Distichiasis is a condition where extra eyelashes (cilia) grow from the glands of the upper or lower eyelid. Hair follicles develop from deep within the glands rather than from the skin surface of the eyelids. As these hairs grow, they follow the ducts of the gland and exit from the gland’s opening along the smooth surface of the eyelid. These eyelashes called distichia, rub against the cornea and cause irritation or tearing, and sometimes corneal abrasions.
Distichiasis is an inherited disorder and are seen in many breeds, including the American Cocker Spaniel, Miniature and Toy Poodles, Golden Retriever, Miniature long-haired Dachshund, Shetland Sheepdog, Chesapeake Bay Retriever, English Bulldog, Lhasa Apso and Shih Tzu.
Look for: corneal vascularization (blood vessel accumulation), dark coloring of the cornea, corneal ulceration, scarring (which will appear as white areas) on the cornea, conjunctival redness, squinting and excessive tearing from the eyes.
Your vet will diagnose your dog from a thorough visual eye examination to identify the lashes emerging and from where. He may also administer a Schirmer test which will assess tear production from both eyes. He might order a fluorescein staining of the cornea in order to detect any corneal abrasions or ulcers.
Treatments will vary. Some dogs will require no treatment at all, as some dogs have short, fine distichia or if the symptoms presented are mild enough to barely require attention. American Cocker Spaniels are often very tolerant of the extra eyelashes. The next least invasive treatment will be ophthalmic lubricant ointments that will protect the cornea and coat the eyelashes in an oily film. Expect to use this method if your dog is experiencing mild tearing or if he has a few distichia that are short and fine in texture. If your dog isn’t a good candidate for surgery, you’ll be asked to partake of this method.
However, if your dog is extremely bothered by the extra eyelashes or is experiencing corneal damage, your dog will have to undergo surgical correction to remove the distichia and try to kill the hair follicles responsible. Unfortunately, these follicles are difficult to kill. Sometimes portions of the eyelid need to be removed. Other times, the meibomian glands need to be cauterized or frozen with cryotherapy. The obvious worry here is for excessive scarring to occur on the eyelids. Still, regrowth is often common and your dog may need multiple surgeries. It isn’t uncommon for new hairs to spring up in different locations either.
Worse still, there is no preventative care for distichiasis.