While brushing my horse's tail I noticed that he has dandruf at the top of his tail. This is not unusual and I know how to treat it.
But, at the end of his tail bone, there are large crystal like chunks of dandruf. Looks like large salt that you would sprinkle on the ice. The chunks break away just as if they were dandruf.
Does anyone know what this is, or how to get rid of it?