title: Removing the threat of diclofenac to critically endangered Asian vultures.
abstract: Veterinary use of the nonsteroidal anti-inflammatory (NSAID) drug diclofenac in South Asia has resulted in the collapse of populations of three vulture species of the genus Gyps to the most severe category of global extinction risk. Vultures are exposed to diclofenac when scavenging on livestock treated with the drug shortly before death. Diclofenac causes kidney damage, increased serum uric acid concentrations, visceral gout, and death. Concern about this issue led the Indian Government to announce its intention to ban the veterinary use of diclofenac by September 2005. Implementation of a ban is still in progress late in 2005, and to facilitate this we sought potential alternative NSAIDs by obtaining information from captive bird collections worldwide. We found that the NSAID meloxicam had been administered to 35 captive Gyps vultures with no apparent ill effects. We then undertook a phased programme of safety testing of meloxicam on the African white-backed vulture Gyps africanus, which we had previously established to be as susceptible to diclofenac poisoning as the endangered Asian Gyps vultures. We estimated the likely maximum level of exposure (MLE) of wild vultures and dosed birds by gavage (oral administration) with increasing quantities of the drug until the likely MLE was exceeded in a sample of 40 G. africanus. Subsequently, six G. africanus were fed tissues from cattle which had been treated with a higher than standard veterinary course of meloxicam prior to death. In the final phase, ten Asian vultures of two of the endangered species (Gyps bengalensis, Gyps indicus) were dosed with meloxicam by gavage; five of them at more than the likely MLE dosage. All meloxicam-treated birds survived all treatments, and none suffered any obvious clinical effects. Serum uric acid concentrations remained within the normal limits throughout, and were significantly lower than those from birds treated with diclofenac in other studies. We conclude that meloxicam is of low toxicity to Gyps vultures and that its use in place of diclofenac would reduce vulture mortality substantially in the Indian subcontinent. Meloxicam is already available for veterinary use in India.
authors.affiliation: Department of Paraclinical Sciences, Biomedical Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors.forename: Gerry
authors.initials: G
authors.lastname: Swan
authors.forename: Vinasan
authors.initials: V
authors.lastname: Naidoo
authors.forename: Richard
authors.initials: R
authors.lastname: Cuthbert
authors.forename: Rhys E
authors.initials: RE
authors.lastname: Green
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Pain
authors.forename: Devendra
authors.initials: D
authors.lastname: Swarup
authors.forename: Vibhu
authors.initials: V
authors.lastname: Prakash
authors.forename: Mark
authors.initials: M
authors.lastname: Taggart
authors.forename: Lizette
authors.initials: L
authors.lastname: Bekker
authors.forename: Devojit
authors.initials: D
authors.lastname: Das
authors.forename: Jörg
authors.initials: J
authors.lastname: Diekmann
authors.forename: Maria
authors.initials: M
authors.lastname: Diekmann
authors.forename: Elmarié
authors.initials: E
authors.lastname: Killian
authors.forename: Andy
authors.initials: A
authors.lastname: Meharg
authors.forename: Ramesh Chandra
authors.initials: RC
authors.lastname: Patra
authors.forename: Mohini
authors.initials: M
authors.lastname: Saini
authors.forename: Kerri
authors.initials: K
authors.lastname: Wolter
mesh_terms: D000821:Animal Feed; D000818:Animals; D000835:Animals, Wild; D002417:Cattle; D003247:Conservation of Natural Resources / Q000331:legislation & jurisprudence* / Q000379:methods*; D004008:Diclofenac / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity; D053476:Extinction, Biological; D046093:Falconiformes / Q000378:metabolism*; D007194:India; D000077239:Meloxicam; D011157:Population Dynamics; D013843:Thiazines / Q000493:pharmacokinetics; D013844:Thiazoles / Q000493:pharmacokinetics; D014527:Uric Acid / Q000097:blood
chemical_list: D013843:Thiazines; D013844:Thiazoles; D004008:Diclofenac; D014527:Uric Acid; D000077239:Meloxicam