Information on sodium pentobarbital

Veterinarians use highly concentrated solutions containing sodium pentobarbital for the humane euthanasia of both pets and farm animals. This potent drug is usually given intravenously and produces rapid unconsciousness without pain or distress to the animal. The method is considered one of the most humane methods of euthanasia. Unfortunately, there are hazards with its use. If the body of the euthanized animal is not properly disposed, usually either by deep burial or incineration, scavenging wild or domestic animals can be poisoned by the drug remaining in the dead animal.

This type of secondary poisoning occurs sporadically in BC and elsewhere in North America but significant numbers of animals can be involved. Notable cases in BC include 26 bald eagles that became ill after feeding on a euthanized cow (with 5 dying), several circus tigers and lions that became sedated with one dying after being fed meat from a euthanized horse and a recent case of at least 5 bald eagles affected after consuming part of a single euthanized dog improperly buried at a landfill. In most locations bald and golden eagles are the species most commonly affected. Poisoned birds may be found near the carcass source or at a distance and may be dead or found sedated. Farm animals can be sources of poisoning but dog and cat carcasses that are not properly buried in landfills are perhaps more common. In some parts of the province cases may be more frequent in the winter when frozen ground prevents easy burial of carcasses.

Sodium pentobarbital is well known to veterinary professionals; clinical signs in poisoned mammals and birds include drowsiness, incoordination and ultimately unconsciousness and death. Affected animals may recover if given supportive care; removal of the crop or stomach contents and treatment to reduce absorption of the drug may be helpful in improving survival. The best samples to confirm sodium pentobarbital poisoning are stomach contents or liver from the poisoned animal but serum samples can be tested from affected animals still alive. Liver samples from a suspect source carcass are also useful.

Veterinarians, landfill operators and farmers who improperly dispose of carcasses can be held legally responsible for wildlife deaths so awareness of the proper methods of handling and disposal is important. Veterinarians that euthanize pets should warn owners who wish to bury their pets of these dangers.