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Human visceral leishmaniasis is endemic in the northeast of Brazil, where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. In this study, we evaluated the clinical signs of canine visceral leishmaniasis (CVL), serum protein profile and the antileishmanial IgG antibody production in 86 dogs living in northeast endemic areas of leishmaniasis. Thirty dogs from a leishmaniasis-free area were used as a control group. The major clinical signs of CVL seen were emaciation and skin ulcers (80%), followed by onychogryphosis and conjunctivitis (73%). Depilation was observed in 60% of animals while lymphadenomegaly, splenomegaly, liver enlargement or kidney involvement was less frequent (< or =20%). VL seropositive dogs presented with serum hyperproteinemia, hypoalbuminemia, hypergammaglobulinemia and decreased albumin/globulin ratio. A lower sensitivity and higher specificity was observed for promastigote indirect fluorescent antibody test (IFAT) (83 and 100%, respectively) compared with enzyme-linked immunosorbent assay (ELISA) (94 and 90%), which uses a crude extract of Leishmania. There was a positive correlation between IFAT and ELISA titers of antileishmanial IgG antibodies (Spearman test, P < 0.05), which was augmented in CVL dogs. This study found that the determination of serum protein, A/G ratio and the use of two different leishmanial serological tests like IFAT and ELISA are essential in CVL screening.

Recently, an unknown disease, 'sudden death', in calves has been found in Japanese beef production farms. A previous study conducted by Taira and Ura indicated that sudden death can be effected in calves by hyperinfection of Strongyloides papillosus (SPL) and that the disease is possibly caused by SPL infection. In the present work, an experimental infection of SPL in calves was conducted to confirm the field occurrence. Fifteen Holstein Friesian calves, ranging from 45.5 to 85.6 kg in body weight, were divided into six groups. Calves of Groups A, B, C, D, E and F were infected once at the rate of 100,000, 320,000, 1,000,000, 3,200,000, 10,000,000 and 32,000,000 SPL larvae per 100 kg of body weight, respectively. Five calves were assigned to Group B, while two calves were assigned to the other groups. After showing no premonitory signs, sudden death of ten calves took place. The survival time of these calves was 27.4 and 16.8 days (Group B), 14.8 and 14.8 days (Group C), 13.3 and 14.2 days (Group D), 11.0 and 11.1 days (Group E) and 11.6 and 10.8 days (Group F). Three calves of Group B did not exhibit sudden death. The results of this study demonstrate that strongyloidiasis was the cause of sudden death.