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THE HORSE (Lexington, Kentucky) 04 October 05 Article # 6165 Snake Bite Preparedness (Edward D. Voss, DVM, Dipl. ACVIM)

Our area has a healthy population of rattlesnakes. We spend six to 10 hours a week on trails where we have seen snakes. I would like to be prepared in the event one of our horses gets bitten. What are the procedures and supplies we should have on hand? Pat

When on excursions into areas frequented by pit vipers (also called crotalids, including rattlesnakes), it is prudent to consider some basic precepts concerning bites. Approximately 20-60% of bites are "dry" or defensive type of bites with little or no venom injected by the snake. These are bites that do not swell much within 10 to 15 minutes of being bitten and are not overly painful. It is difficult to ascertain whether a bite is dry, so assume envenomation (injection of venom) and proceed to obtain veterinary care. Rapid swelling and pain suggest venom injection. Venom has a Super Glue-like consistency and is absorbed rapidly from the bite site within 30 seconds to several minutes. Cutting an incision on the bite and suction is not recommended; icing of the bite is not a good idea, nor is a tourniquet.

Most bites occur on the muzzle in curious horses, and application of a dry absorbent wrap is not possible. Things to consider bringing on such excursions would be:
Wrap material (dry sheet cottons);
Vetrap, two rolls;
Two 12-inch sections of three-quarter-inch or one-inch diagonal gauze;
Garden hose or taped 35-cc syringe casings with the ends bored out to insert into nostrils of horses with rapidly increasing muzzle swelling from a facial strike; and
Non-steroidal anti-inflammatory medication (prescription from your veterinarian).

If a horse is bitten, time is of the essence and prompt evacuation for veterinary care is recommended even though death is rare in adult horses. Complications days or weeks later are often responsible for adult horse deaths from rattlesnake bites. Asphyxiation from massive throat swelling might necessitate a tracheotomy in rare cases. A non-steroidal anti-inflammatory can minimize swelling and pain. Walking, not running, is recommended to avoid elevation of blood pressure and venom absorption.

Leg and torso bites are especially troublesome, and the bitten limb can be promptly wrapped to compress tissue and minimize swelling and absorption of toxin into general circulation. Antibiotics (likely injectable) should be considered once veterinary care is secured due to the "dirty" nature of snake fangs and infection potential. Maintain a current tetanus vaccination.

In summary, minimize swelling and venom absorption, maintain nostril airflow, and seek veterinary assistance immediately. These steps should allow most horses to recover without antivenin (antitoxin active against venom) administration. Do not incise, ice, or apply a tourniquet to snake bites.

Garden hose!! ... garden hose?? Wes
Snake Bite Preparedness

Yeah, Wes, I can see where a couple of 8" pieces of garden hose could keep a snake-bitten horse breathing. Beats the heck out of doing a tracheotomy on one.

~~Greg~~

Hey guys....

At least the Horse doesn't have to worry about being allergic to the Horse Serum in the Antivenom

Al
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If you give somebody a match and they can keep warm for a while.
If you light them on fire, They will be warm for the rest of their life.

These protocols are better than the bite procedures of some private idividuals I have seen who keep venomous snakes them selves!

John
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"Its no help to hide behind the statement that snake bite accidents are a rarity and that the average Dr seldom or never will treat one. For the bitten patient, it is a matter of life or death, and the rarity of the event is of no interest to him."

INDEPENDENT RECORD (Helena, Montana) 04 October 05 Late-summer snakebite (Tia Nelson)
"Doctor, I have an emergency call about a rattlesnake bite on a horse," announced my answering service when I answered the phone on a hot August Saturday afternoon. I got the owner's phone number and told the answering service I'd call right away.
Jon sounded relived to hear me on the phone. His good gelding, DJ, had just been bitten by a large rattlesnake; he wanted to know what he should do. Keep the horse quiet until I can get there I told him.
That's when he said they'd been out riding and he was about 5 miles from the trailhead. He and his wife had been on their way up to the Mann Gulch Fire site when he heard the snake and felt his horse jump under him. He never actually saw the snake but as the fang marks were about three centimeters apart he assumed it was a large snake.
Many snake bites are dry bites, the snake is simply trying to warn the animal or human to stay away. It would rather save its venom for its prey than to waste it on some creature too large to eat.
In August and September, however, snakes shed their skins and are less likely to rattle a warning and more likely to bite with venom. They feel vulnerable because they don't move quickly when shedding and, because the scale that covers each eye is also shed at this time, they don't see as well as usual. In short, they are much more irritable and dangerous in late summer than almost any other time of year.
I asked Jon where the gelding had been bitten. On his foot, was the response, just above his hoof. I felt some relief. A bite in the nose of a horse is often fatal because the swelling that results will block its airway and the horse may suffocate.
Horses are obligate nose breathers: They cannot breath through their mouths so if a snake bites a horse in the nose and injects venom, the subsequent massive swelling may kill the horse. I advise people who have horses in areas frequented by rattlers to carry two eight-to-10-inch pieces of heavy duty garden hose one inch in diameter. If a snake bites a horse in the nose, placing the hoses into the horse's nostrils about six inches will give the horse an airway in case severe swelling occurs.
A bite on the leg is still of concern if there is envenomation as the swelling can be quite impressive. DJ's leg was already swelling up toward his elbow. This indicated the snake had injected venom. We needed to get him out of the backcountry as quickly and safely possible. Jon gave me directions to the trailhead and we agreed to meet there.
Jon would lead DJ out at a walk; I'd drive up with all the treatments and equipment I thought we'd need.
I told my husband Derek what was happening as we drove to the clinic to retrieve antibiotics, pain relievers, rolled cotton and bandage material to create a wrap to help minimize the swelling. I wanted to ice DJ's leg as well but was stymied about how to create something that would hold ice on his leg and still allow him to move around. Derek looked around his shop and found the perfect solution: A tube made of heavy duty black plastic that we could slip over DJ's leg and fill with ice.
We picked up four bags of ice on the way out of town. Antivenin is available, but as it's given by weight it is quite expensive to treat a horse. Also, the serum can cause serious, potentially deadly, anaphylactic reactions in horses. Horses often recover quite nicely from snake bites with good supportive care; so I decided against tracking down antivenin.
Thoughts of the Mann Gulch tragedy floated in my mind as we drove about 40 miles first up I-15 and then down paved roads that turned to gravel then to simple tracks. We talked about that day many years ago when those brave young men lost their lives in that fire and wondered if it was as hot then as today.
There was little wind today; the dust plume from the car hung above the road for miles behind us as we drove further and further into the country. I wondered how we would find Jon and his gelding as it seemed like we were getting to the end of the road.
"There they are!" exclaimed Derek pointing up a side hill. The pickup and horse trailer were slowly coming down a track that was barely even a road. We drove through the creek to meet them.
DJ stood in the back half of the trailer, seemingly not concerned about the swelling in his front leg. Horses often seem philosophical about even catastrophic injuries. He wasn't terribly upset that a rattlesnake had just bitten him and that he'd had to walk about 5 miles to get to help. His sorrel hide was wet with sweat, however, and his heart rate was elevated, giving lie to his stoic demeanor.
I gave him a drug that would act like morphine does in humans for pain, then we unloaded him and got a closer look. The bite was on his heel. The swelling had progressed to his elbow, so his whole leg looked like a stove pipe. We created a support wrap to contain the swelling then invented what we came to call "the ice trouser."
It was a one-legged trouser that slipped on over DJ's leg and the support wrap. We filled it with the ice. I gave him some bute intravenously. Bute is like aspirin for horses. Then I gave him penicillin in the big muscle of his thigh to help his body fight any infection from the bite wound. He had been vaccinated against tetanus this spring, so he was not revaccinated.
We loaded him back in the trailer and he went home with bute to be given by mouth and penicillin. I checked him two days later and as the swelling was still impressive, gave him some steroids to help correct it. Soon the swelling was reduced to near normal.
He wore the ice trouser for two days, having new ice put in as the old melted and leaked out. He could move easily around his paddock with the ice trouser on. His owners followed his treatment schedule precisely and his recovery was uneventful.
The only possible future concern is in rare cases horses who have been bitten by rattlesnakes develop heart problems. Their body's response to the venom produces antibodies that attacks the heart muscle. DJ's owners will monitor his heart rate for the next year for that unlikely possibility.
For now, Snakebite Super Stud (the horse formerly known as DJ) is fine and back to pleasure riding with Jon.
Late-summer snakebite