Clinical signs and pathological changes in dogs with single and conjunct experimental infections of Trypanosoma brucei brucei and Ancylostoma caninum

The clinical and pathological changes in dogs experimentally infected with single and conjunct infections of Trypanosoma brucei brucei and Ancylostoma caninum were studied. Four groups of dogs (GPI, GPII, GPIII and GPIV) of five in each were used for this study. GPI was uninfected control while GPII, GPIII and GPIV were infected with A. caninum, T. b. brucei and conjunct A. caninum/T. b. brucei, respectively. Results showed severe infection in the conjunct than in the single infections. Prepatent period of T. b. brucei infection was 4–6 days in GPIV and 6–9 days in GPIII. Prepatent period of A. caninum was 13 days and 19 days in GPIV and GPII, respectively. All the infected dogs in GPIII and GPIV died whereas only two out of the five dogs died in GPII. The mean death time for the dogs was 26 ± 5.7, 28 ± 1.1 and 31 ± 1.8 days in GPIV, GPIII and GPII, respectively. The dogs in GPIII and GPIV showed pyrexia, pale mucous membrane, anorexia, swollen abdomen, ocular discharge, swollen face and hind limbs, enlargement of superficial lymph nodes, weakness and recumbence. One of the dogs in GPIII voided dark coloured urine prior to death. Dogs of GPII and GPIV had unilateral and bilateral corneal opacity, respectively. GPIV showed hydropericardium and one member excreted tarry faeces. There was no significant difference (p< 0.05) in the weight of GPII and GPIII. GPIV had an initial increase in weight which peaked by week 3 postinfection and decreased sharply.