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Naidoo V, Taggart MA, Duncan N, Wolter K, Chipangura J, Green RE, Galligan TH. The use of toxicokinetics and exposure studies to show that carprofen in cattle tissue could lead to secondary toxicity and death in wild vultures. Chemosphere 2018; 190:80-89. [PMID: 28985539 DOI: 10.1016/j.chemosphere.2017.08.167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 08/18/2017] [Accepted: 08/30/2017] [Indexed: 06/07/2023]
Abstract
Veterinary medicines can be extremely damaging to the environment, as seen with the catastrophic declines in Gyps vulture in South Asia due to their secondary exposure to diclofenac in their primary food source. Not surprisingly, concern has been raised over other similar drugs. In this study, we evaluate the toxicity of carprofen to the Gyps vulture clade through plasma pharmacokinetics evaluations in Bos taurus cattle (their food source) and Gyps africanus (a validated model species); tissue residues in cattle; and the effect of carprofen as a secondary toxicant as both tissue-bound residue or pure drug at levels expected in cattle tissues. Carprofen residues were highest in cattle kidney (7.72 ± 2.38 mg/kg) and injection site muscle (289.05 ± 98.96 mg/kg of dimension of 5 × 5 × 5 cm). Vultures exposed to carprofen as residues in the kidney tissue or pure drug equivalents showed no toxic signs. When exposed to average injection site concentrations (64 mg/kg) one of two birds died with evidence of severe renal and liver damage. Toxicokinetic analysis revealed a prolonged drug half-life of 37.75 h in the dead bird as opposed to 13.99 ± 5.61 h from healthy birds dosed intravenously at 5 mg/kg. While carprofen may generally be harmless to Gyps vultures, its high levels at the injection site in treated cattle can result in lethal exposure in foraging vultures, due to relative small area of tissue it is found therein. We thus suggest that carprofen not be used in domesticated ungulates in areas where carcasses are accessible or provided to vultures at supplementary feeding sites.
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Affiliation(s)
- V Naidoo
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa; Biomedical Research Centre, Faculty of Veterinary Science, University of Pretoria, South Africa.
| | - M A Taggart
- Environmental Research Institute, University of the Highlands and Islands, Castle St, Thurso, Scotland, KW17 7JD, UK
| | - N Duncan
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - K Wolter
- VulPro, Plot 121, Rietfontein, 0048, South Africa
| | - J Chipangura
- Biomedical Research Centre, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - R E Green
- RSPB Centre for Conservation Science, David Attenborough Building, Cambridge, Cambridgeshire, CB2 3QZ, UK; Conservation Science Group, Department of Zoology, University of Cambridge, David Attenborough Building, Cambridge, Cambridgeshire, CB2 3QZ, UK
| | - T H Galligan
- Conservation Science Group, Department of Zoology, University of Cambridge, David Attenborough Building, Cambridge, Cambridgeshire, CB2 3QZ, UK
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Galligan TH, Taggart MA, Cuthbert RJ, Svobodova D, Chipangura J, Alderson D, Prakash VM, Naidoo V. Metabolism of aceclofenac in cattle to vulture-killing diclofenac. Conserv Biol 2016; 30:1122-1127. [PMID: 26931376 DOI: 10.1111/cobi.12711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/11/2016] [Accepted: 02/26/2016] [Indexed: 06/05/2023]
Abstract
The nonsteroidal anti-inflammatory drug (NSAID) diclofenac is highly toxic to Gyps vultures, and its recent widespread use in South Asia caused catastrophic declines in at least 3 scavenging raptors. The manufacture of veterinary formulations of diclofenac has since been banned across the region with mixed success. However, at least 12 other NSAIDs are available for veterinary use in South Asia. Aceclofenac is one of these compounds, and it is known to metabolize into diclofenac in some mammal species. The metabolic pathway of aceclofenac in cattle, the primary food of vultures in South Asia, is unknown. We gave 6 cattle the recommended dose of aceclofenac (2 mg/kg), collected blood thereafter at intervals for up to 12 h, and used liquid chromatography with mass spectrometry in a pharmacokinetic analysis of aceclofenac and diclofenac in the plasma. Nearly all the aceclofenac administered to the cattle was very rapidly metabolized into diclofenac. At 2 h, half the aceclofenac had been converted into diclofenac, and at 12 h four-fifths of the aceclofenac had been converted into diclofenac. Therefore, administering aceclofenac to livestock poses the same risk to vultures as administering diclofenac to livestock. This, coupled with the risk that aceclofenac may replace diclofenac in the veterinary market, points to the need for an immediate ban on all aceclofenac formulations that can be used to treat livestock. Without such a ban, the recovery of vultures across South Asia will not be successful.
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Affiliation(s)
- T H Galligan
- RSPB Centre for Conservation Science, The Lodge, Sandy, Bedfordshire, SG19 2DL, U.K..
| | - M A Taggart
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, Scotland, KW14 7JD, U.K
| | - R J Cuthbert
- RSPB Centre for Conservation Science, The Lodge, Sandy, Bedfordshire, SG19 2DL, U.K
- Wildlife Conservation Society, P.O. Box 277, Goroka, Eastern Highlands Province 441, Papua New Guinea
| | - D Svobodova
- Environmental Research Institute, University of the Highlands and Islands, Castle Street, Thurso, Scotland, KW14 7JD, U.K
| | - J Chipangura
- Biomedical Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, 0110, South Africa
| | - D Alderson
- SAC Consulting Veterinary Services, Janetstown, Thurso, Scotland, KW14 7XF, U.K
| | - V M Prakash
- Bombay Natural History Society, Hornbill House, Mumbai, 400023, India
| | - V Naidoo
- Wildlife Conservation Society, P.O. Box 277, Goroka, Eastern Highlands Province 441, Papua New Guinea
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