Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report / Mastocitoma cutâneo em um cachorro-do-mato vinagre (Speothos venaticus) de cativeiro: aspectos patológicos e imunofenotípicos - relato de caso

A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.(AU)

Um cachorro-vinagre (Speothos venaticus) apresentou um nódulo cutâneo pequeno na região perianal. Histologicamente havia neoplasia cutânea de células redondas e ulcerada, constituída por mastócitos bem diferenciados, com abundantes grânulos citoplasmáticos metacromáticos na coloração de Giemsa e infiltrado eosinofílico difuso. A imuno-histoquímica demonstrou que 30% das células neoplásicas eram positivas para a proteína Kit no citoplasma e na membrana celular. As células foram negativas para MAC e CD3. Menos de 10% das células neoplásicas foram positivas para Ki67. Durante a necropsia, foram identificados outros tumores primários, como adenoma intestinal, adenoma cortical da adrenal e tumor de células intersticiais do testículo.(AU)

Extranodal lymphoma in a bush dog (Speothos venaticus) - case report / Linfoma extranodal em um cachorro-do-mato-vinagre (Speothos venaticus) - relato de caso

A captive 7-year-old male bush dog (Speothos venaticus) was diagnosed with lymphoma affecting the kidneys, adrenal glands, liver, and spleen. The animal developed renal failure and was euthanized due to poor prognosis. Grossly, both kidneys were enlarged with multiple nodules. Histologically, the neoplasm was an infiltrative and poorly demarcated round cell tumor. Two morphologically distinct cell populations were observed, smaller cells with a lymphocytic morphology, and another population of larger and pleomorphic cells. Most of the smaller cell population, approximately 40% of the population within the neoplasm, were CD3 positive. Neoplastic cells were CD45, CD11d, and granzime B positive, and negative for CD20, CD79a, PAX5, CD163, and myeloperoxidase. This is the first reported case of lymphoma in a bush dog. This report demonstrated the suitability of several cell surface markers for differential diagnosis of round cell tumors in this species.(AU)

Um cachorro-do-mato-vinagre (Speothos venaticus), de sete anos de idade, mantido em cativeiro, foi diagnosticado com linfoma que havia afetado os rins, as adrenais, o fígado e o baço. O animal desenvolveu insuficiência renal e foi submetido à eutanásia devido ao prognóstico desfavorável. Macroscopicamente, ambos os rins estavam aumentados de tamanho, com múltiplos nódulos. Histologicamente, a neoplasia era infiltrativa, pobremente delimitada e constituída por células redondas. Duas populações distintas foram observadas: células pequenas com morfologia linfocítica e células grandes e pleomórficas. A maior parte da população de células pequenas, correspondendo a aproximadamente 40% da população celular na neoplasia, foi positiva para CD3. As células neoplásicas foram positivas para CD45, CD11d e granzima B e negativas para CD20, CD79a, PAX5, CD163 e mieloperoxidase. Este é o primeiro caso de linfoma em um cachorro-do-mato-vinagre. Tal relado demonstra a utilidade de vários marcadores de superfície celular para o diagnóstico diferencial de tumores de células redondas nessa espécie.(AU)

An outbreak of compressive myelopathy due to pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine - case report / Surto de mielopatia compressiva associada à reação piogranulomatosa ao adjuvante oleoso da vacina contra Febre Aftosa em Minas Gerais - relato de caso

Cases of compressive myelopathy syndrome associated with post vaccinal pyogranulomas were diagnosed post mortem in three cows from a farm in Minas Gerais state, Brazil. These cows presented ataxia and bilateral paresis of the pelvic limbs, which evolved to paralysis, and sternal recumbence. On necropsy, locally extensive areas of the longissimus dorsi muscle were replaced by pyogranulomas supported by moderate amounts of fibrous connective tissue. On the cut surface, some nodules contained yellowish and viscous fluid (purulent exudate) or whitish fluid (interpreted as the oily adjuvant of a vaccine). In the spinal canal of the subjacent vertebrae, compressing the spinal cord, were pyogranulomas identical to those described in the skeletal muscle. Histologically, the pyogranulomas were composed of a central clear vacuole (consistent with the space left by the oil adjuvant droplets), surrounded by neutrophils and, more externally, by large numbers of epithelioid macrophages and fewer multinucleated giant cells. In the white matter of the spinal cord were numerous well-defined, clear vacuoles (Wallerian degeneration). The association of the clinical history and pathological findings allowed the diagnosis of compressive myelopathy associated with pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine, in this case, due to its inadequate application.(AU)

São descritos casos de síndrome de compressão medular, associada a granulomas pós-vacinais, em bovinos Nelore, provenientes de uma propriedade em Minas Gerais. Esses bovinos apresentavam ataxia e paresia bilateral dos membros pélvicos, que evoluiu para paralisia e decúbito esternal. Na necropsia, áreas focalmente extensas da musculatura na região torácica dorsal (músculo longissimus dorsi) eram substituídas por numerosos piogranulomas, separados por tecido brancacento e firme (tecido conjuntivo fibroso). Ao corte, alguns nódulos continham material amarelado e viscoso (exsudato purulento) ou material esbranquiçado e fluido (sugestivo de adjuvante de vacina). No canal medular das vértebras subjacentes, havia granulomas idênticos aos observados no tecido muscular. Histologicamente, os piogranulomas continham, no centro, vacúolo, bem delimitado e arredondado (consistente com o espaço deixado pela gotícula de lipídio do adjuvante), circundado por variável quantidade de neutrófilos degenerados e íntegros e, mais externamente, por numerosos macrófagos epitelioides e algumas células gigantes multinucleadas. Nas áreas da medula espinhal, circundadas pelos granulomas, numerosos vacúolos, bem definidos, eram observados na substância branca (degeneração walleriana). A associação do histórico clínico e de achados patológicos permitiu o diagnóstico de mielopatia compressiva associada à reação granulomatosa ao adjuvante oleoso da vacina contra febre aftosa, no caso, induzida pela aplicação inadequada da vacina.(AU)

Estudo retrospectivo da casuística de felinos domésticos no Hospital Veterinário da Universidade Federal de Minas Gerais, no período de 2005 a 2014 / Retrospective study of the case load of domestic cats at the Veterinary Hospital of the Universidade Federal de Minas Gerais from 2005 to 2014

O objetivo deste estudo foi caracterizar as doenças dos gatos domésticos provenientes dos casos de necropsia e histopatologia do Hospital Veterinário da Universidade Federal de Minas Gerais (HV/UFMG), de 2005 a 2014. Foram analisados 408 exames de necropsia e 197 de biópsias, segundo o sexo, a faixa etária e a raça. Os diagnósticos mais frequentes incluíram doenças infecciosas/inflamatórias ou parasitárias (22,5%), agentes físicos (18,1%), doenças proliferativas (15,2%) e degenerativas (13,5%). Politraumatismo (10,8%) foi responsável pelo maior número de mortes em felinos, sendo as chances três vezes maiores em animais com até 24 meses de idade (P=0,005 OR 3,47 [IC 95%: 1,40-8,57]). Neoplasias epiteliais corresponderam a 26 diagnósticos, sendo 20 (4,9%) casos de malignidade. A ocorrência de carcinoma e seus subtipos foi 18 vezes maior em gatos idosos (P<0,01 OR 18,15 [IC 95%: 7,41-44,45]). A insuficiência renal crônica foi mais frequente em gatos com mais de 120 meses (P=0,01). Machos apresentaram nove vezes mais chances de desenvolver doenças do trato urinário inferior quando comparados às fêmeas (P=0,001 OR 9,50 [IC 95%: 2,78-32,48]). Em relação às biópsias, animais adultos a idosos foram 10 vezes mais representados (P<0,001 OR 10,8 [IC 95%: 3,22-36,79]).(AU)

The aim of this study was to characterize the diseases of domestic cats based on necropsy and histopathological examinations at the Veterinary Hospital of the Universidade Federal de Minas Gerais (HV/UFMG) from 2005 to 2014. A total of 408 necropsy and 197 biopsy samples were analyzed according to gender, age, and breed. The most frequent diagnoses included infectious/inflammatory or parasitic diseases (22.5%), physical agents (18.1%), proliferative (15.2%), and degenerative (13.5%) diseases. Polytrauma (10.8%) was responsible for the highest number of feline deaths, with the odds three times higher in animals up to 24 months of age (P= 0.005 OR 3.47 [95% CI: 1.40-8.57]). Epithelial neoplasms corresponded to 26 diagnoses, with 20 (4.9%) malignant cases. The occurrence of carcinoma and its subtypes was 18-fold higher in older cats (P< 0.01 OR 18.15 [95% CI: 7.41-44.45]). Chronic renal failure was more frequent in cats over 120 months (P= 0.01). Males were nine times more likely to develop lower urinary tract diseases when compared to females (P= 0.001 OR 9.50 [95% CI: 2.78-32.48]). Regarding the biopsies, adult to elderly animals were ten times more represented (P< 0.001 OR 10.8 [95% CI: 3.22-36.79]).(AU)

Tuberculosis Caused by Mycobacterium bovis in a Capybara (Hydrochoerus hydrochaeris).

Tuberculosis, associated with Mycobacterium bovis, was diagnosed post mortem in an adult female capybara (Hydrochoerus hydrochaeris), kept at the Pampulha Ecological Park, Belo Horizonte, Brazil, in a large metropolitan area. On post-mortem examination, there were numerous firm white nodules scattered throughout all lobes of both lungs. Tissue samples were collected for histological and microbiological examination. Microscopically, the pulmonary nodules were multifocal to coalescing granulomas and intralesional acid-fast bacilli were evident in Ziehl-Neelsen-stained sections of the lung and spleen. Colonies with morphological features of Mycobacterium spp. were isolated from lung samples and conventional polymerase chain reaction (PCR) with genomic DNA from the isolates was positive for M. bovis; sequencing indicated 100% identity with the region of difference 4 (RD4) of M. bovis. In addition, M. bovis DNA was detected in the lung by quantitative PCR. The finding of M. bovis in a capybara indicates a potential public health risk in a zoological collection.

Immunohistochemical expression of ionized calcium binding adapter molecule 1 in cutaneous histiocytic proliferative, neoplastic and inflammatory disorders of dogs and cats.

Ionized calcium-binding adapter molecule 1 (Iba1) has been used widely as a marker for microglial cells and, recently, was also recognized as a 'pan-macrophage marker', as it is expressed by all subpopulations of cells of the monocyte/macrophage lineage. To determine the specificity of Iba1 as an immunohistochemical marker for canine and feline histiocytic proliferative, neoplastic and inflammatory disorders of the skin, we evaluated its expression in two types of histiocytic tumours, two non-neoplastic histiocytic proliferative conditions, one case of granulomatous dermatitis and four non-histiocytic tumours. Cells of the monocyte/macrophage lineage in all cases of canine cutaneous histiocytoma (9/9), reactive histiocytosis (9/9), histiocytic sarcomas (5/5), feline progressive dendritic cell histiocytosis (3/3) and macrophages in cutaneous mycobacteriosis (7/7) showed strong cytoplasmic expression of Iba1. Neoplastic cells of melanomas (10/10), lymphomas (7/7), mast cell tumours (7/7) and plasmacytomas (4/4) did not express Iba1. Iba1 is therefore a useful marker of cells of the monocyte/macrophage lineage in canine and feline inflammatory, proliferative and neoplastic conditions and can be used to identify these cells in formalin-fixed, paraffin wax-embedded tissues. Iba1 is not able to differentiate between macrophages and dendritic antigen presenting cells and expression does not allow classification of these histiocytic disorders.

A retrospective study of 586 tumours in Brazilian cattle.

Records from 6,706 necropsy examinations of cattle performed over a 45-year period were surveyed and 586 cases of neoplasia were identified. The organ system most frequently affected by neoplastic disease (n=139 cases) was the alimentary tract. This finding was attributed to a high incidence of squamous cell carcinoma of the upper alimentary tract associated with the chronic ingestion of bracken fern (Pteridium aquilinum). This carcinogenic plant was also associated with a relatively high incidence (n=35 cases) of urinary bladder tumours (enzootic haematuria). Tumours of the alimentary tract were followed, in decreasing order of frequency, by tumours of the skin and subcutis (n=129 cases), haemopoietic tissue (n=101 cases), the eye and periorbital tissues (n=88 cases), the urinary system (n=44 cases), the female reproductive system (n=21 cases), the endocrine system (n=16 cases), the liver and pancreas (n=12 cases), the nervous system (n=6 cases), the respiratory system (n=6 cases) and the mammary gland (n=1 case). The primary anatomical location of 16 tumours was undetermined.

Pathological findings associated with experimental infection by Trypanosoma evansi in cats.

Five cats were experimentally inoculated with Trypanosoma evansi in order to evaluate the pathological changes induced by this protozoan infection. Clinical signs observed included vomiting, diarrhoea, hyperthermia, weight loss, facial oedema, corneal opacity, lymphadenopathy and hindlimb instability. Reduction in hematocrit was observed from 7 days post-infection (dpi) (P<0.05). One cat died at 40 dpi and the other four cats were humanely destroyed. Necropsy examination was performed in two cats at 56 dpi and two cats at 120 dpi. Gross findings in all cats included generalized muscle atrophy, pale mucosae, icterus of the subcutaneous and serosal tissue and the intima of arteries, lymphadenopathy and splenomegaly. Other findings included corneal opacity, subcutaneous oedema (mainly of the head) and hydropericardium. Trypomastigotes of T. evansi were observed in impression smears prepared from the aqueous humor. Microscopically, there was lymphoid hyperplasia of the spleen and lymph nodes. The animals with corneal opacity had mild corneal oedema and accumulation of fibrin and inflammatory cells (neutrophils and plasma cells) in the anterior chamber. Similar inflammatory cells infiltrated the iris, ciliary body, corneoscleral limbus and conjunctiva.