My Pearl will over groom her lower tummy area sometimes. My vet wasn't too concerned about it because it wasn't that bad. She's never completely bald and sometimes she'll even let her fur grow back. I'm sure that hers is caused by stress or boredom. Luckily she doesn't need to be on meds at this time. I hope that Tiger Kitty will start growing his fur back soon and feel better too. Good luck.