Snake bite: Symptoms and treatment
Envenomation from the toxins contained in snake venom is always a serious and life threatening incident that must be treated swiftly to save the life of a pet that has been bitten
How to recognise a snake bite
If your pet is unfortunate enough to have an encounter with a snake you can help by being aware of the signs and symptoms of snake bite, and getting the affected animal to the hospital as quickly as possible. Dogs, cats and horses are all at risk, although curious dogs are the most frequently affected.
The first signs of snake envenomation are usually excitement, trembling, salivation and vomiting, gradually developing into weakness, wobbly gait and eventually paralysis. Afflicted dogs often have dilated pupils and slow light reflex, with clotting problems in their blood. Depending on the type of snake and how much venom has been injected, an animal bitten by a snake may show any of the following symptoms:-
- Localised swelling and irritation
- Drooling and trembling
- Dilated pupils
- Involuntary bladder or bowel release
- Red or brown discolouration of urine
- Rapid breathing and/or panting
- Bleeding from bite wounds or bloody diarrhoea
- Collapse. An animal may collapse immediately but then apparently recover, then develop symptoms over the course of the next hour
- Paralysis (starting with the hind legs and progressing towards the head)
Identifying the offender
Venomous snakes are prevalent all over Australia. Pets in rural and country areas are at greater risk of being bitten. In the Alpine region we see a number of different types of venomous snakes, including Red-bellied Blacks, Tiger snakes, Death Adders and Brown snakes.
There are a few signs that can indicate what type of snake has envenomated your pet. When bitten by brown snakes some pets may experience a sudden collapse followed by a temporary recovery, while black snake bites will often create an area of localised swelling and irritation.
If you see the snake biting your pet and can identify the type you should tell us, but do not waste time trying to find it; we have facilities at the hospital to test your pet’s blood and quickly determine the type of venom involved.
Most snake bites in humans occur when people try to capture or kill snakes, often after seeing them bite a pet. It’s almost always best to leave the snake alone — it’s only doing what snakes do after all — and concentrate on helping your pet. There can also be legal ramifications if you kill a native reptile.
How to help a pet bitten by a snake
If your pet is still breathing keep him calm and as still as possible to minimise venom absorption. An elevated heart rate will allow the venom to move more quickly through the bloodstream.
Most snake bite wounds are not visible but if a limb has been bitten, bandage the entire leg firmly to limit venom movement through the lymphatics. Do not use a tourniquet to cut off circulation.
If your pet has stopped breathing, attempt mouth to nose resuscitation, and, if possible, continue this during transport of your pet to the hospital.
What we do to save your pet’s life
Once the affected animal reaches the hospital, treatment for snake envenomation may use some or all of the following techniques/procedures.
- Blood or urine tests to identify the type of snake.
- Oxygen therapy, and intravenous fluid therapy, to maintain blood pressure and protect the kidneys.
- Give intravenous medications and antivenin if required. Some animals will need multiple doses.
- Put your pet on a ventilator, a machine that breathes for your pet until it has recovered sufficiently to breathe on its own.
- Use special feeding tubes to provide nutrition if the food pipe muscles are affected.
Treatment usually involves hospitalisation for at least 24 hours. In some cases your pet may be in the hospital for several days. After being discharged we recommend they be confined and rested for up to two weeks.
It is possible for your pet to be bitten by a snake and not become envenomated. In cases where clinical and laboratory evidence shows that the animal has not been envenomated we may only need to monitor your pet for any delayed symptoms for 12 – 24 hours.
Road to recovery
These days the treatment of snake bite has a good success rate and, with appropriate and timely medical therapy, many patients recover completely. But treating snake bite is always challenging — for the affected pet, for anxious pet parents and for the treating vet and nurses.
An animal that has suffered a snake bite will require constant monitoring, day and night, every one or two hours for the first 24 hours then every three hours for the next two days, with high rate intravenous infusions, blood clotting products and regular blood tests. Consequently, it can be expensive, although it may be covered by pet health insurance if you have it. It’s always better to keep your pets out of likely snake habitat and avoid the risk.