Is there a reason behind this?

My ferret has been diagnosed with adrenal disease so he had to stay overnight at the vet for tests. But when i got him back the vet shaved him! My old vet went out of business so i found this vet in another city. I have had a ferret with adrenal surgery but the vet didn't shave him! Is there a reason my vet shaved him? Does he need to be shaved for the upcoming surgery? He looks like really ugly! lol