Effects of Trypanosomiasis And Treatment on Peste Des Petites Ruminants Vaccination in West African Dwarf Sheep

ABSTRACT

The effects of Trypanosoma congolense infection and treatment on Peste des petits ruminants (PPR) vaccination in West African Dwarf (WAD) sheep were determined. Twenty (20) WAD sheep assigned to five (5) groups, of four (4) sheep each were used. Group A (Gp A) was the unvaccinated and uninfected control, Gp B- the vaccinated and uninfected control, Gp C- the vaccinated, uninfected and treated group, Gp D- the vaccinated, infected and treated group and Gp E- the vaccinated, infected and untreated group. Sheep in groups B, C, D and E were first vaccinated with PPR vaccine and then groups D and E were infected with T. congolense one week post-vaccination (PV), after which groups C and D were treated with diminazene aceturate 3 week post-infection (PI). A prepatant period of 12-14 days was recorded and PPR antibody titres detected one week PV in all vaccinated sheep. The antibody levels progressively increased and peaked at 8 week PV. Following parasiteamia, there was a depression in the sero-conversion rate of antibody. The vaccination had no effect on clinical (temperature, pulse rate, weight gain) and red blood cell (packed cell volume, haemoglobin concentration and total erythrocyte count) parameters. The infection was characterized by fluctuating parasitaemia and pyrexia, decreased appetite, slightly pale mucous membrane, starry hair coat and enlargement of the prescapular and prefermoral lymph nodes. There was no significant change (p>0.05) in the mean body weight and pulse rate of the infected sheep. Significant (P