I always had trouble keeping weight on Izzy. (WCS now aged 6.) She has been on Millies Wolfheart for at least 3 years and I found the food really suited her but I had to almost double the recommended daily amount. Last year I talked to one of the staff and they recommended Peak Performance which has slightly more meat fat. It has been very successful and I have been able to reduce the amount of food given each day. Her coat is great too.
Julia