Sílvia Regina Ricci Lucas

Toxoplasma gondii infection in Brazilian domestic outpatient cats

The occurrence of Toxoplasma antibodies in domestic outpatient cats in the city of São Paulo was evaluated using the indirect immunofluorescence assay. A total of 248 blood samples obtained from male and female cats seen at the Veterinary Teaching Hospital at the University of São Paulo between February 1996 and January 1997 were tested. Of these, 17.7% were positive, with a 64 titer being detected in most animals. The frequence of Toxoplasma antibodies was significantly higher in older cats, those fed raw meat and those with free access to the outdoor environment. There was no significant difference in reactivity between males and females. We conclude that diet and free access to the outdoor environment were equally important as predisposing factors to the risk of Toxoplasma infection.

Ocorrência de anticorpos antitoxoplasma em gatos infectados naturalmente pelo vírus da imunodeficiência dos felinos

Foram avaliadas, pela tecnica de imunofluorescencia indireta, a frequencia e a magnitude dos titulos de anticorpos antitoxoplasma (Toxoplasma gondii, Nicolle; Manceaux, 1909), em gatos infectados naturalmente pelo virus da imunodeficiencia dos felinos (VIF). Utilizaram-se 115 amostras de soro sanguineo de gatos negativos ao virus da leucemia felina que foram divididas em 3 grupos. Os 22 animais do grupo I eram positivos ao VIF. Os 58 animais que compuseram o grupo II eram doentes porem negativos na pesquisa de anticorpos anti-VIF e os 35 felinos do grupo III eram higidos e negativos ao VIF. Os resultados obtidos permitiram concluir que a frequencia de anticorpos antitoxoplasma foi maior no grupo I do que nos grupos II e III. A analise estatistica mostrou forte associacao entre a infeccao pelo VIF e a presenca de anticorpos antitoxoplasma. Nao se observou diferenca entre a magnitude dos titulos de anticorpos antitoxoplasma nos animais positivos e negativos ao VIF. Embora gatos que desenvolvam imunidade raramente eliminem oocistos, nao se sabe exatamente como esta imunidade pode influenciar a eliminacao de oocistos naqueles gatos infectados pelo VIF. Em face da alta frequencia de anticorpos antitoxoplasma observada nos animais positivos ao VIF, acredita-se que todos os gatos positivos a esse virus devam ser avaliados quanto a presenca de anticorpos antitoxoplasma.

Skin fragility syndrome in a cat with cholangiohepatitis and hepatic lipidosis

A case of acquired skin fragility syndrome associated with hepatic disease in a 9-year-old, spayed female, domestic shorthair cat is described. The cat was admitted to the veterinary hospital of the University of São Paulo (Brazil) with a 6-week history of vomiting, inappetence and weight loss. Remarkable signs were weakness, lethargy and profound jaundice that had been present for 10 days according to the owner. On completion of the physical examination, when the cat was gently manipulated for blood collection the thoracic limb and interscapular skin tore. Liver enzymes and bilirubin levels were all above the normal range. On histological examination of skin and liver, Massons trichrome stain showed collagen fibre alteration and major hepatocyte abnormalities. Findings were consistent with feline skin fragility syndrome associated with cholangiohepatitis and hepatic lipidosis.

Serum amyloid A is not a marker for relapse of multicentric lymphoma in dogs

BACKGROUND Serum amyloid A (SAA) is an acute phase protein whose concentration increases in inflammatory, infectious, and neoplastic conditions in animals and human beings. Multicentric lymphoma is a common cancer in dogs, and chemotherapy is indicated to attain long-term survival. However, frequent relapses lead to changes in chemotherapeutic protocols. OBJECTIVES The aims of this study were to evaluate SAA as a marker for relapse of multicentric lymphoma in dogs and to determine whether chemotherapy induces changes in the concentration of SAA during treatment. METHODS SAA was measured by an ELISA test in healthy control dogs (n=20), in healthy dogs receiving chemotherapy (n=8), and in dogs with lymphoma (n=20). All dogs receiving chemotherapy were randomly assigned to 2 treatment groups, one receiving cyclophosphamide, vincristine, and prednisone (CVP) and the other receiving vincristine, cyclophosphamide, methotrexate, and L-asparaginase (VCMA) protocols. SAA concentration was determined before chemotherapy at weeks 1-4 in healthy dogs receiving chemotherapy and in dogs with lymphoma, then every 3 weeks for 4 months in healthy dogs, and at relapse and in the sample prior to relapse in dogs with lymphoma. SAA was measured only once in the healthy control dogs. Results were analyzed using repeated measures ANOVA followed by Tukey multiple comparison tests to compare groups and weeks of treatment. RESULTS Mean SAA concentration was significantly higher in dogs with lymphoma before chemotherapy compared with healthy and chemotherapy control dogs. No increase in SAA concentration was found at relapse. No differences were observed in SAA concentration based on type of chemotherapy protocol. CONCLUSIONS SAA is not a marker of relapse in dogs with multicentric lymphoma, nor does chemotherapy regimen affect SAA concentration.

Carmustine, Vincristine, and Prednisone in the Treatment of Canine Lymphosarcoma

A chemotherapeutic protocol using carmustine in combination with vincristine and prednisone was tested in dogs with multicentric malignant lymphosarcoma. Of seven dogs treated, six (85.7%) achieved complete remission. A partial response occurred in one dog. Median survival time was 224 days (mean 386 days), and median duration of remission was 183 days (mean 323 days). Marked neutropenia was observed following carmustine administration. There were no significant alterations in platelets and red blood cell counts during treatment, and no abnormalities attributable to the chemotherapy were found in serum biochemical profiles. Results of this study showed that carmustine is an effective alternative option in the treatment of canine lymphosarcoma.

Valores de referência das provas de funções hepática, renal e de alguns eletrólitos em Cebus apella, anestesiados com cetamina

Blood serum samples obtained from 127 Capuchin monkeys, anesthetized with ketamine, were analysed. Hepatic function tests (total protein, albumin, glucose, bilirrubins and enzimatic activity of ALT, AST and ALP), renal function tests (urea and creatinine), and some electrolytes (sodium, potassium, chloride, calcium and inorganic phosphorus) were quantified. Differences related to sex and age were studied. Among the hepatic function tests, the values of ALP and ALT were higher in the young animals, while the levels of AST were higher in the young males when compared to adult males. The albumin parameters were more elevated in adult males and females than in young males and the total protein showed higher in adult females. In relation to the renal function tests, the levels of creatinine were more elevated in adult males and the urea were more elevated in young males than in adult animals. Chloride were higher in young females while sodium showed more elevated in adult males than young females.

Fragilidade osmótica eritrocitária em gatos acometidos por hepatopatias e gatos com insuficiência renal

Erythrocyte osmotic fragility (EOF) evaluates the resistance of red blood cells to saline solution of decreasing concentrations. Cells resistance is related to their shape, volume and size, as well as to the hemoglobin content and half life and can be altered by physiologic or pathologic mecanisms. There are few descriptions and litlle is known about EOF in cats. To clear up this point, EOF of healthy cats, and those with liver disease and cats with renal failure were studied. Twenty-seven adult cats were divided in three groups. Hemolysis 50% occurred similarly in all groups, although relevant differences in relation to 100% hemolysis were found. Erythrocyte from cats with renal failure and from icteric animals with hepatic disease showed higher osmotic fragility and elevated cholesterol serum levels when compared to those belonging to the control group. These findings may be associated to the metabolic characteristics of this specie.

Evaluation of preprandial and postprandial serum bile acids and plasma ammonia concentrations in healthy domestic cats and the effects of frozen storage on plasma ammonia concentrations

Preprandial and postprandial (2 and 4 hours) serum bile acids (SBA) and pre and postprandial (2 hours) plasma ammonia concentrations were evaluated. Additionally, the effects of freezing (for 24 and 48 hours at -20oC) were observed on plasma ammonia concentrations in 22 healthy dogs. The preprandial SBA concentration was 2.1 ± 0.3 mmol/l and 7.5 ± 1.2 mmol/l and 7.8 ± 1.4 mmol/l for samples obtained 2 and 4 hours after feeding, respectively. Fasting and postprandial (2 hours) plasma ammonia concentrations were significantly different when measurement was performed within 30 minutes after blood collection (118.2 ± 13.2 mg/dl or 67.3 ± 7.5 mmol/l and 227.9 ± 59.2 mg/dl or 129.9 ± 33.7 mmol/l), but the difference between pre and postprandial concentrations was not observed when ammonia was measured in samples stored (-20o) for 24 and 48 hours. Plasma freezing makes ammonia concentrations fall considerably when these levels were initially too high, mainly in postprandial samples. From these results it may be suggested that canine plasma cannot be stored for later ammonia determination by using freezing as the sole stabilizer, and for SBA determinations, blood samples might be collected 2 or 4 hours after feeding. Plasma ammonia values obtained in this study should allow comparisons to data obtained from dogs with hepatic disease or hepatoencephalopathy, so as to confirm the importance of its use as means of diagnosis and prognosis in future.