Sammy is six months old and has had the runs for some time now. She finally tested positive for round worm and was dewormed again (she was before I got her too). I then gave her a follow up dose of dewormer from the Vet after 2 weeks. The runs haven't cleared up and here are my questions: My roomates have a 4 month old kitten who has been dewormed right after Sammy was positive. She also developed the runs the day after she was dewormed (never had them before). How long does it take for the stool to firm up and can the dewormer upset their tummies for extended periods?