Dog owners may be vigilant when it comes to protecting their pooches from rabies and heartworm disease, but veterinarians in certain parts of the country are sounding the alarm about canine influenza, which is on the rise in some areas.
There are outbreaks of dog flu right now in the New York metropolitan area and near San Antonio, Texas, and other states have reported epidemics throughout the year. Since the virus, known as H3N8, was first identified in 2004, thousands of dogs in 38 states have become sick with the flu, and veterinarians say that number continues to climb.
"We're seeing an increasing number of dogs being affected by this virus," said Dr. Cynda Crawford, clinical assistant professor in shelter medicine at the University of Florida's College of Veterinary Medicine.
Canine influenza is endemic in several states, including New York, New Jersey, Pennsylvania and Colorado. But like the virus that causes the flu in humans, the dog flu virus is very easily spread and highly contagious.
The American Veterinary Medical Association recommends that dogs that are in frequent contact with other dogs be vaccinated against canine influenza to help prevent the spread.
"This is a very mobile virus, and we live in a highly mobile society that contributes to the spread of influenza, which means it can go from one community to another simply by travel of infected dogs that are still contagious," said Crawford.
As with the human form of the illness, dogs who have the flu will experience coughing, nasal discharge, a low-grade fever and sneezing.
"The problem you face with dogs is secondary bacterial pneumonia," said Edward Dubovi, director of the virology laboratory at the Animal Health Diagnostic Center at Cornell University's College of Veterinary Medicine.
"There's increased risk for dogs that board, go to day care, are in shelters or that travel to areas of the country where canine influenza is circulating," said Crawford.
She added that people who work with dogs, such as veterinary and animal shelter staff, may unknowingly transmit the virus to their own dogs.
"People are one of the biggest transmitters of canine influenza. They may handle an infected dog, and the virus is shed and it gets all over their hands and their clothing."
So far, the canine influenza virus hasn't transformed into any other strains, unlike the human flu virus.
"We've been isolating the virus and doing genetic sequences to see if it's changing, " said Dubovi. "In the New York City area and in Colorado, it's had only minor changes, but it has the potential to mutate into something much more serious."
Although the virus hasn't changed much in the seven years it's been in existence, it is still very unpredictable.
"If you want to have a proactive strategy to protect against the unpredictability of canine influenza virus, the best preventive strategy is vaccination," said Crawford.