This sounds like a case of oral ulceration - this often follows nausea, as nauseated ferrets often claw at their mouths and the end results is ulcers on the roof of the mouth. Close inspection may reveal these ulcers. But do make sure you have the ulcers before trying the medication. I'm going to lose them. At this point, you shouldn't let the stress get you down, nor should you agonize over every upturn or downturn in thwir progress.
REcovery takes a while, and animals tend to vacillate with their symptoms.
If you are still feeding kibble, it may be why they are not progressing as you would expect. All rights reserved.