Occurrence of Trypanosoma evansi Infection in Rottweiler Dog from Cauvery Delta Region of Tamil Nadu, India: A Case Report

Trypanosomes are the extraerythrocytic haemoflagellate protozoan parasites of domestic and wild animals including dogs. A male Rottweiler dog was presented with the history of anorexia, cloudy eyes and vomiting for a week. The dog was examined both physically and clinically. Blood was collected and subjected to haematological and biochemical analysis. Echocardiography of the thoracic cavity and ultrasonography of the abdominal cavity were performed. Molecular confirmation of parasite was carried out by PCR and DNA was sequenced to identify strain variations. Upon clinical examination, the dog revealed emaciation with high fever, unilateral corneal opacity, anemia, enlarged lymph nodes and distended abdomen. Echocardiography of the thoracic cavity showed ventricular hypertrophy and cardiomyopathy. Ultrasonography of the abdominal cavity showed splenomegaly and renomegaly. Haematological findings revealed decreased haemoglobin and erythrocyte count and biochemical findings revealed increased BUN and creatinine, hypoglycemia and hypoalbuminemia. Wet film and blood smear examination revealed actively motile trypanosomes and massive infection of trypanosomes, respectively. Molecular confirmation of species was carried out by amplification of 227 bp partial VSG gene of <i>Trypanososma evansi</i>, subsequently sequenced and phylogenitically analysed. The infected dog was treated intramuscularly with diminazene aceturate @ 3.5 mg/kg b.wt along with the supportive therapy. The study described the occurrence and diagnosis of trypanosomosis in dog. Early diagnosis and timely treatment is the most reliable way to safeguard the companion animals. It is the first report on trypanosomosis in dog from Cauvery delta region of Tamil Nadu, India.