Q: Where are the most common sites for melanomas in grey horses?

A: In grey horses, melanomas are very common – some studies suggest up to 80% of greys over 15 years old will develop at least one. While many are benign and slow-growing, their location can affect comfort and management.

Most common sites for melanomas

1. Under the tail and around the dock – the single most common site.
2. Around the anus, perineum, and genital area – particularly sheath in geldings/stallions, vulva in mares.
3. Lips and commissures of the mouth – can cause problems with bitting.
4. Around the eyes and eyelids – may interfere with vision or tear drainage.
5. Parotid region (throat latch/jaw area) – can obstruct salivary ducts or airway if they enlarge.
6. Under the mane/crest and around the head – less common, but still seen.
7. Occasionally internal – liver, spleen, or guttural pouches, though these are harder to detect without imaging.

Key takeaway

The majority of grey horse melanomas appear under the tail, around the anus, and in the sheath/vulva region, but growths can also develop around the mouth, eyes, and throat latch. Many are slow-growing, but because of their locations, they can interfere with vital functions if left unchecked.