Pet Care – Snake Bites, A common summer emergency
Since the summer began, we have seen an increase in snakebites. In general the dry season and the strong winds seem to be the main causes of this outbreak. This is why we want to explain a little bit of what really happens with a snakebite.
Toxicity caused by the venom of a snake 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 are the keys for achieving an optimal outcome in venomous snakebites.
In our pets, bites usually are to the face and front legs for both dogs and cats, usually due to their curious nature. Fang punctures can be evident; sometimes it’s just like a line, or due to the fur will not be visible until there is already an abscess or necrotic tissue. A swollen area is usually found and sometimes feels hot to the touch. If the animal is bitten in the tongue or mouth in general, airway obstruction might be found. Neurotoxic venoms may exhibit no local signs other than bite wounds. Complications may occur due to coagulopathies. The venom is producing assaults on blood clotting and tissue integrity, and altering fluid (blood and serum) distribution. In some cases, depending on the species of the snake, the central nervous system function will be impaired. Most venoms induce a drop in blood pressure resulting in shock. Coagulopathies are seen due to inhibition of blood clotting factors and compromise of fibrinogen and platelets function. The rate of distribution of venom toxins can be quite rapid in intravenous-bites, slower in intra-muscular bites and slowest in subcutaneous bites (majority). Bites to the 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 can redistribute with time back into circulation, resulting in recurrent toxicity. This can occur even days after the bite. Some snake venoms can be both neurotoxic and hemotoxic. Systemic toxic effects occur greatly in highly perfused tissues with organs more susceptible to thrombocytopenia (low platelets), hypofibrinogemia and the result of coagulopathy.
- Respiratory, skin: tissue destruction, cardiovascular: shock, renal/urologic: renal failure, gastrointestinal: vomit and diarrhea, neuromuscular: generalized weakness( Osweiler, Gary et al, 2011).
Risk factors are: age, size, history of been bitten already, pre-existent disease or medication taken (Osweiler, Gary et al, 2011).
Local signs: angioedema, fang punctures, swelling, bleeding through the site of bite, erythema, ecchymosis, lymphangitis. Systemic signs: low blood pressure, respiratory changes, weakness, bleeding, excessive salivation, fasciculation, vomiting, hematemesis, diarrhea and oliguria (Osweiler, Gary et al, 2011).
In our hospital we have had really good results with these cases and applying the antivenom in the first 12 hours after the accident occurs has been really important in this success against intoxication. It is an emergency that can not be treated at home. If you see that a snake attacked your pet or you think that it might be a snake bite, take your pet to the veterinarian as soon as possible. In our country we use antivenom for Coral and other poisonous snake types. The complete treatment differs depending on the type of snake that attacked your pet, the risk factors involved and the time since the animal got bitten. In general, fluids (intravenous), antibiotics, anti-inflammatories, hepatic and liver protectors are some of most common protocols.