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Viral neurologic diseases are common in cattle, although most non-suppurative meningoencephalitis (NSM) remains etiologically unknown. We compared the epidemiological, clinical, and pathological data among 79 cases of rabies, 12 cases of NSM of unknown etiology (NSM-UE), and 8 cases of herpetic meningoencephalitis previously diagnosed in cattle in Southern Brazil. Neurological clinical signs were similar among rabies and NSM-UE and different in cattle with herpetic meningoencephalitis. Only two herpetic meningoencephalitis cases had gross lesions in the central nervous system, characterized by malacia and hemorrhage. Histologically, all three groups had mild to severe multifocal infiltrates of lymphocytes, plasma cells, and macrophages/microglial cells in the Virchow-Robin space, neuropil, and leptomeninges, and gliosis. Other findings included malacia and eosinophilic intracytoplasmic inclusion in rabies, and malacia and intranuclear amphophilic inclusion in herpetic meningoencephalitis. By immunohistochemistry, the predominant inflammatory cells in all cases were T lymphocytes, followed by macrophages/microglial cells, B lymphocytes, and astrocytes. The T lymphocyte count showed statistically significant differences between the diseases. Our results revealed few differences between the groups. Although the etiological agent involved has not been identified in cases of NSM-UE, the characteristics observed in this study showed similarity with viral diseases., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Although tick infestation is a significant health problem in livestock, there are limited studies on the dermatopathological aspects of natural tick infestation in cattle. This study aimed to describe the gross and histologic aspects of cutaneous lesions caused by tick infestation in cattle. Thirteen cases were selected based on necropsy data from a 10-year retrospective study. Predispositions were observed in beef cattle ( P = .049) and the Angus breed ( P = .012), and lesions occurred mainly in the fall ( P = .007). Gross lesions included hypotrichosis (13/13; 100%), scales (12/13; 92%), alopecia (11/13; 85%), ulcers (7/13; 54%), crusts (7/13; 54%), and erosions (2/13; 15%). These gross lesions were mainly located in the thorax (12/13; 92%), head (11/13; 85%), abdomen (10/13; 77%), neck (9/13; 69%), limbs (9/13; 69%), and perineum (9/13; 69%). Histologically, all cases had ticks adhered to the epidermis with erosions (13/13; 100%), ulcers (11/13; 85%), orthokeratotic hyperkeratosis (13/13; 100%), irregular acanthosis (13/13; 100%), intraepidermal pustules (13/13; 100%), crusts (10/13; 77%), and ballooning degeneration (4/13; 31%). In the dermis, just below the tick insertion site, there was coagulation necrosis, fibrin deposition, and inflammatory infiltrate composed of mixed cells (neutrophils, lymphocytes, plasma cells, macrophages, and few eosinophils) (9/13; 69%), neutrophils (3/13; 23%), or eosinophils (1/13; 8%). This study reinforces the different patterns of cutaneous lesions caused by tick infestation in cattle, which should be considered as a potential cause of dermatitis in this species., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Primary pulmonary neoplasms in cattle are rare. There are few studies on the pathological findings of these neoplasms in this species. This study aimed to describe the histological and immunohistochemical findings of primary and metastatic pulmonary carcinomas in cattle. We conducted a retrospective study of 19 cases of epithelial neoplasms with pulmonary involvement. Histologically, most of the neoplasms were classified as primary pulmonary neoplasms, including different adenocarcinoma subtypes (4/19, 21%) and adenosquamous carcinomas (3/19, 16%), followed by squamous cell carcinoma (6/19, 32%), metastatic uterine adenocarcinoma (4/19, 21%), metastatic hepatocellular carcinoma (1/19, 5%), and metastatic cholangiocarcinoma (1/19, 5%). By immunohistochemistry, all neoplasms were positive for pancytokeratin, and 4/19 (21%) were positive for vimentin. Primary pulmonary neoplasms had immunoreactivity for thyroid transcription factor-1 (6/7), while only 2 of these cases were positive for napsin A. All cases with squamous differentiation (9/9) had immunoreactivity for cytokeratin (CK) 5/6, while only 7 of these cases were positive for p40. CK20, CK7, and CK8/18 showed varied immunoreactivity in the primary and metastatic pulmonary carcinomas but were important markers to confirm the diagnosis of primary mucinous adenocarcinoma and metastatic cholangiocarcinoma. HepPar-1 was only positive in the metastatic hepatocellular carcinoma. The limited number of cases of metastatic uterine adenocarcinomas in this study precluded identification of a specific immunophenotype for this tumor. Immunohistochemistry proved to be an important tool to confirm the proper classification of these neoplasms., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

This study aims to report a spontaneous and experimental intoxication in cattle by Melanthera latifolia (Asteraceae) for the first time, and to describe its epidemiological, clinical, and pathological findings. An outbreak of acute toxic hepatopathy in cattle occurred from December of 2021 to January of 2022 in a beef cattle farm from Rio Grande do Sul state, Southern Brazil, and resulted in 94 deaths from a herd of 430 animals. At necropsy, lesions consisted of enhanced lobular pattern of the liver, transmural gallbladder edema, and hemorrhages on the surface of multiple organs. The main microscopic lesion was marked hepatocellular necrosis in the centrilobular region associated with hemorrhage and infiltration of neutrophils. During the outbreak, multiple specimens of M. latifolia were noted in the paddocks where affected cattle were grazing and many showed signs of consumption. No other known acute hepatotoxic plants were found. Two 12-month-old steers were experimentally intoxicated with a single oral dose of the fresh plant (flowers, leaves, and less fibrous stalks). One bovine ingested a dose of 10 g/kg and was euthanized after 48 h, and the other ingested 15 g/kg and was euthanized 17 h later. Clinical signs, macroscopic, and microscopic lesions in both animals were similar to those observed in the spontaneous cases. Thus, this study demonstrates that M. latifolia was the cause of the outbreak of acute toxic hepatopathy with significant mortality in cattle. M. latifolia nor any plant of the genus Melantherahad ever been reported as toxic., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

We describe a case of penile tuberculosis in a bull. The prepuce was thickened, firm and pale with multifocal to coalescent caseous nodules, and the inguinal and mesenteric lymph nodes were moderately enlarged. Lesions in the prepuce, penis and lymph nodes were characterized by multifocal to coalescent areas of caseous necrosis and marked granulomatous inflammation. Acid-fast bacilli were seen within necrotic foci and Langhans giant cells. Mycobacteriumtuberculosis var. bovis was identified in inguinal lymph nodes by the polymerase chain reaction technique and by bacterial isolation. Although rare, tuberculosis should be considered in the differential diagnosis of granulomatous lesions in the genital tract of bulls., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this study, we described the morphological features and unusual presentations of hydatidosis, fasciolosis, and eosinophilic myositis caused by Sarcocystis species diagnosed at the slaughterhouse lines. Twenty-seven samples of atypical parasitic lesions from distinct cattle were evaluated, of which 12 corresponded to hydatidosis, 11 to fasciolosis, and 4 to eosinophilic sarcocystosis. Hydatid cysts were observed mainly in the heart, with all cases involving the left ventricle. Fasciolosis lesions involved mainly the lungs, and were characterized by a focal nodular elevated area involving the edges of the lobes. Intralesional trematodes were observed in three cases. Sarcocystosis lesions were observed in four cases, and lesions were primarily located in the skeletal and cardiac muscles. Grossly, they presented as focal or focally extensive streaks, patches, or numerous nodules that were greenish to mildly yellowish. Histologically, all the cases had intralesional ruptured cysts of Sarcocystis that were associated with severe eosinophilic myositis and myocarditis. Parasitic lesions in atypical locations and/or with aberrant responses should be promptly identified because it may mistakenly diagnosed as other potentially zoonotic diseases, such as cysticercosis and tuberculosis.