Clinical and laboratorial evaluation of Nellore cattle experimentally infected with Trypanosoma vivax

In order to evaluate the clinical-laboratorial alterations, six Nellore calves were inoculated with 10(7) Trypanosoma vivax isolated from Pocone region, Mato Grosso, Brazil. The animals were evaluated daily for rectal temperature, packed cell volume (PCV), parasitemia, antibody production, color of mucous membranes, behavior and appetite. Blood and serum samples for biochemical evaluation for aspartate aminotransferase (AST), alkaline phosphatase (AF), gamma glutamyltransferase (GGT), cholesterol, urea, creatinine, creatine kinase (CK), calcium, phosphorus and proteinogram were collected oil days 4, 8, 12, 16, 23 and 30 Post inoculation (DPI). During the following 6 months rectal temperature, PCV and parasitemia were evaluated weekly T vivax was evidenced from I DPI in all calves and persisted until day 30 ill five of six animals. A remarkable decrease (p<0.05) of PCV mean value (25%) was observed oil 10 DPI. The animals presented no alterations in their clinical or serum biochemical state during the trial. Seroconversion took place 6 and 8 DPI, and all the animals remained seropositive during the 30 days of experiment. In all the experimental animals the occurrence of T vivax infection was verified, characterized by the increase of corporal temperature, presence of the blood protozoa and reduction of the globular volume, without alterations in the other variables analyzed. Nellore calves, when experimentally inoculated with T vivax, are able to establish a balance between host-parasite relationship.