Ovine and Caprine Fly Strike Study Guide

Overview and Clinical Importance

Fly strike (cutaneous myiasis) is a parasitic skin condition caused by the larvae (maggots) of blowflies that infest living tissue of small ruminants. It represents a significant welfare concern and causes substantial economic losses in sheep-producing regions worldwide. Sheep are far more commonly affected than goats due to their dense, moisture-retaining fleece.

The condition is characterized by rapid onset and progression, making early detection and treatment critical. Untreated fly strike can lead to toxemia, septicemia, and death within 3-7 days. For the NAVLE, understanding the etiology, clinical presentation, treatment protocols, and prevention strategies is essential.

Etiology

Causative Organisms

Fly strike is caused by dipteran larvae of the family Calliphoridae (blowflies). The specific species varies by geographic region. Flies are classified as primary (initiate strike on healthy tissue) or secondary (attack already damaged tissue).