Daniela Bernadete Rozza

Morphological changes and parasite load of the adrenal from dogs with visceral leishmaniasis

The objective of this study was to analyze morphological changes and parasite loads in the adrenal gland from 45 dogs with visceral leishmaniasis (VL). The animals were from the Zoonosis Control Center of Araçatuba, state of São Paulo, which is an endemic region for the disease. These animals were euthanized due to positive diagnoses of VL. The dogs were classified into asymptomatic, oligosymptomatic and symptomatic groups. The parasite load was determined by immunohistochemistry, using VL-positive dog hyperimmune serum. Nine dogs showed an inflammatory infiltrate composed, predominantly, of plasma cells and macrophages. However, only eight dogs showed macrophages with amastigote forms of the parasite, immunolabeled in the cytoplasm. The medullary and reticular layers were the most affected areas, possibly due to a favorable microenvironment created by hormones in these regions. The density of parasites in the glandular tissue was not associated with clinical signs of VL (P > 0.05). However, the presence of the parasite was always associated with the presence of a granulomatous inflammatory infiltrate. This gland may not be an ideal place for the parasites multiplication, but the presence of injuries to the glandular tissue could influence the dogs immune system, thus favoring the parasites survival in the hosts different organs.

Intoxicação por veneno de sapo em um canino

The toads of the genus Bufo produce, in their parotoid glands, a mucoid secretion containing toxins such as bufagins and Bufotoxins, which are cardiogenic steroids. The mucous membranes of dogs can absorb this venom when they attack the toads. A French bulldog with a history of probable toad venom intoxication was referred to Veterinary Pathology Section of Federal University of Rio Grande do Sul (UFRGS) for necropsy. The necropsy revealed enlarged, reddish, edematous lungs, and kidneys displaying a dark red color. The microscopic alterations indicated the presence of congestion, hemorrhage, and pulmonary edema. Congestion was observed in the kidneys, spleen and lymph nodes. The routine toxicological analyses for venom detection were negative. Nevertheless, the toad venom test result was positive as assessed by thin layer and gas chromatography, indicating that toad venom intoxication was the cause of death.

Mecanismos da intoxicação do fígado de rato causada pelo gossipol

ABSTRACT.- Carvalho W.L., Maioli M.A., Mendes L.C.N., Rozza D.B. & Mingatto F.E. 2013. [Mechanisms of the intoxication of rat liver caused by gossypol.] Mecanismos da into-xicacao do figado de rato causada pelo gossipol. Pesquisa Veterinaria Brasileira 33(3):339-344. Curso de Zootecnia, Campus Experimental de Dracena, Universidade Estadual Pau-lista, Rodov. Comandante Joao Ribeiro de Barros SP-294 Km 651, Dracena, SP 17900-000, Brazil. E-mail: fmingatto@dracena.unesp.brThe liver plays a central role in metabolism due to its interposition between the diges-tive tract and the general circulation of the organism. It is also the main organ involved in biotransformation of exogenous substances (xenobiotics), with ability to convert hydro-phobic compounds in water-soluble, more easily eliminated by the body. Gossypol is a toxic phenolic substance present in cotton seed ( Gossypium sp.). Aiming to study the mechanis-ms involved in the hepatotoxicity of gossypol we evaluate its effects on the antioxidant system of rat liver performing an experiment that investigated the oxidative stress and the histopathological alterations. In this study, we used Wistar rats, divided into two groups, one that received canola oil (vehicle, Control group) and another that received gossypol at a dose of 40mg/kg body weight of the animal for 15 days (Treated group). The treatment with gossypol caused alterations in the activity of seric enzymes that indicate hepatic in-jury and a significant oxidative stress characterized by a decrease of reduced glutathione (GSH) levels and a consequent increase in oxidized glutathione (GSSG), including further damage to the plasma membrane and organelles showed by lipid peroxidation. The result of histopathological evaluation showed degeneration of the hepatocytes.

Disseminated Transmissible Venereal Tumour Associated With Leishmaniasis in a Dog

This report addresses an atypical transmissible venereal tumour in an 8-year-old bitch that was pluriparous and seropositive for leishmaniasis. There were ascites and a serosanguineous discharge from the vulva, but no lesions on the external genital mucosa. An aspirate of the peritoneal fluid showed mononuclear round cells characteristic of transmissible venereal tumour (TVT). Exploratory laparotomy revealed light red, granulomatous structures in the peritoneum, omentum, spleen, liver and uterine horns. Cytological and histopathological tests confirmed the diagnosis of intra-abdominal TVT. Dissemination of the TVT to several organs inside the abdominal cavity probably resulted from immunosuppression caused by leishmaniasis, which favoured the presence and aggressiveness of TVT.

Miocardite chagásica em caninos no Estado do Rio Grande do Sul

Acute Chagas disease caused sudden death in two dogs from Porto Alegre rural zone of, Rio Grande do Sul, southern Brazil. A 9-month-old Pit Bull male (dog 1) and a 2-year-old Labrador Retriever female (dog 2) died in January 2005 and May 2008, respectively. At necropsy, the hearts were enlarged. In dog 2, heart was remarkably globoid with multiple pale areas scattered in the myocardium, especially in the right ventricle. Heart chambers, especially in the right side, were dilated. Histological findings were similar in both cases and consisted of diffuse non suppurative myocarditis predominantly with lymphocytic interstitial infiltrates. Within myocardial fibers were observed pseudocysts filled with amastigotes forms of Trypanosoma cruzi. Serologic test TESA-blot resulted positive in samples from dog 2 and showed IgM e IgG anti-T.cruzi antibodies characteristic of acute Chagas disease. The results indicate that Trypanosoma cruzi infection must be considered in the differential diagnosis of sudden death in dogs in southern Brazil and that the specie may act as a reservoir and sentinel for the disease in human beings.

Immunodetection of myeloid and plasmacytoid dendritic cells in mammary carcinomas of female dogs

Dendritic cells have attracted great interest from researchers as they may be used as targets of tumor immune evasion mechanisms. The main objective of this study was to evaluate the relationship between the dendritic cells (DCs) subpopulation in simple type mammary carcinomas in female dogs. Two groups of samples were used: the control group consisted of 18 samples of mammary tissue without changes and the tumor group with 26 simple type mammary carcinomas. In these groups, we evaluated the immunodetection of immature and mature myeloid DCs, plasmacytoid DCs and MHC-II. In mammary tumor, mature myeloid DCs predominated in the peritumoral region, while immature myeloid DCs and plasmacytoid DCs were evident in the intratumoral region. Immunostaining of MHC-II was visualized in mammary acini (control group), in tumor cells and inflammatory infiltration associated with tumors. The comparison between the control and tumor groups showed a statistically significant difference between immature myeloid DCs, mature myeloid DCs and plasmacytoid DCs. The immunodetection of MHC-II was not significant when comparing the groups. The predominance of immature DCs in the tumor group is possibly related to an inefficient immune response, promoting the development and survival of tumor cells. The presence of plasmacytoid DCs in the same group suggests a worse prognosis for female dogs with mammary tumors. Therefore, the ability of differentiation of canine dendritic cells could be influenced by neoplastic cells and by the tumor microenvironment.

Granulomatous rhinitis in a case of feline leishmaniasis

This is a case report of leishmaniasis with granulomatous rhinitis in a 2-year-old domestic cat. Clinically, an obstruction in the right nostril was observed, with cytopathological examination positive for Leishmania sp. Euthanasia was performed, and multinodular, diffuse and smooth pinkish lesions were observed in the mucosa of the nasal cavity. Microscopically, nodular lesions corresponded to an intense granulomatous inflammation with macrophages containing large numbers of Leishmania sp. amastigotes. Macrophages containing amastigotes were also occasionally observed in the popliteal lymph node, skin, and spleen. Based on immunohistochemistry, amastigotes were confirmed as Leishmania sp. and Leishmania sp. DNA was also detected by qPCR in lymph nodes samples. Although it is an uncommon manifestation, leishmaniasis should be considered as a differential diagnosis in diseases affecting the nasal cavity in domestic felines.