Equine vitiligo-like depigmentation in grey horses is related to genes involved in immune response and tumor metastasis.
Authors: Druml Thomas, Brem Gottfried, Velie Brandon, Lindgren Gabriella, Horna Michaela, Ricard Anne, Grilz-Seger Gertrud
Journal: BMC veterinary research
Summary
# Editorial Summary: Equine Vitiligo-Like Depigmentation in Grey Horses Vitiligo-like depigmentation—characterised by patchy loss of pigmentation around the eyes, muzzle and perianal region—represents an autoimmune condition of considerable concern in grey horses, where prevalence ranges from 26–67% compared to just 0.8–3.5% in non-grey animals. Druml and colleagues conducted a genome-wide association study (GWAS) to identify the genetic loci underlying this depigmentation disorder, analysing DNA from affected and unaffected horses to pinpoint candidate genes responsible for the condition. The research revealed that vitiligo-like depigmentation in grey horses correlates with genes involved in immune response regulation and tumour metastasis pathways—mechanisms previously implicated in human vitiligo but not previously characterised in the equine condition. These findings suggest a polygenetic autoimmune aetiology, offering a biological framework for understanding why grey horses develop the condition at substantially higher rates. For practitioners managing grey horses with progressive depigmentation, these results provide genetic context for counselling owners about heritability, inform selective breeding decisions, and may eventually enable development of genetic screening tools or targeted therapeutic approaches based on immune regulation rather than symptomatic management alone.
Read the full abstract on PubMed
Practical Takeaways
- •Grey horses have significantly higher risk of vitiligo-like depigmentation; screening and client education about this cosmetic condition should be part of routine care for grey horses
- •Understanding the genetic basis may enable future selective breeding strategies to reduce prevalence in grey bloodlines
- •The autoimmune nature of this condition suggests management should focus on minimizing immune triggers and monitoring for progression
Key Findings
- •Vitiligo-like depigmentation occurs in 26.0-67.0% of grey horses compared to 0.8-3.5% in non-grey horses
- •The condition is associated with genes involved in immune response and tumor metastasis pathways
- •Vitiligo in horses has a polygenic background similar to human vitiligo
- •Depigmentation predominantly affects skin around eyes, muzzle, and perianal regions