Journal of Veterinary Diagnostic Investigation最新文献

Enzootic nasal adenocarcinoma (ENA) is a contagious neoplasm of the ethmoid turbinate mucosa in sheep, caused by enzootic nasal tumor virus 1 (ENTV1; family Retroviridae, unclassified Betaretrovirus). We report an outbreak of ENTV1-associated ENA in a sheep flock in South Dakota, USA. Affected animals had dyspnea, unilateral nasal discharge, and progressive weight loss. Postmortem examination revealed unilateral nasal masses that were diagnosed histologically as invasive nasal adenocarcinoma. PCR amplification followed by Sanger sequencing of the gag and env gene regions confirmed the presence of ENTV1. Our proviral genome assembly via next-generation sequencing is only the second ENTV1 sequence submitted to GenBank from the United States. Our isolate clustered within the ENTV1 clade and was closely related to the reported U.S. and Canadian isolates, indicating a shared evolutionary lineage. To further investigate tumor biology, we established 3-dimensional organoids derived from the nasal adenocarcinoma, which maintained the histologic features of the primary tumor and tested positive for ENTV1. These organoids also had an invasive phenotype, demonstrating their potential utility as a novel in vitro model for studying ENA pathogenesis and evaluating therapeutic interventions.

Interstitial pneumonia and lymphocytic bronchiolitis with interstitial emphysema is an unusual reaction pattern in fetal and neonatal calves. These changes often are thought to suggest a chronic bacterial infection acquired in utero, and an associated placentitis is expected. Viral agents can also be implicated. Specific known pathogens that can induce a similar inflammatory response include Ureaplasma diversum, Mycoplasmopsis bovis, Brucella abortus, bovine viral diarrhea virus, and bovine parainfluenza virus 3. We describe a series of 15 cases of interstitial pneumonia and lymphocytic bronchiolitis with interstitial emphysema in fetal and early neonatal (up to 3-d-old) beef calves collected over 10 y in Alberta, Canada. Where reported, calves appeared small, weak, and occasionally were dyspneic. On autopsy, lungs appeared diffusely voluminous with interstitial emphysema, bulla formation, and rarely mediastinal emphysema and pneumothorax. A few calves had additional features of bacterial infection, such as pericarditis. Placenta was not received. Histologic lung findings in the affected calves included alveolar septa expanded by mononuclear cells, sparse neutrophils and macrophages within alveoli, variable lymphocytic and histiocytic peribronchiolar cuffing, prominent lymphoid aggregates surrounding bronchioles, occasional vascular necrosis, and subpleural and interlobular emphysema. PCR testing and immunohistochemistry for the previously noted pathogens were negative, and the cause of this unique condition, although presumably infectious, remains unknown.

Interstitial and bronchointerstitial pneumonias of undetermined etiology in young foals are relatively common in autopsy services with an equine focus. Unknown viruses, toxins, hyperthermia, surfactant or alveolar macrophage function deficiency, certain antibiotics, and aberrant responses to Rhodococcus equi or other bacteria have been proposed as causes. We performed a retrospective study of autopsies on foals with a diagnosis of interstitial or bronchointerstitial pneumonia with an unidentified etiology. Forty-one foals (median age: 3-mo-old) were included. Most were received in summer (n = 28) and spring (n = 10). The most frequently reported clinical signs were dyspnea and/or tachypnea (n = 28) and fever (n = 19). Antibiotic treatment was reported in 21 cases, and the most frequently used antibiotics were penicillin (n = 9) and gentamicin (n = 8). Grossly, most of the lungs were diffusely rubbery-to-firm (n = 35) and did not collapse (n = 22). Histologically, combinations of exudative (E; hyaline membranes), proliferative (P; type II pneumocyte hyperplasia), and fibrotic (F; fibroplasia) phases were common (E + P, n = 15; E + P + F, n = 13) in the interstitial component. Necrosis of the bronchiolar epithelium was rare (n = 4), concurrent suppurative bronchopneumonia was common (n = 22), and a few foals (n = 5) had pulmonary pyogranulomas. Pneumocystis spp. organisms were observed in 8 cases using Grocott-Gomori methenamine silver stain. Bacteria were recovered from the lungs in 22 cases, with R. equi (n = 7) and E. coli (n = 6) being the most common isolates. No unequivocal viral causes were identified during the regular diagnostic work-up and after using novel diagnostic approaches such as herpesvirus consensus PCR and viral metagenomics in a subset of the cases.

Highly pathogenic avian influenza (HPAI) A(H5N1) virus, clade 2.3.4.4b, genotype 3.13, was first confirmed in dairy cattle in March 2024 in a Texas dairy herd and has since spread to other states, likely via movement of subclinically affected cattle. On 2024 May 5, a backyard poultry farm in Idaho reported sick and dying chickens. This pasture-based farm included 1,100 chickens, 32 ducks, 18 alpacas, 13 yaks, 3 cats, 3 dogs, 1 llama, and 1 goat. Most animals had direct access to a pond filled by the stream bordering the property. Additional dairy premises in the same county had been confirmed with HPAI during the same timeframe. The poultry were depopulated on May 10, the same day the first alpaca abortion was observed. Overall, 4 abortions occurred among the alpacas. In one of the abortions, HPAI A(H5N1) virus was isolated from fetal tissues. Additional testing documented seroconversion in several alpacas and detection of HPAI A(H5N1) virus in milk from an alpaca with a cria. To our knowledge, HPAI A(H5N1) virus, clade 2.3.4.4b, has not been reported previously in alpacas.

An 18-mo-old Aberdeen Angus steer was unable to rise without assistance; and, when standing, the steer walked with flexed forelimbs. Due to the poor prognosis, it was euthanized and autopsied. Grossly, the cervical spinal cord was markedly enlarged at C5-C6 by a yellow, soft, well-demarcated nodule that affected ~70% of the parenchyma. Microscopically, the expansive, multinodular, unencapsulated neoplasm affected mostly the white matter and consisted of 2 distinct cell populations. Small, pleomorphic cells with scant cytoplasm predominated; nuclei were positive for oligodendrocyte transcription factor 2 (OLIG2) and cytoplasm was negative for glial fibrillary acidic protein, compatible with oligodendrocytes. A second population of large round cells with abundant cytoplasm had positive cytoplasmic staining for S100 protein and synaptophysin (SYN), compatible with mature neurons. We diagnosed a spinal cord ganglioglioma in this steer based on histologic features and OLIG2 and SYN immunolabelling.

Bovine botulism is a lethal disease caused by Clostridium botulinum neurotoxins (BoNT). In cattle, the most frequent form of this disease in several South American countries and elsewhere is caused by BoNT type D, which has been associated with phosphorus deficiency, leading to pica and osteophagy. An outbreak of botulism occurred in a fully vaccinated 600-steer herd of cattle. The cattle were grazing on native pasture in a paddock in which several decomposing animal carcasses were found; the animals had performed osteophagy. The first 2 deaths were recorded in November 2016, and the number of fatalities increased to 84 through April of 2017. All the cases had similar clinical signs, which were consistent with botulism. The affected animals had hypophosphatemia and rear-leg weakness, ataxia, progressive flaccid paralysis of several muscles, recumbency, and death. Autopsies were performed on 3 animals; gross findings included hydropericardium, congestion of the cerebellum, and bone fragments and stones in the rumen and reticulum. Botulism was confirmed in the 3 animals by detecting BoNT type D by mouse bioassay. A large outbreak of botulism in vaccinated cattle associated with phosphorus deficiency and osteophagy has not been reported previously in Argentina, to our knowledge. Our case demonstrates that, even in vaccinated herds, rigorous carcass management is essential to reduce the risk of environmental contamination and to prevent fatal botulism outbreaks, especially in phosphorus-deficient areas. Improved reporting of similar cases is vital to refine prevention strategies and reduce the economic impact of the disease.

A 12-y-old, 654-kg, Santa Gertrudis cow was presented to the veterinary hospital with acute abdominal distension and a large mass on the left side of the neck. Upon presentation, the patient was bright and alert, with a corticosteroid stress leukogram, hyperglycemia, and mildly increased blood urea nitrogen and creatine kinase activity. A firm, 15 x 10-cm, non-painful left-sided proximal cervical mass and ruminal tympany were appreciable. A fine-needle aspirate of the mass was performed, and cytological findings were consistent with a neuroendocrine neoplasm. Given the large size of the mass and poor prognosis, the owner elected euthanasia. At autopsy, a firm 15 x 12 x 8-cm mass effaced the left lobe of the thyroid gland. Histological examination confirmed a thyroid follicular-compact carcinoma with metastasis to the deep cervical lymph nodes. Neoplastic cells showed immunolabeling for thyroglobulin, 10% of the neoplastic cells exhibited immunolabeling for thyroid transcription factor 1 (TTF1), and none of the neoplastic cells showed immunolabeling for synaptophysin. Although the cytological features were typical of neuroendocrine neoplasia, immunohistochemistry excluded a thyroid medullary neoplasm. Unlike C-cell and ultimobranchial neoplasms, thyroid follicular carcinomas are rarely reported in cattle. The thyroid follicular-compact carcinoma described herein was associated with acute tympany.

Disorders of the intestinal vasculature in animals include arteriovenous malformations, telangiectasia (ectasia, angiodysplasia), hamartomas, and neoplasia (hemangiomas, hemangiosarcomas). Two, 2-d-old, female Nigerian dwarf goat kids born to different dams on the same farm had severe and progressive abdominal distension and were euthanized. The autopsies revealed segmental circumferential dark-red areas that caused focal constriction of the mid-jejunum. The constriction led to obstruction of the intestinal lumen and proximal dilation of the jejunum and duodenum in both cases. Clostridium perfringens type D enterotoxemia was also diagnosed in one case. Histologic examination in both cases revealed a focal, moderately well-demarcated proliferation of medium- to small-caliber vascular channels with luminal erythrocytes, lined by morphologically normal endothelial cells, that expanded the tunica muscularis and serosa of the jejunum and compressed the mucosa and the lumen. The congenital nature of these lesions favors a diagnosis of vascular hamartomas; however, the histologic findings were indistinguishable from those of intestinal hemangiomas reported in young humans, horses, a pig, and a dog. The age of the affected goats, the location of the lesions in the same segment of the jejunum, and the presence of only one buck on the farm were suggestive of a genetic origin for these lesions. It is speculated that intestinal obstruction was the predisposing factor for C. perfringens type D enterotoxemia in one of the goats.

Bovine interstitial and bronchointerstitial pneumonias are common and important diseases of cattle, caused by several infectious and non-infectious causes. Here, we review the roles of bovine respiratory syncytial virus, bovine parainfluenza virus 3, bovine alphaherpesvirus 1, bovine viral diarrhea virus, bovine coronavirus, influenza D virus, malignant catarrhal fever virus, and bovine adenovirus in interstitial or bronchointerstitial pneumonia. We describe the possible causes, pathogenesis, and diagnosis of bacterial septicemias that result in interstitial pneumonia, including E. coli, Salmonella, and Pasteurella multocida septicemias. We also review the parasitic causes of interstitial or bronchointerstitial pneumonia, primarily Dictyocaulus viviparus. Reaching a definitive postmortem etiologic diagnosis of interstitial or bronchointerstitial pneumonia can be challenging because infectious and non-infectious causes may look very similar grossly. Moreover, other conditions-that do not cause interstitial or bronchointerstitial pneumonia but rather pulmonary edema, congestion, and hemorrhage-can resemble interstitial pneumonia grossly. To guide the process of diagnosing interstitial and bronchointerstitial pneumonia, we offer an algorithm that integrates findings obtained from postmortem examination and ancillary laboratory testing. Our algorithm includes details on the gross characteristics of the lungs with interstitial or bronchointerstitial pneumonia, and we discuss other disease processes that may grossly resemble interstitial pneumonia. We highlight the key histologic features for differentiating specific causes and describe the most common ancillary laboratory tests to detect infectious and non-infectious causes.

Interstitial lung disease refers to lesions involving primarily any of the 3 layers of the alveolar wall (endothelium, basement membrane, alveolar epithelium) and the contiguous bronchiolar interstitium. Toxic agents are a significant cause of interstitial lung disease in cattle, primarily interstitial pneumonia. We review the most important substances associated with interstitial lung disease in cattle, addressing their epidemiology, clinical signs, pathogenesis, and lesions. These include the amino acid L-tryptophan (ingested with lush green forages), the toxin 4-ipomeanol (produced by moldy sweet potatoes infected with Fusarium solani), toxic plants such as Perilla frutescens and Zieria arborescens, and nitrogen dioxide (NO₂) released from recently filled silos. The diagnosis of these disorders may be challenging because the clinical signs and lung lesions often overlap regardless of the cause. Thus, a definitive diagnosis typically relies on a thorough epidemiologic investigation and confirmation of exposure of affected cattle to the potential cause. Laboratory confirmation of specific toxins is often limited because many are rapidly metabolized and unstable after ingestion, making their detection difficult.