I had the same with two off my ferrets my young hob year old and my Jill who was about 6 the Jill didn't make it but the hob did out of the two the hob was worse at the time, the where eating a little bit egg and mince but not a lot, I mixed sugar and water gave it them in a syringed sat with them both for about 4 hours keeping them warm. The hob got a little better but the Jill went down hill. Just try keep him hydrated that's what I did and it worked for the hob ? Just thought I'd give you a bit of advice what I did because it said atheists same as what mine had.