I wonder if the ivomec & Cortizone shots cover yeast infection? The cortizone is suppose to be good up to six weeks. When I farrowed sows years ago they would get a yeast infection we called it greasey pig. We offered them showers with the garden hose & once they were weaned off their babies they could go roll in the mud & the greasey pig would leave. We kept them in a clean environment but they really needed to get out in the dirt & mud to keep their skin free of infections. I went to the web sites & it seems to bother certain breeds of dogs too.