We had a pup born years ago that had a hernia, we were told if it DIDN'T move then it was fine to be left as it had closed and was probably just a fatty lump. If it moved, or could be pushed in then it would have to be operated on, but no immediate danger, and recommended having it sorted out when the pup was around 12 weeks old. The new owners took the pup home, knowing about the hernia, when the pup was just 10 weeks, running around part of the bowel pushed through the hole, luckily her owner was home and rushed her to the vet, she was operated on immediately, part of her bowel was bruised but nothing worse which it could have been had it not been noticed immediately.
When she took the pup home, her own vet agreed with my vets diagnosis that there was no immediate danger, it was around the size of a malteser too, the morning it popped out it was around the size of a golf ball.
She had the op and has been absolutely fine since, she's now coming up 8 years old.