Accidental secondary pentobarbital intoxication in small domestic animals and wild birds in Europe

This study aimed to investigate accidental secondary pentobarbital intoxications in domestic and wild animals in Europe.Case reports of accidental secondary pentobarbital intoxication were searched for in 2 veterinary pharmacovigilance databases (VigilanceVET and EudraVigilance Veterinary). In addition, 2 toxicology laboratories were asked for information concerning pentobarbital intoxications in animals.Overall, reports were found for 178 animals affected by secondary pentobarbital intoxication including 109 domestic animals (2 cats, 107 dogs) and 69 wild birds. The source of accidental secondary exposure was identified in all cases involving domestic animals and included various ingested organic materials, such as blood, tissue, and whole carcasses of farm and pet animals. The most frequently reported clinical signs in dogs were neurological disorders, such as ataxia, disturbances of consciousness, or convulsions, and systemic disorders, such as lethargy, recumbency, hypothermia, and even death in 9 dogs. In total, 34 cases involving 69 wild birds were identified. Of these 69 wild birds 57 died. The material that caused the intoxication was reported in only 5 cases and included tissue from farm animals and pets. A detailed medical history was available for one case involving a wild common buzzard (Buteo buteo) that had survived exposure to pentobarbital.Ingestion of tissue or blood from euthanised animals may lead to pentobarbital intoxication in domestic and wild animals, which may remain undiscovered due to non-specific clinical signs. Screening for pentobarbital should be considered in free-roaming dogs and cats presenting with neurological signs, as well as in carnivorous or scavenging wildlife exhibiting unclear neurological symptoms or dying from unknown causes.