The present study was conducted on various flocks of Kacchi and Lohi breeds of sheep in Southern Punjab, Pakistan to investigate the prevalence of gastrointestinal tract (GIT) parasites.  A total of 523 sheep were examined.  Out of which 240 were found to contain various GIT parasites.  The overall prevalence rate was 46.33%.  The prevalence of Fasciolia hepatica, Avitellina centripunctata, Haemonchus contortus and Trichuris globulosa was 21.41, 12.23, 6.50 and 5.73%, respectively.  Sex wise prevalence of gastrointestinal parasites was higher in male than female hosts (P<0.05).  The maximum infection was observed in lambs compared to adults (P<0.05).  The prevalence of different species of endoparasites also varied in sheep of different body weight groups (P<0.05).  The highest infection was observed in Kacchi breed than Lohi breed.  In conclusion, the data obtained in this study suggest that the age, sex, body weight and breed are important factors which influence the prevalence of gastrointestinal parasites.

Key words: Age; Body weight; Endoparasites; Prevalence; Sex; Sheep