I have a friend at work who adopted her puppy from my breeder at the same time that I adopted Pippin. Different litters (she has 2 females). Maria took her pup to the vet yesterday and was told he has an umbilical hernia that must be fixed when they do his neuter surgery. I have never heard of an umbilical hernia before....how serious is it and is it something that is relatively common? How and why do they occur? I am a little surprised that her vet is just telling her this now because this is the 2nd time she has brought him there and they did not make mention of it at the time of the first exam. She is very worried about her pup and I am hoping that we can give her some words of encouragement and advice!