Q: I have an older dog named Valentine. She suffered a stroke and was diagnosed with dry eye in only her left eye. It was all of a sudden very nasty with thick discharge around it and hard for her to open. Her nose on that side became clogged with drainage, and she won’t let me clear it out for her. I don’t think she can breathe on that side. I washed it a lot and took her to the vet after a day because she was so miserable. They started her on medicine for dry eye and asked me to come back in a few days to recheck her tears. Well, she is no better and it has been over a week. Her tear test was still less than two! Do you have any thoughts?
A: Interesting. Keep rechecking that tear production. In veterinary medicine we diagnose dry eye, or keratoconjunctivitis sicca (KCS) often, especially in older dogs. There seems to be breeds that are predisposed to it, like cocker spaniels, but any dog can develop the disease.
Most dogs with dry eye will respond beautifully to a topical medicine called cyclosporine placed directly in the eye. I am sure that is what your veterinarian has placed her on. There are a tiny percentage of dogs that develop a different type of dry eye that needs to be treated a little differently.
You may want to discuss a condition called neurogenic dry eye with your veterinarian. It affects one eye, not both eyes like common dry eye affects. Often along with low tear production, as measured by a little piece of paper called a Schirmer Tear Test, there is a condition affecting the nose called xeromycteria. This is where an animal has very dry nasal mucosa and develops almost a complete occlusion of the nasal opening on the affected side only. (Xeromycteria is also a great Scrabble word using the letter x for those of you who still play).
In neurogenic kcs, animals develop a lesion in the nervous system pathways that stimulate both the nasal gland and the gland that produces tears. Sometimes with this we see middle and inner ear infections and other nerve issues on the head like a facial paralysis or even vestibular syndromes, which are quite like a stroke. Sound familiar?
The good news is that there is a medicine to treat this condition in addition to your topical cyclosporine. It is called pilocarpine and it stimulates the nerves that reach the tear glands and the glands of the nasal mucosa. You place theses drops in your pet’s food twice daily. If all goes well you should start to see some improvement within two weeks.
You will be able to tell that the treatment is working because there will be less debris and drainage from her eyes and her nose will become clear of the nasty obstruction. No more picking her nose! Always a plus. Your veterinarian will be able to judge her improvement by her Schirmer Tear Test. Hopefully it will go from 2 to 15 or higher, which is more normal.
Most pets will require lifelong treatment of eye drops and drops in the food, so be prepared. Get into a routine of medicating her and cleaning her eye and stick with it. Sometimes your veterinarian will also add in another drop in her eye called tacrolimus which can further aid in her recovery from this disease.
Whatever your veterinarian decides to do, know that if they feel that Valentine’s non-responding dry eye is really a neurogenic form of dry eye there is a treatment that works great. Good luck.
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