Oestrid head maggots in slaughtered sheep in Cairo abattoir

Area of Science:

• Veterinary Parasitology
• Sheep Husbandry
• Entomology

Background:

• Oestrosis, caused by Oestrus ovis (sheep bot fly) larvae, is a significant parasitic disease affecting sheep, goats, and occasionally humans worldwide.
• While often benign, severe Oestrosis can lead to fatal outcomes in sheep and serious ocular or nasopharyngeal complications in humans.

Purpose of the Study:

• To investigate the prevalence, seasonal distribution, and larval stages of Oestrus ovis infestation in sheep.
• To determine the influence of sheep age and sex on infestation rates.

Main Methods:

• Examination of 1200 slaughtered sheep heads at Cairo abattoir.
• Collection and staging of Oestrus ovis maggots throughout the year.
• Analysis of infestation prevalence based on sheep age and sex.

Main Results:

• A prevalence of 8.67% (104 out of 1200 heads) was recorded for Oestrus ovis infestation.
• Sheep were infested year-round, with peak infestation observed in September (12.5%).
• Older sheep exhibited higher infestation rates (12.0%) compared to younger ones (6.87%).
• Larval peaks varied seasonally: first instar in September (17.4%), second instar in March (15.7%), and third instar in June (11.6%).
• A total of 556 maggots were recovered, with a seasonal peak in March (12.6%).
• The sex ratio of parasitized sheep (female to male) was 1:2.71.

Conclusions:

• Oestrus ovis infestation is a prevalent issue in the studied sheep population.
• Seasonal patterns and age-related susceptibility to Oestrosis were identified.
• Findings highlight the importance of understanding Oestrus ovis epidemiology for effective control strategies in sheep farming.