It is also often the same time that some farmers report treating for sheep scab with an injectable or pour-on product and sheep not improving or the same with lice.

The underlying reason for no improvement, in many cases, is the use of the incorrect product. Dipping, with sheep immersed for 60 seconds in product which is diluted to the correct recommendations, remains the only route to treat all external parasites with one treatment. If opting for an injectable or pour-on product, the first port of call should be to see if it is lice or sheep scab that is causing the problem.

While difficult, it is possible to visually identify the parasite causing the problem. Sheep scab mites are brown in colour, round and 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 and shaped similar to a wasp with a yellow or pale brown colour. If in doubt, your vet will be able to diagnose by examining using magnification or taking a sample for examination under a microscope. Take note of the products that treat lice and those that treat sheep scab. In general, pour-on products are aimed at lice with injectable products targeting sheep scab. Also, be aware that some require retreatment seven to 14 days later.

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