This is so fucking retarded it hurts.

If a dog is running around, playing, snout to snout with other dogs I can pretty much promise you that dog does not have anything resembling parvo. Not to mention the fact if you don't want your dog to catch parvo, don't bring it to a fucking dog park at that young of an age, and don't let it eat shit and mud.

You sound like one of those uppity bitches who polices the dog park.