Parvo is such a horrid thing for a dog to have, I recently resigned from a animal shelter, we had several cases of parvo this year, all were dogs from various pounds, one pound sent us dogs, twice over 2 months, that came down with parvo, one dog was sent from another pound that had already tested POSITIVE to parvo before they sent it to us! This was a just one of the reasons I left, it didnt feel like the shelter had the animals best interests in mind, we took in so many dogs, and cats, we were overloaded. We had dogs that were sick for months due to the fact that we just keep taking them in, more dogs, more illness... We didnt have the space for so many dogs, but we just kept taking them in, we would have room for maybe 5 dogs in a day, but the manager would take in 10, i'd say we were maybe 50% over capacity, now imagine one outbreak of parvo in that environment...it doesnt end well