Veterinarian Shannon Sierra, who works at Best Friends Animal Hospital in Talent said he's seen a "dramatic increase" recently, treating six cases in the last three months alone. All those dogs survived, including one recovering pup he sent home Thursday.

The Jackson County Animal Shelter has seen five cases in the last 30 days, including dogs who came to the shelter sick, a litter that sickened Saturday and a puppy that died Tuesday after going home with new owners.

The disease-causing virus is transmitted in excrement and is highly contagious to unvaccinated dogs. It attacks the intestinal lining, causing diarrhea and vomiting and blocking the absorption of nutrients and water. Untreated, dogs with parvo can die of dehydration or secondary infections within days, Sierra said. The disease can't spread to people or other animals.

Prevention requires three shots delivered in boosters three weeks apart, starting when a puppy is 6 to 8 weeks old. Treatment can run hundreds of dollars a day for several days, clinics reported.

Because of the rise in parvovirus, the Jackson County animal shelter has stepped up sanitation, requiring visitors to walk through a sanitizing solution. People adopting animals can't bring other pets to meet potential new additions and must sign an adoption agreement outlining the risk that shelter animals could have been exposed to disease

Alan Stroud, of Medford, said the warning should be heeded. He adopted a border collie-Australia shepherd mix for his wife last weekend. Although warned about parvo, the Strouds attributed the pup's vomiting and diarrhea to the stress of change, which shelter workers told them could upset a puppy's tummy.

By Tuesday, a vet told the couple the extremely ill dog had parvo and a limited chance of recovery. They had their new puppy put to sleep.

"If I could just warn people that this is out there, that's the least I could do," Stroud said.

(Copyright 2005 by The Associated Press. All Rights Reserved.)