our 9 month old pug was similar and had been to the vets then one morning he was really not himself and they kept Ralph in and found Giodarno (pos. spelt wrong) virus and we nearly lost him. After two weeks he came home and we were told to feed him the Hills sensitive (sold by the vet!) as his tummy was still sensitive, which we did and and I have now gradually changed him over to Natures Diet which I buy from amazon which is all half the cost but better still seems to have the most natural ingredients of all the foods I have looked at. He was always loose but on both of these foods is nice and solid!