I got two puppies and while I was at the pet store, the mail threw up some food (I think he got too hot) but we saw a white worm in the vomit. I immediately went and got wormer medication for them. I have seen worms in the poop as well, but yesterday I saw the worms, and they were still wiggling around. Today, the worms I've seen in the poop (no vomit today) have been very still, and what seems to be dead.
How do I know that the wormer medication is working the way it should?