Journal of Veterinary Diagnostic Investigation最新文献

Four beef cows grazing in a mountainous grassland area had acute onset of drooling, frothy oral discharge, hyperemic mucous membranes, diarrhea, anorexia, dyspnea, and recumbency. Two cows died within 7-8 h of the onset of signs; the remaining 2 cows succumbed 24 h later. Scattered, 3-6-mm, gray-white solids were found on the grassland, suggesting potential contamination. Postmortem examination found abdominal distension, nasal hemorrhage, and distended rumens containing undigested forage. Hemorrhagic lesions were observed in the reticulum, omasum, abomasum, jejunum, and ileum. Yellow, 2-3-mm granular solids were identified in the rumen contents. Toxicologic analysis using scanning electron microscope-energy dispersive X-ray spectroscopy and high-performance liquid chromatography-inductively coupled plasma-mass spectrometry detected high concentrations of trivalent arsenic [As(III), up to 1,070 mg/kg] and pentavalent arsenic [As(V), up to 1,180 mg/kg] in the rumen contents and grassland solids. Elemental analysis revealed magnesium, aluminum, calcium, arsenic (As), silicon, carbon, and oxygen in the residues, suggesting industrial byproducts from As removal processes.

The lung is composed of conducting airways, a gas-exchange region, and a dual circulatory system. Any of these components may be altered in respiratory disease, and complicated cases can be a diagnostic challenge. For veterinary pathologists, a solid foundation in normal anatomy is essential for recognition of patterns of disease. Additionally, the structure of the lungs informs the function; therefore, knowledge of how normal structures are disrupted provides insight into the pathogenesis of lung diseases. We detail the organizational structure, microanatomy, and cell types of the lungs of several species of veterinary importance: cattle, horses, pigs, sheep, goats, dogs, cats, mice, and rats. Animals with a thick pleura and interlobular septa have associated separation of secondary lobules, whereas those with a thin pleura lack interlobular septa and have indiscernible secondary lobules. The transition between terminal bronchioles and gas-exchange regions, presence of respiratory bronchioles, and cellular composition of the bronchioles are highly variable among species. Other species variations include bronchial structure and glands, collateral ventilation, and patterns of blood supply to the conducting airways, gas-exchange regions, and pleura. Examples of histopathologic correlates offer relevance of pulmonary microanatomy to the veterinary pathologist.

Diagnosis of lymphoid hyperplasia and neoplasia due to lymphoproliferative disease virus (LPDV; Retroviridae, Alpharetrovirus) infection in turkeys is challenging due to histopathologic similarities with nonspecific inflammation and cellular responses to other retroviral infections. Localization of LPDV RNA or protein antigens within affected tissues, which has previously not been shown, would allow for more definitive diagnoses. We evaluated formalin-fixed paraffin-embedded tissues from 32 turkeys, including 15 naturally infected wild turkeys, 11 experimentally infected domestic turkeys, and 6 uninfected wild and domestic turkeys, using RNAscope in situ hybridization (ISH) and immunohistochemistry (IHC). ISH probes targeted a segment of the gag gene, and IHC antibodies were designed to recognize the capsid protein. Tissues from 4 infected turkeys were subjected to concurrent ISH and IHC labeling. All infected turkeys had ISH and IHC cytoplasmic and/or nuclear labeling of lymphocytes in at least one tissue, including within lymphoid tumors. ISH labeling was widely scattered in lymphocytes, whereas IHC labeling distribution was more limited. Spleen consistently exhibited the strongest and most widespread ISH and IHC labeling in both wild and domestic turkeys. Labeled lymphocytes typically were localized to splenic germinal centers and around periarteriolar lymphoid sheaths in the thymic cortex. Lymphocytes occasionally had simultaneous ISH and IHC labeling in selected cases. No uninfected turkeys had ISH or IHC labeling. Our 2 methods of LPDV detection in formalin-fixed paraffin-embedded tissues can aid in distinguishing lymphoid proliferation due to LPDV from other etiologies and further characterize pathogenesis.

Canine astrovirus (mamastrovirus 5 [MAstV5], formerly CaAstV; family Astroviridae, taxon species Mamastrovirus canis) and canine kobuvirus (aichivirus A2 [AiV-A2], formerly CaKoV; Picornaviridae, Kobuvirus aichi) are emerging enteric viruses increasingly detected in both diarrheic and subclinical dogs. Although primarily associated with gastrointestinal illness, recent evidence suggests a potential for systemic dissemination, which remains insufficiently explored. To improve detection, we developed and validated a duplex quantitative real-time PCR (dqPCR) assay for simultaneous identification of MAstV5 and AiV-A2. Primers and TaqMan probes were designed based on conserved regions of the MAstV5 ORF1b and AiV-A2 3D polymerase genes. Assay optimization included primer-probe concentration titration and thermal gradient analysis. Analytical performance was assessed using synthetic plasmid standards and RNA from non-target viruses, including canine parvovirus (CPV), canine morbillivirus (CDV), and canine enteric coronavirus (CCoV). Our dqPCR assay had high linearity (R² > 0.99) and sensitivity, with limits of detection of 10 copies/μL for MAstV5 and 100 copies/μL for AiV-A2. No cross-reactivity or interference was observed in coinfection simulations across various target ratios. Intra- and inter-assay CV values were <2.2%, indicating excellent reproducibility. Validation using 50 clinical rectal swabs and tissue samples from 25 autopsied dogs revealed 1 additional AiV-A2-positive case undetected by RT-PCR but confirmed by sequencing. Importantly, viral RNA was also found in extraintestinal tissues-spleen, liver, trachea, and mesenteric lymph nodes-suggesting systemic distribution in naturally infected dogs. Our dqPCR assay provides a sensitive, specific, and efficient tool for the detection of MAstV5 and AiV-A2, supporting both clinical testing and epidemiologic studies.

Abnormal sudden mortality of 2 goats and 10 sheep occurred in a 27-head flock in Verona province (northeastern Italy). In the 24 h before death, animals had acute ataxia, lateral recumbency, spastic convulsions, and dyspnea. Autopsy of 4 animals was performed at the Verona Veterinary Diagnostic Laboratory of the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe; Italy). In the forestomachs, abundant fibrous material and numerous seeds were observed. Bacteriologic, parasitologic, and histologic investigations were carried out; samples of rumen contents and liver were analyzed by direct analysis real-time high-resolution mass spectrometry (DART-HRMS), which allows rapid screening of toxic substances. The combination of DART-HRMS and liquid chromatography high-resolution tandem MS (LC-HRMS/MS) confirmed the acute intoxication and provided insights into the clinicopathologic findings due to the ingestion of Chimonanthus praecox (wintersweet), a plant species that contains alkaloids including calycanthine, which is known to be toxic in several domestic species, including small ruminants.

Urinary cystatin B (uCysB) is a biomarker of kidney injury in dogs and cats. A high-throughput agglutination immunoassay (Idexx Laboratories) was developed for widespread commercial availability of uCysB testing in a reference laboratory setting. We evaluated immunoassay performance and included analyses of precision, accuracy, linearity, interference, analytical specificity, lot-to-lot variation, and stability. CVs from precision studies on the range of 50-500 ng/mL were 0.38-2.53% (canine) and 0.44-3.5% (feline) for within-run precision, and 1.49-5.09% (canine) and 0.65-5.05% (feline) for between-run precision. Accuracy was measured by recovery percentage and was 89-101% (canine) and 91-112% (feline). Amoxicillin, ciprofloxacin, low concentrations of doxycycline, bilirubin, glucose, ketones, RBCs, hemoglobin, cloudiness, lipids, protein, and pH did not affect results. Urinary cystatin A did not cross-react with the uCysB immunoassay. Results of lot-to-lot linear regressions were 0.90-1.07 (slopes) and 0.97-1.00 (coefficient of determination). One or more freeze-thaw cycles and storage at 30°C impacted the immunoassay stability of canine samples but not feline samples under the same conditions. Our results validate this novel agglutination immunoassay for accurate and precise measurement of uCysB in canine and feline urine samples. For optimal immunoassay performance, samples should be kept at 4°C for a maximum of 1 wk. Our uCysB immunoassay is a useful and practical tool to be used in assessing kidney injury in canine and feline patients in the clinical setting.

Six 11-wk-old, commercial, Broad-Breasted White, meat turkeys were submitted to the Turlock branch of the California Animal Health & Food Safety (CAHFS) laboratory for autopsy and diagnostic work-up. Clinical signs in the turkeys of the affected flock included depression, ruffled feathers, swollen periorbital areas, rales, and sneezing. A mortality of 50% (5,000 of 10,000) was reported at the time of case submission. Flock morbidity was 100% by 12 wk of age, and mortality eventually exceeded 90%. Fibrinous pleuropneumonia, airsacculitis, increased luminal mucoid exudate in the nasal cavities and tracheas, mottled and enlarged spleens, and hepatomegaly were the most remarkable gross findings. Microscopically, fibrinoheterophilic pneumonia and epicarditis with intralesional bacterial colonies, and necrotizing hepatitis and splenitis, were noted. Mycoplasmoides (Mycoplasma) gallisepticum (MG) was detected in tracheal and sinus pools by quantitative real-time PCR. Multilocus sequence analysis of the mgc2 gene and IGSR segment of MG differentiated our strain from MG vaccine strains, but were similar to MG isolates detected previously in other commercial turkey operations in California. Pasteurella multocida was isolated from air sacs, lungs, tracheas, hearts, and livers, and classified as profile HhaI 0001, strain X-73, by restriction enzyme analysis DNA fingerprinting. Coinfection with P. multocida and MG in a susceptible flock resulted in rapid elevation of mortality and significant economic losses in this commercial meat turkey operation.

An adult male western grey kangaroo (Macropus fuliginosus) developed lameness, a stiff gait, and weight loss, and deteriorated despite medical treatment. Postmortem examination revealed a primary gastric squamous cell carcinoma (SCC) with associated cardiac, pulmonary, diaphragmatic, hepatic, and vertebral metastases with lytic bone lesions. Before histologic examination, the macroscopic appearance of the liver lesions had raised concerns about mycobacteriosis. Metastatic gastric SCC has not been reported previously in a western grey kangaroo, to our knowledge.