Weird Black Mark

[booboo]

Hia
had has occured a weird balck mark, hes bay horse and since he has had injections for DJD a black mark has started to appear, it started off small and has grown like the length of his neck and quite wide , ive included a pic what ive drawn on to show how big it is, sorry its in red but then its easier to see,
so just wondering why hes got this mark is it anything to do with the injections or just because hes bay?Its also not the same texture to his normal coat .
thanks xxx

http://i5.photobucket.com/albums/y154/del_newton/jumpinedatshow_editedbalckmark.jpg

[Est]

I'd get your vet to take a look asap! That's a big, sudden change - definitely better to get your mind put at rest by a professional :)

[booboo]

yes hes coming soon to do crackers injections so will ask him then, do you know what it could be ?:confused: