PARASITOLOGICAL AND MOLECULAR CHARACTERIZATION OF A VENEZUELAN ISOLATE OF Babesia canis

Babesiosis is one of the most important tick-borne hemoproto-zoan diseases that affects dogs worldwide. In the last years, there has been a sharp increase in positive cases of Babesia canis infection in the Falcon State, Venezuela. Although recent studies conducted in South America suggest that B. canis vo-geli might be the species present in Venezuela, no data on the pathogenesis and molecular characteristics of Venezuelan pi-roplasms are available at this moment. By this reason the pres-ent work was undertaken to describe the evolution of an ex-perimental infection induced in dogs, as well as the first mo-lecular characterization of the 18S rRNA gene of the Venezue-lan B. canis isolate used for inoculating the experimental ani-mals. Experimental infection was carried out in four dogs, two of them splenectomized. The animals were inoculated with 1 x 10 B. canis infected-red blood cells. Parasitemia, packed cell volume and body temperature were measured daily. Prepatent period of the infection oscillated between 2-6 days. All of the inoculated dogs developed a mild-type disease. Symptoms of canine piroplasmosis were moderate, and main clinical findings consisted in low parasitemia, short febrile period and slight anaemia. Imidocarb dipropionate showed to be the treatment of choice, since it cleared parasites from blood, as demon-strated by PCR assays. The partial sequence of the ssu rRNA gene of the Venezuelan piroplasm showed 100 % identity with a Brazilian isolate of Babesia canis vogeli, which is in full con-cordance with the clinical signs caused by this subspecies in the experimental animals, as well as those reported previously by other authors