Made available in DSpace on 2014-12-17T14:03:42Z (GMT). No. of bitstreams: 1 JoseFlavioVC.pdf: 1066045 bytes, checksum: 95695454c994be62f483dac7ee237cd8 (MD5) Previous issue date: 2005-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Canine Visceral Leishmania (CVL) is an important zoonotic disease that has a world wide distribution and has a large impact on public health on the American Continent, especially in Brazil, where the nature of endemic diseases in humans affects a large part of the nation. The influence of the prevalence of CVL in the increased rate of human cases in endemic areas and in the unleashing of epidemic outbreaks shows the need for a more profound understanding, that would generate significant advances in the current measures used to control the reservoirs of sickness that are practiced by the Programa Nacional de Vigil?ncia e Controle da Leishmaniose Visceral. The present work describes and compares the clinical-laboratorial and histopathological findings of twenty-three dogs that were naturally infected by Leishmania chagasi, from endemic areas in metropolitan Natal, Rio Grande do Norte, Brazil. These animals, that were selected and given physical and serological exams (IFI and ELISA rK-39), were classified according to the degree of clinical severity and had blood samples drawn (whole blood and serum) for a complete hemogram and a coagulogram to be done as well as biochemical tests for kidney and liver function. The confirmation of infection by L. chagasi was done after the euthanasia of the animals, through the direct demonstration of the parasite in the impression of the spleen and liver crowned with GIEMSA and through a cultivation by means of NNN/Schneider. According to the clinical evaluation, the animals were classified as asymptomatic (7), oligosymptomatic (7) and polysymptomatic (9). Among the animals that were chosen to be autopsied, there were 2 asymptomatic, 3 oligosymptomatic and 3 polysymptomatic, for the purpose of studying their histopathology, having collected fragments of the spleen, liver, kidneys and skin and were fixed in 10% tamponed formol. The comparison between the average parameters of the clinical-laboratory tested animals in the groups was done through the Student t test (a<0.05). The main clinical signals observed were lymphadenomegaly, alopecy, dermatitis, exfoliation, cutaneous ulcers, onicogriphosis and emaciation. The main clinical-laboratorial alterations established, mainly in the polysymptomatic group, were anemia, hyperproteinemia, hyperglobulinemia, alterations in the albumin/globulin ratio and increased ALT activity. Renal alterations were not verified (urea and creatinine levels were normal). Thrombocytopenia was observed in three clinical groups. However, the other indicators of coagulation function (TAP and TTPA) did not have abnormal variations. There were inflammatory infiltrations and leishmania amastigotes in the skin of polysymptomatic dogs, however, they were not found in the skin of asymptomatic animals. Hypertrophy and hyperplasia of the phagocyte mononuclear system, leishmania amastigote parasites were found in the macrophages, extramedullary hematopoiesis and degenerative alterations were detected in the spleen and liver of 8 of the animals submitted to histopathological exams. In accord with these results, it was demonstrated that the expected alterations in the hematological and biochemical parameters in function of their viscerotropic nature of CVL are mainly observed in the more advanced stages of the disease. The absence of inflammatory infiltration and parasite load in the skin suggest that infected animals without symptoms may have an importance irrelevant to the infectiousness of the vector / A leishmaniose visceral canina (LVC) ? uma importante zoonose de distribui??o mundial com grande impacto em sa?de p?blica no Continente Americano, especialmente no Brasil, onde a natureza end?mica da doen?a humana afeta boa parte do territ?rio nacional. A influ?ncia da preval?ncia da LVC na amplia??o da taxa de casos humanos em ?reas end?micas e no desencadeamento de surtos epid?micos ainda carece de um entendimento mais profundo, o que geraria avan?os significativos nas atuais medidas destinadas ao controle de reservat?rios da doen?a preconizadas pelo Programa Nacional de Vigil?ncia e Controle da Leishmaniose Visceral. O presente trabalho descreveu e comparou os achados cl?nico-laboratoriais e histopatol?gicos de vinte e tr?s c?es infectados naturalmente pela Leishmania chagasi, provenientes de localidades end?micas da ?rea metropolitana de Natal-RN. Estes animais, escolhidos a partir de exame f?sico e sorologia (IFI e ELISA rK-39), foram classificados de acordo com o grau de comprometimento cl?nico e submetidos a coleta de sangue (sangue total e soro) para realiza??o de hemograma completo, provas bioqu?micas de fun??o renal e hep?tica, e coagulograma. A confirma??o da infec??o por L. chagasi foi realizada ap?s a eutan?sia dos animais, pela demonstra??o direta do parasita em impress?o de ba?o e f?gado corado com GIEMSA e atrav?s de cultivo em meio NNN/Schneider. De acordo com a avalia??o cl?nica, os animais foram classificados em assintom?ticos (7), oligossintom?ticos (7) e polissintom?ticos (9). Dentre os animais necropsiados, foram selecionados 2 c?es assintom?ticos, 3 oligossintom?ticos e 3 polissintom?ticos para o estudo histopatol?gico, sendo colhidos fragmentos de ba?o, f?gado rins e pele e fixados em formol a 10% tamponado. A compara??o entre as m?dias dos par?metros cl?nico-laboratoriais testados nos grupos foi realizada atrav?s do teste t de Student (&#945;<0,05). Os principais sinais cl?nicos observados foram linfadenomegalia, alopecia, dermatite esfoliativa, ?lceras cut?neas, onicogrifose e emacia??o. As principais altera??es cl?nico-laboratoriais estabelecidas, principalmente no grupo polissintom?tico, foram anemia, hiperproteinemia, hipoalbuminemia, hiperglobulinemia, altera??es no ?ndice albumina/globulina e aumento da atividade da ALT. Altera??es renais n?o foram verificadas (ur?ia e creatinina normais). Trombocitopenia foi observada no tr?s grupos cl?nicos, contudo, os outros indicadores da fun??o de coagula??o (TAP e TTPA) n?o apresentaram varia??es anormais. Foi observado Infiltrado inflamat?rio e amastigotas de leishmania na pele de c?es polissintom?ticos, por?m n?o na pele de animais assintom?ticos. Hipertrofia e hiperplasia do sistema fagocit?rio mononuclear, macr?fagos parasitados por amastigotas de leishmania, hematopoiese extramedular e altera??es degenerativas foram detectadas no ba?o e f?gado dos 8 animais submetidos a exame histopatol?gicos. De acordo com esses resultados, foi demonstrada que as altera??es esperadas nos par?metros hematol?gicos e bioqu?micos em fun??o da natureza viscerotr?pica da LVC s?o observadas principalmente em est?gios mais avan?ados da doen?a. A aus?ncia de infiltrado inflamat?rio e carga parasit?ria na pele sugerem que animais infectados sem sintomatologia talvez tenham import?ncia irrelevante na infectividade para o vetor