Veterinary Snake Bite Treatment Reference (Pit Viper)
Pre-hospital advice, workup, antivenom indications, and treatment protocol for pit viper envenomation in dogs and cats.
Pre-hospital advice for owners
| Do | Don't |
|---|---|
| Keep pet calm and minimise movement | Don't apply tourniquets |
| Carry to vehicle if possible (limit muscle activity) | Don't apply ice or cut the wound |
| Transport immediately to nearest emergency vet | Don't attempt to suck venom or capture the snake |
| Photograph the snake from a safe distance if possible | Don't give NSAIDs or other meds |
Initial workup
| Test | Why |
|---|---|
| Vital signs + serial physical | Track progression of swelling, neuro signs |
| CBC (with platelet count) | Pit viper bites cause thrombocytopenia, RBC echinocytosis |
| Coagulation (PT/aPTT, fibrinogen) | Pit viper venom causes DIC-like coagulopathy |
| Chemistry + UA | Baseline organ function; CK rising = muscle damage |
| Lactate | Marker of perfusion and systemic toxicity |
Treatment
| Treatment | Details |
|---|---|
| Antivenom (F(ab) or F(ab')2) | 1 vial IV diluted in 100-250 mL saline over 30-60 min. Repeat as clinically indicated. |
| IV fluids | Crystalloid replacement; aggressive resuscitation if shock |
| Analgesia | Opioid (methadone 0.3 mg/kg IM). AVOID NSAIDs (coag risk). |
| Antibiotics | Broad-spectrum if open wound; ampicillin/sulbactam reasonable empirical choice |
| Tetanus prophylaxis | Not routinely needed |
| Wound care | Conservative - debride necrotic tissue once stable |
When to use antivenom
| Indication | Notes |
|---|---|
| Progressive swelling beyond initial bite area | Strongest indication |
| Coagulopathy (prolonged PT/aPTT, low fibrinogen) | Antivenom can reverse if given early |
| Thrombocytopenia | Hallmark of pit viper envenomation |
| Neurological signs (Mojave rattler, coral snake) | Time-critical - antivenom should be given immediately |
| Cardiovascular instability | Indicates systemic envenomation |
Antivenom is most effective when given within 4-6 hours of envenomation but can still help up to 24 hours later. Monitor for delayed serum sickness 7-14 days after antivenom.
Frequently asked questions
Should owners apply a tourniquet to a snake bite?
No - tourniquets cause local tissue damage and don't prevent systemic venom spread. Keep the pet calm, transport quickly, and avoid suction, cutting or ice. The single best action is rapid transport.
When is antivenom indicated?
Progressive swelling beyond the bite, coagulopathy, thrombocytopenia, neurological signs (Mojave rattler, coral snake), or cardiovascular instability. Early administration (within 4-6 hours) is most effective but later doses can still help.
Do I need antibiotics for snake bites?
Routinely no for clean fang punctures. Indicated if there's significant tissue necrosis, secondary contamination, or open wounds. Broad-spectrum coverage (e.g. ampicillin/sulbactam) when needed.