My cat, Mr. Kitty, has been squinting his right eye on and off for the better part of a year. I’m not sure if it was longer because I only noticed it when I started working from home last March. His right eye sometimes gets red and puffy and a bit watery. I took him to see a vet, who said he didn’t have any corneal scratches, and was given a cream to put on the eye, but I don’t think it’s working. What should I do?
The signs you’re describing could indicate lots of different disease process, adding credence to the importance of a thorough ophthalmic examination. However, since your veterinarian hasn’t identified any intraocular abnormalities or corneal ulcerations (sometimes casually called “corneal scratches”), it’s reasonably likely Mr. Kitty is dealing with recurrent conjunctivitis.
Feline conjunctivitis often manifests with squinting, ocular discharge, and redness and swelling of the conjunctiva (which is the mucous membrane overlying the white part of the eye). Conjunctivitis may be caused by viral (Feline Herpes Virus-1, Calicivirus), bacterial (Chlamydophila, Mycoplasma), and autoimmune diseases. However, in adult cats, recurrent episodes of conjunctivitis are most commonly due to feline herpes virus-1 (FHV-1) infection, which may also cause sneezing and nasal discharge. This is why many veterinarians and pet owners misconstrue signs of herpetic infection with a “kitty cold”.
Testing for FHV-1 infection is often inaccurate, with frequent false positives and false negative. Consequently, I usually recommend a trial course of antiviral therapy targeted at the infection. Both compounded topical cidofovir and commercially-available oral famciclovir are usually effective options. You may wish to talk to your veterinarian about these products. Fortunately, feline herpes virus is not contagious to people!