What would happen if you mated two dogs with the same grandparents?

Bit close for my liking. Problem is that anything carried in the line as a recessive is likely to come crawling out of the woodwork. Great Grandparents is about as close as I like to see unless there is a very good reason to breed this close.

Regards, John

for me it would depend on the virtues of the grandfather , what was in the lines you'd be doubling on, what did he tend to throw etc, also what breed he is .health etc of his progeny, if he didnt stamp good type and there was health problems then it wouldnt be a good idea

Problem is, he could be carrying almost anything as a recessive and no one would know until the puppies arrive

John