Q: “Billy Bob,” my little French Bulldog, has “dry eye.” I’m not sure his eye medicines are working, because he still has a lot of discharge in his eyes. Sometimes he seems uncomfortable too. My neighbor says I should just give him Restasis instead! Can you guide me please? P.E., Farragut
A: “Dry eye,” or keratoconjunctivitis sicca, does run in certain breeds, including French Bulldogs. Dry eye occurs in dogs (and cats) when they do not produce enough tears.
The most common reason that dry eye occurs in dogs is an immune reaction in the lacrimal tissue (tear ducts) that decreases the pet’s ability to produce their own tears. Less common causes include abnormalities in the nerves that supply the tear ducts, viruses, trauma, and certain medications known to decrease tear production.
You did not mention what medication Billy Bob is taking. The eye medication prescribed for most dogs is cyclosporine. For some dogs, it can take 8-12 weeks for adequate tear production to begin. If it has been longer than 12 weeks since he started his medications and you haven’t seen improvement, you should have him rechecked. Your veterinarian will repeat the Schirmer teat test, which will measure the tear production in both eyes.
Interestingly, cyclosporine is the same drug that is in Restasis, the human dry eye medicine that your neighbor mentioned. The concentration is higher (stronger) in the canine version compared to the human version, as dogs simply have different needs with this disease.
Although Restasis would not harm Billy Bob at all, it is likely to be too weak for most dogs and not help him.
For pets that don’t initially respond, the strength of this medication can be increased. A compounding pharmacy can formulate this medication to a higher, stronger concentration.
For some dogs, a different medication altogether may be needed. Few dogs are unresponsive to both medicines, and for those pets, we recommend a referral to the veterinary ophthalmologist.
Clinical signs to watch for include yellow or green eye discharge, red eyes, and/or corneal dullness. Some dogs will even rub or paw at their eyes because their eyes feel itchy and uncomfortable. Secondary bacterial infections can also occur. Untreated dry eye can result in corneal scarring and eventual blindness.
Dogs with dry eye usually need lifelong medication, and although these medications may need occasional adjustments, this disease can generally be managed.
If you have questions about your pet, you may email Dr. Myers at email@example.com