Small ruminants Oestrus ovis infestation in Burkina Faso

Abstract

A post mortem examination of 879 small ruminants (541 sheep and 338 goats) was carried out from November 1985 to October 1986 to study Oestrus ovis infestation in Burkina Faso. A route of the larva inside the head was proposed. High infestation rates were observed and the average values were the following 90.9 p. 100, 92.4 p. 100 and 88.5 p. 100 respectively for both species, sheep and goats. Sheep showed a significant higher infestation rate (79.5 p. 100) in L₁ than goats (58.3 p. 100) while the reverse was observed in L₃ (respectively 56.5 p. 100 and 38.3 p. 100 for goats and sheep). Average values for infestation degree were 15.5, 17.4 and 12.2 larva respectively for both species, sheep and goats. The larval stages showed the same relationship than those observed for infestation rate between sheep and goats. There appears to be no influence of age on the infestation rate while older animals (8 adult teeth) showed a higher Infestation degree than younger animals. Seasonal variations were observed for both infestation rate and infestation degree and an ideal period (April) was suggested for the treatment of small ruminants infested with Oestrus ovis.