Here is some information about Parvo. This summer saw an increase in the number of local cases of Parvo, so it's not just a problem "far away."
Drs. Foster and Smith: Parvovirus: Serious Diarrhea in Puppies & Dogs
Merck Vet Manual Canine Parvovirus
Baker Institute at Cornell University Canine Parvovirus
Mar Vista Vet Canine Parvovirus