With the start of summer in Costa Rica, we can expect to see an increase in snakebites. In general, the dry season’s weather conditions, including strong winds, seem to be the main causes. Due to the higher risk to pets and humans alike at this time of year, it’s important to understand what really happens when a snake bites.
Toxicity caused by snake venom can be local or systemic. In humans, 20% of the bites caused by venomous snakes are dry, meaning no venom was injected. In all species, the onset of clinical signs may be delayed up to six hours. That’s why urgent and supportive care is the key for achieving an optimal outcome in venomous snakebites.
For both dogs and cats, due to their curious nature, snakebites are usually to the face and front legs. Fang punctures may be evident, sometimes appearing like a line, but often concealed by fur and not visible until an abscess or necrotic tissue develops. A swollen area is usually found and sometimes feels hot to the touch. If the animal is bitten in the tongue or mouth, airway obstruction might occur. Neurotoxic venoms may exhibit no local signs other than bite wounds.
Possible outcomes
Complications may result from coagulopathies (blood’s inability to coagulate properly). The venom compromises fibrinogen — the protein involved in forming blood clots to help stop bleeding and heal wounds — as well as platelets function, tissue integrity and blood and serum distribution.
In some cases, depending on the snake species, the central nervous system function of a bitten dog or cat will be impaired. Most venoms induce a drop in blood pressure resulting in shock.
Some snake venoms can be both neurotoxic and hemotoxic. Systemic toxic effects occur significantly in highly perfused tissues. Organs are more susceptible to thrombocytopenia (low platelets), hypofibrinogenemia (abnormal deficiency of fibrinogen in the blood) and the result of coagulopathy.
How much time
The venom toxin distribution rate can be quite rapid for intravenous-bites, but is slower for intramuscular bites. It takes the longest time for venom toxins to spread following subcutaneous bites, representing the majority of cases.
Bites to the pet’s face and extremities have slower venom uptake than to the tongue or abdomen. Some toxins can form a depot on the bite site, while others can penetrate deeper tissues and later redistribute back into circulation, resulting in recurrent toxicity. This can occur even days after the bite.
Risk factors are: age, size, history of being bitten already, pre-existent disease or medication taken.
Emergency response
Any snakebite to your pet is an emergency that cannot be treated at home. Whether you witnessed a snake attack or suspect it might have happened, take your pet to the veterinarian as soon as possible.
Our hospital has had very good results with these cases. Applying the antivenom within the first 12 hours after the snakebite is really important to ensure success against intoxication.
In Costa Rica, veterinarians use antivenom for coral and other poisonous snake species. The complete treatment differs depending on the type that attacked your pet, the risk factors and the time elapsed since the bite. In general, the most common protocols include intravenous fluids, antibiotics, anti-inflammatories, and hepatic and liver protectors.
Risk factors for snakebite reactions in pets include age, size, history of previous bites, pre-existing medical conditions and medications.
