Oestrus ovis is a species of fly known as the sheep nasal botfly. It primarily affects sheep and goats, laying its eggs in the nostrils of these animals. The larvae then develop in the nasal passages, causing irritation and potential health issues. Infection by Oestrus ovis can lead to symptoms such as nasal discharge, sneezing, and difficulty breathing. While the condition is generally not life-threatening, it can affect the overall well-being and productivity of the affected livestock. Control measures include proper management practices and, in some cases, insecticides.