There is a boxer somewhere (I've seen him on TV, all over the net etc..) that had the same problem. IF I remember right he had took the worlds record for the longest tongue on a dog?????? Anyways it ended up being some sort of muscle control problem.

Here's an article I just found about him:
* The Boxer Dog With The Longest T-o-n-g-u-e!

A boxer dog called Brandy featured on Ripley’s 'Believe It Or Not' due to her incredible 17 inch long tongue! Brandy, from Michigan, USA, was bought from a local breeder in 1995 and her new owner was assured the dog would eventually grow into her l-o-n-g t-o-n-g-u-e! She didn’t and on television she was shown performing antics such as eating from a bowl 13 inches away. Her owner, John Scheid, says brandy likes sunbathing and even gets tan lines on her tongue, but says the beautiful Boxer is fit, happy and healthy, so her unique feature isn’t a problem at all. She even has her own web site at: www.tungdog.com
http://www.tungdog.com/


Here's a site with simialr dogs. I don't have time to really look into it so I do not know how much help you will find there but hopefully you will.
http://cairotheboxer.blogspot.com/2006/05/yogi-pug.html