Occurrence of Trypanosoma evansi in Horses in the State of Minas Gerais, Brazil

Ttrypanosomosis caused by Trypanosoma evansi is a condition that causes significant losses to farmers in endemic areas. This study aimed to report one case of trypanosomiasis in the municipality of Itabira, state of Minas Gerais, Brazil. In November 2010, on a farm with 16 horses, three horses had clinical signs of anemia, limb edema, weight loss, lameness, muscle atrophy, and incoordination of the hind limbs. Trypanosomosis was suspected, and the animals with clinical signs were treated with two doses of diminazene aceturate (7 mg/kg, intramuscular) every 7 days; the treated animals recovered from the clinical symptoms. Blood samples were collected from six horses on the farm, including the three treated animals, to perform polymerase chain reaction specific for T evansi. Four samples were polymerase chain reaction negative, including those collected from three treated horses. However, two other asymptomatic horses were positive for the parasite based on the molecular testing. Based on the results, we concluded that the initial clinical suspect of trypanosomosis was correct, and the treatment used was effective. Probably the disease was introduced to Minas Gerais State through a stallion, which acquired the infection in an endemic area in southern Brazil.