Veterinary pharmaceuticals as a threat to endangered taxa: Mitigation action for vulture conservation

Do Pharmaceuticals in the Environment Pose a Risk to Wildlife?

The vast majority of knowledge related to the question "To what extent do pharmaceuticals in the environment pose a risk to wildlife?" stems from the Asian vulture crisis (>99% decline of some species of Old World vultures on the Indian subcontinent related to the veterinary use of the nonsteroidal anti-inflammatory drug [NSAID] diclofenac). The hazard of diclofenac and other NSAIDs (carprofen, flunixin, ketoprofen, nimesulide, phenylbutazone) to vultures and other avian species has since been demonstrated; indeed, only meloxicam and tolfenamic acid have been found to be vulture-safe. Since diclofenac was approved for veterinary use in Spain and Italy in 2013 (home to ~95% of vultures in Europe), the risk of NSAIDs to vultures in these countries has become one of the principal concerns related to pharmaceuticals and wildlife. Many of the other bodies of work on pharmaceutical exposure, hazard and risk to wildlife also relate to adverse effects in birds (e.g., poisoning of scavenging birds in North America and Europe from animal carcasses containing pentobarbital, secondary and even tertiary poisoning of birds exposed to pesticides used in veterinary medicine as cattle dips, migratory birds as a vector for the transfer of antimicrobial and antifungal resistance). Although there is some research related to endocrine disruption in reptiles and potential exposure of aerial insectivores, there remain numerous knowledge gaps for risk posed by pharmaceuticals to amphibians, reptiles, and mammals. Developing noninvasive sampling techniques and new approach methodologies (e.g., genomic, in vitro, in silico, in ovo) is important if we are to bridge the current knowledge gaps without extensive vertebrate testing. Environ Toxicol Chem 2024;43:595-610. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Exposure to salinomycin dysregulates interplay between mitophagy and oxidative response to damage the porcine jejunal cells

Salinomycin (SAL) has caused widespread pollution as a feed additive and growth promoter in livestock such as pigs, exerting a negative impact on public health. The toxicity mechanism of SAL has been widely studied in chickens, but the underlying mechanisms of SAL-induced toxicity to pigs and the ecosystem remain undefined. In this study, we explored the potential damage of SAL in IPEC-J2 cells to identify the effects of excessive SAL on the interplay between mitophagy and oxidative stress. The results showed that a concentration-dependent response was observed for SAL in altering cellular morphology and inducing cell death in IPEC-J2 cells, including the induction of cell cycle arrest and lactic dehydrogenase (LDH) release. Meanwhile, we found that excessive SAL led to oxidative damage by activating the Nrf2/Keap1/HO-1 pathway, accompanied by reactive oxygen species (ROS) elevation and the reduction of antioxidant enzyme activity. We also found that PINK1/Parkin-dependent mitophagy was activated by SAL exposure, particularly with mitochondrial membrane potential reduction. Interestingly, SAL-induced oxidative damages were prevented after the autophagy inhibitor 3-methyladenine (3-MA) treatment, and mitophagy was alleviated following ROS scavenger (N-acetylcysteine, NAC) treatment. Overall, our findings showed that SAL stimulated oxidative stress and mitophagy in IPEC-J2 cells resulting in cellular injury, and there was a strong connection between SAL-induced oxidative stress and mitophagy. Targeting ROS/PINK1/Parkin-dependent mitophagy and oxidative stress could be a novel protective mechanism in SAL-induced cell damage.

Veterinary pharmaceuticals and declining Cape Griffon Vulture (Gyps coprotheres) numbers: A potential threat to developing embryos

Cape Vultures (Gyps coprotheres) are a vulnerable Old-World Vulture species in southern Africa. Of the numerous threats to their survival, malicious and accidental poisonings remain a major concern. Despite the dangers of poisonings little is however known about the more insidious effects of toxins on egg survival, despite the species known to have a long generational length. For this study, an extensive literature review focusing on veterinary pharmaceuticals was undertaken. Literature for vultures was scarce, with most studies focusing on the domestic chicken. Using information for domestic chickens, the risk was characterised from likely vulture exposure to production animal carcasses with residues of said drugs. From this various antibiotics, medetomidine and albendazole were identified with embryotoxic or teratogenic effects. We suggest that these drugs be tested to elucidate their dose-response relationship and/or mitigation measures to minimise vulture exposure.

Anthropogenic threats to the Vulnerable Andean Condor in northern South America

Vultures comprise one of the most threatened groups of birds worldwide. With a total population not exceeding 6700 mature individuals, and in rapid decline across its range, the Andean Condor (Vultur gryphus) is listed as a Vulnerable species in the IUCN red list. Local population extinctions and decline are of particular concern in northern South America, where no more than 340 condors may exist at present. Despite this, no quantitative assessments exist in Ecuador, Colombia, and Venezuela regarding the threats affecting Andean Condor populations. To address this, we compiled records of Andean Condors injured, or killed, between 1979 and 2021. We obtained data of 164 condors affected by different causes of injury, of which 83.5% were reported in Ecuador, 15.2% in Colombia, and 1.2% in Venezuela. Of the total number, 84.7% of the injured individuals died. Between 1979 and 2021, in Ecuador, Colombia and Venezuela, at least 103 Andean Condors were presumably poisoned, 22 were shot, and 39 individuals were affected by other causes. The total number of individuals affected by different causes represents between 48% and 72% of the total population estimated in northern South America. Of great concern is the fact that, between 2007 and 2021, poisoning and shooting together caused the loss of 19-31% of the estimated population of condors in Ecuador, and 7-21% of the estimated population in Colombia. Given the important mortality induced by humans, environmental education programs, socio-ecological research, application of environmental laws, and management strategies based on scientific evidence to prevent and mitigate human-wildlife conflicts are urgently required for effective Andean Condor conservation in northern South America.