About: Due to their strong hunting instinct, cats are at risk of snake bites or be prey to large constrictor snakes.
Cats are bitten most often on the face and legs, symptoms can vary depending on the species, but may include:
Blood in the urine or feces
Treatment: Administration of antivenom, as well as supportive care, while your cat recovers.
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.
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.
One snake catcher I spoke to told me the following…
Between 10 am and 4 pm is generally when they are out. Red-bellied black snakes optimal temp is 24 to 28 and Eastern Brown Snakes are 28 to 32. You will normally see them basking in a sunny position.
But I need to reiterate, it is still possible for them to be out during other hours of the day. It is common to find snakes 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.
Contrary to popular belief, pythons and boa constrictors kill their prey by cutting off the blood supply and not by suffocation. By coiling themselves and squeezing tight, the heart doesn’t have enough strength to circulate blood against the pressure created by the snake. This, in fact, is a far quicker and more efficient way to kill than by suffocation.
Can cats kill snakes?
Yes, it is possible for a cat to kill a small snake but it’s not something you should allow your cat to do. Even small, non-venomous snakes have the potential to inflict damage on a cat through biting. As much as I don’t personally like snakes, they serve an important ecological role in our environment. Do not encourage cats to hunt any wildlife, including snakes.
Even small pythons can quite easily kill a small dog or cat. Baby venomous snakes are still able to inject venom, and non-venomous snakes will still bite a potential threat which can be extremely painful and lead to infection.
If you do have a snake problem in your area, there are more effective ways to reduce numbers by making changes to your environment to make it less snake-friendly (such as moving wood piles away from the home), or calling in a snake catcher to relocate a snake.
What is snake venom and what does it do?
Venom is a modified saliva which is stored in sacs behind the eye on each side of the head. It contains zootoxins (toxins produced by an animal) which the snake injects into the skin via the hollow fangs in the snake’s mouth. It is used as a defensive mechanism against predators and to 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). The main function of venom is to kill prey the snake is hunting as well as protect the snake against predators.
Snakes are able to control the amount of venom is injected and in some cases may not inject any, this is known as a dry bite. Of course, it goes without saying that if your cat has been bitten by a snake, immediate veterinary attention is essential as you have no way of knowing if or how much venom has been injected.
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 respiratory muscles. Rendering your cat unable to breathe.
These toxins 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.
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).
As well as the blood, hemotoxins can also attack other organs and tissues.
Cytotoxins destroy tissue, usually specific cells, usually those of an organ such as kidney cells (nephrotoxins).
Mycotoxins 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.
What is antivenom?
Antivenom (also known as antivenin) is used to counteract the effects of the 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.
There can be considerable variables including:
Species and size of snake
Age of the cat (kittens and senior cats are at increased risk)
Underlying medical conditions
Amount of subcutaneous fat and thickness of fur
Number of bites and location
If the cat has been bitten previously (a repeat bite can cause a severe allergic reaction)
Microbes in the snakes mouth
Puncture wounds may not necessarily be observed, they are either hidden by the fur or due to localised 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, neck, chest, and limbs.
There are two stages which develop after a snake bite, pre-paralytic and paralytic. Symptoms can develop between a few minutes to 24 hours after being bitten and may include:
Fang marks and/or swelling at the location of the bite
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 from lack of oxygen
Blood in urine (hematuria) due to coagulation dysfunction
Tea coloured urine (due to breakdown 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.
Emergency first aid:
Any snake bite needs immediate veterinary attention, 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 the affected limb to slow down venom spreading to the heart, the bandage 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.
Be careful when handling a cat who has been bitten, they are usually in a lot of pain and may lash out.
Allow your cat to walk
Cut the bitten area
Attempt to suck the venom out of the bite (this will increase blood flow to the area)
Apply a tourniquet
Attempt to catch or kill the snake
Treatment is aimed at reversing the effects of the venom as well as treating symptoms. Your veterinarian will use snake venom test kit to determine the kind of snake that has bitten your cat as well as other tests to evaluate your cat. These may include:
Complete blood count, biochemical profile and urinalysis
Check blood pressure
Blood smear to evaluate the red blood cells
Clotting times, fibrinogen and platelet counts as some types of venom can affect your cat’s ability to clot
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.
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 is unable to eat due to muscle paralysis.
Cats suffering from paralysis will need to have their bladder manually expressed until they are able to urinate on their own.
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.
Cats who have been discharged from hospital need some recovery time, they 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, between 80-90% of cats who receive antivenom will survive a snake bite.
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.
Maintain your garden so that is free of overgrown plants, regularly mow the lawn.
Keep the garden free of debris, such as corrugated iron, building materials, overgrown weeds, old junk etc
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.
What should I do if I find a snake in my garden?
Bring all pets indoors.
Contact your local wildlife group or a licensed snake catcher. Do not attempt to catch or kill the snake.