Eyelash abnormalities

What is ... ?: 

 Normally the eyelashes (or cilia) grow from follicles in the eyelid. Abnormalities of the eyelash are a common hereditary problem in dogs. The three types are:

distichiasis, in which extra eyelashes grow from abnormal follicles located on the inside edge of the eyelid. They may be singular or multiple.

ectopic cilia, in which the extra eyelash grows through the eyelid to the inside.One or more ectopic cilia may be present.

trichiasis, in which eyelashes growing from normal sites turn inward. The eyelashes are often abnormally long.


With any of these disorders, the clinical signs relate to irritation of the cornea (the surface of the eye). The degree of discomfort varies greatly, depending on the number of abnormal cilia, and whether they are very fine, or more coarse.

How is ... inherited?: 

The mode of inheritance has not been established. It is most common in the breeds listed below, but can be seen in any breed.

What does ... mean to your dog & you?: 

 Often the extra eyelashes are very soft and fine, and cause no problems. However if there is reduced tear production or if the hairs are coarse and stiff, you will likely see signs of irritation such as reddening of the conjunctiva (the inside of the lid), excessive tearing, and squinting. Your dog may paw or rub the eyes. Corneal ulceration may occur, and this will increase your dog's discomfort.

Ectopic cilia are particularly irritating and likely to cause corneal ulcers.

How is ... diagnosed?: 

 Very bright light and magnification are required to see the extra eyelashes. Your veterinarian will also do a fluoroscein dye test if there is a possibility of corneal ulceration. Sometimes the extra eyelashes can be very difficult to see, and may only be found when your veterinarian is trying to determine the cause of recurring corneal ulcers in your dog.

How is ... treated?: 

 No treatment is required for extra eyelashes that are fine and causing no irritation. If corneal ulceration is present, it is treated with antibiotic medication. If abnormal eyelashes are the cause, they must be treated as well or the ulcers will recur.

Where there is chronic irritation with or without ulceration, there are several procedures that can be done, depending on the number and location of the abnormal lashes. These range from electroepilation (effective if there are only a few abnormal lashes), to removal of the aberrant follicle for an ectopic cilium, to cryosurgery to destroy the abnormal hair follicles. Cryosurgery is the most effective treatment for distichiasis, and is less commonly associated with recurrence than electrolysis.

Breeding advice: 

 It is best to avoid breeding affected dogs, to try to minimize these problems.


What breeds are affected by ... ?