SITUATION: University of Florida, College of Veterinary Medicine researchers report that outbreaks of canine influenza virus, which causes an acute respiratory infection, have been identified in dogs in shelters, humane societies, boarding facilities and veterinary clinics in Florida, predominantly in Broward, Dade, Palm Beach and Duval Counties. This highly contagious virus is a newly emerging respiratory pathogen in dogs and causes a clinical syndrome that mimics “kennel cough.” Canine influenza virus infections are frequently mistaken for infections caused by the Bordetella bronchiseptica/parainfluenza virus complex.

CLINICAL SIGNS: Because this is a newly emerging pathogen, all dogs, regardless of breed or age, are susceptible to infection and have no naturally acquired or vaccine-induced immunity. Virtually 100 percent of exposed dogs become infected. Nearly 80 percent have clinical signs. There are two general clinical syndromes – the milder syndrome and a more severe pneumonia syndrome. The milder disease syndrome occurs in most dogs.

In the milder disease, the most common clinical sign is a cough that persists for 10 to 21 days despite therapy with antibiotics and cough suppressants. Most dogs have a soft, moist cough, while others have a dry cough similar to that induced by Bordetella bronchiseptica/parainfluenza virus infection. Many dogs have purulent nasal discharge and a low-grade fever. The nasal discharge likely represents a secondary bacterial infection that quickly resolves with treatment with a broad-spectrum, bactericidal antibiotic.

Some dogs develop a more severe disease with clinical signs of pneumonia, such as a high fever (104°F to 106°F) and increased respiratory rate and effort. Thoracic radiographs may show consolidation of lung lobes. Dogs with pneumonia often have a secondary bacterial infection and have responded best to a combination of broad-spectrum, bactericidal antibiotics and maintenance of hydration with intravenous fluid therapy.

FATALITY RATE: The fatality rate for the serious form has been between 1 – 5%.

INCUBATION/SHEDDING PERIOD: The incubation period is two to five days after exposure before clinical signs appear. Infected dogs may shed virus for seven to 10 days from the initial day of clinical signs. Nearly 20 percent of infected dogs will not display clinical signs and become the silent shedders and spreaders of the infection.

PREVENTION: There is no vaccine for canine influenza virus at this time. This virus is spread by aerosolized respiratory secretions, contaminated inanimate objects and even by people moving back and forth between infected and uninfected dogs. This is an enveloped virus that is most likely killed by routine disinfectants, such as quaternary ammoniums or 10 percent bleach solutions. Because the virus is highly contagious and all dogs are susceptible to infection, veterinarians, boarding facilities, shelters and pet stores should use isolation protocols for dogs that have a “kennel cough.”

WHAT IS BEING RECOMMENDED? Be on the alert for this disease, particularly in the animal facility setting. Veterinarians who are overseeing disease control at kennels, shelters and other animal facilities should review the sanitation and infection control practices with the management of these facilities. Suspect canine influenza cases should be placed in respiratory isolation (different airspace) from other canines as soon as possible and examined by a veterinarian. Ventilate the facility thoroughly; clean and disinfect potentially contaminated areas/objects (food and water bowls, toys, etc) with the cleaning compounds noted above or others with strong anti-viral properties.

Facility staff and veterinarians institute infection control practices to avoid inadvertent spreading of the virus on contaminated clothing, shoes, and other fomites. NOTE: Frequent hand washing is vital in preventing the spread of all diseases. Report suspect outbreaks to the DHSS (see below). Suspect cases being treated should remain in respiratory isolation until their shedding period is over (see above); a 14 day period post-onset date is recommended to be on the safe side, assuming the dog has recovered.

DIAGNOSIS: Veterinarians can submit diagnostic specimens from suspect cases to the New Jersey Department of Agriculture (NJDA), Animal Health Diagnostic Laboratory for testing. More information on laboratory testing is available here: (http://www.state.nj.us/agriculture/divisions/ah/pdf/feeschedule.pdf) or by calling (609)-292-3965.

FOR MORE INFORMATION/REPORTS/CONSULTATIONS: Contact Dr. Faye Sorhage or Dr. Colin Campbell, New Jersey Department of Health and Senior Services via phone (609)-588-3121 or email: faye.sorhage@doh.nj.state.us or colin.campbell@doh.state.nj.us .