My friends rottweiller bitch is now 4.  Over the last few months she has started to go very grey on her head, and also continuing along her back.  Also her nose has started to go pink, and the skin at the side of her mouth (which is normally black).  My friend has taken her to the vet and they don't know what it is, but said if she was okay not to worry about it.  She is only 4, but with the grey on her face, she looks really old, you would think she was a really old dog.  Has anyone got any ideas on this?  Also my friend said that it looks like her pads are pigmented also.

I had a Dobermann many years ago with similar symptoms. It turned out to be an underactive thyroid gland, once put on Soloxine her coat reverted back to it's normal black. May be worth getting her thyroid checked.

Sounds like this

http://www.upei.ca/cidd/Diseases/dermatology/vitiligo.htm

Thank you for the reply I will pass on to my friend.