A serious viral infection that can kill unvaccinated dogs is generating concerns across southwestern Ontario.
PAWS Canada (Progressive Animal Welfare Services), a London-based charitable organization, is warning dog owners about canine parvovirus, a highly contagious and potentially deadly virus. The volunteer-based organization has addressed parvovirus outbreaks in London and Windsor that have claimed the lives of several dogs.
Last month, CBC News reported on an outbreak of canine parvovirus at a London community housing complex that left at least two dogs dead.
Dr. Rebecca Greenstein, veterinary medical adviser for rover.com and chief veterinarian at Kleinburg Veterinary Hospital, said while parvovirus vaccination isn’t required under Ontario law, it’s a “non-negotiable” requirement for all dogs in her practice.
Parvovirus symptoms
“Canine parvovirus causes a terrible mix of lethargy, loss of appetite and typically vomiting and bloody diarrhea,” said Greenstein. “It also practically wipes out a dog’s immune system, leaving them vulnerable to secondary infections.”
Cause of virus
Canine parvovirus can impact breeder facilities, puppy mills, shelters and other places where dogs are housed closely together.
The disease can spread through direct contact between animals and fecal contamination.
Cost of missed vaccination
While the canine parvovirus vaccine can cost up to $250, the cost of missed vaccination can be much greater, Greenstein noted.
Almost every infected dog will need to be hospitalized and some dogs will require blood transfusions and intensive care. Infected dogs must be kept in isolation from other canines due to the highly transmissible nature of the disease, Greenstein added.
About 10 years ago, while working in a veterinary emergency room, Greenstein treated five unvaccinated Dobermans from the same household, all suffering from parvovirus.
The clinic struggled to find sufficient isolation rooms for the canines and the bill for treatment was an estimated $8,000. Clinic staff managed to save four of the five dogs. But Greenstein said dog owners could easily spend thousands of dollars to treat parvovirus, with no guarantees of survival.
“It was such a poignant reminder that vaccines are created to eradicate and prevent life-saving diseases,” Greenstein said. “To not give them to animals places a tremendous risk.”
In 2023, the Ontario SPCA posted a story about an 11-week-old puppy named Sally, who was lethargic, dehydrated and emaciated after testing positive for parvovirus. The puppy was successfully treated at the Sudbury and District Animal Centre. She was later adopted by a family in Barrie.
Vaccine intervals
While not mandatory in Ontario, Greenstein said the parvovirus vaccine is considered a core vaccine, like the rabies vaccine, which is required by law.
A combination vaccine that includes parvovirus protection is usually administered when a puppy is eight weeks, 12 weeks and 16 weeks old.
Following the series of vaccines given to puppies, dogs typically receive a booster one year later and subsequent boosters at three-year intervals.
Many dogs from shelters or breeders typically have their first parvovirus booster, Greenstein said. But it’s important for adoptive pet parents to continue the vaccine series.
“The good news is if you keep up to date on boosters, you really only have to administer them once every three years, so it provides a built-in incentive to keep your dog up to date,” said Greenstein.
While vaccinated dogs can still get sick, they will hardly ever require hospitalization and are much more likely to survive a parvovirus infection, said Greenstein.
Know your pet’s vaccine history
Greenstein urges dog owners to know their pet’s vaccine history.
“A lot of people will wrongly assume their dog is fully vaccinated when they’re not. It’s important to know how many boosters they still need to get,” she said.
If you’re late between boosters by more than four to six weeks, you may need to repeat previous vaccine doses.
“Staying up to date means your dog needs to be vaccinated less,” Greenstein added.
Dobermans, German Shepherds and Rottweilers can be more susceptible to parvovirus, but any unvaccinated dog is vulnerable, said Greenstein.
Dog owners looking for low-cost parvovirus vaccines can check for mobile clinics offered by the Ontario SPCA or local animal welfare organizations.
