Robert Poppenga

Robert Poppenga
University of California, Davis | UCD · California Animal Health & Food Safety Laboratory System - CAHFS

About

169
Publications
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Publications

Publications (169)
Article
To describe the rapid diagnosis, treatment, and clinical course of a dog that ingested an amanitin‐containing mushroom. A 2‐month‐old female intact Australian Shepherd presented with diarrhea and vomiting, along with a possible mushroom exposure. Upon presentation, the dog's urine was collected and tested positive by a point‐of‐care rapid diagnosti...
Article
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A presumptive postmortem diagnosis of oleander (Nerium oleander) poisoning is made based on the histological observation of cardiomyocyte degeneration and necrosis, which is considered to be a reliable diagnostic marker, and can be confirmed via the detection of oleandrin in tissues or fluids. However, cardiac lesions may not be present in every ca...
Article
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Bromethalin toxicosis is an increasingly common clinical presentation in dogs that may be fatal depending on the extent of intoxication. Antemortem diagnosis of bromethalin toxicosis was achieved in three dogs by demonstration of the active metabolite desmethylbromethalin in fat or serum. Magnetic resonance imaging (MRI) findings were consistent wi...
Article
Poisoning of nontarget species is a major concern with the use of anticoagulant rodenticides (ARs). At postmortem examination, differentiating toxicosis from incidental exposure is sometimes difficult. Clotting profiles cannot be performed on postmortem samples, and clinically significant serum, blood, and liver AR concentrations are not well-estab...
Article
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Using diagnostic data and contemporary sampling efforts, we conducted surveillance for a diversity of pathogens, toxicants, and diseases of muskrats ( Ondatra zibethicus ). Between 1977 and 2019, 26 diagnostic cases were examined from Kansas and throughout the Southeast and Mid-Atlantic, USA. We identified multiple causes of mortality in muskrats,...
Article
Rattlesnake envenomation is an important cause of morbidity and mortality in humans and animals in the southwestern United States and elsewhere. Two Visayan warty pigs ( Sus cebifrons) from a regional zoo were submitted for autopsy after being found dead close to a southern Pacific rattlesnake ( Crotalus helleri) in their enclosure. Both pigs had s...
Article
Objective: To report history, physical examination findings, clinicopathologic abnormalities, treatments, and outcomes of dogs with confirmed α-amanitin toxicosis resulting from ingestion of α-amanitin-containing mushrooms, and to report whether any differences were significant between survivors and nonsurvivors. Animals: 59 dogs. Procedures:...
Article
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Two horses that consumed well water with high fluoride content exhibited clinical signs of chronic dental and skeletal fluoride toxicosis and were later euthanized and autopsied. Both horses had degenerative disease of multiple joints and multiple dental defects. Elevated fluoride concentrations were found in bone and tooth samples of both horses,...
Article
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Retinol (vitamin A) and α-tocopherol (vitamin E) concentrations were measured in tissue samples (liver, heart, pectoral muscle, and brain) from Anna's Hummingbirds (Calypte anna). Hummingbirds were after-hatch year birds that were sourced from various rehabilitation centers throughout California. Tissues samples were analyzed using high-performance...
Article
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Globally, mushroom poisonings cause about 100 human deaths each year, with thousands of people requiring medical assistance. Dogs are also susceptible to mushroom poisonings and require medical assistance. Cyclopeptides, and more specifically amanitins (or amatoxins, here), are the mushroom poison that causes the majority of these deaths. Current m...
Article
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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...
Article
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External feather rinses and homogenized whole-carcass tissue matrix from two hummingbird species found in California (Calypte anna and Archilochus alexandri) were analyzed for the presence of nine insecticides commonly used in urban settings. Using a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analytical method, samples were q...
Article
Diagnosing mushroom poisoning in dogs can be difficult and often includes identification of suspect mushrooms. Visual identification may be hindered by mastication, oral medications, or poor quality of environmental mushroom samples. Other analytical techniques may thus be necessary to aid in mushroom identification. A 5-y-old neutered male Labrado...
Article
We developed and validated a liquid chromatography–high-resolution mass spectrometry (LC-HRMS) analytical method for quantitatively measuring pesticide concentrations in small-body avian tissue samples using homogenized 1–2-d-old chicken carcasses as the test matrix. We quantified the following key insecticides: sulfoxaflor (sulfoximine class) and...
Article
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We describe and illustrate lesions in an outbreak of lead arsenate poisoning in beef cattle that ingested pesticide residues stored in an abandoned building of a former orange orchard. Of 70 exposed cattle, 14 had diarrhea, paresis, ataxia, recumbency, and/or seizures. Ten of the affected animals died after a clinical course of 12–18 h. Pathologic...
Article
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En el amplio campo de los rodenticidas, la Brometalina es una molécula bastante desconocida en la Unión Europea, siendo sin embargo muy habitual y conocida para los profesionales veterinarios norteamericanos. Con una elevada toxicidad (pues ha sido diseñada para ser eficaz a una dosis única), genera intoxicaciones tanto primarias como secundarias e...
Article
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 test...
Article
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The documentation of anticoagulant rodenticides (AR) in nontarget species has centered around wildlife that inhabit urban or agricultural settings. However, recent studies in California have shown that AR use in remote forest settings has escalated and has exposed and killed forest carnivores. Anticoagulant rodenticides have been documented as phys...
Article
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White muscle disease (WMD), nutritional myodegeneration or enzootic muscular dystrophy, is a nutritional condition associated with selenium and/or vitamin E deficiency in ruminants. These elements are constituents of the major body antioxidant systems. Depletion of selenium results in oxidative damage to cardiac and skeletal muscle cells, resulting...
Article
Use of the neurotoxic rodenticide bromethalin has steadily increased since 2011, resulting in an increased incidence of bromethalin intoxications in pets. Presumptive diagnosis of bromethalin toxicosis relies on history of possible rodenticide exposure coupled with compatible neurologic signs or sudden death, and postmortem examination findings tha...
Chapter
The release and use of toxic substances, the exploitation of resources, and physical alterations of the environment have had substantial unintended consequences affecting human health and the environment. They proposed that public health actions to protect human health and the environment are necessary even in the face of uncertainty. This chapter...
Article
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In racehorses, sudden death (SD) associated with exercise poses a serious risk to jockeys and adversely affects racehorse welfare and the public perception of horse racing. In a majority of cases of exercise-associated sudden death (EASD), there are no gross lesions to explain the cause of death, and an examination of the cardiovascular system and...
Article
Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, Unite...
Conference Paper
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Arsenic (As) is a ubiquitous toxic element that is concentrated in the environment as a result of industrial activities. Before the 1960s As was used extensively in insecticides, herbicides, fungicides, paint and preservatives. Lead arsenate (LA) is an inorganic insecticide that was used extensively in agriculture. Although acute As poisoning is in...
Article
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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 pro...
Article
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Anticoagulant rodenticides (ARs) are increasingly recognized as a threat to nontarget wildlife. High exposure to ARs has been documented globally in nontarget predatory species and linked to the high prevalence of an ectoparasitic disease, notoedric mange. In southern California, mange associated with AR exposure has been the proximate cause of a b...
Article
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Five horses originating from 4 different California race tracks were submitted to the California Animal Health and Food Safety Laboratory for necropsy and diagnostic workup. The 5 horses had a history of sudden collapse and death during exercise. In all of them, massive hemoperitoneum and hemorrhages in other cavities or organs were observed. The l...
Article
Cobalt has been used by human athletes due to its purported performance-enhancing effects. It has been suggested that cobalt administration results in enhanced erythropoiesis, secondary to increased circulating erythropoietin (EPO) concentrations leading to improvements in athletic performance. Anecdotal reports of illicit administration of cobalt...
Article
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Large-scale poisoning events are common to scavenging bird species that forage communally, many of which are in decline. To reduce the threat of poisoning and compensate for other persistent threats, management, including supplemental feeding, is ongoing for many reintroduced and endangered vulture populations. Through a longitudinal study of lead...
Article
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...
Article
Diisocyanates, commonly used in the production of polyurethane foams, paints, elastomers, varnishes, and coatings, are considered among the most hazardous inhalation toxicants. The present report describes 2 unusual cases of mortality in pigeon chicks associated with nesting material contaminated by diisocyanates. Case 1 was submitted by a racing p...
Conference Paper
Full-text available
In April 2009, an adult male fisher being monitored as part of an ongoing Southern Sierra research project was found dead on the forest floor with no obvious cause of mortality. Upon necropsy, it was discovered that the animal died of acute anticoagulant rodenticide poisoning. Follow-up investigation identified illegal marijuana cultivation sites o...
Conference Paper
The exposure of fishers to anticoagulant rodenticides has been well documented over the past few years and a link to illegal marijuana cultivation sites in our forests has been implicated. Long term demographic monitoring of fishers across their current range in CA has provided us with a small fraction of the total level of impacts. Our efforts to...
Article
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Abstract Notoedric mange was responsible for a population decline of bobcats (Lynx rufus) in 2 Southern California counties from 2002-2006, and is now reported to affect bobcats in Northern and Southern California. With this study, we document clinical laboratory and necropsy findings for bobcats with mange. Bobcats in this study included free-rang...
Article
Two adult llamas (Lama glama) previously exposed to oak trees (Quercus spp.) were presented with a history of depression and anorexia. Clinicopathological abnormalities included severe gastroenteritis, acute renal failure, and increased liver enzymes. This is believed to be the first report of oak toxicosis in South American camelids.
Article
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Sodium fluoroacetate is an organofluorine compound toxic to mammals, insects, and birds, currently registered for use only in livestock protection collars as a predacide in some North American states, with restricted use in California. A flock of 445 lambs and ewes in California were moved into a native pasture on a municipal refuse disposal site....
Article
Objective: To identify dogs with anticoagulant rodenticide (AR) screens submitted, determine whether detected concentrations of the anticoagulants correlated with severity of clinical signs for dogs with positive results on AR screens, and identify the most common disease processes present and the prognosis for those with negative AR screens. Des...
Article
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Secondary exposure of wildlife to pesticides has been well documented, yet exposure is typically associated with agricultural or wildland-urban interface areas. Wildlife in undeveloped areas is generally presumed free from risk. In 2009, a male fisher was found dead in the Sierra National Forest and subsequent necropsy revealed that the animal died...
Article
Context: Hydroxocobalamin has been reported to interfere with the blood leak alarm on hemodialysis machines making it difficult to use this treatment modality after hydroxocobalamin infusion. Objective: The objective was to determine if this interference with hydroxocobalamin occurs across hemodialysis machines by different manufacturers. Additi...
Article
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Background: A 4-year-old, 37 kg, male German shepherd developed hyperthermia, tachycardia, and agitation following consumption of ground meat found in the backyard of its owner. When presented to a veterinary clinic, plasma ethylene glycol (EG) testing was positive, and the dog was given ethanol and lactated Ringer's solution intravenously. Approx...
Article
Full-text available
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 recen...
Data
Results of spatial scan statistics to detect clusters of anticoagulant rodenticide (AR) exposed fishers within each California fisher project. Number of individual fisher minimum convex polygon (MCP) centroids used for each temporal period, specific AR types, generation class of AR and distribution of numbers of ARs per fisher (number of AR positiv...
Data
A two-way ANOVA analyzing the effects of California fisher (Martes pennanti) populations and sex on the number of anticoagulant rodenticides found per individual. (DOCX)
Article
Several flocks of Cedar Waxwings (Bombycilla cedrorum) were found dead after colliding with solid objects such as picture windows, plexiglass, and fences. Necropsy examination revealed that all birds had engorged themselves with over-ripe berries of the Brazilian Pepper Tree (Schinus terebinthifolius) and had hemorrhages in the breast muscles and t...
Article
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An alpaca was presented with a history of respiratory difficulty and death. Histology of the phrenic nerves and diaphragm revealed degenerative changes consistent with denervation atrophy, and a diagnosis of diaphragmatic paralysis was established. No gross or histological abnormalities were observed in the spinal cord or other organs. The etiology...
Poster
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Several cases of intoxications with cyanobacterial and marine toxins were diagnosed by the CAHFS-Toxicology Laboratory in various animal species. Anatoxin-a intoxications were the most common among dogs, poisonings by microcystins were diagnosed in livestock and wildlife, domoic acid and tetrodotoxin exposures were confirmed in wildlife. Various sa...
Article
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Whole blood and serum mineral concentrations were measured in diverse bighorn sheep (Ovis canadensis) metapopulations in California, and 90% reference intervals were determined. While there were some statistical differences between median concentrations among the different metapopulations, detected values were generally in good agreement with conce...
Article
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Hematology and plasma biochemistry parameters are useful in the assessment and management of threatened and endangered species. Although reference ranges are readily available for many mammalian species, reference ranges for snakes are lacking for most species. We determined hematology and plasma biochemistry reference ranges for giant garter snake...
Article
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Urban and agricultural land use may increase the risk of disease transmission among wildlife, domestic animals, and humans as we share ever-shrinking and fragmented habitat. American badgers (Taxidae taxus), a species of special concern in California, USA, live in proximity to urban development and often share habitat with livestock and small perid...
Article
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Two 2- and 3-month-old beef calves from 2 separate herds, locations, and times were found dead and were submitted to the veterinary diagnostic laboratory for diagnostic work-up. In both cases, no premonitory signs were seen by the owners. Histopathology revealed acute panlobular hepatic necrosis in both calves. In addition, calf A had copper and se...
Article
Full-text available
Amanitin is a toxic cyclopeptide present in several species of poisonous mushrooms. Amanitin toxicosis was diagnosed in 2 cats from separate premises. Both cats initially had lethargy and vomiting, and they rapidly developed depression and neurological signs over 24-48 hours. Marked elevation of alanine aminotransferase was the primary finding, wit...
Article
To describe the outcome of 3 cases of ivermectin toxicosis in dogs homozygous for the ABCB1–1Δ gene mutation treated with intravenous fat emulsion (IFE). One Australian Shepherd and 2 Miniature Australian Shepherds were treated for naturally occurring ivermectin toxicosis with IFE. All 3 dogs were homozygous for the ABCB1–1Δ gene mutation. Serum iv...
Article
To describe the clinical course, treatment, and outcome of a dog with propylene glycol intoxication. An adult castrated male Australian cattle dog presented to an emergency clinic for an acute onset of ataxia and disorientation after roaming a construction site unsupervised. He tested positive for ethylene glycol using a point-of-care test kit. Tre...
Article
A method combining QuEChERS extraction, ultra-high pressure liquid chromatography and full scan high resolution mass spectrometry was evaluated for its use in screening for chemical residues and contaminants in animal-related food matrices. The method was evaluated by analysis of multiple replicates of whole milk, muscle tissue, liver tissue and co...
Conference Paper
Full-text available
Sodium fluoroacetate (1080) is an organofluorine chemical toxic to mammals, insects and birds. In the US, 1080 is currently registered for use only in livestock protection collars as a predacide in States that have registrations and US EPA approved certification and training programs; it is not approved for use in California. The present work descr...
Article
Full-text available
Much of the Laurentian Great Lakes region is a mercury-sensitive landscape, in which atmospheric deposition and waterborne sources of mercury (Hg) have led to high concentrations of bioavailable methylmercury (MeHg) in predatory fish and piscivorous wildlife. Efforts since the early 1990s have established the common loon (Gavia immer) as the primar...
Article
There are many potentially hazardous commercial or industrial products used in or around ruminant environments. Although some products are highly toxic, their proper storage and use minimize their hazard to ruminants. Although most exposures to such materials occur via ingestion, inhalation or dermal exposures also are possible. The diagnosis of in...