Snake Bite. Every Second Counts.
Authored by Dr. Mark Tonzing & Dr. Romilly Haslam
Australia is home to the most venomous snakes in the world. Snake envenomation can look deceptively mild at first, but patients will deteriorate rapidly.
Snake envenomation is a time-critical, life-threatening emergency. The venom of Australian Elapids travels quickly through the lymphatic system, launching a devastating attack on the nervous system, muscles, and blood clotting cascades. Outcomes are unpredictable: stable patients can crash abruptly, and severe cases can still recover with aggressive intervention.
This guide provides crucial first-aid steps for local pet owners, alongside a rapid clinical reference for objective monitoring and emergency treatment.
The Bardon & Mt Coot-tha Corridor
Properties backing onto Mt Coot-tha, Ithaca Creek, and the leafy gullies of Bardon and Ashgrove provide perfect habitats for rodents and frogs—the primary food source for local snakes. During the warmer months (September to April), snake activity peaks.
While we frequently see non-venomous Carpet Pythons and Common Tree Snakes, the primary lethal threats in our geographical area are the Eastern Brown, the Red-bellied Black snake, and occasionally Whip snakes.
Eastern Brown (Pseudonaja textilis)
Highly aggressive when cornered. Venom is a profound procoagulant that causes a consumptive coagulopathy (rapid clotting that uses up platelets) resulting in uncontrollable bleeding, and a potent neurotoxin. Often found in dry bushland, rock retaining walls, and suburban gardens.
Red-bellied Black (Pseudechis porphyriacus)
Generally shyer, prefers damp areas near creeks and drainage lines. Venom is highly myotoxic (destroys muscle tissue), causing severe pain, muscle breakdown, and dark/red urine, alongside mild neurotoxicity.
Whip Snakes (Demansia spp.)
While systemically less toxic, they cause severe localized swelling and total limb paralysis—especially dangerous for cats. Note: There is no antivenom available for whip snakes; recovery requires intensive 24-hour supportive care.
For Pet Owners: Spotting the Signs
Unlike tick paralysis, which takes days to develop, snake bite symptoms often occur within minutes—but can take up to 24 hours to appear. Do not wait to find a bite mark, as they are often invisible under fur.
The "Collapse & Recover"
This is the hallmark sign of a Brown Snake bite. Your dog may suddenly collapse, vomit, or defecate, and then appear to completely recover 10-15 minutes later.
This temporary recovery is deceptive. The lethal venom is circulating, and they will rapidly crash again. Get to the vet immediately.
Systemic & Critical Signs
Neurological: Wobbly gait, hindlimb weakness, or total paralysis; dilated pupils unresponsive to light; drooling, progressing to seizures or coma.
Respiratory & Cardiac: Breathing difficulty, rapid heart rate, or arrhythmias.
Muscular: Muscle tremors, shaking, reduced eye blinking, severe pain, extreme weakness, and loss of bladder control.
Bleeding: Unexplained bleeding or dark, blood-tinged urine.
First Aid: Rules of Survival
- Keep them STRICTLY still. Venom travels through the lymphatic system. Movement pumps venom faster. Carry your pet to the car; do not let them walk.
- Apply a Firm Bandage (NO Tourniquets). If you know exactly where the bite is, apply a firm pressure bandage over, above, and below the site to slow lymphatic spread. However, do not apply a tight tourniquet that cuts off blood flow, as this causes tissue death.
- Call ahead. Let us know you are coming so we can prepare oxygen, IV lines, and antivenom.
The Road to Recovery (Post-Discharge)
Patients are hospitalized until they can eat, drink, walk, and urinate independently. However, the battle does not end at discharge. Lifelong organ damage can occur. Nerve and muscle damage takes weeks to fully resolve. Pets must be kept strictly quiet and indoors for at least 4 weeks. Monitor closely for delayed reactions to venom or antivenom, such as swelling, lethargy, or breathing difficulty.
Veterinary Protocol: Australian Elapids
1. Local Toxidromes & Pathophysiology
Brown Snake (Pseudonaja spp.)
- Coagulopathy (VICC): Venom contains a prothrombin activator causing Venom-Induced Consumptive Coagulopathy. Rapid depletion of fibrinogen leads to spontaneous hemorrhage.
- Neurotoxicity: Pre-synaptic neurotoxins. Causes ascending flaccid motor paralysis. May be irreversible once bound to motor endplate (takes weeks to regenerate).
- Clinical picture: Pre-paralytic collapse, tachycardia, hypotension, hematemesis, prolonged bleeding, progressive lower motor neuron paresis.
Black Snake (Pseudechis spp.)
- Myotoxicity: Severe rhabdomyolysis causing extreme somatic pain.
- Systemic: Hemolysis and marked pigmenturia (myoglobinuria / hemoglobinuria), risking secondary acute kidney injury (AKI). Multiple organ failure in severe cases.
- Coagulopathy: Mild, usually incomplete compared to Browns.
- Clinical picture: Clinical picture: Painful swollen bite site (unlike Browns), dark red/brown urine, reluctance to move due to muscle pain, variable neurotoxicity.
2. Rapid Diagnostics & SVDK Usage
Clotting (WBCT / PT / aPTT)
Place 1-2ml whole blood in a glass tube. Do not agitate. If unclotted at 20 mins = VICC (highly indicative of Brown snake envenomation). Normal clotting is <5 mins. Also run full bloods to assess RBC levels and baseline organ function.
Biochemistry & UA
Expect massive CK (Creatine Kinase) elevations with Black snakes. Monitor renal parameters. Free catch urine to evaluate for pigmenturia.
Observation
If bite is uncertain: Admit, observe strictly, and regularly repeat PT/aPTT, CK +/- SVDK testing as signs can take over 12 hours to evolve.
Snake Venom Detection Kits (SVDK): Clinical Considerations
Pros
- Targeted Antivenom: Identifies specific snake families, allowing the use of cheaper, targeted monovalent antivenom rather than broad-spectrum polyvalent.
- Confirms "Dry Bites": A negative test (paired with zero clinical signs) can confirm a non-envenomating strike, saving owners thousands.
- Multi-Dog Scenarios: Vital for identifying exactly which dog was envenomated if multiple dogs interacted with a snake.
Cons
- Critical Time Delays: Takes 15-25 minutes to process. Delaying antivenom for a deteriorating patient can be fatal.
- Sample Unreliability: Blood/serum samples are notoriously prone to false negatives. Urine is highly accurate, but acquiring urine from a critically collapsed dog is difficult.
- High Economic Cost: The kits themselves are highly sophisticated and expensive.
Summary
Polyvalent antivenom is often administered without prior testing to avoid critical treatment delays, potentially improving survival rates while reducing overall hospitalisation costs.
3. Treatment & Antivenom Protocol
A. Criteria for Administration & Dosing
Antivenom acts to neutralize circulating venom in the blood; it cannot reverse venom already bound to tissues. Early administration is critical. When to give: Confirmed witnessed envenomation OR evolving coagulopathy/clinical signs.
- Mild/Moderate Signs: Administer 1 to 2 vials and monitor for progression.
- Severe Signs: Administer 2 vials immediately. Severe cases may require 4 to 8 vials total depending on progression.
B. Pre-medication & Infusion
Antivenom is a hyperimmune equine serum carrying a high anaphylaxis risk. Pre-medicate with antihistamine and IV Corticosteroids. Have subcutaneous adrenaline on standby.
- If SVDK is not utilized, Tiger-Brown Bivalent is standard in SEQ.
- Dilute chosen vials in 100ml to 250ml of 0.9% NaCl. Administer IV slowly over 30-45 minutes via infusion pump.
- Monitor continuously for urticaria, facial edema, tachycardia, or hypotensive shock. Stop infusion and administer IV adrenaline if severe anaphylaxis occurs.
C. Advanced Supportive Care
Ongoing therapy scales strictly with the severity of the envenomation. Implement:
- Aggressive IV fluid therapy (crystalloids) is critical, especially to flush kidneys if myoglobinuria is present.
- Airway protection: Oxygen therapy or full ventilation (life support) for respiratory paralysis.
- Coagulation management: Fresh Frozen Plasma (FFP) or Whole Blood Transfusions for catastrophic bleeding (administered after antivenom neutralization). Once antivenom is administered, the liver rapidly synthesizes new clotting factors.
- Nursing: Placement of urinary catheters, tube feeding, nutritional support, and proactive pain relief.
Frequently Asked Questions
Can a dog or cat survive a snake bite without antivenom?
Generally, no. The overall survival rate without antivenom is exceptionally low. While a "dry bite" (where the snake strikes but injects no venom) can occasionally happen, a true envenomation from an Eastern Brown or Red-bellied Black snake is almost universally fatal without the swift administration of veterinary antivenom.
Why is snake bite treatment so expensive?
Snake antivenom is highly specialised. It is produced by immunizing horses over many months and purifying their hyperimmune serum. A single vial can cost hundreds to over a thousand dollars to procure, and severe cases may require 4 to 8 vials. Combined with specialised Snake Venom Detection Kits, intensive round-the-clock ICU care, mechanical ventilation (life support), plasma transfusions, and IV fluid therapy required to keep the pet alive, treatment costs are substantial. Pet insurance is highly recommended.
Should I kill the snake and bring it in?
Absolutely not. All native snakes are protected by law in Queensland. Most human snake bites occur when untrained people attempt to kill or capture a snake. If it is safe to do so, take a photo from a safe distance. Our polyvalent antivenom can be used without needing to formally identify the snake.
Are Carpet Pythons dangerous to pets?
Carpet pythons are common in Brisbane and are non-venomous. They pose a threat by constriction to very small pets (like guinea pigs, kittens, or small chihuahuas), but a bite to a medium or large dog will only cause mechanical tissue damage and a risk of infection, not systemic poisoning. However, if you cannot positively identify the snake, always assume it is venomous and seek immediate veterinary care.
En route to the Clinic?
Snake bites are a Code Red Emergency. Please call ahead while in transit so our critical care team can prepare antivenom and life-saving equipment before you arrive. Keep your pet perfectly still.