Is it possible for a guinea pig to be allergic to wood and wood products? A guinea pig came in a week or two ago to the shelter and his former owners told the staff that he is allergic to anything made out of wood. So we have been using cat litter, towels, and hay for bedding at the shelter. He has some patches of missing fur with red irritated skin. And his skin is also flaky. I told one of the staff members to have the vet check him for mites, because being allergic to all wood products seems far fetched.