Intraocular melanomata in the horse.

The research explores an observed connection between grey horses and the occurrence of intraocular melanoma, a type of eye tumor. It builds on previous cases and introduces six new cases, reinforcing the established link between grey coat colors in horses and this particular type of cancer.

Background

• Relationships between the coat color of grey horses and the incidence of cutaneous melanoma (a type of skin cancer) have been acknowledged since hundreds of years ago.
• Between skin melanomas, a high propensity (80%) was noted among older grey horses, reported by McFadyean in 1933.
• The researchers previously suggested a possible link between grey coat color and intraocular (inside the eye) melanoma in horses. However, past evidence was insufficient to establish a firm connection.

Intraocular Melanomata

• Despite being noted as the most common intraocular tumors in horses by Matthews and Crispin in 1987, intraocular melanomata are still considered rare inside the horse community.
• Only 12 cases of intraocular melanomata in horses were publicly documented before this study, emphasizing the rarity of this particular type of cancer.

Research Findings

• In this research, an additional six cases were described, combining with the past documented cases to solidify the correlation with the grey coat color in horses.
• This implies that horses with a grey coat are at a higher risk of developing intraocular melanoma, reinforcing the theory of an association.

Age-Related Incidence

• The research also found that the incidence of intraocular melanomata in grey horses was not as heavily age-related as cutaneous melanomata, indicating that the risk does not increase significantly with age as with skin melanoma.