Cats are hunters by nature and unfortunately not able to discriminate between harmful prey and non-harmful prey. Many housecats will think nothing of chasing down and attacking a snake, not realising how much danger they are putting themselves in.
There are poisonous snakes throughout the world and it would be too hard to list poisonous snakes country by country so this article will aim to provide general information on snake bites, but not snake species specific to any one country.
The most common snake bites to occur in cats in Australia are from the Eastern brown snake, tiger snake, death adder, copperhead, black snake and the red-bellied black snake.
Venomous snakes in the United States can include the copperhead, rattlesnake, cottonmouth, coral snake.
The majority of snake bites occur on the cat's head, neck and legs. Bites on the body can happen, and tend to be more dangerous, the closer to the heart the quicker the venom can travel around the body and the more dangerous.
There is a lot of information in this article which may not be what readers want during an emergency. I have broken this article down into multiple sections, with clearly marked titles in blue for you to skip to the relevant part if necessary.
Where and when can snakes be found?
Snakes are more prevalent in the warmer months of spring and summer, but in some areas they can be found year-round. We have had a red-bellied black snake in our garden in June (which is winter in Sydney, Australia). As snakes are cold-blooded, they need the heat of their surroundings to warm up. They tend to come out as the day warms up and can be found basking in the sun on the warm ground. They are also commonly found close to the water of creeks or dams. When not sunning or hunting, they like to hide under rocks and logs and in dense shrubbery and long grasses.
What is the difference between a venomous and non-venomous snake?
Most (but not all) venomous snake has elliptical pupils (slit-like, like a cat) and a triangular or diamond shaped head. A non-venomous snake has round pupils and a rounded head. Even non-venomous snakes have teeth and will bite, and while they may not poison the cat, the bite can cause pain and infection.
Larger snakes such as pythons kill their prey by constriction, that is they coil themselves tightly around the animal causing it to die from asphyxiation.
What is snake venom?
Venom is a modified saliva containing zootoxins (toxins produced by an animal) which is injected into the skin via the hollow fangs in the snake's mouth. It is used as a defensive mechanism against predators and to also kill and digest the snake's prey. Venom can vary depending on the species, and may contain toxins which affect the blood (hemotoxins), certain cells (cytotoxins) and nervous system (neurotoxins).
Snake bites can affect various organ systems. Breathing difficulty, acute kidney failure (nephrotoxicity), bleeding disorders, paralysis (including the respiratory system), tissue death and severe allergic reaction. There are different types of toxin, many snakes have more than one type of venom.
- Neurotoxins cause neuromuscular paralysis which leads to weakness of the limb muscles and eventually paralysis of the respitatory muscles. Rendering your cat unable to breathe.
- Hemotoxins destroy red blood cells (hemolysis), lower blood pressure and disrupt blood clotting by destroying platelets which are non nucleated cell fragments that form a clump to plug a damaged blood vessel as well as removing fibrinogen, which helps to mesh the platelet plug, resulting in internal bleeding. Destruction of the red blood cells means the blood is unable to provide adequate amounts of oxygen to the organs, leading to organ damage. As well as the blood, hemotoxins can also attack other organs and tissues. Other types of venom activate prothrombin (a blood factor responsible for coagulation, the process in which blood turns from a liquid into a gel when damage occurs to a blood vessel) causing disseminated intravascular coagulation (systemic activation of blood clots throughout the small blood vessels).
- Cytotoxins destroy tissue, usually specific cells, usually those of an organ such as kidney cells (nephrotoxins).
- Myotoxins destroy skeletal muscle cells, the break down of muscle fibre releases myoglobin (a protein in the muscle cells) into the blood plasma results in rhabdomyolysis which can seriously damage the kidneys.
Antivenom (also known as antivenin) is used to counteract the effects of venom. It is obtained by 'milking' snakes of their venom, which is diluted and a small amount is injected into horses or sheep. These animals mount an immune response, producing antibodies against the venom. Antibodies bind to the venom, thus neutralising it. However, they are not able to reverse the damage already done. This is why it is so important to seek immediate veterinary treatment.
What are the symptoms of a snake bite in cats?
There can be considerable variation in symptoms of snake bite depending on the species of snake, its size, the age of the snake as well the amount and potency of the venom. The size of the cat, any underlying medical conditions your cat may have, the amount of subcutaneous fat, as well as the thickness of the fur, can also be factors. That is not to say that a snake bite in a fully grown Maine Coon should be treated any less seriously than a snake bite in a young kitten. All snake bites are all extremely dangerous to all cats, and veterinary treatment is always necessary.
You may not necessarily see puncture wounds on your cat, they are either hidden by the fur or due to swelling. So don't assume that the absence of puncture marks means your cat has not been bitten by a snake. The most common areas cats are bitten are the face and limbs.
There are two stages which develop after your cat has been bitten. Pre-paralytic and paralytic. Symptoms can develop between a few minutes to 24 hours after being bitten and may include:
Ptosis (drooping eyelids)
Photophobia (sensitivity to light)
There may or may not be extreme pain. Hemotoxins are extremely painful but are slower acting, neurotoxins are relatively pain free, but faster acting.
Dilated (large) pupils (mydriasis) and fixed pupils which don't respond to light, normally the pupils would constrict (become smaller) due to increased light
Change in meow
In-coordination (drunken gait)
Rapid pulse and heartbeat
Difficulty breathing or increased/shallow breaths (tachypnea)
Blue tinged gums due to lack of oxygen
Blood in urine (hematuria)
Tea coloured urine (due to break down of muscles)
Paralysis which starts at the back legs and moves towards the cat's head
It is important to repeat that not all signs will be present, they may also wax and wane.
What should you do if your cat is bitten by a snake?
Get your cat to the veterinarian immediately. Call ahead to let them know you are on your way. In some cases, your veterinarian may not have antivenom on hand, another important reason for you to call ahead, so you can be re-directed to another practice if necessary.
If you have a person to help you, do the following below on the way to the veterinarian:
Remove the cat's collar.
Keep the bitten area lower than the heart.
Keep the cat quiet and calm, a rapid heart rate will help the venom to move more quickly around the body.
Apply a pressure bandage over and around the bite to slow down venom spreading to the heart, this should be firm but not so much that it cuts off circulation.
If possible, immobilize the affected limb.
If there is no heartbeat or pulse, administer CPR.
This should only be carried out if there's more than one person. It is better to drive your cat straight to the veterinary practice than waste additional time and delaying urgent medical treatment.
What NOT to do:
- Do NOT allow your cat to walk.
- Do NOT cut the bitten area.
- Do NOT attempt to suck the venom out of the bite.
- Do NOT apply a tourniquet.
- Do NOT attempt to catch or kill the snake.
- Do NOT apply ice.
How is a snake bite treated?
Treatment is aimed at reversing the effects of the venom as well as treating symptoms. He will use a snake venom test kit to determine the kind of snake that has bitten your cat as well as complete blood count, biochemical profile, urinalysis, clotting times, fibrinogen and platelet counts.
Once the type of snake bite has been determined your veterinarian will administer the appropriate antivenom. Some cats will need multiple vials of antivenom during treatment. Occasionally a cat will have an allergic reaction to the antivenom although this appears to be more common in dogs than cats.
Supportive care will also be necessary and will include:
Intravenous fluids to maintain blood pressure and help protect the kidneys from the toxins and maintain cardiac output.
To reduce your cat's chances of having an allergic reaction to the antivenom, your veterinarian may also administer antihistamines, steroids and adrenaline prior to giving your cat the antivenom.
Oxygen therapy or if your cat is unable to breathe on his own will be placed on a ventilator.
A feeding tube may be required if your cat us unable to eat due to muscle paralysis.
Cats suffering from paralysis may also need to have their bladder manually expressed until they are able to urinate on their own.
Antibiotics may be prescribed to treat secondary infections.
Analgesics may be necessary to treat pain.
When can my cat come home?
This depends on the severity of the emergency and how quickly treatment began. The earlier he receives antivenom, the better. All cats respond differently to treatment.
Some cats may be able to come home in as little as 24 hours after treatment, as soon as they can eat, drink, go to the toilet and eat on their own. Some cats may take a little longer to recover and it may be several days.
Even cats discharged from hospital will still need some recovery time and should be kept quiet, calm and indoors during this period.
Can a cat survive a snake bite?
If your cat receives prompt veterinary attention, the prognosis is good with between 80-90% of cats who receive antivenom will survive.
Administer all medications as instructed by your veterinarian.
Keep your cat indoors while he recovers.
Please be aware that antivenom doesn't offer your cat lifetime protection from snake bites. It is not a vaccine and only works during that particular exposure, not against future snake bites.
Keeping snakes out of your garden:
The best way to avoid snakes in your garden is to provide an environment which isn't attractive to snakes.
Keep the garden free of long or overgrown plants.
Keep the garden free of debris, such as corrugated iron, building materials, overgrown weeds, old junk etc.
Keep your lawn short.
When installing fences, dig them at least 8-12 inches into the ground.
Don't leave containers of water lying around.
If you have a shed, keep it free or rodents.
Remove fallen fruit from the ground as this encourages rodents, which will, in turn, encourage snakes.
Avoid wood piles, especially in the summer months. If you do have a wood pile, make sure it is well away from your house and not accessible to your cats or children.
Avoid rockeries, which provide an excellent habitat for snakes to hide.
Last updated 16th December 2016.