Treatment and long-term follow-up of distichiasis, with special reference to the Friesian horse: a case series.
Authors: Hermans H, Ensink J M
Journal: Equine veterinary journal
Summary
# Distichiasis in Horses: A Friesian-Predisposed Condition with Predictable Treatment Outcomes Distichiasis—the presence of an extra row of eyelashes—remains poorly documented in equine medicine, yet this retrospective analysis of 18 cases (predominantly Friesians) treated between 2003 and 2012 provides valuable clinical guidance for practitioners encountering this condition. All affected horses presented with corneal irritation or ulceration, with 45% showing fluorescein-positive corneal defects; importantly, lower eyelid involvement was more prevalent than upper. Electrocautery proved effective and practical, achieving complete resolution of clinical signs in 46% of horses after a single treatment and satisfactory long-term outcomes in 77% following an average of two treatments, though eyelid scarring occurred universally and recurrence affected 54% of cases overall. Critically, the number of ectopic hairs correlated significantly with recurrence rates (P<0.002), suggesting that horses with fewer than five distichiae have considerably better prognoses and lower retreatment demands. Given the apparent breed predisposition in Friesians presenting with unexplained corneal disease, eyelid margin examination should become routine protocol, and practitioners can confidently counsel owners that standing sedation and electrocautery offer a minimally invasive, cost-effective approach with manageable complication rates and predictable outcomes based on hair burden.
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Practical Takeaways
- •Examine eyelid margins carefully in Friesian horses presenting with unexplained corneal irritation or ulceration, as distichiasis is a breed-predisposed condition
- •Electrocautery is an effective, minimally invasive, inexpensive treatment suitable for standing sedated horses with low complication rates
- •Horses with fewer than 5 distichiae have lower recurrence rates; multiple treatments (mean 2) may be needed for satisfactory long-term resolution in some cases
Key Findings
- •17 of 18 cases were Friesian horses, indicating strong breed predisposition for distichiasis
- •Electrocautery treatment achieved successful resolution of clinical signs in 46% after one treatment and 77% after mean of 2 treatments
- •Clinical recurrence occurred in 54% of cases with significant correlation between number of distichiae hairs and recurrence (P<0.002)
- •Lower eyelid was affected more frequently than upper eyelid, with 45% of affected corneas showing fluorescein-positive defects