Pudden is rubbing her eyes again this winter and just gave herself another corneal abrasion. It's not too bad and will heal in a few days with her blow up collar on. I however need to get this under control fast or she will do it every time the collar comes off. Pudden gets very constipated from chlorpheniramine and can't have it. Whenever she is on it her numbers sky rocket and I don't want her to relapse. I am looking for an antihistamine that doesn't cause her to get constipated and actually works. We tried cromolyn, an eye drop antihistamine, but she just scratched her eye today, so it looks like it's a dud. I have heard great things about zyrtec, but want to make sure it is safe for diabetic cats. Has anyone used it and did it turn your cat into a zombie? on the chlor she was a total zombie and needed an enema once a week to poop. It was terrible.