Three of my dogs have passed away within 2 weeks. They tested negative for parvo via the snap test. After the second passed, we had a necropsy done and they sent off a portion of necrotic intestine, a portion of seemingly normal intestine, blood, etc. After that I lost another dog. I had blood draws done on my three smaller dogs that had been around the sick dogs and all came out normal. Within 2 hours after this, one of the smaller dogs started showing symptoms (lack of appitite). This dog was the third one I lost. All of my dogs were UTD on vaccines. The tests came back as an extremely virulent strain of Parvo. This killed each dog, even with treatment, within 36-52 hours. All of my other dogs have been put on antibiotics and we are spraying everything with bleach. I am wondering how a strain of parvo can show normal bloodwork, kill vaccinated dogs, and not show up on snap test if it was this harsh of a strain. I also have no idea as to where it could have come from. We do not go many places. We never go to dog parks, etc. We are in the country and have raccoons, foxes, and deer, along with many other wildlife, but my vet says they could not have gotten it this way. I do not know how to try and make sure none of my other dogs get ill other than the bleach and watching them closely. I was a vet tech for 10 years and I never saw parvo manifest and kill this quickly. I need to understand. Please help me if you can.