Hi everyone, I have 3 minis and am noticing some dandruff and dry looking skin. Any reason? Anything I can give them to make it better? They are on a good quality orchard grass hay. I also use a probiotic (Probios) chews mostly as their treat. They were rescues and loaded with worms when we got them a year and a half ago, so just trying to make them have a healthy gut after worming. These are my first horses, and we also have a larger pony he has a little too and it has always been there. Is it just normal or can I fix it?