Dont mean to worry you, but steroids aren't good with mouth issues, if you read Dr Addie's site, they state not to be used, they can ultimately make things worse, and steroids aren't good with FIV either. Sam was a probable calici carrier and had mouth ulcers, but luckily his was fairly well controlled, he did still get ulcers after having all his teeth out though, bless him. There are other suggestions on her site, such as Classic cat food (did help Sam's gums). I would ask them to keep a very close eye on his ulcers though, I lost Sam last week to probable oral SCC, and one vet missed it cos he thought it was an ulcer.