic system), which result in neuromuscular damage. There are often minimal symptoms and signs seen at the bite site.
How is a diagnosis of snakebite envenomization made?
Diagnosis is primarily made on medical history and clinical signs. If the type of snake is unknown, diagnosis and treatment will be directed at the presenting clinical signs.
What first aid treatment should I do on my way to the veterinarian?
First aid is aimed at reducing rapid spread of venom in the body:
If possible, carry the dog rather than allowing the dog to walk.
Bathe the wound with cold water to control swelling.
If a limb is affected, apply a tourniquet using a tie, stocking etc. Loosen for approximately half a minute every five to ten minutes.
Keep your pet quiet and warm on the journey to vet.