We have seen two cases of rattlesnake bites in dogs so far this season. Typically we see maybe one per year. Thus, the environmental trigger points are primed for the rattlesnake numbers to be up and they are out.

Rattlesnakes are the only true venomous threat in our area and account for the most bites and almost all deaths of any venomous snake in the United States.

What are the signs of snakebite?

In dogs bitten by a nonvenomous 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 cases.

The clinical signs associated with a venomous snakebite are 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 fang wounds 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 shock, hypotension (low blood pressure), and lactic acidemia. The venom of Mojave and Eastern Diamondback rattlesnake venom may cause serious neurologic deficits.

How is a diagnosis of snakebite 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 it to walk.

Bathing the wound with cold water controls swelling.

If a limb is affected apply a tourniquet using a tie, stocking etc. Loosen for approximately half a minute every 5 to 10 minutes.

Keep your pet quiet and warm on the journey to vet.

What is the treatment for snakebite?

Venomous snakebites are medical emergencies requiring immediate attention. Before treatment is begun, it must be determined whether the snake is venomous and whether envenomization occurred. Fortunately, a venomous snake may bite and not inject venom. Rattlesnake envenomization involves treatment for shock and administering appropriate antivenom, antibiotics and pain medications. Rattlesnake antivenom is extremely costly at around $800.00 per vial/treatment.

What is the prognosis for a dog bitten by a rattlesnake?

The prognosis depends on several factors, including: the size and age of the snake; the amount of venom injected (baby rattlesnakes inject more venom than adults); the number of bites; the location and depth of the bite (bites to the head and body tend to be more severe than bites to the legs or paws); the age, size, and health of the dog; the time elapsed before treatment; and the dog's individual susceptibility to the venom. The site of the bite is important. Swelling from bites around the muzzle and face can lead to breathing difficulties due to obstruction of the airway.

I want you to come away with two points from today's article. If your pet is bitten by a snake get to a veterinarian ASAP, preferably on who has anti-venom on hand. There is also a rattlesnake vaccine, which is two doses initially, three weeks apart, and an annual booster one month before rattlesnake season. The season begins approximately March 1 in our area. This vaccine buys your pet time to get to your veterinarian to get treatment.

In closing be aware of rattlesnakes and if your pet's lifestyle allows potential exposure then consider vaccination.

Dr. Darren Woodson has practiced veterinary medicine in the Farmington area for more than 28 years and has a passion for educating pet owners. If you have a question you would like him to address, email dwoodson@valleyvetpet.com. Please understand Dr. Woodson will choose the questions that are most relevant to our readers.