Approximately three weeks ago, my Chicago practice experienced a tremendous rise in the number of dogs experiencing respiratory diseases. Initially many of these dogs were energetic with deep, harsh coughs without a fever. The doctors at Animal Medical Center of Chicago tentatively diagnosed them with Canine Infectious Tracheobronchitis, or "Kennel Cough". Viral agents, like Canine Adenovirus 2 or Canine Parainfluenza, and bacterial agents, like Bordetella Bronchiseptica and Mycoplasma, can cause Canine Infectious Tracheobronchitis. All of our patients responded well to supportive therapy, which included antibiotics and cough suppressants. However, recently we have been seeing a number of dogs with more severe respiratory disease. These dogs are presenting with high fevers (103 to 105 degrees Fahrenheit), moderate to profound lethargy, nasal discharge, depressed appetites and labored respiration. These patients, we suspect, have Canine Influenza caused by the Influenza virus H3N8 strain.
Canine Influenza Facts:
Morbidity: 20-50 percent of the dogs exposed to this virus will make antibodies against this virus and will successfully clear the infection. These pets will not show overt signs of their infection.
50-80 percent of the dogs exposed to the virus will show flu like symptoms -- like fever, lethargy, coughing and purulent nasal discharge. A small percentage of these pets will develop pneumonia and it is this population that is at risk for death.
Mortality: 5-8 percent.
Most pets will recover with supportive care only.
Incubation Period: 2-5 days.
Length of Infection: 2 weeks.
Transmission: The virus can persist on toys, bedding, clothing, leashes and other objects for days. Regardless if they display illness or not, all dogs infected with the virus will shed the virus in their respiratory secretions for 14 days. People exposed to dogs with Canine Influenza should wash their hands and change their outer clothing to minimize the spread of this virus to other dogs.
During the next few weeks in Chicago, I would strongly advise all pet owners to avoid or at best, minimize, your dog's exposure to other dogs and areas of high concentration of dogs, such as dog parks, boarding, grooming and training facilities. If you chose to go to these facilities, please call them in advance of your pet's arrival to see if any ill pets have been there recently.
Treatment: Supportive therapy may include intravenous fluid therapy, antibiotics for secondary bacterial infections, nebulization therapy, and/or cough suppressants. As a result of viral damage to lung tissue, opportunistic bacteria invade the lung and may cause pneumonia.
Immunity: Dogs that recover from Canine Influenza are believed to be protective for 2 years. A Canine Influenza (H3N8) vaccine exists and aids in reducing the shedding and severity of the infection. This vaccine does NOT prevent the disease. The vaccine is given in two doses separated by 2-3 weeks. Yearly re-vaccination is recommended for high-risk dogs.
Dogs that travel, who have contact with many other dogs, frequent boarding or training facilities, or go to dog parks may benefit from this vaccine. At this time, Canine Influenza vaccine is not considered a core annual vaccine, which means it is not a vaccine recommended to all dogs. Just because a vaccine exists, does not mean that your dog should receive it. Please consult with your veterinarian to assess your pet's risk for acquiring Canine Influenza virus and need for this vaccine.
Zoonosis: No. This strain is not contagious to humans.
If your pet is experiencing flu-like symptoms, like coughing, runny nose and lethargy, please contact your veterinarian as soon as possible for medical advice. This disease can progress quickly and it is best to medically address it as soon as possible to increase your pet's chance of a swift recovery.
Dr. Donna Solomon is a veterinarian at Animal Medical Center of Chicago and invites you to email her your questions or future topic ideas to firstname.lastname@example.org