Surtos de anaplasmose bovina na Bahia: aspectos clínicos, laboratoriais e anatomopatológicos

Abstract

Bovine anaplasmosis is a disease caused by rickettsia Anaplasma marginale, a compulsory intraerythrocyte parasite. Epidemiological studies show that one of the main risk factors for the appearance of anaplasmosis in the properties is the movement of cattle from areas of enzootic instability and also free areas of tick Rhipicephalus microplus to regions of enzootic stability. This animal transport management is frequent in Bahia, especially in dry seasons, where producers of semi-arid regions sell their animals to producers of areas with higher incidence of rainfall, and this has led to the appearance of bovine anaplasmosis frequently in the state. Thus, the present study aimed to report two outbreaks of bovine anaplasmosis in two municipalities of Bahia. One took place in December 2017 in Maragogipe, Recôncavo region and the other in the Low South in April 2019, in the municipality of Jaguaripe. In both cases, the animals were of the Nelore breed (Bos taurus indicus) and were moved from areas considered of enzootic instability (municipalities of Rafael Jambeiro and Guanambi - BA) to one of enzootic stability and introduced in the lots. According to the ranchers, 30 to 60 days after the arrival of the new cattle, some showed signs of aggression, isolation of the herd, weight loss, appetite reduction, dry stools, prostration, tremors, evolving to death. Clinical examination revealed tachycardia, tachypnea, reduced ruminal movements, elevated rectal temperature, icteric ocular mucosa, enlarged lymph nodes and signs of dehydration. In addition, there were tick infestations in the herds. Blood counts and ear smears were performed. All tests showed intense anemia with signs of regeneration, active infectious process, and the presence of A. marginale in all slides, confirming, together with the clinical signs, the diagnosis of Anaplasmosis. Herd treatment with Imidocarb Dipropionate (3 mg / kg bodyweight subcutaneously) and parenteral hydration was recommended. Subsequently the animals were properly treated eliminating the disease and ceasing the deaths of the herd. Given this, it is concluded that breeders in the Recôncavo Baiano and Baixo Sul region of Bahia should be careful when introducing animals to the herd, especially when coming from regions of enzootic instability. In addition, it is recommended to use prophylactic methods such as the use of vaccines or chemoprophylaxis, and concomitantly to control ticks and hematophagous diptera.