Bovine babesiosis (Piroplasmosis, Texas fever, redwater, tick fever) is a febrile, tick-borne disease of cattle, caused by one or more protozoan parasites of the genus Babesia and generally characterized by extensive erythrocytic lysis leading to anemia, icterus, hemoglobinuria, and death.

There are probably at least six Babesia species responsible for bovine babesiosis. Most can be categorized as being small or large Babesia. Morphological and serological differences are used to distinguish the different species. The two that are of most concern in our country are Babesia bigemina and Babesia bovis which are inflecting considerable losses to the livestock especially cattle.

The present study was conducted to find out the prevalence of babesiosis in cow calves at livestock experimental station Qadir Abad and adjacent areas of District Sahiwal and to find out the comparative efficacy of two babesicidal drugs i.e Fa-try-banil (diminazene aceturate) Prix Pharmaceutica. Lahore, Pakistan and Imizol (Tmidocarb dipropionate) ICI, Pakistan. In this study effect of babesiosis on different blood parameters i.e hemoglobin estimation and total ervthrocytic count was also studied.

For this purpose 415 calves were examined for the presence of babesiosis. Out of these 30 calves were found positive showing 7.2 percent prevalence. For treatment purpose 40 calves were selected randomly i.e. 30 infected and 10 healthy. i'hcse were divided into 4 groups A, B, C and D comprising 10 animals each. Diagnosis was confirmed on the basis of blood smear method. The animals of group A were treated with Fa-try-banil (dirninazene aceturate) @ 3.5 mg/kg body weight intramuscularly at day zero.

Four out of 10 calves recovered at 3" of injection, one calf recovered 7 day of 1S' injection, 4 calves recovered at 10th day of injection. This drug showed 90% efficacy while the calves of group B were treated with Imizol (Imidocarb dipropionate) lml/l00 kg body weight at day zero. Seven out of 10 calves recovered at 3rd day of injection, two recovered at 7 day of injection and remaining recovered at l0" day of 1S1 injection. This drug showed 100 percent efficacy at 10th day. Animals of group C served as infected untreated control and group D served as healthy non-infected control. Comparative efficacy of both the drugs was determined on the basis of disappearance of clinical signs and babesia from the blood. No side effects of the drugs were noted.

Haematological examination revealed a significant decrease in haemoglobin concentration and total erythrocytic count pre-medication. It has been observed from the present study that Imizol was the drug of choice for the treatment of babesjosis in calves.