Senior Veterinary Officer, Veterinary Department, Zoological Society of London, Regents Park, London, UK
The once ubiquitous Gyps spp. vultures of India, Nepal, and Pakistan have, over the last decade, suffered a catastrophic population crash.1 As the magnitude of the decline became apparent, national and international organizations moved to determine its cause and conserve the species. The postmortem finding in affected vultures of visceral gout and residues of diclofenac, a non-steroidal anti-inflammatory drug (NSAID), was a turning point.2 Disease-modeling and a direct investigation strongly incriminated secondary ingestion of diclofenac as the cause of the vulture decline.3-6
Tests have been carried out on related Gyps species to determine an alternative NSAID to replace diclofenac. Meloxicam was found to be safe in vultures7 and thus offers an alternative drug for use on domestic ruminants. Despite diclofenac being banned by the Indian government in March 2005, this legislation had not been fully enacted over 1 year later.
In India, the Zoological Society of London (ZSL) is working in partnership with the Bombay Natural History Society (BNHS) and the Royal Society for the Protection of Birds (RSPB) to run a program for vulture conservation.
An initial research center, funded by the Darwin Initiative in the UK, to study the cause of the decline was established at Pinjore, Haryana. This has been expanded into a breeding center as part of the captive breeding program. A second center is being built at Buxa in West Bengal, and additional centers have been proposed. It is proving increasingly difficult, because of continuing population declines, to collect birds from the wild to form founder breeding groups. However, there are now representative groups of all three threatened species (G. bengalensis, G. indicus and G. tenuirostris) in captivity. A number of the birds are permanently disabled individuals that have been rescued by wildlife rehabilitators.
The BNHS now employs three full-time veterinary surgeons to work on the vulture project, with the ZSL providing veterinary and husbandry advice and support, both from the UK and on-site in India through regular visits to the project.
The Indian veterinary undergraduate course includes avian medicine teaching, but it is exclusively devoted to poultry-related topics. Thus, the ZSL has provided veterinary training in India pertinent to the management of the vultures, with the goal of ensuring that the in-situ project veterinary team can become more self-sufficient and expand their expertise within this specialized field.
In October 2005, a 6-day workshop was conducted. Veterinarians and biologists from the BNHS were trained, with additional veterinarians and wildlife rehabilitators participating. Through lectures, postmortem dissections, and wet labs, many aspects of avian medicine, anesthesia, surgery and more general wildlife rehabilitation were covered.
In addition to establishing the skills needed to manage the vultures held in the breeding centers, part of the rationale for the workshop was to preemptively train a veterinary team in anticipation of the 2006 Kite Festival in Ahmedabad, Gujarat. During this annual festival, many bird species are injured or killed by the kite strings that are covered with powdered glass. After the 2005 Kite Festival, a visit to a rescue facility run by the Animal Help Foundation (AHF) showed them to be overwhelmed by the volume of injured birds. (The AHF is a charity primarily devoted to the care of domestic species and runs a stray dog neutering program.) The ZSL and BNHS extended an invitation for an AHF veterinarian to attend the October workshop.
For the 2006 Kite Festival, the AHF facilities were relocated at a new site outside the city limits and the AHF was better prepared to accept the influx of birds. Their veterinary team was augmented by a BNHS veterinarian, a veterinarian from the Central Zoo in Katmandu, and the author. The large number of casualty birds, including the black kite (Milvus migrans), allowed the veterinarians to familiarize themselves with equipment and techniques while providing improved management of the injured birds. A protocol had been set up so that injured vultures would be prioritized for rescue. When an injured vulture was reported, a team, including a veterinarian, would be sent out to provide on-site first aid. Initial treatment was often restricted to the critical placing of hemostats on major vessels to prevent exsanguination. After transport to the AHF, center vultures were stabilized on intravenous crystalloid fluids and given antibiotics and meloxicam. They were then triaged for anesthesia and surgery.
On the Saturday of the Kite Festival, seven injured vultures underwent emergency general anesthesia (using isoflurane) and surgery to stop continued blood loss and to repair the propatagial injuries. All seven vultures survived.
Over the time during and directly after the 3-day Kite Festival, 20 injured vultures were admitted to the center, comprising over 20% of the remaining Ahmedabad population. Survival rates were markedly higher than in previous years, with only two vultures dying after admission compared with over 50% of those rescued in 2005. The residual disabilities are far less severe than in previous years but still preclude the release of these birds back to the wild. It is anticipated that the casualties will join other birds at one of the BNHS breeding centers.
The current vulture decline is limited to several countries in Asia. It reached a crisis point, with three species on the verge of extinction, in just a few years. This is a completely novel population collapse in terms of its cause and the species involved. Thus, the in-situ conservationists and veterinarians could not be expected to have the range and depth of expertise required to immediately address and arrest the decline. Ex-situ veterinary support by colleagues with broad avian skills and specific experience within zoological collections has facilitated establishment of the founder groups of birds. Further involvement is anticipated in future years as the vulture groups mature, breed, and provide offspring for release into the wild.
The precipitous decline of the Gyps species where diclofenac has been used in agricultural veterinary medicine should be noted by all involved in conservation. Lobbying should be actively undertaken to ensure that diclofenac is not distributed to other continents for use in the veterinary field.
Thanks are due to colleagues at ZSL, in particular Nick Lindsay, Head of International Programmes at ZSL and Claire Cunningham and Ilona Furrokh in the Veterinary Hospital who organized equipment acquisition and shipping. Thanks also to colleagues at RSPB and the BNHS, in particular Drs. Prakash and Das. Both the AHF and Kartik Shastri were pivotal to the success of the work during the 2006 Kite Festival in Ahmedabad. Work on the project has been supported by a Darwin Initiative Grant and the Bird of Prey Trust. The Universities Federation for Animal Welfare provided financial support for the October 2005 workshop in Pinjore. The isoflurane vaporizer, that has proved so invaluable in providing safe anesthesia for the vultures, was a donation from the AZA Raptor TAG members, coordinated by Scott Tidmus.
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