is this from eating so much in the past couple of days or is it something else?and should i take him to the vet even though he doesn't like be handled or picked up and bit me hard that my hands are swollen. he may bite the vet and i'd get sued!and how can i be sure he doesnt have parvo.... he hasnt thrown up and his poop is soft but not diarrhea. so is he ok?

Sounds like since he was a stray he was just super hungery and he is eating until his belly is so full because he probably isnt sure when he will get another meal! You should take him to the vet for a checkupp and his shots but if it was parvo he would be super sick!They will just put a muzzle on him to keep him from biting

One of the most common causes of a pot belly - (other than eating too much) is intestinal worms. If his belly feels quite hard (not soft and podgy) then worms are likely. Have you wormed him since you started looking after him? If not then get a good all wormer from a vet or pet shop and see if that solves the problem. If you see worms in his next poo then that means the wormer has done the job and killed the worms...If you don't know his history then you should definitely take him to the vet. You should also probably get him tested for heartworms because depending on where you live, heartworm can be a serious problem.I doubt your vet will sue you if your dog bites him - thats part of the job - though if you want to be sure then buy a soft muzzle from a pet shop and put it on him before you go.