Image courtesy Australian Venom Research Unit
There are sixty-five venomous snakes in Australia and at CVH we regularly see envenomation in dogs and cats from 4 of these: brown, copperhead, black and tiger snakes. All can kill rapidly, depending on the bite location and the amount of venom injected.
Snake venoms contain a wide variety of toxins and enzymes that vary from species to species. The brown snake venom, for example, contains mostly neurotoxin plus a toxin that alters blood clotting, black snake venom also includes a toxin that causes tissue damage (in fact, of those we see at CVH, the black snake is the only species to cause swelling and reaction at the bite site). The largest proportion of most snake venom is neurotoxin, the poison that immobilises the snake’s prey. Injected by the snake into a frog or mouse, it can render them helpless within seconds.
Each bite injects a variety of toxins, and the age, type and size of the snake is important, as is the part of the body it strikes and the amount of venom injected. A snake just out of hibernation will have a full sac of venom for its first bite, whereas one that has recently bitten prey will have far less.
Snakebite in cats
Cats show quite different symptoms to dogs, regardless of the snake involved. Cats become lethargic and develop a generalised weakness that progresses to complete paralysis. Unable to move, the cat’s body temperature monitors stop working and often we are presented with a cat unable to move with an extremely low temperature and dehydration.
Snakebite is an emergency! If in doubt, ring us first on our 24 hour line (02 4832 1977), then bring your pet in immediately.
We can now confirm snakebite and identify the species with blood and urine tests. This assists in the choice of anti-venene. We also stock polyvalent anti-venene, which covers all Australian snake venoms.
Following administration of the anti-venene, intensive care with I/V fluids, oxygen and constant monitoring of dehydration and temperature will assist in recovery. In some instances, the bite will still be fatal regardless of treatment – the earlier treatment starts the better the chance of recovery.