Parasitological and molecular diagnosis of canine trypanosomiasis by Trypanosoma evansi in dogs associated with hunting in two sites of Artigas Department, Uruguay

Abstract

The aim of this work is to report two fatal autochthonous cases of canine trypanosomiasis caused by Trypanosoma evansi, a disease also known as surra, in cross breed dogs used for hunting from two sites of Artigas Department, Uruguay. The cases appeared in the months of September and November of 2017. The clinical signs were anemia, ocular, oral and posterior limbs edema, inappetence and progressive general deterioration. The diagnosis was made taking into account clinical signs and paraclinical analysis: hemogram, liver function test, blood  smear and PCR/sequencing. Blood smears showed trypomastigotes whose morphology was compatible with Trypanosoma spp. In hemogram and liver function test it was noted hypochromic anemia and thrombocytopenia, in addition to high levels of liver enzymes (AST/GGT/GOT/Alkaline Phosphatase). Three PCRs were performed that amplified a partial fragment of the 18S ribosomal RNA gene (18S rRNA) as well as two overlapping fragments of the internal transcribed spacer ITS (ITS1+5.8S+ITS2). The sequences obtained had a homology of 100% for the 18S rRNA gene and 99% for the ITS region with T. evansi. These cases represent the second diagnosis for Uruguay of T. evansi and the first reports of death due to this trypanosomiasis in dogs for the country. It is a disease to be taken into account, since, in addition to being considered emerging disease for the country; it can seriously affect other species, being an OIE (World Organisation for Animal Health) notified disease.