Yes, it was parvovirus. Fortunately the house burned down and my parents moved, so there's no risk of any of the other dogs getting it. How he caught it is we (the humans) went to a seedy pet store where there were some pomeranian puppies, the puppies were rumored to have died of parvo after being purchased (we didn't buy any or anything, only looked and came home.) He caught it from us having been at that petstore.
Edit: of course we did not find out about the poms dying until we mentioned it to our vet "you know, I've had a couple of poms in here with parvo before you guys came in". And of course we thought nothing of visiting strange dogs and coming home, since all of our dogs were over 6 months old and "adequately vacc'd" Turned out wrong.