I have 2 labradors, Molly and Bess. Molly is 19 months old and Bess is 13 months old. Molly is a typical chunky labrador and can eat anything. Bess is very thin, looks more like a whippet and has a very delicate tummy. We have tried to fatten her up by supplementing Iams with cooked chicken. Recently she has had bouts of diarrhoea and has lost weight. She weighs 21.8KG having lost 2KG in the last month. Any advice on diet would be most appreciated.

personally i would take her to the vet to make sure there is no problem if you have already done this then hopefully someone with more knowlege will be along here soon with some advice sorry for not beinging any help,maybe you should speak to your vet about a diet that would hopefully suit her