Although quite difficult, it is possible to visually identify the parasite causing the problem. Sheep scab mites are brown in colour, round and are tiny – barely visible to the naked eye. They feed on flesh and are generally found on the skin where scabby lesions and wool loss are characteristic of scab.
In contrast, lice are easier seen by the naked eye and move through the wool. Lice are long, shaped similar to a wasp with a yellow or pale brown colour. If in doubt, consult your vet as outside of plunge dipping, alternative treatments generally do not cover both ailments.
Treatment
Some injectable products with the active ingredients ivermectin, moxidectin and doramectin treat sheep scab. Doramectin-based products have a single treatment claim while Moxidectin based products have a residual activity meaning they offer a protective component. Take note that some products require repeat treatment seven to 14 days later.
In general, pour-on products are aimed at lice with injectable products targeting sheep scab. It is also important to consider that both lice and sheep scab can be present at the same time.
Targeted approach critical for successful ectoparasite control