Distichiasis is the term used to describe abnormal eyelash growth. It is a common health condition in dogs, but rare in cats. Pets with distichiasis have eyelashes that grow from the wrong place. Meibomian glands are tiny glands located on the eyelid and are responsible for producing an oily substance called meibum, which helps prevent the evaporation of tears. Distichia are eyelashes that arise from (or next to) the meibomian glands. Usually, there are multiple distichia present, and often more than one lash exits from the same meibomian gland.
Distichiasis affects many, many breeds of dogs. One of the most commonly affected breeds is the Cocker Spaniel, but other breeds include:
- English Bulldog
- Flat Coated Retriever
- Golden Retriever
- Lhasa Apso
- Long-haired Dachshund
- Shetland Sheepdog
- Shih Tzu
- Yorkshire Terrier
Diagnosis is made by visually examining the eyelash originating from the meibomian gland. Often, the hairs are so fine that magnification is needed to identify them. Distichia can occur on the upper or lower lashes, and may affect one eye or both. Puppies who have inherited distichia may have visible lashes as early as 6 weeks of age. Most dogs with distichiasis are diagnosed before their third birthday.
Clinical signs of distichiasis vary between individuals and depend on the coarseness of the abnormally originating lashes. If the lashes are short and fine, they can float easily in the tear film, largely undetected by your pet. These kinds of lashes may cause some increased tearing, but most dogs are asymptomatic. Long or sharp distichia that directly contact the cornea can be troublesome. These long hairs irritate the cornea, causing increased tearing and blinking. Increased mucoid discharge can be seen in the eye, and corneal irritation can turn into painful corneal ulceration and pigmentation.
Pets with chronic corneal ulcers or increased corneal pigmentation should be evaluated for distichiasis. Many breeds affected by distichiasis are also more prone to other ocular diseases such as keratoconjunctivitis sicca (KCS), which may mask distichiasis as an underlying condition.
Treatment of distichiasis centers on removing the offending hairs. Manually pulling the hairs is not recommended, as the hairs can grow back thicker, causing even more problems. Cryotherapy is the most common treatment for distichia, but meibomian gland cautery and the excision of the affected glands are also done if there are only a few abnormal lashes. You may be referred to an ophthalmologist if your regular veterinarian doesn’t perform these services.
Even if distichia aren’t causing clinical signs, it’s best to have them checked out to ensure that corneal damage is not occurring. Luckily, Petplan pet insurance can cover the cost to examine and treat hereditary conditions like distichia – so you can get your pet the best treatment and get him back on all four paws again!