ectoparasites of sheep: sheep scabdr ruth wonfor: ibers, aberystwyth university take home messages: sheep scab is caused by mites which live on the skin of the sheep, causing lesions, severe itching, loss of wool and ultimately a loss in production. all sheep with scab must be treated, but a correct diagnosis must be made first to avoid misdiagnosis with lice, for which treatment may be different. there are several treatments available, you should always consult your vet before treating. sheep scab can be effectively controlled and prevented through strict biosecurity measures such as quarantining bought in sheep.  the wales animal health and welfare framework sets out the plan for continuing and lasting improvements in standards of animal health and welfare for kept animals, whilst also helping to protect public health and making a contribution to the economy and the environment.  sheep scab is a priority within the wales animal health and welfare framework implementation plan ...