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Snake Bites

If your dog encounters a poisonous snake in the United States chances are that it will be a pit viper. Pit vipers are a general class of poisonous snakes that are identified by their triangular heads, retractable fangs, and a special heat-sensing pit between the eye and nostril. Most dog/snake encounters are not deadly but the bite can be very painful and bitten animals should be treated immediately. North American pit vipers include five subspecies of copperheads, three subspecies of water moccasins, three subspecies of pygmy rattlesnakes, three subspecies of massauga, and at least 26 subspecies of rattlesnakes. Water moccasins and copperheads are found in the eastern United States and Southward through Texas. Rattlesnakes are found throughout the contiguous United States, with the highest concentration in the South and Southwest.

Pit vipers and snakes in general have been unfairly villainized by humans since the beginning of time and to this day are hunted down and killed for sport or out of fear. Despite the potential threat of a severe reaction, the vast majorities of bites are not deadly and can be effectively treated. The benefits of pit vipers are tremendous. They are very effective rodent killers and consume hundreds of thousands of mice and rats every year. They are essential to keeping the rodent population from exploding out of control. If people and their pets avoid areas that are likely to harbor large numbers of snakes particularly at certain times of the day and during certain times of the year, and use a little common sense, very few dangerous encounters are likely to occur. While not everyone finds these animals fascinating adaptions to nature, they can still respect them as important pieces in a balanced ecosystem and give them the little space which they require.

What are the symptoms?
Many times the owners of dogs that get bitten by a pit viper are not there at the time of the bite. Signs that your pet has been bitten include puncture wounds (often bleeding), immediate severe pain, swelling, and tissue necrosis. The more severe systemic signs may take up to several hours to appear and include hypotension and shock, lethargy and weakness, muscle tremors, and neurological signs including depressed respiration.

How are pit viper bites treated?
Animals suspected of being bitten by a pit viper should have immediate veterinary attention even if the bite occurred several hours earlier.
Animals suspected of being bitten should be hospitalized and monitored for at least eight hours. If you see your pet bitten by a pit viper, or suspect a bite has occurred, you should immediately take your pet to the nearest veterinarian. Suction kits to remove the venom can be tried but due to the large amount of hair present will likely have poor results. In addition, the use of such kits takes valuable time that would be better spent in travel. Decreasing the amount of activity and keeping the pet calm is beneficial. Applying tourniquets is of little benefit and they are often poorly applied and create more harm then good. Ice or cold compresses applied to the bite may help relieve some of the pain.

If the animal is showing signs of a reaction, the veterinarian will:


What is the mortality rate in animals that receive antivenin?
A study of animals bitten by pit vipers showed that those treated with antivenin, intravenous fluids and antibiotics had a mortality rate less than 1% and local tissue damage was rare. The mortality rate in untreated patients depended on the species of snake involved. For example in patients bitten by the Northern Pacific Rattlesnakes the mortality rate was about 10%. In the much more dangerous Mojave rattlesnake it could be as high as 35%.

Where is antivenin available?
Two companies, Fort Dodge and Wyeth Ayerst Laboratories produce antivenin. Veterinary clinics and human hospitals in areas that have a high population of pit vipers have this product on hand. Many owners want to carry this product with them but because of the intravenous administration and instability of the product it is recommended that a veterinarian give it. Even animals that have gone several hours and show severe symptoms have shown good response once treated with the antivenin. So owners of animals suspected of being bitten by a pit viper should seek out immediate veterinary attention for their pet even if the bite occurred several hours earlier.

Summary
Pit vipers compose the largest group of poisonous snakes in North America. With a little common sense and snake courtesy most snake encounters can be avoided. If a snake does bite your pet, a veterinarian can successfully treat him and death is very rare.

The information on this page was obtained from the site www.peteducation.com