10th June 2006
The swelling on the horse’s face will extend up to the eyes and they may nearly swell shut. The ears will also probably become enlarged and swollen. The horse’s initial bodily reaction to the snake bite may also cause life threatening heart arrhythmia (irregular heartbeat).
It is fair to assume that many horses would get bitten by non-poisonous snakes, but even if a horse does get bitten by a poisonous snake, the bite may not be deep enough to cause envenomation (venom going into the lymph system).
If someone has witnessed the snake bite, they should attempt to take a photo of the snake, so as to allow for proper identification of the snake, which is most important from a veterinary perspective. The same logic applies to assist human snake bite victims. For instance in Australia, there are numerous types of brown snakes. Having the snake available will also allow the vet to see the size of the snake, which will give him/her an idea of the amount of venom that it was likely to contain. In something readers will find fascinating, if a black snake bites the lip of a horse, the associated haemorrhage area around the puncture wound, will also turn black.
Snake bite, with envenomation from a poisonous snake, is a genuine emergency, but like all other emergencies in life, Step 1 is not to panic. Stay calm and call a veterinarian immediately and keep the horse as still as possible. If it hasn’t got a halter on it, get one and put it on. If you are a person around horses all the time, you should keep a halter and lead in your car boot at all times anyway – I’ll guarantee you that one day in your life you’ll use it – you’ll see a horse loose on the road, or an escapee near a racetrack etc.
When the horse has a halter on it, keep it as still as possible, as any movement in terms of walking, or running, will only speed up the venom’s travel through the lymph system.
If the horse stands with his head lowered towards the ground, leave it that way, as simple gravity from the horse’s head being lowered will help slow the venom’s movement upwards. Don’t think you are doing the right thing by lifting the horse’s head up, or touching the swollen area.
On arrival, the vet will treat the horse’s pain and swelling. The vet will also bring the horse’s tetanus immunization up to date, as snake bite puncture marks are notorious for allowing dreaded tetanus to infiltrate the horse’s body. A horse should have a tetanus toxoid booster each 12 months.
The vet may clean the wounds to reduce the risk of infection around the bite site. In the short term following the bite, the horse may lose a layer or more of skin off its face and when that happens, the vet may well treat the area as an open wound for the following two or three weeks.
The severe tissue damage that can result from snake bite, can later develop into a bone infection, or even gangrene.
Horses bitten by a snake may take weeks – or even months – to return to normal.
If used as part of the initial treatment to stop suffocation, the lengths of garden hose in the horse’s nasal passages will both fall out as swelling subsides.