Distichiasis causing recurrent corneal ulceration in two Friesian horses

Abstract

Summary Two cases of distichiasis with subsequent recurrent superficial corneal ulceration are described in Friesian horses. Case 1 was a 9‐year‐old Friesian stallion with distichiae on the superior and inferior eyelids of both eyes corresponding to areas of recurrent superficial corneal ulceration. Case 2 was a 5‐year‐old Friesian gelding with a single distichia on the inferior lid associated with recurrent superficial corneal ulceration in the right eye. Case 1 underwent cryotherapy and epilation twice under standing sedation without resolution of distichiasis. A partial tarsal plate excision was then performed on the inferior left lid, which was the most severely affected. Cryotherapy was repeated one and 4 months post operatively due to recurrence. Cryotherapy was associated with skin depigmentation and repigmentation several months following the procedure. No recurrence has been reported up to 3 years following the fourth cryotherapy procedure. Case 2 was treated with epilation. Distichiasis should be included as a differential diagnosis when presented with a horse experiencing recurrent superficial corneal ulcerations. There has been no established breed association for Friesian horses and distichiasis but, due to the inherited nature of this condition in some human patients and dogs, this possibility should be investigated.

Treatment and long‐term follow‐up of distichiasis, with special reference to the Friesian horse: A case series

“…Distichiae are a differential for corneal ulceration in the horse, particular in the Friesian breed . This case series supports this statement, revealing a predisposition for distichiasis in the Friesian breed, as 17 out of 18 horses presented with this condition were Friesians (94%), whereas Friesians comprise only 7% of the general hospital population .…”

“…Recently, 2 cases of distichiasis in Friesian horses have been described, suggesting the possibility of a breed predisposition . In the current report we describe 18 cases of distichiasis in the horse over a period of 9 years, causing recurrent corneal irritation and/or superficial corneal ulceration and provide details of electrocautery treatment with long‐term follow‐up.…”

“…Distichiasis is commonly described in man and dogs but in cats and horses it is very uncommon [1,[5][6][7][8][9][10]. In humans, distichiasis can be congenital or acquired in the setting of chronic inflammation and following chemical injuries of the eyelid [9,11].…”

The search for causes of nonhealing or recurrent ulcerative keratitis in horses

“…In the case series in this issue by Utter and Wotman (2012), 2 Friesian horses had chronic or recurrent superficial corneal ulceration and diagnostic testing was performed as described above. Distichia was observed that directly contacted the ulcerated area of the cornea.…”

“…This author has observed a few cases of distichia and ecotopic cilia in Thoroughbreds and therefore these conditions may be underreported in other breeds. Because of the recurrent nature of distichia as reported in the Friesian horses (Utter and Wotman 2012), more studies of the pathogenesis and treatment of distichiasis in horse are also needed.…”