Diagnosis and therapeutic management of horses infected with Trypanosoma evansi

Abstract

Equine trypanosomiosis caused by Trypanosoma evansi is an important disease owing to high susceptibility and mortality throughout the world including India. In the present study a total of seventeen (n=17) horses tested positive for presence of T. evansi were evaluated for diagnosis and therapeutic management with two drugs (Quinapyramine sulphate and chloride, Isometamidium HCl) along with supportive therapy. The horses were diagnosed for presence of T. evansi by two methods i.e. based on clinical signs, thin blood smear with Geimsa stain. Among 72 horses, 17 (23.61%) showed clinical signs of T. evansi whereas 14 (19.44%) were found positive for T. evansi infection as observed by examination of Giemsa stained blood smears. Diagnosis of T. evansi based on the clinical signs and blood smear examination were found to be appropriate in clinical cases. Surra positive animals were divided into two group. GroupI (n=8) received quinapyramine sulphate and chloride whereas Group II (n=9) were treated with isometamidium chloride HCl . Apart from this, the horses of both the Groupoups were administered Dextrose 25%, DNS intravenously and Tribivet intramuscular. Moreover, Meloxicam was used as common NSAID for both the Groupoups. The horses which manifested stiffness as one of the clinical signs were administered with Phenylbutazone. Supportive therapy and NSAID were used for at least 3 days or depending upon severity of infection. In GroupI, following the treatment three horses died on 2nd, 3rd and 38th day post treatment (PT), respectively whereas, in Group II, three horses died on 1st, 2nd and 4th day PT, respectively. After a period of two month and 17 days PT, two horses of GroupII were suspected for T. evansi. Examination of Geimsa stained blood smears of these horses revealed presence of T. evansi which indicated possible reinfection.