Nutrical is a great supplement. It is high in calories and nutrients.

Poor Charlie. Did you ask whoever it was that took care of him what happened? Did he not eat because he was stressed, or did they just not feed him the way he's supposed to be fed. I think they have some explaining to do. 4 pounds is ALOT of weight to lose in only 3 weeks.

Another thing you can do to put weight on Charlies is kitten food, both canned and dry. It's also high in calories and protein.

Good luck.