Occurrence and distribution of Malassezia species on skin and external ear canal of horses.

This study reveals the occurrence and distribution of Malassezia species on different parts of the skin and in the external ear canal of healthy horses, indicating that the prevalence of these species varies by body site and age, with M. pachydermatis being the most prevalent.

Methodology and Sample Collection

• The researchers collected samples from the body skin and the external ear canal of 163 healthy horses.
• The skin samples were collected through a technique known as scraping from the nose, groin, and dorsum (the upper side of the horse).
• Subsequently, swabs were taken from the outer ear canal of the horses.
• These samples were then incubated on two types of agar – Sabouraud dextrose agar and modified Dixon agar. These mediums are used to cultivate fungi, in this case, Malassezia, a genus of fungi.

Findings and Implications

• Theirs findings concluded that Malassezia species were present in 34.9% of the horses sampled
• The distribution of Malassezia species varied based on breed type; they found the distribution percentages of Malassezia were highest in Arab horses (64.3%), followed by Persian horses (35.7%), Thoroughbred horses (35.4%) and least in Turkmen breeds (27.1%).
• The researchers observed that the greatest concentration of Malassezia species was in the external ear canal (47.7%). This was a statistically significant difference compared to other sites. Following the ear canal, the distribution was found as follows: nose (26.3%), groin (15.8%) and dorsum (10.5%).
• Six different Malassezia species were detected, with M. pachydermatis being the most common (33.3%) followed by M. globosa (26.3%), M. sympodialis (14.1%), M. restricta (10.5%), M. obtusa (8.8%) and M. furfur (7%).
• The researchers also noted that variations were present based on age. Horses within the age group of 1-3 years were affected the most (59.4%).
• This implies that the cutaneous Malassezia microbiota in healthy horses varies by body site and age, but not by breed and gender. This may have implications for regulation and preventative measures with respect to fungal diseases in horses.