ROCKFORD, Ill. (WTVO) — Dog owners need to be on the lookout for parvovirus, local animal experts warn, especially with the warmer season ahead.

The parvovirus is extremely contagious and the symptoms include vomiting and diarrhea, followed by avoidance of food and infected stool.

In just days, a dog can go from healthy to dying, experts say.

Dr. Kevin Thrall, the medical director at Rockford’s Animal Emergency Clinic, said, “They often don’t drink well once they dehydrated, that can really spark up a lot of problems that they can end up dying from. The bone marrow aspect of it is that the white blood cell count will drop down, so the virus will stop the immune [system]. So then, we get a dehydrated puppy that doesn’t have a lot of white cells with a damaged [gastrointestinal] tract.”

The combination can lead to septic shock three to four days after getting the virus.

Vaccines are expensive, but not compared to the cost of treatment once the animal has become infected, according to We CARE for PETS executive director Stephanie Hicks.

“The most important thing I could say, having touched a lot of dogs that have had parvovirus, is to vaccinate pets. That’s number one. I don’t care if you do it through your [veterinarian] or through a store vaccination,” Hicks said. “The way that they die from parvovirus is absolutely the worst death you can imagine.”

“If you have a puppy, don’t take the puppy out where there could be exposure,” Thrall added. “Keep the puppy in isolation when we are in our vaccine series, and then make sure the vaccines are given on the schedule that the veterinarian recommends.”

Local animal shelters say they have been dealing with an unusually large number of parvovirus cases this year.