I adopted two ferret one is 5 and really skinny but, pooping fine. Her sister is 4 she is having seedy poo I changed her food because, her other owners were just giving her low grade kitten food. I'm now giving her the EVO ferret food and Eukanuba kitten food she has been on it for two weeks now and she is still having seedy poo... they both got seedy poo when I gave them Tast Of The Wild and I took that away and one got better but the other one didn't. I don't know what to do. I change her water, food, and litter box everyday and still no change. I give her PeptoBismol two times a week only a little, home made duck soup, the Marshall ferrets duk soup, and FerretVite. I let my ferrets out for 2 hours 2 times a day.
When you change your ferrets food, it's very wise to change over very gradually. Only add a little of the new food each day. Each day add just a little more of the new food until you've completely made the transition.
Lots of things can cause a ferret to have diarrhea. A sudden change of environment, new people, or new pets. Sometimes they will have a reaction to things such as laundry detergent, fabric softeners, new toys or bedding. Vitamins can also cause diarrhea if you exceed the recommended dosage. Vitamins are VERY important but be careful to follow the instructions. In all these cases, once you resolve the situation, the problem will clear up in a day or two. If the problem continues, a trip to the vet is highly recommended. These little guys can go downhill very quickly and it's better to be safe than sorry.
You can try to put a little weight on your skinny guy by offering about a teaspoon of Gerber Junior Ham & Gravy baby food once a day. Serve it along side a little bit of his regular food. For treats I suggest plain (no salt) boiled chicken - no more than two or three slivers a day. ABSOLUTELY NO FRUITS OR VEGGIES!!!
Letting your furry little friends out to play 2 hours twice a day is great. Also remember to handle them often - they are very social little animals and need plenty of bonding time with you. If lonely and missing you, they can suffer from depression.
Overall it sounds like you're doing everything you should. GOOD JOB! If I can help you further let me know.