An outbreak of canine influenza that has been described as nearing "pandemic" status in sections of southern and central Pennsylvania may have started to appear in Chester Counties and Montgomery Counties, an area veterinarian said Thursday.
Doctor Jennifer Fry of Banfield Pet Hospital in Pottstown said she treated a suspected case of the disease about two weeks ago.
"We are definitely seeing cases of it," Fry said. "I had a six-week old puppy that just lay on the exam table, which is not normal. It's similar to our flu. You just don't feel well at all."
The canine influenza virus, which is also known among epidemiologists as H3N8, had been observed in horses for decades but in 2005 was identified as having jumped to dogs, according to the Centers for Disease Control (CDC).
WPMT in York and WGAL in Lancaster reported last week that the veterinarians in the Susquehanna Valley region have seen a recent spike in the number of canine influenza cases coming into their offices.
The highly contagious disease, which manifests in dogs as a cough, runny nose, and fever, is "mild" in about 80 percent of dogs that are infected, according to the CDC. WGAL, citing unspecified officials, reported that about six percent of infected dogs die from the disease.
Socially active dogs at higher risk
The disease can spread between dogs via aerosol transmission such as sneezes and through contact with infected surfaces.
Fry said the dogs most at risk are those that frequently socialize with other dogs or regularly visit facilities that care for dogs, such as boarding kennels or pet grooming salons.
"It's airborne, and can also be transmitted through objects that are not properly sanitized," Fry said. "If you're going to be going to playgroups or dog parks, it's a wise idea to get the vaccinations."
The disease can easily be mistaken for "kennel cough," a much less serious upper respiratory condition that can affect groups of dogs kept in close quarters.
The disease is not believed to be communicable to humans, but there is always a danger that the virus could mutate into a strain that can infect people, according to the CDC.
"Influenza viruses are constantly changing and it is possible for a virus to change so that it could infect humans and spread easily between humans. Such a virus could represent a pandemic influenza threat," the CDC said in a canine influenza fact sheet on its website.
Cats potentially at risk
Fry discounted the likelihood of transmission to humans but said cats living in the same household as an infected dog could conceivably be at risk. There is no canine influenza vaccine available for cats.
Not all infected dogs would show symptoms of canine influenza. Fry said about 20 percent of infected dogs could show no symptoms but instead be carriers of the virus, capable of infecting other dogs.
Confirming infection is difficult because there's no rapid test for the virus, Fry said. Blood tests and other lab work could be required to be certain that a dog's illness is due to canine influenza.
Some boarding kennels and pet day care facilities are now requiring immunization against the virus, Fry said.
A canine influenza vaccination for a dog requires two injections, two to four weeks apart, with annual boosters thereafter. The vaccine costs between $25 and $45 in the Philadelphia region. Fry said that dogs not previously seen by a veterinarian would need to undergo a physical exam before the vaccine could be administered. As with human flu, very young dogs and elderly dogs are most at risk from the disease.
"Vaccines are for healthy pets," Fry said. "A sick pet would not be vaccinated," but would instead receive a course of treatment.