dandruff skin itchiness

I have a boar who has had ongoing skin issues over the last 12months. I've been to the vet, a few times, they've done a physical exam but no skin testing. He has flaky skin at the base of the hair follicle, especially around his rump area. When I groom to dislodge it, he tries to excessively...

Hi I have a guinea pig that has been suffering with itchiness and dandruff for weeks, she has been checked for mites by the vet and he suggested shampooing her. Shall I try nizoral shampoo as other Guinea pig ones have not worked, thanks in advance.