Brazilian Journal of Veterinary Pathology
The purpose of the BJVP, a peer-reviewed journal, is to publish original full papers, short communications, case reports, letters, reviews (by invited experts) and abstracts of scientific meetings. The preferable subjects is natural and experimental pathology. All the articles are submitted to scientific reviewers.
Canine large t-cell intravascular lymphoma – report of two cases
Intravascular lymphoma is rare in all species and is characterized by the intravascular proliferation of neoplastic lymphocytes, with the central nervous system being the most affected site. The aim was to report two cases of dogs diagnosed with large T-cell intravascular lymphoma. Both dogs showed neurological signs, including ataxia, seizures, and difficulty walking. Macroscopically, malacia in the brain were noted. Microscopically, there was a predominance of large neoplastic lymphocytes within the vasculature, with CD3 positive and negative to CD20, CD79a, PAX-5 immunohistochemical staining, confirming large T-cell intravascular lymphoma. The complexity of this neoplasm highlights the importance of interdisciplinary collaboration among veterinarians for differential diagnosis of central nervous system diseases.
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Toxoplasma encephilitis in a Collared Peccary (Dicotyles tajacu): clinical and pathological findings
Toxoplasmosis is a widespread zoonosis affecting numerous mammalian species. Wild suoids have been confirmed as susceptible hosts of Toxoplasma spp., and their meat is frequently consumed by hunters, their families, and domestic dogs, posing a growing foodborne risk in South America. We conducted a pathological study on a young captive Collared Peccary that showed neurological signs. Severe brain lesions were observed, including parenchymal necrosis with demyelination, gliosis, meningitis, and perivascular cuffing. Toxoplasma cysts containing tachyzoites, as well as free tachyzoites, were identified within these lesions. Additionally, focal necrosis with inflammatory infiltration was noted in the liver and heart, along with marked pulmonary edema. Immunohistochemistry for canine distemper virus in the brain was negative. To the best of our knowledge, this is the first report detailing the pathological findings of T. gondii infection in a wild suoid (Dicotyles tajacu).
Benign sebaceous gland tumor in a giant otter (Pteronura brasiliensis)
The giant otter (Pteronura brasiliensis) is the largest species in the Mustelidae family currently found on the Amazon, Cerrado, and Pantanal biomes, characterized by its semi-aquatic lifestyle. Globally classified as endangered, the species faces multiple anthropogenic threats, including illegal hunting, habitat destruction, human-wildlife conflicts, hydroelectric dam construction, pollution, and increased tourism activities that disturb its natural behavior and environment. This case report describes a sebaceous gland tumor in a giant otter housed in a zoological park in São Paulo state, Brazil. The animal exhibited discomfort and difficulty eating due to a neoformation in the labial commissure. Following a veterinary examination, the mass was surgically removed, and the otter recovered successfully, returning to its enclosure without complications. Histopathological analysis confirmed a benign sebaceous gland tumor, representing the first documented case in this species under human care. Further research on neoplasms in wild animals is essential to understanding cancer development, prevalence, and implications for conservation and veterinary medicine.
Primary and metastatic alveolar rhabdomyosarcoma: clinical case reports in canines from the Peruvian Amazon
This report presents four cases of alveolar rhabdomyosarcoma in canines, affecting the striated muscular tissues of the rostral skin, mandible, uterus, and multiple metastases. These cases were treated at veterinary clinics across the San Martín region (provinces of San Martín, Moyobamba, and Tocache), Peru, from a total of 118 neoplastic cases diagnosed histopathologically at the Animal Histopathology Laboratory of the Professional School of Veterinary Medicine, National University of San Martín, between 2020 and 2024. Diagnosing alveolar rhabdomyosarcoma requires a combination of histopathological analysis, immunohistochemical markers, and molecular techniques to distinguish it from other neoplastic variants. These cases highlight the importance of histopathological analysis, appropriate selection of chemotherapy or surgical resection, owner compliance, and the limitations of empirical therapies which, in the absence of a diagnostic foundation, often lead to recurrence and treatment failure in tumor management. In recent years, cytological and histopathological diagnosis has become a key resource in the San Martín region, contributing significantly to therapeutic decision-making and the prognostic evaluation of various types of canine neoplasms.
First report of gastroschisis in black-eared opossum (Didelphis aurita)
Black-eared opossums (Didelphis aurita) are neotropical marsupials least concern with extinction in Brazil. Pathologies involving this species are rarely described, and gastroschisis has never been reported before. This study aims to report a case of gastroschisis in a black-eared opossum newborn and describe the main characteristics observed. A newborn black-eared opossum in the developmental stage in marsupial pouch was received lifeless by Núcleo de Estudos e Pesquisas em Animais Selvagens (NEPAS) of Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF). The animal was examined externally, and herniated intestinal loops were observed without the presence of the peritoneum covering them, indicating gastroschisis. This report aims to contribute to the literature on small marsupial medicine by describing the occurrence of this malformation in an individual of D. aurita.
Angiostrongylus vasorum infection in a fox
A juvenile, gray fox arrived at the zoo with dehydration, depression and poor body condition. He died the day after arrival.
A 6.5-year-old spayed female domestic toy rabbit (Oryctolagus cuniculus) presented with a history of apathy, weight loss for approximately 2 weeks and paralysis of both hind limbs. Due to the worsening of its condition and poor prognosis, the rabbit was euthanized.
Bursal cryptosporidiosis in a kelp gull (Larus dominicanus)
A juvenile kelp gull (Larus dominicanus) was found dead.
Necro-hemorrhagic enteritis and necrotizing hepatitis in green anaconda (Eunectes marinus)
An adult, male, green anaconda (Eunectes marinus) from “Universidade Federal de Mato Grosso” (UFMT) Zoo’s collection showed apathy, anorexia and bloody feces. This snake died during clinical evaluation and was necropsied.
Fatty liver hemorrhagic syndrome in a hen
Diffusely pale yellow, soft, friable liver with focal rupture of the right lobe and regionally extensive intrahepatic and coelomic hemorrhage
Nodular typhlitis from Heterakis isolonche
A captive, 4-year-old, 1 kg, female, Bornean crested fireback pheasant (Lophura ignita) with no previous medical history was presented for necropsy.
Pulmonary thromboembolism associated with caudal vena caval thrombosis in a heifer
A 2-year-old heifer from a herd of approximately 300 Angus crossbred heifers kept at range was evaluated because of a 3-day history of hemoptysis (Fig. 1). The cow stopped eating and spent long periods standing in a pond away from the herd. Anti-inflammatory and antibiotic treatment was initiated with no avail. The heifer was euthanized and autopsied on the fourth day after the onset of clinical signs.
Congenital vascular hamartoma in the spinal cord of a neonatal foal
A three-day-old Arabian filly with a history of not being able to stand unassisted after birth and lack of control over the right front and right hind limbs. The filly had inadequate proprioceptive responses, with absent pain/withdraw answer, and failed to respond to medical therapy. Due to the poor prognosis, euthanasia was elected, and a full necropsy was performed.
An adult female mixed breed dog was found in a local street market and taken to an animal rescue center. A hemogram on the day of arrival revealed anemia, lymphopenia, as well as thrombocytosis and neutrophilia. The patient received prophylactic treatment with praziquantel, febendazole, toltrazuril, and doxycycline, but died 6 days after arrival.
Fatal infection by Acinetobacter baumannii in Ramphastos toco (Muller, 1776)
Acinetobater baumannii is a critically important bacterial pathogen due to its multidrug resistance and association with severe clinical conditions, including septicemia. Its presence in animal hosts and environmental reservoirs underscores the importance of a One Health approach. We describe a fatal case of pneumonia, pericarditis, and aerosaculitis in a juvenile Ramphastos toco infected with A. baumannii, in Brazil. Postmortem examination revealed multifocal necrotizing lesions in the lungs and air sacs, with Gram-negative coccobacilli confirmed as A. baumannii via MALDI-TOF mass spectrometry. This report highlights the emerging threat of A. baumannii in wildlife populations and emphasizes the need for enhanced surveillance under a One Health framework.
Natália Coelho Couto de Azevedo Fernandes
Metastatic ovarian carcinoma in white-tailed deer (Odocoileus virginianus) from a conservation center in Medellín-Colombia
Wildlife animals in human care can develop pathological processes that rarely occur in their natural habitats, including neoplastic disorders. This report presents the post-mortem pathological findings of a white-tailed deer (Odocoileus virginianus) from a conservation center in Medellín, Colombia. O. virginianus had lung metastases originating from a primary papillary ovarian carcinoma. The post-mortem examination revealed macroscopic and microscopic involvement of multiple organs, including the ovaries, uterus, lungs, kidneys, liver, and spleen. Immunohistochemical analysis showed positive staining for pancytokeratin in neoplastic epithelial cells. This case underscores the importance of recognizing and understanding the multi-causal pathological processes contributing to the death of a wild animal in captivity.
Ebstein’s anomaly is a rare congenital cardiac abnormality characterized by an abnormal positioning of the cusps of the tricuspid atrioventricular valve. This study aimed to report the clinical and pathological aspects of the condition in an adult medium-sized mixed-breed dog, treated at a veterinary hospital in Brazil, through clinical evaluation, echocardiography, and post-mortem examination. This case highlights the importance of imaging exams for accurate diagnosis and the formulation of therapeutic strategies aimed at patient survival. To our knowledge, this is the first report of this congenital cardiac anomaly in a medium-sized mixed-breed dog.
Unusual mediastinal abscess to Pseudomonas aeruginosa in a cat in southern Brazil
A two-year-old male Siamese cat was submitted for necropsy. The animal had been anorexic, exhibited aggressive behavior, and had collided with objects around the house. Radiographic evaluation revealed an opaque abscess in the thoracic mediastinal region, and the cat died two days later. At necropsy, a slightly irregular abscess was found in the mediastinal region, varying from white to yellow, measuring 6 x 4 cm. The cut section contains yellow, irregular, and poorly defined areas interspersed with discrete red areas of firm consistency, along with hard areas. Histologically, the mediastinal abscess showed proliferation of poorly collagenized fibrous connective tissue, intense angiogenesis, and a marked infiltration of macrophages and epithelioid macrophages surrounding extensive areas of liquefactive necrosis with cellular debris, as well as abundant viable and degenerated neutrophils and areas of mineralized bone matrix formation. Aseptically collected fragments of the mediastinal abscess were submitted for bacterial culture, which isolated Pseudomonas aeruginosa. The anatomopathological and microbiological findings confirmed a diagnosis of mediastinal abscess due to Pseudomonas aeruginosa in a cat. We highlight the importance of both pathological and microbiological evaluation in such cases, expanding the differential diagnoses of mediastinal masses in cats.
Rhinosporidium seeberi infection in a male mule in the State of Tocantins (Brazil)
Rhinosporidiosis is a chronic disease caused by Rhinosporidium seeberi, which can infect several host species, including domestic animals and humans. The taxonomy of R. seeberi is still controversial, but scientific evidence supports the classification of this organism as a Mesomycetozoan. Considering the absence of previously reported cases of rhinosporidiosis in the Northern Region of Brazil, the goal of this report was to describe the clinical and pathological findings of a case of R. seeberi infection in a male mule in Araguaína (Tocantins State, Brazil). An 8-year-old male mule presented respiratory difficulties due to a polypoid exophytic lesion that partially obstructed the nasal cavity. The lesion was surgically excised and submitted for microscopic analysis. Microscopically, there was multifocal erosion, epithelial hyperplasia, diffuse inflammatory infiltrate, composed of many histiocytes and plasma cells, and fewer neutrophils and lymphocytes, with numerous intralesional organisms with diameters ranging from 10 to 400 μm compatible with sporangia exhibiting numerous nuclei and endoconidia compatible with R. seeberi.
Rodolfo Olinto Rotoli Garcia de Oliveira
Ovarian granulosa cell tumor in bovine fetus
Ovarian granulosa cell tumor (GCT) is a common type of sex cord neoplasm in cattle. This paper reports a rare case of GCT identified in a bovine abortion. A necropsy was performed on an 8-month-old bovine fetus, revealing an enlarged right ovary measuring 5.5 cm. The cut surface displayed reddish cystic areas with mucinous content, interspersed with whitish to blackish regions. The histopathological evaluation identified a benign epithelial neoplastic proliferation with an acinar arrangement supported by fibrocollagenous stroma. Immunohistochemistry was performed using antibodies against cytokeratin AE1/AE3, vimentin, protein S-100, chromogranin A, inhibin, and somatostatin. The tumor stained positive for cytokeratin AE1/AE3 and vimentin, while protein S-100, inhibin, chromogranin A, and somatostatin were non-reactive. Polymerase chain reaction (PCR) tests for Toxoplasma gondii, Neospora caninum, and bovine viral diarrhea virus yielded negative results. This report provides a detailed anatomical, histopathological, and immunohistochemical characterization of a congenital GCT in a bovine fetus.
Natalia Coelho Couto de Azevedo Fernandes
Angiostrongylus spp. in the nasal mucosa of Didelphis sp
Nematodes of the genus Angiostrongylus are parasites capable of inhabiting the pulmonary arteries, heart, bronchioles, and mesenteric veins of various hosts. Opossum species of the genus Didelphis are considered synanthropic animals, cohabiting with humans and domestic animals and potentially disseminating zoonotic pathogens. This study aimed to report the changes caused by Angiostrongylus sp. nasal infection in Didelphis aurita and D. albiventris. Five animals were admitted to the Veterinary Hospital of the Federal University of Paraná, Curitiba, PR, Brazil, due to traumatic accidents. Three animals exhibited neurological clinical signs and, due to the severity of their condition, were euthanized or died. The necropsy of deceased animals revealed numerous adult worms in the nasal sinuses of all five individuals. Tissue sections, including nasal sinuses, were collected and submitted for histological evaluation. Adult parasites were recovered for generic morphological identification. Histopathological evaluation showed fibrinosuppurative and necrotic rhinitis along with sinusitis rhinitis and sinusitis with intralesional nematodes. Morphological identification demonstrated that the parasites belong to the genus Angiostrongylus (Metastrongylidae). This study is the first report of the genus Angiostrongylus sp. infecting the nasal mucosa of free-living opossums (Didelphis aurita and Didelphis albiventris).
Cervical Physeal dysplasia and subchondral synovial cyst in a case of compressive myelopathy in a six-year-old Warmblood gelding
A 6-year-old, 604 kg. History of progressive incoordination, difficulty to jump and ataxia. Euthanized with barbituric overdose.
A euthanized, 14-year-old, Warmblood gelding that had participated in an equine show was presented for necropsy and diagnostic workup to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory System. The animal had a 4-day history of mildly swollen limbs and hyperthermia, and developed neurologic signs shortly before euthanasi
Vitamin A deficiency in peafowl withsecondary visceral urate deposition
In a flock of approximately 180 peafowl, several were showing signs of a possible upper respiratory infection and had mouth gaping per the owner. They were also reported to be lethargic, to have excessive phlegm or mucus in the mouths, had trouble swallowing, and were losing weight. They were being treated with Baytril and Metronidazole with no improvement. Approximately eight had died. Five peafowl were submitted for necropsy and diagnostic work-up, including three peahens and two peacocks.
A 5-year-old, Holstein-Friesian dairy cow was evaluated by a veterinary practitioner for a 30-day history of unilateral exophthalmos (Fig. 1). After 15 days, the cow presented lameness followed by progressive weight loss and pelvic limbs paresis, culminating in persistent sternal recumbency (Fig. 2). The superficial inguinal lymph nodes were enlarged. Due to the poor prognosis, the cow was euthanized and submitted to a postmortem examination.
Small intestinal entrapment through a mesovarium ligament rent in a mare
An 18-year-old, American Paint mare presented for acute colic for a suspected colon torsion. On presentation, the blood and abdominal lactate were 1.3 mmol/L (normal range 0-2 mmol/L) and 5.3 mmol/L (normal range <2 mmol/L), respectively. In the following morning, her blood and abdominal lactate increased to 7.3 mmol/L and 9.9 mmol/L. Due to uncontrollable pain, lack of a surgical option due to financial limitations, and increasing suspicion for a strangulating lesion, euthanasia was elected.
A 10-month-old dog with a history of vomiting with blood and diarrhea after ingesting plastic bags. An ultrasound examination revealed peritonitis and multiple gastric ulcers. The dog was referred for surgery. During the surgical procedure, extensive ulcers were observed in the stomach mucosa. A gastrectomy of the affected region was performed. The dog didn’t recover from the surgical procedure.
Granulomatous disease associated with Halicephalobus sp. in a horse
An 18-year-old English thoroughbred gelding was evaluated because of incoordination, circling, and head pressing. The horse died 5 days after the clinical signs started.
Feedlot with 3,700 animals. About 20 animals died in one month (December 2023). In January 2024, 7 new animals died within 2 days, prompting a visit to the establishment. On physical examination, clinical signs included apathy, lethargy, marked ptyalism and sialorrhea, watery diarrhea, and dyspnea with superficial tachypnea. The affected animals often adopted a kyphotic posture and refused to move when stimulated (Fig.1). Clinical signs began 15 to 45 days after arrival at the feedlot. Treatments with tilmicosin, tylosin, florfenicol, and tulathromycin were administered without a favorable response. The cattle had been fed a low-fiber, high-cereal diet containing monensin.
Cases of neurologic disease occurred in a sheep farm in late 2023, with a surge in cases in July 2024. The disease affected lambs more frequently. Clinical signs lasted from 7 days to 1 month and included blindness, ataxia, lateral deviation of the head, circling, and reflux of ruminal contents through the nose. One animal had exophthalmos. There were several dogs on the farm. The total number of sheep on the farm was 100 and 50 were in the group where the disease occurred. Six of those 50 had clinical signs and died. All sheep were free in the pasture.