I don't think anything actually causes this except genes.
When Buddy was a puppy he was jet black as he got older his coat
continually changed turning red or golden on the tips then it became
more and more up into the coat as he got older. I posted
a thread here a couple of years ago and a breeder stated it was
known as running gold. Today this running gold is throughout his
back. He almost looks like he's turning gold. If I shave him down
he's once again jet black.
Hope this helps you, |