I did some research on this today. I cannot believe I did not REALLY know what this was.
I found many on places such as 'yahoo answers' and other forums who discussed the main concern is giving the dog some 'breathing air' so they do not get yeast infections or tail infections.
Many use a playpen for sleeping at night, toss some blankets in, and so their dog could go diaper-less overnight. (and give their bottoms some 'breathing' time). They put new blankets in the bed each day, they launder the soiled blankets every other day. Many are pretty fiesty if someone even speaks of putting a dog with spina bifida to sleep, because they say it is a bit of extra work with laundry and diapering, and they need bathing more often, but for the most part, their dogs are just like any other dog.
I am sure there are differences in severity though, and probably what diet they are on, ect. would make a difference as well.