Efficacy of secnidazole-diminazene aceturate combination therapy in the late treatment of Trypanosoma brucei brucei infection in dogs

This study evaluated the efficacy of combination therapy of secnidazole-diminazene aceturate (SEC-DA) in late treatment of dogs experimentally infected with relapsing strain of Trypanosoma brucei brucei. Fifteen dogs were randomly assigned to 5 groups (A - E) of 3 per group. Group A (uninfected untreated), B (infected untreated), C (infected and treated with DA (3.5 mg/kg) IM stat), D (infected and treated with secnidazole (SEC) (100 mg/kg) orally for 5 days and DA (3.5 mg/kg) IM stat), E (infected and treated with SEC (200 mg/kg) orally for 5 days and DA (3.5 mg/kg) IM stat). Dogs were infected intraperitoneally with 5 x 105 trypanosomes and treatment started 14 days post-infection. Data on parasitaemia, hematology and rectal temperature were recorded. Parasitaemia cleared within 3 days in all the SEC-DA treated dogs and there was no relapse parasitaemia. Parasitaemia did not clear in DA monotherapy dogs. All the SEC-DA treated dogs showed significantly (P < 0.05) higher leucocyte counts, red blood cell count, packed cell volume, hemoglobin concentration and lower rectal temperature than DA monotherapy. It was, therefore, concluded that SEC-DA combination is therapeutically more efficacious than DA monotherapy in the late treatment of T.b. brucei infection in dogs.