It happens quickly: a rustle in the bushes, a hiss, a rattle and a sharp cry in pain as your dog goes nose to nose with a rattlesnake. Although numbers are not tracked, there may be as many as 100 dogs that get bitten every summer in Larimer County, compared to just a handful of people.
Rattlesnake bites are true emergencies, and just as with people the best first aid plan is to get your dog to a veterinary hospital as soon as possible. To save valuable time, call ahead, and also confirm that the hospital has the required antivenin to treat your dog.
Rattlesnake bites in the northern foothills are usually not fatal, with appropriate treatment, because the prairie rattlesnakes’ venom is not as potent as that of some other pit vipers, the sub-family of snakes rattlesnakes belong to. Without treatment your dog will suffer miserably, and smaller dogs may succumb to the effects of the toxins in the venom.
The cornerstone of treatment is intravenous fluids, pain meds and antivenin. Previously, treatment plans included antihistamines (like Benadryl), antibiotics, and steroids, and these are rarely needed. The toxins in venom cause multiple reactions in a dog, which can lead to a cascade of debilitating metabolic changes. The bite is initially quite painful, and as the toxin spreads, it causes profound swelling and discomfort. Most dogs are bitten on the head, although bites to the front legs are also common.
Antivenin sources have improved so that the current version, imported from South America, is very effective with minimal side effects. Smaller dogs need more vials than larger dogs, since they are dealing with a relatively larger dose of venin. Although a typical human patient may receive as many as 10-20 vials of antivenin, in our veterinary patients one to two vials typically is effective, especially if given within several hours after the bite.
Close monitoring is required, since the toxins in the venom can sometimes lead to kidney damage and ultimately kidney failure in some dogs, especially if they are initially dehydrated and overheated. Platelets, the particles in the blood that cause clotting, can also be affected and drop to precipitously low counts that could cause spontaneous bleeding. Hypotension, or low blood pressure, can lead to collapse and cardiovascular problems.
Additional treatment modalities are now available and can help reduce hospitalization time and decrease pain and swelling. Laser therapy, involving the use of a therapeutic light source at programmed wavelengths and frequencies, will reduce swelling, inflammation and pain at the site of the bite wound. Laser therapy is usually used two to three times in a typical snakebite case.
Hyperbaric oxygen can quickly reduce the profound facial and limb swelling that accompanies rattlesnake bites, and improve oxygenation of tissues that might be affected by the toxins in the venom. Hyperbaric oxygen therapy, or HBOT, usually involves just one or two treatments of one hour each to completely resolve the swelling and edema associated with the bite.
Treatment of rattlesnake bites in dogs is not inexpensive. Veterinarians acknowledge that not everyone can afford all of the recommended treatment; however, critical parts of the treatment not to be bypassed include IV fluids for shock and antivenin to neutralize the venom, along with pain medication. A 12-24 hour stay in the hospital is usually necessary for monitoring and fluid administration. Every case is different depending upon the size of the dog, where they got bitten and the amount of venom in the bite.
Snakebites are easily prevented by avoiding areas known to harbor rattlesnakes. For those that live in snake-infested areas, there is a vaccine available, but its effectiveness has not been determined. Your dog can be professionally trained to develop an aversion to rattlesnakes. Unfortunately, cats do not fare well with snakebites due to their small size, and intensive treatment is required.
Jon Geller is a veterinarian at the Fort Collins Veterinary Emergency and Rehabilitation Clinic.