infectious dog influenza

Canine Influenza


The first Canine Influenza patient of 2013 has been diagnosed at Veterinary Medical Center of CNY.  Canine influenza (or canine flu) was first noted in 2004 among racing Greyhounds.  Since then, outbreaks have occurred around the country, including New York, Florida, and Colorado.  We are currently hospitalizing the first case of canine influenza documented at the Veterinary Medical Center this year.  This patient’s story is a great example of how this virus can spread among the pet dog population, and why early detection and treatment is key in complicated cases.

According to the Center for Disease Control, the canine influenza virus is most commonly spread from dog to dog through small droplets that are released into the air when an infected dog coughs  These droplets can also contaminate objects (toys, blankets, beds), which can then infect other pets that come into contact with the objects.  People can also transmit this virus between dogs, since they can carry the virus on their hands or clothes.  Although the amount of virus shed by an infected dog is low, areas of high dog population, such as kennels, dog parks, and shelters are at high risk for viral attack.  On average, approximately 60-80% of dogs exposed to the virus will succumb to some form of infection, which can range from a mild cough to severe pneumonia.  This infection can also be fatal, although this is rare (approximately 8% of cases).

Dogs that are exposed to this virus usually start to show symptoms 2-5 days after exposure.  Signs of an infection include a runny nose or eyes, cough, lethargy, and chills.  The severity and duration of the infection varies among dogs, with some dogs only suffering from a mild cough for a few days while others develop severe pneumonia that can last a few weeks.  The cause of the pneumonia is usually due to a secondary bacterial infection, for which antibiotics may be prescribed.  Antiviral medications are of questionable use, as they need to be administered early in the infection.   To date, no studies investigating the benefit of antivirals in canine influenza have been published.


Diagnosing canine influenza can be a challenge, as there are multiple other viral and bacterial causes for a cough and pneumonia in dogs.  Also, the timing of testing is important.  Tests that identify virus DNA can be performed early in the disease process (usually within the first week).  After one week of illness, however, the virus is no longer shed.  During this period, diagnosis of canine influenza can be made using a test that screens for antibodies.

Because peak shedding of the virus occurs within the first few days after exposure, and because this frequently occurs before the onset of any clinical signs, an infected dog has usually contaminated an area before anyone is aware a disease is present.  The virus does not live long in the environment (about one week), and can be killed by many disinfectant products.  A vaccine approved by the FDA does exist.  Although this vaccine does not prevent infection, it can reduce the severity of clinical signs and decrease the duration of viral shedding.  Dog owners should discuss the benefits and risks of the vaccine with their primary care veterinarians.

In our patient’s case, we believe she acquired the virus while boarding at a kennel facility.  Since coming home from the kennel, both she and her other canine companion had a cough.  Although her companion continued to act normally despite her cough, our patient became lethargic, began to shiver, and was eating and drinking a bit less.  When evaluated by the Emergency Service at the Veterinary Medical Center of Central New York, this patient was noted to have a fever, a moist cough and difficulty breathing.  Blood work showed an elevated white blood cell count, and x-rays of her lungs showed evidence of pneumonia.  A PCR test was submitted to test for multiple viral and bacterial causes of pneumonia, and she was hospitalized in the isolation ward and treated with IV fluids, nasal oxygen and antibiotics.  This patient has been hospitalized for the past four days and she has responded well to treatment.  Her PCR test was positive for canine influenza.  At this time, her canine companion has not developed any additional signs of infection other than her cough, and no treatment for her was necessary.  While our patient will need a long course of antibiotics and recheck x-rays in a few weeks to monitor her recovery, we believe she will make a full recovery and be back to normal in a few weeks.  She will need to remain less active and rest for a few weeks, and she will definitely need to avoid dog parks, kennels, pet stores and shelters.  The kennel has been contacted regarding this infection, and we hope that corrective measures have been taken to prevent this infection from spreading.

So what should you do if your dog develops a cough?  Any changes in your pet’s health should prompt a visit by your veterinarian for evaluation so he or she can recommend an appropriate course of treatment.  Should your veterinarian not be available, 24 hour emergency centers can evaluate your pet after hours.  The VMC of CNY is always available to those in the Central New York region.   Please visit to find an emergency veterinary hospital near you if you are out of our area.

This blog post was written by the VMC's Medical Director, Maureen Luschini, VMD, DACVECC