I have used Feline Dophilus, which is made by Natren, for my
cat who has had various skin
allergies, and it helped a lot. It also helped with her constipation, vomiting, and diarrhea. You can give it to your cat every day for three days, then every other day for a week or so, then cut back gradually to twice a week for maintenance. It is worth a try, and can't really hurt, since it is non-invasive for your kitty.