Would the fact that my Golden Retriever dog has a black pigment mark on his tongue preclude him from entering in any shows?

Hi, The pigment mark will make no difference what so ever. I have a Stafford bitch with one as i call it a birthmark.
All the Best Gwen

gwens right. I had a irish soft coated wheaten terrier and she had a big black spot on her tongue and it never stopped her being shown.

sarah xxxx

On my way to a show last year I was chatting to a policeman (as one does ;) ) and he said that a dog with a patch on it's tongue is supposed to be a good one! I don't know if he meant good at working, showing, or just good natured. :D My Chance has one and he's been good (?) enough to be at the last 2 Crufts (he's only 2!)

My old lab I lost last year and she had a huge black patch on her tongue, and boy she was better than a good one!!!!!!!! She was exceptional!

My Akita Sheena as a black patch on her tongue.

All my black Flatcoats have black marks on their tongues, my older boy even has a row of hairs growing up the middle!!