Four alpine goats developed diarrhea soon after the owner placed plant clippings believed to be yellow oleander (Thevetia peruviana) into their pen on a suburban property near Palm Desert, CA, USA. A 1-y-old female goat died suddenly ~1 h after eating the plant clippings and was submitted to the San Bernardino Branch of the California Animal Health and Food Safety Laboratory System for postmortem examination. The main autopsy and histopathologic findings were myocardial hemorrhage and necrosis, consistent with cardiac glycoside intoxication. Rumen contents were analyzed by LC-MS/MS; peruvoside, a cardiac glycoside, was detected, but oleandrin, the cardiac glycoside of common oleander (Nerium oleander), was not. An LC-high-resolution MS (LC-HRMS) analysis revealed the presence of peruvoside and neriifolin in the rumen contents and in a tested plant fragment, indicating that the plant was a member of the Thevetia genus. A clipping from the plant fed to the goats and submitted by the owner was identified as yellow oleander, Thevetia peruviana (also known as Cascabela thevetia).

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 the neonicotinoids dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, and imidacloprid. We used fortified chick carcass samples to validate method accuracy (80-125% recoveries), precision (<20% relative standard deviation), and sensitivity (≤1.2 ppb) for these targeted analytes. This method also uses full-scan, high-resolution MS to screen for the presence of a wide variety of other xenobiotics in bird carcasses. The utility of our screening process was demonstrated by the detection of carbaryl in some samples. This sensitive LC-HRMS analytical method for insecticide detection in a matrix of homogenized carcass is ideal for evaluating small birds for insecticide exposure. This novel whole-carcass method may allow for research studies of small-bodied, free-ranging avian species, and could provide insight regarding their exposure to multiple classes of environmental contaminants.

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 case, and autolysis can often preclude the identification of subtle changes in the cardiomyocytes. Several studies of experimental oleander poisoning have noted the presence of renal lesions in multiple mammalian species, and case studies of accidental exposure have found similar, although more variably severe, renal abnormalities. Kidney pathology in horses with oleander poisoning has been only briefly mentioned. In this study, we reviewed 21 cases of spontaneous oleander poisoning in horses, evaluated the kidneys microscopically, and compared the renal microscopic lesions with those detected in 10 horses that died or were euthanized due to other causes to assess if histological renal changes could serve as an additional diagnostic marker for oleander poisoning in horses. We found that microscopic renal lesions, principally mild to moderate tubular changes such as hyaline cast formation, neutrophilic casts, epithelial attenuation and necrosis, as well as mineralization and congestion, occur in horses with oleander poisoning. Most of these changes match the descriptions of lesions previously noted in other species, although with less frequency and severity. Similar lesions were found in horses that died spontaneously due to different causes or were euthanized. We concluded that microscopic renal lesions may be detected in horses with oleander poisoning but they cannot be used as a diagnostic marker that allows differentiation from other disease processes or causes of death.

Monofluoroacetate is a highly lethal toxin that causes death by inhibiting cellular adenosine triphosphate (ATP) production. The heart and brain are the primary target organs. Acute death is attributed to cardiac fibrillation and/or convulsions. Although it occurs naturally in some plants, a major source of animal intoxication is access to sodium monofluoroacetate (NaMFA) pesticide, which continues to be a concern in the USA and around the world despite restricted use in some countries including the USA. There are also concerns about misuse of this pesticide for malicious poisoning. Currently, a tissue-based diagnostic method for NaMFA intoxication in animals is lacking. There is a critical need by the veterinary diagnostic community for a simple, sensitive and reliable tissue-based diagnostic test to confirm NaMFA poisoning in animals. We have developed and extensively evaluated a sensitive novel liquid chromatography combined with tandem mass spectrometry method suitable for this purpose. The limits of detection and limits of quantitation are 1.7 and 5.0 ng/g, respectively. The accuracy and precision met or exceeded expectations. The method performance was verified using the incurred kidney obtained from animal diagnostic cases. This novel kidney-based method is now available for clinical use and can help with diagnostic purposes, including detecting potential issues related to animal foods.

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-established in most species. We chose diphacinone for our study because, at the time, it was the publicly available AR most commonly detected in samples analyzed at the University of Kentucky Veterinary Diagnostic Laboratory. We determined an approximate minimum toxic dosage (MTD) of oral diphacinone in 3 horses and measured corresponding serum, blood, and liver diphacinone concentrations. Diphacinone was administered orally to healthy horses. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and serum and blood diphacinone concentrations were measured daily. At the study endpoint, the horses were euthanized, and diphacinone concentration was measured in each liver lobe. The horse that received 0.2 mg/kg diphacinone developed prolonged (>1.5× baseline) PT and aPTT; the horse that received 0.1 mg/kg did not. This suggests an approximate oral MTD in horses of 0.2 mg/kg diphacinone. Median liver diphacinone concentration at this dosage was 1,780 (range: 1,590-2,000) ppb wet weight. Marginal (model-adjusted) mean diphacinone concentrations of liver lobes were not significantly different from one another (p = NS). Diphacinone was present in similar concentrations in both serum and blood at each time after administration, indicating that both matrices are suitable for detection of diphacinone exposure in horses.

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 Labrador Retriever dog developed acute onset of vomiting, diarrhea, tremors, seizures, and somnolence. The dog was treated at a veterinary clinic and was briefly stabilized, but died during transport to an emergency clinic. On postmortem examination at the University of Kentucky Veterinary Diagnostic Laboratory, the dog's stomach was full of mushrooms covered with activated charcoal. Mushrooms were damaged, fragmented, and discolored, precluding accurate visual identification. Mushroom pieces were sent to the Department of Plant Pathology at the University of California-Davis for PCR identification; the neurotoxic mushroom Amanita muscaria was identified. A qualitative liquid chromatography-mass spectrometry (LC-MS) method was developed to detect ibotenic acid and muscimol, the toxic compounds present in A. muscaria. Mushrooms, stomach contents, and urine were analyzed by LC-MS; ibotenic acid and muscimol were detected in all samples. Because identification of ingested mushrooms is sometimes necessary to confirm mushroom poisoning, PCR can identify ingested mushrooms when visual identification is unreliable.

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 methods (predominantly chromatographic, as well as antibody-based) of detecting amatoxins are time-consuming and require expensive equipment. In this work, we demonstrate the utility of the lateral flow immunoassay (LFIA) for the rapid detection of amatoxins in urine samples. The LFIA detects as little as 10 ng/mL of α-amanitin (α-AMA) or γ-AMA, and 100 ng/mL of β-AMA in urine matrices. To demonstrate application of this LFIA for urine analysis, this study examined fortified human urine samples and urine collected from exposed dogs. Urine is sampled directly without the need for any pretreatment, detection from urine is completed in 10 min, and the results are read by eye, without the need for specialized equipment. Analysis of both fortified human urine samples and urine samples collected from intoxicated dogs using the LFIA correlated well with liquid chromatography-mass spectrometry (LC-MS) methods.