I recently had a pup pass away from parvo...it was heartbreaking to us. We did everything right, but even with veterinary care it swept him away within 3 days. I was aware of this virus from my childhood, but the amazing thing to me was that of a litter of 3 pups there was one that, while testing positive for parvo, was FINE! He had a bit of runny stool and maybe one droopy day, but had to be in a separate quarantine area from his brothers because he was so lively and rambunctious. My point in this is that it doesn't hurt to have your puppy tested when you bring him/her home because even if they don't seem sick they could still be spreading the germ.