Hi Guest,
My sympathies to you concerning your puppy. Addison's Disease in humans is a difficult thing to manage, in a dog it's even more so. Because it cannot tell you when it's run down or over stimulated in the adrenal glands.
My mother purchased a beautiful little schnauzer bitch puppy in the mid 1980s. By the time it was a year old, she was diagnosed with Addisons. She had her spayed for the same reasons as you + she had a dog present in the household. We did have her spayed before her first season, so she never had any difficulty there.
I'm sorry I can't help you out. :( But her schnauzer did have ear/skin/heart problems for the rest of her life. My mom swore that the Addison's came from being "over played" and pushed as a very young puppy by a certain individual. It is possible, since findings have shown that dogs that have this disease "cannot cope with stress."
It looks from the various sites that having a dog with this disease has become a bit easier than 15-20 years ago. It was heartbreaking to her to have to put Kyrie to sleep when she was only 4 years old, but she was just not responding to any more of the treatments and she was really beginning to suffer.
These sites have some good information that might help you out a bit. If you do a search on Google for "Addison's Disease" Dogs it comes up with many more possililities.
all my best for you and your puppy.
Sara
Addison's Disease and treatment Canine Addison's disease