Thanks for the reassurances everyone, I've played tug of war with him, he chews bully's all the time, and they are not moving, the 2 upper canines are solid. The one in the back is turning brown and I'm afraid of infection.
Bonny I do brush is teeth every second day, but there is one tooth that looks like it is not in good shape right in the back, the vet said it sounded like a dead tooth, It's been loose for awhile, but not loose enough to fall out!