UNDATED, WI (WTAQ) - Wisconsin veterinarians are reporting Parvo is spreading fast around the state this year. Parvo is a viral disease which makes dogs vomit and suffer with diarrhea. At least 30 dogs have died for it in the past few weeks. Vets say the chances for a dog to contract the highly-contagious disease from other dogs increases dramatically during the warm weather months. They strongly urge dog owners to buy the $15 preventative vaccination.