Some veterinary medicines are toxic to raptors and scavengers
Birds of prey and other scavenging animals may accidentally be exposed to veterinary medicines when they eat the carcasses of animals that are not rendered and have therefore been left in the wild. Certain anti-inflammatories and barbiturates pose a particular risk. The French Agency for Veterinary Medicinal Products (ANMV) is calling on veterinarians and breeders to take all the necessary precautions when administering these drugs to animals liable to be consumed by scavengers after their death.
Birds of prey and scavengers may be exposed to veterinary medicines, especially when the carcasses of treated animals (usually ruminants or horses):
- are left in areas where avian scavengers feed;
- are left in fields because rendering is not possible, or when the carcass is only discovered much later. This may be the case for certain types of livestock farming practised on very large areas of pasture, or in mountain areas where plots of land are difficult to reach.
Flunixin, carprofen and ketoprofen: anti-inflammatory drugs that are toxic to birds
Several vultures in Italy died after ingesting meat contaminated with flunixin, an anti-inflammatory found in several veterinary medicines authorised throughout Europe. Scientific publications have also confirmed the toxicity of this active ingredient to wild vultures. This led the European Medicines Agency (EMA) to conclude that precautions for use should be added to the package leaflets of all medicinal products containing flunixin-meglumine. If the treated animal is at high risk of mortality before the medicinal product has been fully eliminated from its body, and there is no possibility of the carcass being rendered, the ANMV recommends that veterinarians avoid prescribing medicines containing flunixin.
This recommendation has been extended to carprofen and ketoprofen, as some publications have also reported the possible toxicity of these active ingredients to vultures. The ANMV advises choosing anti-inflammatories that are less toxic to wild birds, such as meloxicam.
Pentobarbital: a highly persistent barbiturate
Cases of poisoning of wild birds – griffon vultures, red kites, white storks, bearded vultures, etc. – recorded by the European pharmacovigilance scheme have been attributed to their probable consumption of carcasses of animals euthanised with pentobarbital.
New pharmacovigilance data have led the ANMV to inform veterinarians and animal breeders and owners of the risks of secondary poisoning when the carcasses of animals euthanised with pentobarbital are not quickly removed. This risk is exacerbated by the stability of this compound, which can persist for several months in the tissues of euthanised animals.
Domestic animals also affected
Wild birds are not the only victims of accidental poisoning. Several cases of secondary poisoning have also been reported in farm dogs that ingested pieces of carcass or blood from euthanised animals, and then experienced neurological symptoms in some cases leading to coma and death.
How are these risks taken into account when authorising the placing on the market of a veterinary medicinal product?
When conducting the assessment that will determine whether or not authorisation is granted, the analysis of the benefit/risk ratio considers the safety of the medicinal product for the treated animal, the user, the consumer of any foodstuffs obtained from this animal, and the environment.
For some medicines, a risk to wildlife may be identified. In these cases, specific measures are taken, such as adding precautions for use to the package leaflet. These precautions for use are supplemented as and when data are collected through veterinary pharmacovigilance.