A parvovirus outbreak in Windsor has now claimed the lives of at least 18 dogs, Animal Welfare Services (AWS) reports.

15 of those dogs were euthanized under AWS care due to the progress of the potentially fatal yet preventable illness, though some of the dogs died before AWS became involved.

"AWS continues to monitor the number of impacted animals given the dynamic nature of the outbreak," said Brent Ross, a spokesperson for the provincial Ministry of the Solicitor General, under which AWS operates.

Since identifying the outbreak on Dec. 4, the agency said it's aware of 34 total dogs impacted by the outbreak -- 24 of which were removed by AWS and the other 10 taken to local veterinary clinics for treatment.

Four dogs have been returned to their owners so far, Ross said. The other 12 dogs are currently receiving treatment.

The virus is spread from dog to dog and can cause lethargy, vomiting, diarrhea, abdominal pain and fever, even becoming fatal if left untreated. Symptoms usually appear within a week.

But the illness can be prevented almost 100 per cent of the time with the routine vaccinations dogs receive from their vet.

The province held a vaccination clinic for dogs in the Glengarry neighbourhood last weekend.

"We were able to interact with some of the residents and just to give them some education," Lynnette Bain, executive director of the Windsor-Essex County Humane Society, previously told CBC Windsor.

"The residents were very grateful for the opportunity to see a veterinarian ... and it was really a good experience."

While potentially deadly for dogs, parvovirus does not impact humans or cats. Despite the additional attention because of the number of animals affected in this outbreak, Bain says the virus is always around.

"While it is concerning, the fact is that parvo does exist on a regular basis in the community, it's just we don't see it in large numbers," Bain said.

"It could be a concern when we let our guards down on the vaccination side."

This is the second parvovirus outbreak in an Ontario community in the past month, after an outbreak in the London area Nov. 19.