Well, this is going to sound a bit gross, but one thing your friend might want to do is check Sammy's poop. If there's anything in it that looks like rice or spaghetti noodles, you're definitely dealing with worms. But that would definitely give your friend the proof she needs. If it is indeed a case of worms, most likely the vet'll give Sammy that magic, worm-killing Drontal pill. I know that Walmart sells dewormer, but I'm not sure how effective it is. I'd also be more worried about that leg than worms. Worms are easy enough to clear up.