First diclofenac intoxication in a wild avian scavenger in Europe

Abstract

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) with a well-known toxicity for old world vultures that ingest the carrion of domestic animals treated with it. Diclofenac intoxication was directly related to the dramatic declines in the populations of three native South Asian Gyps vulture species two decades ago. In 2013, this NSAID was authorised for veterinary use in Spain, which has the largest vulture populations in Europe. One of these species is the cinereous vulture (Aegypius monachus), which is classified as “near threatened” by the International Union for Conservation of Nature (IUCN). This species has been reintroduced and monitored in Catalonia (NE Spain) since 2007, and in 2020 its current population consisted of 15 breeding pairs and a total number of 61 individuals. In September 2020, one fledgling was found dead in the nest. Post-mortem examination revealed severe generalised visceral and articular gout, which was confirmed histologically. Diclofenac was detected at average concentrations of 26.5 ng/g in the liver and 51.4 ng/g in kidney replicates (n = 3), respectively. These findings support a diagnosis of fatal gout caused by diclofenac intoxication. This is the first case of diclofenac poisoning in Spain (and in Europe), in addition to being the first report of diclofenac poisoning in cinereous vultures. This case report, therefore, supports the need to closely monitor vulture populations and carry out strict regulatory measures with which to prevent these poisonings.