« Snake bites: what to do? » | This article presents pet owners with several snake species that pet owners might want to know about. It explains how they affect companion animals and what to expect when snake envenomation is suspected.
- This blog is intended as a source of general information for pet owners. It does not constitute specific veterinary advice towards a particular medical case. If you are concerned with a particular aspect of your pet’s health, please, book a video appointment to talk with a qualified veterinarian.
Several types of venomous snakes
Snakes live all around the world. In some instances, some of them can become a source of extreme worry for pets and their owners.
This section, provides an overview of certain snake species, because they are rather known in the field of veterinary toxicology.
Crotalinae (Agkistrodon, Crotalus, Sistrurus)
Crotalinae are snakes who are also referred to as pit vipers. Agkistrodon (Cottonmouths, Copperheads) are part of this group, as well as Crotalus and Sistrurus which is also known as rattlesnakes.
They share some characteristics such as:
- triangular head,
- retractable fangs
- heat-sensing organ located in a pit, between eyes and nostrils
Those snakes can be found in geographies such as North America. This short video above, explains how pit vipers operate in nature.
Those types of snakes produce a venom composed of various proteins and peptides. They are toxic because they have the power to:
- damage tissues
- disrupt coagulation
- lower blood pressure
- induce schock
- impair the central nervous system
Literature reports that 20% of bites in humans are considered « dry bites » . It is worth noting that toxicity of snake venom can be ranked and some will be more dangerous than others, depending on the type of pit viper involved.
Elapidae (Micrurus fulvius fulvius, Micrurus tenere)
Micrurus fulvius fulvius and Micrurus tenere are 2 species of Elapids which are particulary relevant in North America. They are recognisable by their colour pattern. Some additional characteristics:
- small head
- round pupils
- black snout
Envenomation will occur if they manage to inject the toxic substance after chewing with their fangs. Coral snakes have non-retractable fangs.
However, their venom is known as a neurotoxin which induces muscle paralysis and central nervous system impairment. The severity of the situation will depend on the size of snake as well as the species. Micrurus fulvius fulvius is more dangerous.
How do snake bites affect pets?
Snake venom toxicity in more depth
After injection, the venom can distribute around the body. However, the speed at which it can do this will depend on how easy it is to reach the blood circulation. For example, the distribution of the venom will be slower through a skin bite versus a blood vessel. Usually, bites tend to involve the skin more than a specific blood vessel.
The speed of distribution of the venom will also depend on the location of the bite on the body. It won’t be so quick for a bite on the legs, for example, and can be faster for a bite involving the chest or the tongue of the animal.
Some of the molecules in the venom can also act with a delay or operate through a redistribution pattern, which means they will still be present in the blood circulation days after the envenomation occurred.
Even if the venom produced by those species tend to principally affect the blood circulation, some rattlesnakes are capable of inducing death through neurotoxin.
Eventually, the effects will depend on the dose injected per kg of body weight. Thus smaller animals are at increased risks, as well as those with underlying health issues.
With snakes from this family, bites would generally be found on lips, tongue, mouth and paws. The puncture from the fangs might not appear as obvious and instead, it could look like a skin graze.
The venom is a type of neurotoxin which will impair the neuromuscular junction, which is, at biomolecular level, an area of importance if nerves and muscles are to work properly.
This type of venom is designed is such ways that it could take up to 18h before symptoms start to show.
Symptoms following a venomous snake bite
Coral snake bites will be responsible for neurological symptoms. In cats, respiratory function will be compromised due to the impact on muscles. This will be accompanied by limbs paralysis, decrease in blood pressure and body temperature.
With dogs, the central nervous system is also affected and will lead to symptoms such as: quadriplegia, dyspnoea, dysphoria and accelerated heart rate.
The symptoms could look similar to those exhibited with cases of botulism or tick bite paralysis.
Snake bites: what to do when a pet is bitten?
So, snake bites: what to do? First of all, if the snake has been killed by the pet, it is recommended to keep it for appropriate identification. In such cases, the pet must be checked thoroughly for any sign of bite (punctures, skin scratches).
The second best thing to do is to immediately bring the pet to the closest veterinary hospital:
- for a professional medical examination, even if no symptoms are shown (do not delay)
- for emergency treatment if symptoms of snake bite envenomation are already visible
It is strongly recommended not to attempt to treat the pet at home. Once at the veterinary hospital, depending on the situation, antivenom will be administered as the antidote of choice. This will involve close monitoring because serious complications can arise when using such substances (anaphylactic reactions). Vets will be prepared to address anaphylaxis should it happen.
Note that antivenom might not always be available and that significant costs might be charged to pet owners. In some instances, it might be possible to source antivenom directly from the zoo. Some situations might also require to use antivenom initially developed for people.
The pet would likely have to remain hospitalised for a few days, for the purpose of monitoring the evolution of the situation, as well as to treat wounds, address coagulopathies and/or neurological impairment.
The earlier the antivenom is administered, the better the chance of recovery. Although, it might take some time to achieve full recovery. For example, with coral snake envenomation, it might take months.
Cats are more at risk of dying, especially with coral snake envenomation. Some pets might relapse after an apparent recovery, thus close monitoring is still strongly advised.