Illness/Sickness: Fire bellied newt keeps losing legs

Hello! I looked around the forums for something like this but all I can find is single limbs falling off and not multiple ones. I'm very new to amphibians (though I've had pretty much every other type of pet...) but I'm trying my best!

A couple weeks ago I got a male fire belly from a local pet store, and he seemed fine when I got him and after I put him in the tank. He ate some earthworms I'd chopped up for him and looked okay until I went to change his water today. Three of his feet have come off! I had a bunch of large rocks in his tank, so I'm not sure of they got caught between and came off that way or if it's from him shedding or if it's a condition.

Needless to say, as soon as I noticed his nubs I went straight to work switching out the rocks for soft sand that he won't get caught on. But I was wondering if anyone else has had this happen? Also what do I do when he's shedding, just let it happen?
Thanks for any help!

This almost certainly is a bad case of infection. Sadly, infections that destroy tissues are very common in these poor guys. They are wild-caught in China and shipped in very bad, crammed conditions. Those who survive still have to go through the pet-shops, who generally offer inadequate conditions and negligent care. The result is that many, many newts die during the process or shortly after being purchased and the commonest cause are these terrible infections. Their inmune systems are inhibited because of the stress and the infections just eat their way through the animal.
Unfortunately, these infections are hard to cure...specially when they are as advanced as having destroyed three limbs. You can try salt baths (check the articles in my signature) or Neosporin (WITHOUT pain killers).

In the future, if you decide to acquire more animals, please consider where they come from and the toll it takes. You can acquire captive-bred animals from breeders, which is better for you as a costumer and for the animals themselves as well as the wild populations.

I'll definitely check out those links, thank you for the advice! I did a lot of research before I got him to make sure I could take care of him, but I guess infections happen. I think he likes the sand instead of the rocks anyways. He's still living as of yet, hopefully he'll be able to hang in there!