Identifying the external parasite causing sheep to scratch or bite at their fleeces can be tricky to carry out, but should be the starting point where considering the optimum treatment programme outside of dipping.

The reason I say this is that there is no other treatment route that will match plunge dipping in terms of providing control for all external parasites including sheep scab, lice, ticks, keds, etc.

Identifying the parasites causing the issues may require veterinary assistance, but a brief explanation is detailed below to help.

Sheep scab

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.

Lice

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.

Your vet will be able to diagnose by examining using magnification or taking a sample for examination under a microscope.

Treatment options

Options for farmers who do not have access to dip sheep to treat lice and scab are generally more complicated and require a combination of injectable and pour-on products.

Alternative non-dipping treatment

Outside of dipping, there is no product available that covers both sheep scab and lice. As such, it is hugely important to identify parasites correctly.

For sheep scab, there are numerous products on the market with active ingredients such as ivermectin, moxidectin or doramectin.

Last resort

However, these products are advised against now as a last resort due to the rate of anthelmintic resistance developing.

Take note that most products require re-treatment seven to 14 days later to address eggs that were unhatched at time of treatment.

The exception to this is products such as Dectomax or Cydectin 2% LA which has been recently relaunched on the market which is marketed as a single-treatment product.

Options for treating lice include injectable and pout-on products. It is advisable to study product characteristics closely to assess if biting and suckling lice is targeted.

Irrespective of the type of treatment selected, it is important to treat all sheep in the batch at the same time and prevent mixing of sheep post-treatment.