Snake Bites in Horses

What are Snake Bites in Horses?

Snake bites are a relatively common emergency seen in horses, especially in the late summer and fall when snakes are more active. These injuries can cause significant swelling and are usually seen on the legs and face. If your horse has been bitten by a snake, seek emergency veterinarian care immediately.

Symptoms of Snake Bites in Horses

Swelling and inflammation are the most obvious signs of a snake bite; a horse’s face can sometimes swell up to three times its normal size. If severe swelling of the face is present, breathing may become difficult from the decreased volume of air that can pass through the nasal passages.

Other symptoms of snake bites include:

• Discharge of serum or blood from bite wounds

• Excessive bleeding or delayed clotting times

• Tissue damage (can occur for up to several weeks after a snake bite)

Causes of Snake Bites in Horses

Snake bites usually occur on faces and the lower limbs when horses are out in the pasture grazing. Because horses are so curious, if they see something intriguing, they are likely to get close to, look at, and smell the slithering creature. Horses may be bitten on the leg if they step on or near a snake.

Some of the most common venomous snakes to blame for bites include rattlesnakes, water moccasins, copperheads, and coral snakes. While these animals decide whether to emit venom during a bite, most occasions are non-venomous because the snake is typically startled and trying to get away, rather than kill the large creature that disturbed it.

How Veterinarians Diagnose Snake Bites in Horses

Significant, sudden swelling of the limb or face, lameness, and severe respiratory distress are all common symptoms of snake bites. Occasionally, the bite wounds are evident in the shape of two small circles, but these can be very difficult to see. Venomous bites are usually much more traumatic with more exaggerated clinical signs. Non-venomous or “dry” bites may not have as much swelling or other symptoms.

Treatment of Snake Bites in Horses

If you suspect your horse has been bitten by a snake, call your veterinarian immediately; try to keep your horse calm while either loading and trailering to your veterinary clinic or waiting for your vet to arrive on site. Increased stress and movement will increase your horse’s blood flow, which disperses the potential venom further.

If your horse is in serious respiratory distress and can’t breathe properly, a temporary tracheotomy may be placed to allow your horse to receive adequate oxygen, which will also decrease their stress level. If your veterinarian is initially concerned about this becoming a possibility, they may instruct you to tape a few pieces of cut hose into the nasal passages to maintain an airway until they arrive for an examination.

Steroids (dexamethasone) and anti-inflammatories (Banamine or Phenylbutazone) will be administered to help minimize damage to tissue and to help with potential shock. Your horse may also be administered antibiotics, as many snakes inadvertently transfer bacteria into the wound when they bite. This will also help prevent any infection from necrotic (dead) tissue that might develop.

In certain cases, your veterinarian may discuss administering anti-venin intravenously to help the body heal from the venom’s effects. Unfortunately, most products are snake specific, and because this serum is created for horses, there is always a potential of a possible transfusion reaction. Your veterinarian will likely start this transfusion very slowly to monitor for adverse reactions and keep epinephrine on hand in case of any issues.

As with any wound, if your horse has not received a tetanus vaccine within the past 6 months, they should receive a booster.

Things not to do if your horse has been bitten by a snake:

• Do not suck out the venom as this is unlikely to be helpful for your horse and can be harmful to you.

• Do not apply a tourniquet if your horse has been bitten on the limb.

• Do not attempt to look for the snake in your area if the bite has just occurred; the priority should be keeping your horse calm and seeking veterinary care.

Recovery and Management of Snake Bites in Horse

In cases of face wounds, recovery typically occurs in a few days with appropriate medical management. Leg wounds can often take longer to heal completely, as the lower limbs have less skin and blood flow to swell, so skin can slough off.

If snakes happen to bite near a joint, the horse can become quite lame due to inflammation and pain. If your horse has facial swelling, do not feed your horse on the ground. With gravity, edema will travel and cause yet even more swelling which can make eating, drinking, and breathing more difficult. In rare cases, snake bites can lead to later clotting issues, internal bleeding, and tissue damage.

Prevention of Snake Bites in Horses

While some accidents aren’t always preventable, there are some smart moves you can make at home to help minimize chances of your horse crossing paths with a snake:

• Try to keep your pastures well maintained; clear brush piles and fallen branches when possible

• Avoid riding through standing water

• In the summer, avoid riding on pavement in the late afternoon and evenings, as this is when snakes like to enjoy the heat

• If you are in a snake-heavy area, consider wrapping your horse’s legs for trail rides