Updated Saturday, December 8, 2012 at 12:16 PM
Veterinarians thought it odd when they saw eight cases of the sometimes deadly canine parvovirus in November at a Seattle-area animal-emergency clinic.
That one-month figure was half what doctors at Animal Critical Care & Emergency Services (ACCES) generally see over an entire year. They've treated 28 cases so far in 2012 — almost twice as many cases as they usually treat in a year.
Because most of the pets ACCES sees are referred to them by other vets who have informed owners that parvo treatment can cost thousands of dollars, ACCES medical director Dr. Beth Davidow started worrying that there could be a much larger outbreak.
"It's extremely contagious, which is why it's so important to diagnose it as early as possible," Davidow said of the virus. "Most adult dogs don't get very sick from it, but it kills puppies."
For the first time in 17 years of practice, Davidow said, she saw a vaccinated 15-month-old dog come down with parvo.
So ACCES put out an alert to other Puget Sound-area vet clinics last week to push for better vaccination rates and to warn puppy owners to be careful about where they take dogs that aren't fully vaccinated.
The alert pointed to the same thing vets at South Seattle Veterinary Hospital were seeing.
"We're not sure if this is a particularly virulent strain, but there is a recent across-the-board increase at several local hospitals," said Lisa McCollough-Dutt, a manager at the hospital.
Though vaccinated adult dogs are likely not at risk for contracting the virus — which causes bloody vomiting, diarrhea and dehydration — puppies are. Even puppies younger than 6 months that have had their first or second parvo vaccine can be susceptible, according to Davidow.
"Most of the cases we've seen have been puppies," she said. "Your puppy is not covered until they have a series of three parvo vaccines."
She said most were infected in several different areas of Western Washington while at a shelter, a pet store or simply somewhere on a walk. Because it takes more than one inoculation for a puppy to be fully immune, the virus can sometimes spread at a shelter or store even if the dogs have been properly vaccinated.
Parvo has a symptomless incubation period that can last two weeks, so dogs carrying parvo can't always be identified before they pass it on to others.
Parvo spreads easily to puppies or dogs with suppressed immune systems and can live for as long as six months in dirt, feeding dishes, collars, leashes or anything else onto which dogs can shed the virus.
It is extremely resistant to heat, cold and just about every disinfectant, with the exception of bleach. One close whiff or lick of an infected area is all it takes for some dogs to come down with the virus, Davidow said.
Even after an infected dog has gone through the most severe phase of infection — usually a week or less — the dog can shed the live virus through feces for up to six months.
Socializing puppies is important, but owners should make sure their dogs' playmates are fully vaccinated, Davidow said. It is possible for puppies to survive the disease, but many don't without intensive treatment.
At ACCES, which has offices in Seattle and Renton, the cost of treating a dog with parvo ranges from $1,500 for two days to $7,000 for eight days. The survival rate is 90 percent at ACCES with treatment that includes intravenous fluids, anti-nausea medication, antibiotics and plasma in severe cases.
Owners can nurse a sick dog at home with round-the-clock attention, but many people who can't invest the time or money to keep a puppy alive wind up having their dogs euthanized, Davidow said.
A single parvo combination vaccine shot usually costs about $25, according to Terri Inglis, executive director for Homeward Pet Adoptions Center in Woodinville. Some places, such as South Seattle Veterinary Hospital, offer the shots for as little as $12 each after a free examination for first-time patients.
"There's no cure for parvo, and for puppies, it can be a death sentence," Inglis said.
Because no public agency tracks the number of parvo cases, Davidow said, she believes it's the responsibility of a large clinic like hers to keep track of how prevalent the virus is.
"We treat about 15,000 pets a year, so often if there's an outbreak in something, we're going to notice it before a small practice does," Davidow said.
In response to the ACCES alert, Everett has closed all three of its off-leash dog areas until at least mid-December, and several other cities in the Puget Sound area have posted warnings about making sure dogs are vaccinated before entering a high-traffic dog area.
Seattle Parks and Recreation has signs posted near off-leash dog parks prohibiting unvaccinated dogs and puppies younger than 4 months old. The department said it hasn't received word from any city or county agency that the outbreak is large enough to consider taking extra measures to protect dogs.
Closing dog areas isn't the best solution to a possible outbreak, Davidow says. The solution is getting dogs vaccinated and being careful about where puppies go.
ACCES doesn't give vaccinations because of its focus on critical care, but Davidow recommends puppies get shots at the ages of 8 weeks, 12 weeks and 16 weeks. After that, another shot should come in a year and a booster shot every three years.
McCollough-Dutt, the manager at South Seattle Veterinary Hospital, said she thinks a major contributing factor is people's budgets tightening up.
"We get a lot of low-income owners in here who tend not to vaccinate when they should," she said.
She also said the informal selling and giving of dogs through Craigslist has "definitely" increased the rate of unvaccinated puppies. If there isn't paper documentation that a puppy has been vaccinated, new owners should assume the dog needs to be inoculated.
"Even if someone told you they vaccinated the dog already, it doesn't hurt to do it again," she said.
Davidow said there's also a chance the spike in parvo cases is purely coincidental. While some smaller clinics she's called haven't seen any cases, some, such as one in Shelton, Mason County, recently dealt with a spate of 10 cases linked to one pet store.
There may be several causes for the uptick in parvo cases, Davidow says, but she worries the skepticism some parents have about vaccinating their children has passed on to pet owners.
"We think people may have gotten complacent about vaccination," Davidow said.
Alexa Vaughn: 206-464-2515 or email@example.com. On Twitter @AlexaVaughn.
KEN LAMBERT / THE SEATTLE TIMES
Shiloh, 4 months old, visits Golden Gardens this week with owner Diane Tatum. Cases of the sometimes deadly canine parvovirus have spiked in King County. Tatum said Shiloh is protected, having had all of her shots.
KEN LAMBERT / THE SEATTLE TIMES
The Golden Gardens dog area was busy Wednesday, but Seattle is prohibiting unvaccinated dogs and younger puppies from off-leash areas. Those in Everett are closed.