Distichia are lashes which emerge from the glands along the eyelid margins.
They can come out of the duct of the gland and/or through the gland itself (ectopic cilla). They can cause irritation and ulceration, especially in those breeds which have coarse coat hairs (bulldogs, Staffies).
Distichia are usually treated by electrolysis or cryotherapy. Treatment has to be targeted right into the follicle to stop further growth of the aberrant lashes.
There is sometimes a need to repeat this procedure due to the cyclical nature of hair growth as further lashes can erupt from dormant follicles.
Distichia can cause severe problems in some dogs – the pictures show a 5-week-old Sheltie puppy with many lashes causing severe corneal damage, and subsequent treatment by electrolysis.