Hair/skin losing pigment in patches?

[SnowandSunshine]

Anyone seen this before?

My bay gelding has an irregular shaped patch of white hair under his left eye. It started to appear several months ago and has grown to about the size of a 50p. I can now see a few white hairs appearing in the same manner on the other side of his face.

It is not in a position where anything could rub it and doesn't appear to irritate him in any way. Any ideas?

 

[Maggie2]

I was told by the vet with one of mine that it could be Vitiligo, I thought it was shortage of copper and it went away when she got a better supplement.