Anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore.

Anticoagulant rodenticide (AR) poisoning has emerged as a significant concern for conservation and management of non-target wildlife. The purpose for these toxicants is to suppress pest populations in agricultural or urban settings. The potential of direct and indirect exposures and illicit use of ARs on public and community forest lands have recently raised concern for fishers (Martes pennanti), a candidate for listing under the federal Endangered Species Act in the Pacific states. In an investigation of threats to fisher population persistence in the two isolated California populations, we investigate the magnitude of this previously undocumented threat to fishers, we tested 58 carcasses for the presence and quantification of ARs, conducted spatial analysis of exposed fishers in an effort to identify potential point sources of AR, and identified fishers that died directly due to AR poisoning. We found 46 of 58 (79%) fishers exposed to an AR with 96% of those individuals having been exposed to one or more second-generation AR compounds. No spatial clustering of AR exposure was detected and the spatial distribution of exposure suggests that AR contamination is widespread within the fisher's range in California, which encompasses mostly public forest and park lands Additionally, we diagnosed four fisher deaths, including a lactating female, that were directly attributed to AR toxicosis and documented the first neonatal or milk transfer of an AR to an altricial fisher kit. These ARs, which some are acutely toxic, pose both a direct mortality or fitness risk to fishers, and a significant indirect risk to these isolated populations. Future research should be directed towards investigating risks to prey populations fishers are dependent on, exposure in other rare forest carnivores, and potential AR point sources such as illegal marijuana cultivation in the range of fishers on California public lands

Patterns of Natural and Human-Caused Mortality Factors of a Rare Forest Carnivore, the Fisher (Pekania pennanti) in California.

Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status protection in late 2014 under the United States Endangered Species Act by the United States Fish and Wildlife Service in its West Coast Distinct Population Segment. We investigated mortality in 167 fishers from two genetically and geographically distinct sub-populations in California within this West Coast Distinct Population Segment using a combination of gross necropsy, histology, toxicology and molecular methods. Overall, predation (70%), natural disease (16%), toxicant poisoning (10%) and, less commonly, vehicular strike (2%) and other anthropogenic causes (2%) were causes of mortality observed. We documented both an increase in mortality to (57% increase) and exposure (6%) from pesticides in fishers in just the past three years, highlighting further that toxicants from marijuana cultivation still pose a threat. Additionally, exposure to multiple rodenticides significantly increased the likelihood of mortality from rodenticide poisoning. Poisoning was significantly more common in male than female fishers and was 7 times more likely than disease to kill males. Based on necropsy findings, suspected causes of mortality based on field evidence alone tended to underestimate the frequency of disease-related mortalities. This study is the first comprehensive investigation of mortality causes of fishers and provides essential information to assist in the conservation of this species

Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites

Lead Exposure from Backyard Chicken Eggs: A Public Health Risk?

Although the USA has made significant strides in reducing lead exposure, new and emerging sources are raising cause for public concern. Recent reports of finding lead in eggs from chickens raised in urban gardens has highlighted the need to consider the potential health risks of consuming eggs from backyard chickens. Following the detection of 0.33 μg/g lead in the edible portion of eggs submitted for lead analysis from a backyard chicken owner, further investigation was conducted to determine the source and extent of lead exposure in the flock. Several birds, almost two dozen eggs, and environmental samples were submitted to the California Animal Health and Food Safety Laboratory for further testing. Lead was detected in the blood, liver, kidney, and bone at varying concentrations in all birds but was not detected in the muscle tissue. All egg shells contained detectable amounts of lead, while only a little over half of the edible portion of the eggs contained lead. The detected concentrations in the edible portion approached or exceeded the recommended threshold of lead consumption per day that should not be exceeded by young children if a child consumed one average-sized egg. Peeling paint from a wooded structure adjacent to the flock's coop was the likely lead source containing 3,700 μg/g lead. Thus, removal of the chickens from the source and periodic testing of eggs for lead were recommended. This case illustrates the need for consumers and health care workers to be aware of potential sources for lead exposure such as backyard chickens

Dog and cat exposures to drugs of abuse identified by the California animal health and food safety laboratory system 2013–2023

IntroductionWhile known animal exposures to human “drugs of abuse” (DA) were previously considered relatively uncommon in veterinary medicine, the trends are changing. Marijuana and amphetamines are among the 20 toxicants most frequently consulted about with the Pet Poison Helpline. When such exposures occur, they are typically considered emergencies.MethodsThis retrospective study describes confirmed cases of DA exposure in pets from the California Animal Health and Food Safety Laboratory System (CAHFS), 2013–2023.ResultsFifty-seven samples tested positive for DA through liquid chromatography with tandem mass spectrometry analysis (qualitative method). In 75% (43/57) of the DA screen tests, the detected drugs included amphetamine-type stimulants and metabolites (methamphetamine, amphetamine, or both). In 47% (27/57) of cases, a combination of more than one drug group was found. Most cases were diagnosed from a urine specimen. In at least 32% (18/57) of cases, the samples were submitted due to suspicions of animal cruelty, and at least 41% (23/57) of the patients were deceased when the samples were submitted.DiscussionMore studies on the prevalence of illicit drugs in small animals, using confirmatory testing, are warranted to fully understand the significance of this emerging toxicological hazard in veterinary medicine

Imidacloprid Poisoning of Songbirds Following a Drench Application of Trees in a Residential Neighborhood in California, USA.

In March 2017, 26 American goldfinches (Spinus tristis) were found dead following a drench application of imidacloprid in California (USA). Identical seed fragments were present in the digestive tracts. Imidacloprid was detected in 4 separate pooled samples from 18 birds, in crop/gizzard contents (4.8 ± 1.3 ppm; range 2.2-8.5 ppm) and liver tissues (3.9 ± 0.6 ppm; range 2.1-4.8 ppm). We suspect that fallen elm (Ulmus sp.) seeds were contaminated with imidacloprid during the drench application and subsequently ingested, resulting in acute toxicity and death. Environ Toxicol Chem 2019;38:1724-1727. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC

The Current State of Veterinary Toxicology Education at AAVMC Member Veterinary Schools

This study assessed the depth, breadth, and perception of toxicology education in curricula at Association of American Veterinary Medical Colleges (AAVMC) member veterinary schools. An online questionnaire was sent twice to all 54 AAVMC members and sent once to a veterinary toxicology list serve. The survey covered areas related to instructor demographics, the depth and extent of toxicology taught, and the respondent's perceptions of their student's ability to perform entrustable professional activities (EPA). Results were analyzed using descriptive statistics. Our survey resulted in a 44% response rate. All responding schools included toxicology in their curriculum, and it was a required course in 23 programs. Contact hours in stand-alone veterinary toxicology courses ranged from 14 to 45 h. Most respondents indicated that the current time allotted for toxicology was inadequate, despite indicating that most of their students could perform most EPAs autonomously. One exception related to the ability of students to analyze toxicology data. We found small variations in teaching methods and curriculum content. The results of our study can assist veterinary schools in evaluating their curricula to better prepare new graduates for the management of toxicology issues they may face in their veterinary careers

Lead contamination in backyard chicken layer flocks in California.

Backyard layer chickens may be exposed to a variety of metals in the environment, including lead. The potential public health concerns associated with lead exposure prompted us to systematically screen liver samples from backyard layers submitted to the diagnostic laboratory to estimate the prevalence of lead exposure. Over a period of 1 y, we tested 1,476 chicken livers, of which 45 were found to have lead concentrations of 0.9-41 µg/g. The lead-positive cases were investigated by follow-up questions to the bird owners on the environment, general management of the flock, and egg consumption of family members. Lead concentrations in 14 pooled egg samples were determined, and a conservative estimate of daily exposure of family members to lead was made based on egg consumption. In some cases, estimated daily lead intake exceeded the recommended limits for lead consumption in children. Analysis of feed, water, and environmental samples did not identify a source of exposure in most cases. Only 34% of owners of lead-positive birds submitted eggs or environmental samples, indicating a lack of interest or financial concerns. In most cases, neither the case history nor postmortem findings were indicative of lead intoxication; without systematically testing all birds, some cases could have been missed. Our study highlights the need for backyard chicken owners, veterinarians, and public health personnel to be aware of the risk of lead exposure and undertake preventive and surveillance measures

New Rodenticide on the Block: Diagnosing Bromethalin Intoxication in Wildlife

Bromethalin is being used more widely for commensal rodent control because of increased regulation on second-generation anticoagulant rodenticides. Wildlife losses in California are tracked by the California Department of Fish and Wildlife. Bromethalin is a neurotoxicant which is not thought to cause secondary poisoning. From August 2014 to January 2016, 24 cases of bromethalin intoxication were investigated in California. These include 11 raccoons, 11 striped skunks, one gray fox, and one fox squirrel. Most of these occurred in Marin County, where active surveillance of wildlife for rodenticide exposure is occurring. Bromethalin exposure should be evaluated when a wild animal that may have accessed bait is showing neurological signs. Trauma and distemper should be ruled out. Histological changes may be found in the central nervous system but are not always present. The tissue of choice for toxicological analysis is adipose. It is likely that bromethalin intoxication is under-reported in the rest of the state and may be mistaken for distemper infection or trauma. Primary exposure of wildlife to bromethalin could be prevented by placing baits in tamper-resistant bait stations