Aspectos epidemiológicos, patológicos e imuno-histoquímicos de linfoma em felinos no Sul do Brasil

Os aspectos epidemiológicos, patológicos e imuno-histoquímicos do linfoma em felinos no Sul do Brasil foram avaliados através de um estudo retrospectivo em um período de 12 anos (2004-2016). Em 1356 necropsias de felinos, 125 diagnósticos de linfoma foram revisados com intuito de determinar idade, raça e sexo, topografia tumoral, presença do vírus da leucemia felina (FeLV) e do vírus da imunodeficiência felina (FIV) e imunofenótipo do neoplasma por imuno-histoquímica, além da categorização dos tumores de acordo com o sistema da Organização de Saúde Mundial, aplicado para uso em animais. O linfoma alimentar (33,6%) foi a mais comum, seguido do linfoma mediastinal (28%). A imuno-histoquímica do tecido neoplásico revelou 50,4% de gatos positivos para FeLV e 21.6% positivos para FIV, e 52,8% dos linfomas consistiam de células T e 47,2% de células B. A faixa etária dos gatos com linfoma de células T variou de 10 a 240 (mediana 120) meses e 6 a 204 (mediana 60) meses para gatos com linfoma de células B; 90,4% dos gatos não tinha raça definida. Entre os linfomas alimentares, o linfoma de células T associado à enteropatia do tipo 1 foi o mais frequente e, entre os linfomas mediastinais, o linfoma difuso de grandes células B foi o principal tipo de linfoma encontrado. Considerando apenas linfomas mediastinais e alimentares, houve associação estatística significativa (p≤0,05) entre infecção por FeLV e as categorias de idade. A prevalência de linfoma mediastinal entre os gatos positivos para FeLV foi de 3,21 vezes a do linfoma mediastinal entre gatos negativos para FeLV. Embora não seja estatisticamente significativo, a prevalência de linfoma de células B entre os gatos positivos para FeLV foi 1,44 vezes maior que a prevalência de linfoma de células B entre os gatos negativos para FeLV. A respeito dos padrões histológicos de infiltração pulmonar pelo linfoma, avaliamos retrospectivamente 125 casos com diagnóstico de linfoma, nos quais 16 casos apresentaram infiltração pulmonar (12,8%). Desses casos, 9 gatos eram fêmeas e 7 machos e todos não tinham raça definida. As lesões macroscópicas observadas nos pulmões consistiram em massas (25%) e nódulos (18,7%). No entanto, a maioria dos casos (56,2%) não exibiu alteração macroscópica. O padrão de infiltração neoplásico peribronquial-vascular (93,7%) foi o mais frequente, seguido do pleural (56,2%), intersticial (50%), nodular (37,5%) e alveolar (12,5%), sendo que 75% dos linfomas tiveram mais do que um padrão de infiltração. Entre os linfomas que exibiram infiltração pulmonar, 14 (87,5%) casos foram identificados como linfoma de células B e 2 (12,5%) de células T; o linfoma difuso de grandes células B foi o tipo mais frequente, representando 56% desses casos.The epidemiological, pathological and immunohistochemical aspects of lymphoma in felines in southern Brazil were evaluated through a retrospective study over a 12-year period (2004-2016). In 1,356 necropsies, 125 cats with lymphoma diagnosis were review to determine age, breed and sex, tumor topography, feline leukemia virus (FeLV) and immunodeficiency feline virus (FIV) immunohistochemistry status, immunophenotype of lymphomas, and categorization of the tumors according to World Health Organizations system applied for use in animals. Alimentary lymphoma (33.6%) was the most common, followed by mediastinal lymphoma (28%). Immunohistochemical staining of tumor tissue revealed 50.4% FeLV-positive and 21.6% FIV-positive cats, and 52.8%T-cell lymphoma and 47.2% B-cell lymphoma. The range of age of cats with T-cell varied from 10 to 240 (median of 120) months and 6 to 204 (median of 60) months for cats with B-cell lymphoma, and mixed-breed was the most frequent with 90.4% among all breeds. Alimentary lymphoma exhibited the enteropathy-associated T-cell lymphoma (type 1) as the most common and mediastinal lymphoma showed the diffuse large B-cell lymphoma as the main type of lymphoma. Considering only mediastinal and alimentary lymphomas, there was significantly statistical association (p≤0.05) between FeLV status and the categories of age. The prevalence of mediastinal lymphoma among FeLV-positive cats was 3.21 times the higher than FeLV-negative cats. Although not statistically significant, the prevalence of B-cell lineage among FeLV-positive cats was 1.44 times the prevalence of B-cell lineage among FeLV-negative cats. Regarding the histological patterns of pulmonary infiltration by lymphoma, it was retrospectively assessed 125 reports with lymphoma diagnosis, in which 16 cases showed pulmonary infiltration (12.8%). Of these, 9 cats were females and 7 were males; all of them were mixed-breed cats. Gross lesions observed in the lungs consisted of masses (25%) and nodules (18.7%); however, the majority of cases (56.2%) did not show any gross abnormality. The peribronchialvascular infiltration pattern (93.7%) was the most frequent pattern, followed by pleural (56.2%), interstitial (50%), nodular (37.5%) and alveolar (12.5%), and 75% of the lymphomas had more than one infiltration pattern. Among the lymphomas with pulmonary involvement, there were 14 (87.5%) B-cell and 2 (12.5%) T-cell lymphomas and the diffuse large B-cell lymphoma was the most frequent type accounting for 56% of these cases

EFICÁCIA DO FOSFATO DE LEVAMISOL EM NEMATÓDEOS GASTRINTESTINAIS DE CAPRINOS E OVINOS

O parasitismo gastrintestinal é considerado o principal entrave na produção de pequenos ruminantes e a ocorrência de parasitos resistentes aos anti-helmínticos tem dificultado seu controle. O objetivo deste trabalho foi avaliar a sensibilidade de nematóides gastrintestinais ao levamisol, em rebanho ovino e caprino criados simultaneamente. Foram utilizados 28 caprinos da raça Bôer e 28 ovinos da raça Texel, naturalmente infectados. Ambas as espécies foram divididas em quatro grupos de sete animais: T1) tratados com 9 mg/kg de fosfato de LEV; T2) 6,75 mg/kg; T3) 4,5 mg/kg e T4) grupo controle, sem tratamento. Os animais foram avaliados durante 21 dias para a contagem de ovos por grama de fezes - OPG, coloração da mucosa ocular com o método FAMACHA, hematócrito e peso corporal. Nos ovinos, T1 e T2 foram considerados altamente eficazes (>95%) e o T3 obteve 86%, que é a dose terapêutica recomendada para ovinos. O LEV não tem indicação oficial para ser utilizado em caprinos e apresentou redução da OPG de 30, 11 e 4%, 14 dias após tratamento, comprovando sua ineficácia. As correlações entre os parâmetros avaliados nos ovinos, foram significativas (P84%). Conclui-se que o LEV foi eficaz para ovinos, sendo dose-dependente. O LEV não pode ser considerado como um composto eficaz no controle de parasitos gastrintestinais em caprinos, possivelmente decorrente de alterações na cinética do produto por esta espécie animal quando comparado com ovinos, devendo ser desencorajado o seu uso

Soroprevalência de Rickettsia bellii e Rickettsia felis em cães, São José dos Pinhais, Paraná, Brasil

Brazilian spotted fever (BSF) is a vector-borne zoonosis caused by Rickettsia rickettsii bacteria. Dogs can be host sentinels for this bacterium. The aim of the study was to determine the presence of antibodies against Rickettsia spp. in dogs from the city of São José dos Pinhais, State of Paraná, Southern Brazil, where a human case of BSF was first reported in the state. Between February 2006 and July 2007, serum samples from 364 dogs were collected and tested at 1:64 dilutions by indirect immunofluorescence assay (IFA) against R. rickettsii and R. parkeri. All sera that reacted at least to one of Rickettsia species were tested against the six main Rickettsia species identified in Brazil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis. Sixteen samples (4.4%) reacted to at least one Rickettsia species. Among positive animals, two dogs (15.5%) showed suggestive titers for R. bellii exposure. One sample had a homologous reaction to R. felis, a confirmed human pathogen. Although Rickettsia spp. circulation in dogs in the area studied may be considered at low prevalence, suggesting low risk of human infection, the present data demonstrate for the first time the exposure of dogs to R. bellii and R. felis in Southern Brazil.A febre maculosa brasileira (FMB) é uma zoonose veiculada por carrapatos e causada pela bactéria Rickettsia rickettsii, podendo os cães ser hospedeiros sentinelas para essa bactéria. O objetivo do estudo foi determinar a presença de anticorpos contra Rickettsia spp. em cães de São José dos Pinhais, estado do Paraná, Sul do Brasil. Entre fevereiro de 2006 e julho de 2007, amostras séricas de 364 cães foram coletadas e testadas na diluição de 1:64 por Reação de Imunofluorescência Indireta (RIFI) contra R. rickettsii e R. parkeri. Todos os soros reagentes para pelo menos uma espécie de Rickettsia foram testados contra as seis principais espécies de Rickettsia identificadas no Brasil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii e R. felis. Dezesseis amostras (4,4%) reagiram para pelo menos uma espécie de Rickettsia. Dos animais positivos, dois cães (15,5%) apresentaram títulos sugestivos de exposição a R. bellii. Uma amostra apresentou reação homóloga frente à R. felis, um agente patogênico confirmado para seres humanos. Muito embora os resultados demonstrem uma baixa prevalência de Rickettsia spp. em cães, sugerindo um baixo risco de infecção humana, este estudo relatou pela primeira vez a evidência de exposição a R. bellii e R. felis em cães no Sul do Brasil.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Abordagens subzigomática e infraorbitária para o bloqueio do nervo maxilar em cadáver de gatos

This study compared the accuracy of dye placement on the maxillary nerve by using the percutaneous subzigomatic (SBZ) and infraorbitary (IO) approaches in cats’ cadavers. A second aim was to compare the accuracy of dye placement on the maxillary nerve between different untrained anesthetists. This was a prospective, randomized, blinded study, performed in 40 heads obtained from feline cadavers. Three veterinarians (A, B and C) with no previous experience with the IO approach performed the experiments. The SBZ approach was randomly performed on one side of the head and the IO approach was performed in the contralateral side of the same head. For each approach, 0.2ml of 1% methylene blue dye was injected. Scores for length of nerve staining were as follows: 0 (failure), no staining; 1 (moderate), <6mm of nerve stained; and 2 (ideal), ≥6mm of nerve stained. Median scores (interquartile range) for the SBZ and IO approaches were 2.0 (0.3-2.0) and 1.0 (0.0-2.0), respectively. Scores for length of nerve staining were higher with the SBZ approach than the IO approach (P=0.016). Considering the scores for both the SBZ and IO approaches, there was a significant difference among the three veterinarians (P=0.002). Results of this study do not support the IO approach to perform a maxillary nerve block in cats. A greater accuracy of methylene blue dye placement was observed with the SBZ approach. A variable accuracy may exist between different veterinarians when performing a maxillary nerve block employing the SBZ and IO techniques in cats.O objetivo deste estudo foi comparar o acesso do nervo maxilar pela abordagem subzigomática (SBZ) com a abordagem pelo forame infraorbitário (IO) em peças anatômicas de gatos utilizando o corante azul de metileno. Um segundo objetivo foi comparar a acurácia na coloração do nervo maxilar com o azul de metileno entre diferentes anestesistas que não receberam treinamento prévio. Este estudo foi prospectivo, randomizado, cego, realizado em 40 peças anatômicas de cabeças de gatos. Três veterinários (A, B e C), sem experiência prévia da abordagem IO, realizaram o experimento. A abordagem SBZ foi aleatoriamente realizada em um dos lados da cabeça e a abordagem IO foi realizada no lado contralateral da mesma peça anatômica. Para cada abordagem, utilizou-se 0,2mL do corante azul de metileno 1%. Classificou-se o escore de coloração baseado no comprimento do nervo maxilar corado pelo azul de metileno conforme a escala: 0 (falha da técnica), sem coloração; 1 (moderado), <6mm de coloração do nervo maxilar; 2 (ideal), ≥6mm de coloração do nervo maxilar. As medianas (intervalo interquartil) para as abordagens SBZ e IO (dados de todos os veterinários juntos) foram respectivamente 2,0 (0,3-2,0) e 1,0 (0,0-2,0). A abordagem SBZ foi associada a um escore de coloração, significativamente, maior do que a abordagem IO (P=0,016). Considerando os escores de ambas abordagens (SBZ e IO), houve diferença significativa nos escores de coloração do nervo maxilar entre os três veterinários anestesistas (P=0,002). Os resultados deste estudo não sustentam a utilização da abordagem IO para a realização do bloqueio maxilar em gatos. Uma melhor acurácia na coloração do nervo maxilar com o azul de metileno foi observada com a abordagem SBZ. A acurácia da técnica pode variar quando as abordagens SBZ e IO são realizadas por veterinários diferentes, com o objetivo de se obter o bloqueio do nervo maxila

Enteropatia proliferativa por Lawsonia intracellularis em coelhos no Sul do Brasil

Proliferative enteropathy (PE), also known as ileitis, is a disease caused by the bacterium Lawsonia intracellularis. This disease is characterized by diarrhea and ill-thrift. The aim of this study is to describe a PE outbreak in rabbits that occurred in Southern Brazil. The farm had 700 rabbits at the time the outbreak occurred. The clinical signs were severe diarrhea, dehydration, and apathy. Necropsy was performed in 33 rabbits, and the most evident macroscopic findings were thickening of the intestinal wall, intestinal loops distended by large amounts of gas, and liquid feces. Histopathological examination demonstrated a marked proliferation of enterocytes in intestinal crypts, decrease number of goblet cells, and crypts microabscesses. Silver impregnation technique (Warthin-Starry) demonstrated in intestinal crypts inside of enterocytes cytoplasm, curved vibrioid bacteria compatible with L. intracellularis. Immunohistochemical staining with anti-L. intracellularis confirmed the agent presence. PCR was performed and L. intracellularis was confirmed as the etiological agent.A enteropatia proliferativa (EP), também conhecida como ileíte, é uma doença causada pela bactéria Lawsonia intracellularis, que é caracterizada por diarreia com redução do ganho de peso. O objetivo deste trabalho é descrever um surto de EP em coelhos na região sul do Brasil. A propriedade possuía 700 coelhos, durante o período do surto. O quadro clínico caracterizava-se por diarreia severa, desidratação e apatia. Realizou-se o exame de necropsia em 33 coelhos, e as alterações macroscópicas mais evidentes eram; alças intestinais acentuadamente distendidas por gás e fezes líquidas, além de serosa rugosa e parede intestinal moderadamente espessada. Na análise histopatológica do intestino delgado visualizou-se marcada hiperplasia de enterócitos de criptas, moderada diminuição do número de células caliciformes e microabscessos de criptas. A etiologia das lesões foi confirmada pela técnica de impregnação pela prata (Warthin-Starry), evidenciando bactérias vibrioides compatíveis com L. intracellularis no ápice de enterócitos das criptas intestinais. Ainda, foi obtida imunomarcação positiva de enterócitos de criptas na imuno-histoquímica com anticorpo anti-L. intracellularis e a PCR positiva em amostras de intestino

Autochthonous Canine Visceral Leishmaniasis in Urban Area of Porto Alegre, RS, Brazil

Background: Leishmaniasis is a chronic infectious disease caused by intracellular protozoan Leishmania that affects canine and human. The visceral leishmaniasis (VL) is caused by the Leishmania donovani complex, in which canines are the main reservoir for human VL. In Southern Brazil, case reports of this disease have increased, especially when canines are infected in endemic areas in the country. Canines usually present a systemic disease, characterized by cutaneous lesions, weight loss, generalized lymphadenopathy, hepatomegaly and splenomegaly. This report aims to describe the clinicalpathological features of a case of autochthonous VL in a canine of an urban area of Porto Alegre.Case: A male, mixed breed, dog , 7 year-old, resident at the East Side of Porto Alegre, living together with two other canines, presented at clinical examination progressive weight loss, associated with hyporexia and hyperthermia, evolving to lateral recumbency, paralisys, and death. At necropsy, the dog was cachectic with diffusely pale mucosae. Gross findings included liver enlarged, with multifocal firm brownish areas, spleen enlarged, showing multifocal firm round dark-red areas, and kidneys diffusely pale with evidentiated tranversal striations on cortical zone. At microscopic examination, there was on the spleen diffuse inflammatory infiltrate of macrophages with large cytoplasm containing multiple amastigotes. The liver, exhibited atrophy of hepatocytes and moderate multifocal inflammatory infiltrate in sinusoids of macrophages containing multiple amastigotes. These features were also observed moderately on lymph nodes and lamina propria of large intestine. Immunohistochemistry examination showed marked positive staining for Leishmania spp. in amastigotes located whitin the cytoplasm of macrophages of spleen, liver, lymph nodes and large intestine.Discussion: Canine leishmaniasis is a disease that affects both internal organs and skin. However, the condition is called VL mostly because it is associated with the same species that cause the visceral form in humans. In this case the canine presented liver, spleen and lymph node lesions; however no skin lesion was observed during the clinical examination. A serological evaluation of canids in East Side of Porto Alegre performed in 2005 showed that 3.5% of these dogs were positive for Leishmania; yet neither of these animals presented clinical signs. This demonstrates that the agent was already present, however only 3-10% of the canines infected develop clinical disease. In non-endemic areas VL is related to the migration of canids from endemic areas, where VL is common. However the canine here described was born, raised, and was living in Porto Alegre. Lutzomyia longipalpis is the main vector of VL and despite its wide distribution it was identified only in 2009 in Rio Grande do Sul State. Autochthonous cases of VL were reported in canines and humans in this state, confirming the hypothesis that the vector was widely distributed and it is now present in Porto Alegre, keeping the epidemiological cycle of that disease active. Canine VL occurs prior in humans, since canines are the main domestic reservoirs and are critical for the maintenance of this disease cycle. This is the first autochthonous VL in a canine of an urban area of Porto Alegre; therefore authorities should be alert, and new control measures must be taken to avoid the canine leishmaniasis outbreak due to its potential for zoonotic transmission.Keywords: leishmaniasis, canine, protozoan, immunohistochemistry

Spontaneous poisoning by Ricinus communis in sheep

Background: Ricinus communis (castor bean) is an arbustive plant, popularly known in Brazil as “mamona”. This plant is widely distributed both as a weed in pastures and in specific cultures. All parts of the plant are poisonous and contain the toxic substance ricin, especially the seeds, leaves and pericarp. The ingestion of leaves and pericarp may cause neurological signs. Gross findings are unspecific, however the main finding is the presence of leaves and seeds in the ruminal content. This report aims to describe the clinical, epidemiological and pathological features of a spontaneous poisoning by R. communis in two sheep. Cases: During the month of March of 2015, six sheep that were kept in a native pasture with high amounts of capimannoni (Eragrostis plana) and received alfalfa hay, had access in the morning to an area infested by R. communis, which was previously cut. Two of these animals presented in the same day at the afternoon clinical signs of apathy, dyspnea and recumbency, followed by death. The inspection of the area infested by R. communis revealed that large amounts of seeds and leaves of this plant were consumed. The two sheep were submitted to necropsy, where multiple samples were collected and processed routinely for histology. Grossly, there were cyanotic mucosae and alimentary content around the nostrils. The ruminal content was dry and showed large amounts of partially digested leaves and seeds. Microscopically, rumen, reticulum and omasum had mild hydropic degeneration in the mucosa, in addition to a mild inflammatory infiltrate composed of lymphocytes and plasma cells. Discussion: The diagnosis of R. communis poisoning in two sheep was obtained through the epidemiological aspects, such as the observation of the plant consumption, in addition to the clinical and pathological features The observation of digested seeds and leaves in the ruminal content is similar to the previously described in cattle and essential to the diagnosis of the condition, since the gross and microscopic lesions are usually unspecific and mainly characterized by edema and congestion of the digestive tract from the abomasum to the proximal colon. Sheep and cattle poisoned with seeds of R. communis may show gastrointestinal clinical signs mainly. In the present study, however, the clinical course was peracute with only dyspnea and recumbency, suggesting a nervous form of the condition. This form of poisoning is associated to the consumption of dry leaves and clinical signs may be observed within 3-6h after consumption. These are characterized by unbalance walk, muscle tremors, sialorrhea, chewing movements and excessive eructation, and can rapidly progress to death, as in the present study, and in other spontaneous poisoned sheep. The condition should be differentiated from arsenic poisoning, which presents mainly vascular lesions involving the rumen, reticulum and omasum, as well as other poisonings that cause gastroenteritis, such as Baccharis coridifolia poisoning, which culminates with mucosa necrotic lesions involving the pre-stomachs. A high mortality may have occurred due to the food shortage, which in association to the prolonged mastication of ruminants may have increased the ricin release from the seeds and leaves. Ricinus communis poisoning in sheep may occur spontaneously in association with food shortage. The clinical course of these cases may be peracute (neurological form), usually leading to death, with scarse previous clinical signs. The diagnosis of this poisoning should be based on the observation of the previous consumption of the plant, as well as observation of seeds and leaves of the plant intermixed with the ruminal content, since microscopic lesions are rare

Nefroblastoma com metástase linfática em um bezerro Angus: comunicação científica

Nephroblastoma is a congenital renal neoplasm composed of metanephric blastema and stromal cells. A one-year-old male Angus calf presented with diarrhea, nasal discharge, cough and weight loss. Serum levels of creatinine and urea were increased, with reduction in the level of albumin. After eight days, clinical condition got worse and the calf died. On necropsy, the cranial pole of the left kidney presented a firm whitish mass (30 x 21 x 14 cm). Multifocal to coalescing firm whitish nodules were observed on the serosa of the large intestine, in the mesentery and in the adventitia of the urinary bladder. All lung lobes contained multifocal to coalescing firm whitish elevated nodules (0.5 to 1 cm of diameter). Histologically, renal mass consisted of neoplastic proliferation of embryonal epithelial and mesenchymal cells, intermixed with large amounts of blastema cells. The nodules on large intestine, mesentery, urinary bladder and lungs were composed mainly of blastema cells and mild amount of mesenchymal cells. Blastema cells were also observed within lymphatic vessels in lung parenchyma. Embryonal epithelial, mesenchymal and blastema cells showed, respectively, positive immunostain for cytokeratin, vimentin and S100. Based on pathological and immunohistochemical findings, the tumor was diagnosed as nephroblastoma in a calf with metastasis through lymphatic vessels to lungs, large intestine, mesentery and urinary bladder.O nefroblastoma é uma neoplasia renal congênita composta por um blastema metanéfrico e células estromais. Um bezerro Angus, macho, de um ano de idade apresentou diarreia, descarga nasal, tosse e perda de peso. Os níveis de creatinina e ureia estavam aumentados, com albumina diminuída. Após oito dias, a condição clínica piorou e o bezerro veio a óbito. Na necropsia, o polo cranial do rim esquerdo apresentou uma massa brancacenta firme (30 x 21 x 14 cm). Nódulos brancacentos firmes multifocais a coalescentes foram visualizados na serosa do intestino grosso, mesentério e adventícia da bexiga. Nos pulmões nódulos elevados brancacentos firmes (0.5 a 1 cm de diâmetro) multifocais a coalescentes foram observados. Histologicamente, a massa no rim consistia em proliferação neoplásica de células embrionais epiteliais e mesenquimais, entremeadas a grande quantidade de células blastemais. Os nódulos no intestino grosso, mesentério, bexiga e pulmões eram compostos principalmente por células blastemais e discreta quantidade de células mesenquimais. As células blastemais foram também observadas no interior de vasos linfáticos no parênquima pulmonar. As células embrionais epiteliais, mesenquimais e blastemais apresentaram, respectivamente, imunomarcação positiva para citoqueratina, vimentina e S100. Baseado nos achados patológicos e imuno-histoquímicos este caso foi diagnosticado como um nefroblastoma em um bezerro com metástases através de vasos linfáticos aos pulmões, intestino grosso, mesentério e bexiga