Prevalence of Oestrus ovis Larval Infestation in the Slaughtered Sheep Population of Sardasht County, West Azerbaijan, Iran

Oestrus ovis, commonly known as the nasal botfly, has a global distribution and causes myiasis in sheep and goats. The present study aimed to evaluate the prevalence of Oestrus ovis larval infestation in the slaughtered sheep population of Sardasht County, West Azerbaijan, Iran. This cross-sectional study was conducted over a 12-month period at the local slaughterhouse. Each month, 34 sheep were examined, and data regarding gender, age, breed, and sampling time were analyzed. Among the 408 sheep examined, 138 cases (33.8%) were found positive for infestation. The highest prevalence was observed in sheep older than three years (16.7%), while the lowest was recorded in sheep younger than one year (2.4%), indicating a significant correlation between infestation rate and age (P < 0.05). The highest prevalence was observed in summer (11.0%) and the lowest in winter (5.9%). The month-wise analysis showed the peak infestation in August (3.9%) and the lowest in February (1.7%), with a statistically significant seasonal pattern (P < 0.05). However, no significant association was found between infestation rate and sheep gender or breed (P > 0.05). This study highlights Oestrus ovis as a prevalent parasite in Sardasht County, capable of causing substantial economic losses in sheep farming. Additionally, due to its zoonotic potential, the parasite poses a public health concern.