When I bought my puppy Jill a few weeks ago, the breeder told me her vet did a fecal test which was negative for worms - so the vet told her they did not need dewormer...... which worries me a little. She has horrible diarrhea lately, could she have worms? I think I need to buy a dewormer anyway, but could there be other reasons for the diarrhea? I haven't changed her diet - and now my older BT is getting some runny poops like hers. It worries me that maybe she gave him something...