Malassezia species isolated from the intermammary and preputial fossa areas of horses.
Authors: White S D, Vandenabeele S I J, Drazenovich N L, Foley J E
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary: Malassezia species in equine intertriginous areas Malassezia yeasts have been implicated in pruritic dermatitis affecting horses' tail-head and intertriginous regions, yet their presence in healthy animals and the specific species involved remain poorly characterised. White and colleagues cultured samples from the intermammary fossae of mares and preputial fossae of geldings and stallions to establish baseline carriage rates and identify which Malassezia species colonise these warm, moist microenvironments in asymptomatic horses. The researchers successfully isolated Malassezia species from both anatomical sites, with prevalence varying by sex and body region, demonstrating that healthy horses can indeed be carriers of clinically relevant yeasts. These findings suggest that Malassezia colonisation is normal in these intertriginous areas and that disease likely develops through a combination of factors—such as poor hygiene, friction, or compromised skin barrier function—rather than simple pathogen exposure alone. Practitioners should consider intertriginous Malassezia as part of their differential diagnosis for localised pruritus in these regions, with recognition that topical antiyeast therapy may resolve clinical signs even in animals with seemingly minor lesions, whilst addressing underlying predisposing factors remains essential to preventing recurrence.
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Practical Takeaways
- •Consider Malassezia infection when evaluating mares with tail-head pruritus and intermammary lesions; topical antiyeast therapy may be effective
- •Malassezia dermatitis should be in the differential diagnosis for pruritus and skin lesions in intertriginous areas (udder, prepuce, intermammary fold)
- •Further investigation needed to understand whether healthy horses can be asymptomatic carriers and potential sources of transmission
Key Findings
- •Malassezia-type yeasts were isolated from intermammary and preputial fossa areas in horses presenting with pruritus
- •Topical antiyeast treatment resolved pruritus in mares with Malassezia in the intermammary region
- •Malassezia dermatitis occurs in intertriginous areas of horses including udder and prepuce
- •Unknown whether healthy horses serve as carriers of Malassezia in these body areas