If the animal is showing any signs of systemic poisoning it should receive antivenom by the intravenous route. The required antivenom may be selected following positive identification of the snake involved, or by selecting the antivenom combination recommended for the state (see tables below).
| Choice of antivenom when the snake has been identified | |
| Snake | Appropriate Antivenom |
| Eastern brown snake Dugite Gwardar |
brown snake |
| Mainland tiger snake Black tiger snake Chappell Island tiger snake Copperhead Rough-scaled or Clarence River snake Small-eyed snake Whip snake |
Tiger snake |
| Red-bellied black snake Mulga or king brown snake |
black snake or tiger snake |
| Taipan Fierce snake or inland taipan |
taipan |
| Death adder Bardick |
death adder |
| Sea snake | sea snake |
| Choice of antivenom when the identity of the snake is uncertain | |
| State | Recommended Antivenom for Veterinary Use |
| New South Wales South Australia Western Australia Northern Territory |
tiger-brown snake combined + death adder |
| Queensland, South of Rockhampton | tiger-brown snake combined + death adder |
| Queensland, North of Rockhampton | brown snake + death adder |
| Victoria | tiger-brown snake combined |
| Tasmania | tiger snake |
The amount of antivenom required for treatment will depend on the likely amount of venom injected by the snake. This in turn depends on the size of the snake, the number of strikes, the effectiveness of the strikes, and the fullness of the venom glands. Severely envenomed animals often require multiple vials of the appropriate antivenom to improve their chances of survival. Envenomed patients in which the identity of the offending snake is not established have a higher risk of death.
Care should be taken in the administration of antivenom as it may trigger an acute anaphylactic reaction. It should be diluted and infused slowly, whenever possible, and full resuscitation facilities should be available. Since 1980, brown snake antivenom has been issued for animal use in ampoules containing 500 units because many veterinarians considered this dose adequate in most cases and the smaller ampoules reduced the cost of treatment.
Apart from antivenom, the supportive measures required will vary depending on the clinical conditions. Avoidance of hypoxaemia is essential and ventilation with oxygen may be required. In milder cases all that may be necessary is to ensure that respiratory obstruction does not occur. In severe cases, mechanical ventilation for periods of up to 40 hours may be required to save their lives.
Fluid replacement therapy is often required. If muscle breakdown is occurring a high urine output must be maintained to reduce the risk of tubular necrosis due to myoglobin. Some sedation may be necessary, particularly if muscle spasms are strong, but narcotics are usually contraindicated. Tetanus prophylaxis should be considered.
Good nursing care of the animal is very important. It should be kept warm and at rest and closely observed. Peace and quiet is essential as undue movement will enhance venom absorption and the neurotoxic effects. If the animal has not responded to the first injection of antivenom, the dose should be repeated and the suitability of the antivenom rechecked.
Severely envenomed animals which have been well managed may still take weeks to return to full health, because of the widespread effects of the venom, particularly muscle damage.
Contributed by R. Brooks. Last updated: January 2008
