So we have had our 2 guinea pigs at the vet 3 times now for shots to rid them of mites and I still found mites on them again. They don't seem to be bothered by the mites. I don't see them itching and there is no hair loss. I keep their cage extremely clean washing it out with vinegar once a month and we change the shavings every other day. I'm spending a fortune though on vet bills and the shots don't seem to be working. Is there something I can wash them with? What other options do we have?