Effects of secnidazole-diminazene aceturate combination therapy on parasitaemia and serum biochemical profile after late treatment in Trypanosoma brucei brucei infected dogs

Relapse parasitaemia is a major setback in the chemotherapy of a late stage Trypanosoma brucei brucei infection. An aberrant serum biochemical profile resulting from a T. b. brucei infection in dogs has been attributed to multiple organ injuries resulting from the invasive nature of the organism. Therapy with diminazene aceturate alone has not been satisfactory. This study evaluated the effects of a secnidazole-diminazine aceturate (SEC-DA) combination therapy on parasitaemia and the serum biochemical profile after the late treatment of a T. b. brucei infection in dogs. Eighteen dogs were randomly assigned to 6 groups (n = 3) as follows: Group A: uninfected nor treated; group B: infected without treatment; group C: infected and treated with DA (3.5 mg/kg) (DA-monotherapy) intramuscularly (i.m.) once; group D: infected and treated with SEC (100 mg/kg) and DA (3.5 mg/kg); group E: in-fected and treated with SEC (200 mg/kg) and DA (3.5 mg/kg) and group F: infected and treated with SEC (400 mg/kg) and DA (3.5 mg/kg). Secnidazole was administered orally for 5 days while DA was given i.m. once in groups D-F. The dogs were infected with 5 × 105 trypanosomes intraperitoneally and treatment started 14 days post-infection. The parasitaemia was monitored daily while the serum biochemical indicators were monitored 14, 21, and 28 days post-infection. The total aparasitaemia was achieved in the SEC-DA treated dogs 72 h post-treatment and in 86 h in the DA-monotherapy dogs. A relapse parasitaemia occurred in the DA-monotherapy dogs 17 days post-treatment. The SEC-DA combination therapy caused a significant (P < 0.05) decline in the hitherto elevated urea and creatinine concentrations, and the ALP, ALT, AST activities. Also, there was a significant (P < 0.05) increase in the previously decreased serum albumin in the SEC-DA treated dogs. In conclusion, secnidazole-diminazene aceturate combination therapy prevented the relapse parasitaemia and ameliorated aberrant serum biochemical profiles of T. b. brucei infected dogs after late treatment.