Primary third eyelid lymphoma with aggressive local behavior in a dog.

Lymphoma is the most common hematopoietic neoplasm in dogs. However, cases primarily involving the third eyelid are rarely reported in the species. The subtype most frequently described in this location is marginal zone lymphoma of the mucosa-associated lymphoid tissue, which has an indolent behavior. A 10-year-old intact female Poodle was presented with a 2-month history of a nodule in the left third eyelid for evaluation. This nodule was surgically excised; however, local recurrence was detected nineteen days postoperatively, with the formation of a mass that expanded and replaced the extraocular orbital tissues and infiltrated the eye. Euthanasia was elected due to the deteriorating clinical condition, and a necropsy was performed. Macroscopically, the mass infiltrated and expanded the eyelids with narrowing of the palpebral fissure, expanded into the orbital space, and infiltrated the cornea and bulbar conjunctiva. Histologically, the mass was composed of sheets of intermediate to large neoplastic lymphocytes, with frequent epitheliotropism and tingible bodies. Neoplastic lymphocytes were immunoreactive for PAX5, CD20, and CD79a and were not immunoreactive for CD3. The neoplasm was restricted to the left eyelid and orbit. A diagnosis of primary third eyelid lymphoma (extranodal) with immunophenotype B and locally aggressive behavior was made based on the macroscopic, histological, and immunohistochemical findings.

Pathological findings and patterns of feline infectious peritonitis in the respiratory tract of cats.

Feline infectious peritonitis (FIP) is an important cause of death in cats. Thoracic manifestations are less common than abdominal manifestations, and FIP-associated respiratory disease is poorly documented. This study aimed to investigate pathological findings in the respiratory tract of cats with FIP and the occurrence and distribution of feline coronavirus antigen in the respiratory tract using immunohistochemistry. A retrospective study was carried out on 112 cats with FIP, of which 66 had inflammatory histological lesions in the respiratory tract (58.9%) and were included in this study. Three major gross patterns were defined: marked fibrin deposition in the thoracic cavity with lung atelectasis; marked fibrin deposition in the thoracic cavity with lung pyogranulomas; and lung pyogranulomas without thoracic effusion. Histological analysis revealed primary lesions in the visceral pleura and lung parenchyma at a similar frequency, with multifocal to diffuse presentations. Marked lesions were commonly observed. Five major histological patterns were defined: pleuritis; pleuritis and vasculitis/perivascular injury in the lung parenchyma; pleuritis and pneumonia; perivascular injury in the parenchyma without pleuritis; and pneumonia without pleuritis. In the pleura and pulmonary parenchyma, FIP virus antigen was detected in perivascular and peribronchial macrophages and in macrophages within bronchial-associated lymphoid tissue and foci of necrosis and inflammation in the pleura and lung parenchyma. Co-infections with retroviruses were detected in 47 cats (71.2%), mainly with feline leukemia virus (62.2%). Although FIP is a systemic disease, some cats developed significant lesions in the thoracic cavity, including involvement of the upper respiratory tract and presenting respiratory signs, without other classic signs of FIP. This work advances our knowledge of FIP in the respiratory system, helping veterinarians to recognize the various presentations of this disease.

Septicemic salmonellosis in suckling piglets resulting from improper intramuscular administration of an oral vaccine.

We describe an unusual outbreak of mortality in suckling piglets following the misadministration of an oral vaccine against Salmonella Typhimurium and Salmonella Choleraesuis. Within 3-48 h of vaccination of a batch of ~700 piglets, ~300 developed marked swelling in the dorsal neck region, respiratory distress, fever, recumbency, and apathy. In total, ~100 died, and 4 were submitted for autopsy. Gross and microscopic lesions consisted of focally extensive areas of purple discoloration in the skin of the cervical region, associated with edema and hemorrhage in the subcutis and muscles. Additionally, there was interstitial pneumonia with marked interlobular edema and mild fibrinous pleuritis. Aerobic bacterial culture identified Salmonella Typhimurium (3 cases) and Salmonella Choleraesuis (1 case) in samples of skeletal muscle and lung and from pleural swab samples. Marked immunostaining against Salmonella spp. was observed in the skeletal muscle of the cervical region, as well as in blood vessels and macrophages from the lung, liver, spleen, and kidney. We concluded that inappropriate intramuscular administration of an oral vaccine against Salmonella resulted in septicemia and death in a batch of piglets.

Characterization of cutaneous lesions caused by natural tick infestation in cattle.

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.

Encephalic meningioangiomatosis in a dog with high-grade undefined glioma.

Meningioangiomatosis (MA) is a rare proliferative meningovascular disorder that affects mainly the cerebral cortex, brainstem and spinal cord of humans and animals and can coexist with other proliferative disorders. A 7.5-year-old male Brazilian Campeiro Bulldog died after a convulsive crisis and cardiorespiratory arrest. At necropsy, a firm, white mass involving the piriform and right occipital lobes was seen. Histologically, the mass consisted of two morphologically distinct entities that collided: a congenital malformation characterized by a proliferation of meningothelial cells around blood vessels, within the perivascular spaces; and a neoplasm composed of two cell populations with astrocytic and oligodendrocytic differentiation. Meningothelial cells and neoplastic glial cells immunolabelled for vimentin. This first reported case of encephalic MA with a high-grade undefined glioma in a dog was confirmed through clinical signs, pathological and immunohistochemical findings.

Undifferentiated pleomorphic sarcoma in a white-eared opossum (Didelphisalbiventris).

We report a case of high-grade undifferentiated pleomorphic sarcoma in a free-living white-eared opossum (Didelphis albiventris) in Central Brazil. Grossly, it appeared as a soft yellow mass, approximately 8 cm in diameter, with an irregular, adherent and ulcerated surface, which extended from the proximal epiphysis of the femur to the proximal third of the tibia and fibula. The mass invaded the medullary cavity and had a necrotic centre. Multiple nodular metastases (0.5-1.5 cm) were present in the liver, lungs and spleen. Histologically, the neoplasm was characterized by pleomorphic cells with indistinct boundaries, many multinucleated cells, necrosis and tissue invasion. There was intense cytoplasmic immunolabelling of neoplastic cells for vimentin and moderate cytoplasmic and nuclear labelling for human muscle actin, human smooth muscle actin and lysozyme. Immunolabelling for Iba1, CD18, CD1A, cytokeratin AE1/AE3, glial fibrillary acidic protein and desmin was negative. To our knowledge, this is the first report of an undifferentiated pleomorphic sarcoma in this species.

Glioma with cribriform plate involvement in 6 dogs.

Distinct patterns of local infiltration are a common feature of canine oligodendroglioma and astrocytoma, and typically involve the surrounding neuroparenchyma, ventricles, or leptomeninges. Infiltration of adjacent extraneural sites is rare and has not been well documented in veterinary medicine. Here we describe 6 canine gliomas with cribriform plate involvement (compression or infiltration) and caudal nasal invasion confirmed by neuroimaging, autopsy, and/or histology. All affected dogs were adults (9-12-y-old), and 3 were brachycephalic. Clinical signs were associated with the brain tumor, with no respiratory signs reported. Magnetic resonance imaging in 2 patients revealed a rostral intraparenchymal telencephalic mass with extension into the cribriform plate. All dogs were euthanized. Gross changes consisted of poorly demarcated, white or pale-yellow, soft, and, in oligodendrogliomas, gelatinous, intraparenchymal masses that expanded the rostral portions of the telencephalon and adhered firmly to the ethmoid bone and cribriform plate. Gliomas were classified as high-grade oligodendrogliomas (4 cases) and high-grade astrocytomas (2 cases) based on histology and immunohistochemistry for OLIG2 and GFAP. In all cases, there was evidence of cribriform plate invasion and, in one case, additional invasion of the caudal nasal cavity.

Fatal Simplexvirus humanalpha1 infection in howler-monkeys (Alouatta sp.) under human care: Clinical, molecular, and pathological findings.

BACKGROUND: Simplexvirus humanalpha1 (HuAHV-1) are common anthropozoonosis reported in marmosets but rare in howler monkeys (Alouatta sp.). METHODS: Necropsy of two brown-howler monkeys (A. caraya) and one red-howler monkey (A. guariba clamitans) from different zoo collections were performed. Fragments of all organs were examined through microscopy. Samples were submitted to IHC for Simplexvirus humanalpha 2 (HuAHV-2) [sin. Herpesvirus simplex type 2] and PCR. RESULTS: Grossly, only the A. guariba showed liver lesions characterized by multifocal, pinpoint white areas corresponding microscopically as random necrotizing herpetic hepatitis and ulcerative glossitis. Both A. caraya showed necrotizing meningoencephalitis with Cowdry A-type body inclusions within neurons and astrocytes. Immunolabeling for HuAHV-1/2 was observed in the tongue, liver, and brain. HuAHV-1 was confirmed in all samples by PCR, Sanger sequencing, and phylogenetic analyses. CONCLUSION: Necrotizing meningoencephalitis was appreciated in 2/3 of animals, and it is associated with neurologic signs. Along with ulcerative glossitis, a hallmark lesion in marmosets, it was present in one animal. Regarding herpetic hepatitis, it is not frequent in monkeys and occurs mainly in immunocompromised animals. HuAHV-1 infection was confirmed corroborating with a human source. This is the second report on captive black-howler monkeys and the first gross, histologic, immunohistochemical, and molecular description of herpetic hepatitis and ulcerative glossitis in red-howler monkeys (A. guariba).

Systemic histiocytic disorder in a jaguar (Panthera onca).

A 7-year-old captive female jaguar (Panthera onca) was presented with a 7-day history of dyspnoea and weight loss. Clinical examination revealed hepatomegaly and elevated serum alanine aminotransferase activity. Pulmonary ultrasonography revealed comet-tail images and an alveolar pattern was detected on thoracic radiography. Due to the poor prognosis, the jaguar was euthanized after 10 days. At necropsy, the main gross findings were hepatomegaly, splenomegaly and multifocal to coalescent, slightly elevated grey areas in the lungs. Histological examination revealed neoplastic proliferation of pleomorphic histiocytes arranged in cohesive sheets in the lungs, liver, spleen, kidneys and lymph nodes. Neoplastic cells had intense immunolabelling for vimentin and ionized calcium-binding adaptor molecule 1, and were immunonegative for pancytokeratin, E-cadherin, CD20, CD3 and CD79α. These findings were compatible with a systemic histiocytic disorder, distinct from any well-defined histiocytic proliferative disease in domestic animals.

Pasteurella multocida polyserositis in growing-finishing pigs.

Pasteurella multocida is the main secondary bacterium isolated from cases of swine pneumonia. Although highly pathogenic strains of P. multocida have been associated with primary septic lesions and polyserositis in pigs, studies on this pathological presentation in naturally occurring cases are limited. The aim of this work was to characterize the clinical, pathological and molecular findings in cases of P. multocida polyserositis in growing-finishing pigs in a commercial farm in Brazil. The mean age of 17 investigated pigs was 120 days. Clinically, the disease was acute (11/17), with clinical signs of dyspnoea and apathy. Sudden death occurred in some animals (6/17). The main gross findings included fibrinous serositis affecting the abdominal and thoracic cavities (17/17), fibrinous pericarditis (15/17), marked cranioventral pulmonary consolidation (17/17) and splenic infarcts (3/17). P. multocida was isolated in all cases from systemic sites, including the pericardial sac and abdominal exudate. Molecular typing of genus and species was performed on four isolates, and all were characterized as P. multocida type A. Another five isolates were positive for the pathogenicity marker gene pfhA by polymerase chain reaction. This study reinforces the role of P. multocida as a cause of polyserositis in growing-finishing pigs.

Pathological Aspects and Immunohistochemical Evaluation of Troponin C in the Cardiovascular System of Dogs With Pheochromocytoma.

Functional pheochromocytomas secrete catecholamines and have been associated with cardiovascular lesions in dogs. This study aimed to describe the postmortem pathological findings in the cardiovascular system of dogs with pheochromocytoma and to evaluate the expression of cardiac troponin C in these dogs using immunohistochemical analysis. Twelve cases were identified, with a mean age of 10.6 years. The heart of all dogs was enlarged and with concentric hypertrophy of the left ventricular myocardium. Histological analysis showed cardiomyocyte necrosis and degeneration in the myocardium, with frequent bands of contraction, fibrosis, inflammation, and thickening of the medium-caliber arteries in the myocardium. There was a marked decrease or absence of immunolabeling in necrotic cardiomyocytes. We conclude that IHC for troponin C can be a useful tool for detecting myocardial necrosis in dogs with pheochromocytomas, including early cases of necrosis with only incipient cardiac changes where overt histologic abnormalities are not immediately apparent in the cardiomyocytes.

Rehabilitation and release of confiscated songbirds into the wild: A pilot study.

Songbirds are currently the most prevalent animals in illegal trafficking in Brazil and other countries, so they are often confiscated, and this poses legal, ethical, and conservation challenges. Returning them to nature requires complex and expensive management, a topic that is sparingly addressed in the literature. Here, we described the processes and costs associated with an attempt to rehabilitate and release confiscated songbirds into the wild. A total of 1,721 songbirds of several species were quarantined, rehabilitated, and released, primarily on two farms located within their typical geographical distribution. Health assessments were performed on samples from 370 birds. Serology revealed no antibodies against Newcastle disease, and Salmonella spp. cultures were negative. Real-time polymerase chain reactions detected M. gallisepticum in samples from seven birds. Atoxoplasma spp. and Acuaria spp. infections, sepsis, and trauma were the top causes of bird death. About 6% of the released birds were recaptured, within an average period of 249 days after release, and at a mean distance of 2,397 meters from the release sites. The majority of these birds were found with free-living mates within or close to fragments of transitional ecoregions with native or cultivated grasslands, and native groves/forests, and shrublands. However, eucalyptus plantations with rich understory regeneration provided a suitable environment for the released forest species to settle, since they were recaptured during the defense of these sites. Over half of the recaptured birds presented behavioral profiles with both dominant and tame traits. Birds with dominant traits are more likely to settle in habitats and face the live decoys during fieldwork, whereas birds with tame characteristics tend to accept close contact with humans. Ultramarine grosbeak (Cyanoloxia brissonii), the least common species among those released, at the release sites showed an almost 2-fold recapture rate in the shortest mean distances from the release sites. This suggests less territory competition, perhaps a major factor of bird re-establishment here. The total per-bird cost was USD 57. Our findings suggested suitable survival and re-establishment of confiscated songbirds in the wild, when managed as we describe.

Ophthalmic and immunopathological characterization of systemic infectious diseases in cats.

Ocular involvement in systemic diseases is frequent in cats; however, without concurrent clinical and ophthalmic examinations with gross and/or histologic analysis of the eye, these findings can be underdiagnosed. This article aims to provide gross, histologic, and immunohistochemical characteristics of ocular lesions from cats submitted to necropsy, focusing on those caused by systemic infectious agents. Cats that died due to a systemic infectious disease were selected based on necropsy diagnosis and presence of ocular lesions. Gross, histologic, and immunohistochemical findings were recorded. From April 2018 to September 2019, 849 eyes of 428 cats were evaluated. Histologic abnormalities were seen in 29% of cases, which were classified as inflammatory (41%), neoplastic (32%), degenerative (19%), and metabolic/vascular (8%). Macroscopic changes were present in one-third of eyes with histologic lesions. Of these, 40% were attributed to inflammatory or neoplastic diseases associated with infectious agents. The most important infectious agents causing ocular disease in this study were feline leukemia virus, feline infectious peritonitis virus, and Cryptococcus sp. The most common ocular abnormalities associated with infectious agents were uveitis (anterior, posterior, or panuveitis), optic neuritis, and meningitis of the optic nerve. Ocular lesions secondary to systemic infections in cats are frequent; however, these are not always diagnosed because gross lesions are less common than histologic lesions. Therefore, both gross and histologic evaluation of the eyes of cats is recommended, mainly for cases in which the clinical suspicion or necropsy diagnosis suggests that an infectious agent might be related to the cause of death.

Pathological and immunohistochemical characterization of pancreatic carcinoma in cats.

The aim of this study was to characterize the pathological and immunohistochemical aspects of pancreatic carcinoma in cats, through a retrospective study. From January 2010 to December 2021, 1,908 cat necropsies were performed, in which 20 cases of exocrine pancreatic neoplasia were diagnosed (1.04%). Affected cats were mature adults and seniors, except for one 1-year-old cat. In 11 cases the neoplasm was a soft, focal nodule on the left (8/11) or right (3/11) lobe. In nine cases there were multifocal nodules throughout the pancreatic parenchyma. The size of the single masses ranged from 2 to 12 cm, and the multifocal masses from 0.5 to 2 cm. The most frequent tumour type was acinar carcinoma (11/20), followed by ductal carcinoma (8/20), undifferentiated carcinoma (1/20) and carcinosarcoma (1/20). On immunohistochemical evaluation, all the neoplasms were remarkably reactive to pancytokeratin antibody. The ductal carcinomas were strongly reactive for cytokeratins 7 and 20, which proved to be a good marker for pancreatic ductal carcinoma in cats. The main form of metastasis was abdominal carcinomatosis, with a marked invasion of blood and lymphatic vessels by neoplastic cells. Our findings reinforce the fact that pancreatic carcinoma should be rated highly in the differential diagnosis in mature adult and senior cats with abdominal masses, ascites and/or jaundice.

Feline pulmonary carcinoma: Gross, histological, metastatic, and immunohistochemical aspects.

Feline pulmonary carcinoma (FPC) is an uncommon neoplasm with unique morphological features. We describe the gross, histological, metastatic, and immunohistochemical aspects of FPC, based on postmortem examinations from an 11-year retrospective study. Thirty-nine cases were selected. Predispositions were observed in senior (P < .001) and Persian (P = .039) cats. There were three gross patterns of the pulmonary tumors: (a) a large nodule and additional smaller nodules, (b) a solitary nodule, and (c) small, multifocal to coalescent nodules. Extrapulmonary metastases were present in 22/39 cases (56.4%), mainly in the regional lymph nodes (17/39, 43.5%), skeletal muscles (9/39, 23%), kidneys (6/39, 15.3%), and parietal pleura (4/39, 10.2%). The primary tumor size was correlated with the occurrence of extrapulmonary metastases (P = .002). Histologically, the tumors were classified as papillary adenocarcinoma (19/39, 48.7%), adenosquamous carcinoma (ADS) (8/39, 20.5%), acinar adenocarcinoma (6/39, 15.3%), solid adenocarcinoma (3/39, 7.6%), lepidic adenocarcinoma (2/39, 5.1%), and micropapillary adenocarcinoma (1/39, 2.5%). By immunohistochemistry, 39/39 cases (100%) were positive for pancytokeratin, 34/39 (87.1%) for thyroid transcription factor-1, and 8/39 (20.5%) for vimentin. Immunoreactivity for p40 was detected in the squamous component of all ADSs (8/8, 100%) and occasionally in the glandular component of adenocarcinomas (10/31, 32.2%). Napsin A expression was absent in all feline tissue tested. The results indicate that a modified and simplified histological classification based on current human and domestic animal systems is appropriate for cats. Additionally, this study highlights the utility of p40 as an immunohistochemical marker for the diagnosis of FPC with squamous differentiation.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Verminotic pneumonia in South American fur seal (Arctocephalus australis) in Southern Brazil.

Verminotic pneumonia caused by Parafilaroides spp. nematodes is an underreported disease in beached South American fur seals, with scant literature available on the characteristics of parafilaroidiasis, the nematode itself, as well as its occurrence in pinnipeds in Brazil. The present work aims to identify, describe and detail the histological features of the infection and molecular characteristics of verminotic pneumonia in the South American fur seal. Twenty-six specimens of Arctocephalus australis, found dead on the northern coast of Rio Grande do Sul in 2021, were analysed. These animals were identified and submitted to necropsy and histology. For the molecular identification of metastrongylids, lung fragments were subjected to DNA extraction, polymerase chain reaction targeting the Internal transcribed spacer 2 (ITS-2) gene and subsequent sequencing. In total, 12 animals presented with parasites in the lung parenchyma on histological evaluation, and only 1 showed a granulomatous lung lesion at necropsy. Microscopically, the nematodes were found mainly in the alveoli, associated with little or no inflammatory response, and they had morphological characteristics compatible with metastrongylids. Six ITS-2 gene quality sequences were obtained; after comparative analysis via BLAST, they showed similarity with sequences obtained from Parafilaroides sp. Therefore, verminotic pneumonia caused by Parafilaroides represents an important differential diagnosis of lung disease in South American fur seals found on the northern coast of Rio Grande do Sul.

Nutritional chondrodysplasia in cattle in Brazil.

In this work, we investigated cases of birth of calves with congenital defects in a farm in Southern Brazil. Only calves born from heifers were affected, and the disease occurred in both crossbred and purebred calves. Three necropsies were performed, tissues were collected for histopathology, and samples of liver of calves, blood serum, and food provided for cows and heifers were collected to quantify the levels of the minerals: manganese, copper, and zinc. The calves were born weak, with disproportionate dwarfism, limb deformities, and enlarged joints. Heads were shortened and domed. Long bones had a shortened diaphysis and a normal-sized epiphysis, when compared to the control. In one of the cases, there were white-yellowish lines on the metaphyseal surface of the epiphyseal plate. Histopathology of growth plates revealed premature closure, disarrangement of chondrocyte columns, and collapse of primary spongiosa. These findings supported a diagnosis of chondrodysplasia. Liver manganese levels were under the reference values in the three calves. Food analysis revealed insufficient levels of manganese in the diet of heifers, especially in sorghum silage, which was provided as the main source of food for the category in some periods. Approximately 6 months after the diet was changed, the problem ceased and only normal calves continued to be born. Our findings allowed to conclude the diagnosis of chondrodysplasia of nutritional origin and reinforce the thesis that manganese is the mineral deficient in these cases.