Trypanosoma evansi infections in Himalayan black bears (Selenarctos thibetanus)

The Asiatic or Himalayan black bear (Selenarctos thibetanus) is an endangered species. In South Asian countries, captive tamed Himalayan bears are commonly used by roving bear-charmers to entertain the people in rural and urban areas. In captivity, this species confronts several psychophysical traumas and communicable diseases, which are prevalent in other domestic species. The present report describes four cases of Trypanosoma evansi infection in live Himalayan charming bears, which originated from the Faisalabad and Jhang districts of Pakistan. The condition was characterized by pyrexia, accelerated pulse, tachypnea, depression, anemic mucous membranes, and ataxia (n = 3). Microscopic examination of peripheral blood films revealed moderate (n = 2) or high (n = 2) numbers of T. evansi. All four bears were treated twice at 3-day intervals with suramin sodium by using almost twice the dosage recommended for common domestic animals (10 mg/kg). The treated bears were found aparasitemic on repeat blood testing on days 5, 7, and 10 post-treatment. No adverse effects were noted and all four cases recovered in 3-7 days after completion of the second round of treatment. One bear died 8 days after the second treatment (day 11). This is the first report of T. evansi in bears.