The safety testing (Naidoo et al., 2009) of ketoprofen, which was not reported to cause mortality in clinical treatment of scavenging birds, now proves to be toxic for Gyps vultures after feeding on tissue from cattle dosed with ketoprofen.
Three Gyps vulture species are on the brink of extinction in South Asia owing to the veterinary non-steroidal anti-inflammatory drug (NSAID) diclofenac, which is the same type of drug as ketoprofen. Carcasses of domesticated ungulates are the main food source for Asia’s vultures and birds die from kidney failure after consuming diclofenac-contaminated tissues. Safety testing of the NSAID ketoprofen was undertaken using captive non-releasable Cape griffon vultures (Gyps coprotheres) and wild-caught African white-backed vultures (G. africanus), both previously identified as susceptible to diclofenac and suitable surrogates. The birds were administrated ketoprofen by oral gavage or through feeding tissues from cattle dosed with ketoprofen before slaughter. Mortalities occurred at dose levels of 1.5 and 5 mg kg−1 vulture body weight (within the range recommended for clinical treatment) with the same clinical signs as observed for diclofenac. Surveys of livestock carcasses in India indicate that toxic levels of residual ketoprofen are already present in vulture food supplies. Consequently, they strongly recommend that ketoprofen is not used for veterinary treatment of livestock in Asia and in other regions of the world where vultures access livestock carcasses. The only alternative to diclofenac that should be promoted as safe for vultures is the NSAID meloxicam. (Source: Biology Letters, 23 June 2010)