I have not personally experienced adrenal (crossing fingers I don't) as of yet. I know mant ferrets develop it as they get older & I too have done my best to research it & find answers to the whatifs... I found some links I had book marked, hopefully they will help you out... and btw good luck to you & your little one... give him extra snuggles for me!
I found this most helpful:
Surgery? What can I expect?
The first thing you need to do when your ferret develops adrenal problems is make sure you have a competent and well experienced vet. Unfortunately the cost of surgery can range from $250.00 to $1500.00, depending on which part of the country you live in. But within your area, the price of surgery can range just as dramatically! Here in the Detroit area our vet provides adrenal surgery starting at about $350.00 (additional blood work and histopathology can raise the price). If you visit another vet in the Detroit area who quotes you $1,200.00, you should really ask yourself what that price is paying for! A seriously high quote tells us the vet is inexperienced or simply doesn't want to do the procedure. So it is important to shop around to find the best care!
While the surgery is usually pretty straightforward for the vet, it is of course a big deal in the life of your ferret. The adrenals are located adjacent to the kidneys, which you can imagine are closer to the back of the ferret than the belly. The incision is usually over 3" long, so you may be surprised to see your little friend immediately after surgery. Our friend Jack shows off his new scar for you the evening he had his surgery. Don't worry - he's not dead, he's just pooped after a hard day! One to three days after the surgery, most of the belly around the incision will bruise. These bruises should disappear within a couple of days. Ferrets heal so quickly, you should expect to remove the stitches 10-14 days after the procedure and critters scar will be but a thin pink line. Once the fur grows back, which can take from a week to another shed cycle, you'll never notice the scar.
Some ferrets go right on with life the very night they've had surgery as if nothing had happened that day, but you should plan for critter to at least have a couple of "down" days. Although your vet may advise you to withhold food the night before surgery and the evening of, please remember these are traditional dog/cat guidelines and are not appropriate for ferrets! We get so outraged when the staff of the vet clinic tells people to withhold food. We remove food four hours before surgery ONLY and definitely make sure critter eats something that evening. You should be prepared to force feed your critter, as a critter who's had surgery might not feel like eating kibble (some will eat on their own - just be prepared). The mush need be nothing more complicated than moistened, mashed up kibble, but you could also add some Nutrical. For more information on force feeding a ferret, please visit the "My critter won't eat" page from our Health home page.
Keep your critter warm and quiet the evening of surgery. If you have a large, multi level cage, either remove critter from it or remove the ramps. No climbing, running, jumping or otherwise possible blowing those stitches for a few days. If critter has any bleeding, is excessively cold or is vomiting, consult your vet right away. Complications are possible, so do plan to keep an eye on critter for 2-3 days. Now, once you've been force feeding your critter warm, mushy food, you may find that - although they feel just fine - they will be finicky about going back to regular old hard kibble. Use all the powers of persuasion you have (tee hee)! Trickery, chicanery, all are acceptable. Little ferrotone on piece of kibble...whatever works. It can take a couple of weeks, so don't lose hope! Sophie was just terrible. She so enjoyed being babied she absolutely was NOT going to go back to being a regular old get-your-food-from-the-general-dish-silly weezil. Took some major work to get her extricated from Mom...but eventually she returned to her friends. What you just can't do is stop feeding critter if he/she won't eat on her own. It can be frustrating, but remember critter had major surgery. You know what a baby you would be if you had your whole abdomen explored! Patience and love is the key to getting critter through the whole experience.
and a couple other links:
hope this helps, hang in there