Canine infectious respiratory disease is the name given to respiratory infections in dogs caused by one group, or a combination of groups, of infectious organisms. Once one pathogen compromises the respiratory system, it is common for other infectious organisms to attack, causing secondary infections and worsening clinical signs. The invading pathogens include:

  • Canine influenza virus — The virus that causes canine influenza—or dog flu—is a Type A influenza virus, with two strains known to affect dogs: H3N8 and H3N2. Canine influenza has emerged as a significant threat to dogs, with outbreaks across the country over the last few years. Because this virus is relatively new, dogs do not have natural immunity to it, and 80 percent of exposed dogs develop infection. The influenza virus damages the epithelial lining of the respiratory tract, making it susceptible to other infections. The virus is highly contagious and is also known to occasionally affect cats.
  • Bordetella bronchiseptica — This bacterial pathogen is the most common cause of canine infectious tracheobronchitis, or “kennel cough,” which is characterized by a dry, hacking cough. It mainly affects dogs, but cats exposed to sick canines may rarely develop infection.
  • Parainfluenza virus — The parainfluenza virus can be a primary cause of infectious tracheobronchitis or may cause a secondary infection in dogs already weakened by one of the other infectious organisms mentioned.
  • Adenovirus, type 2 — This strain of the adenovirus can also cause, or worsen, kennel cough.
  • Mycoplasma — Mycoplasma are bacteria that often accompany Bordetella bronchiseptica, parainfluenza, or adenovirus infections.

How can my dog be exposed to these pathogens?

Just like with a human respiratory tract infection, germs are spread when an infected dog sneezes, coughs, or barks. These aerosolized particles can be breathed into the respiratory tract of a nearby dog or can settle onto inanimate objects in the environment. Many of the pathogens that cause respiratory disease can live for up to 48 hours on items like food bowls, blankets, and even clothing.

What are the symptoms of canine infectious respiratory disease?

Unlike the human flu, there is no “season” for canine influenza or other respiratory infections. Dogs may become infected at any time of year. The majority of infected dogs will develop mild, self-limiting clinical signs, such as:

  • Low-grade fever (102.5° – 104°F)
  • Decreased appetite
  • Lethargy
  • Sneezing
  • Coughing
  • Nasal discharge
  • Itchy, red eyes with or without discharge

Some dogs, especially those who are young, geriatric, or immunocompromised, may be affected more severely, developing bronchitis or even life-threatening pneumonia. Signs of a more serious infection include:

  • High fever (104° – 106°F)
  • Increased respiratory rate (>32 breaths per minute)
  • Labored breathing

Most dogs recover from infection, but death is possible if the infection progresses to pneumonia. Because dogs lack protective immunity, canine influenza infections tend to be more severe, with a higher chance of serious illness and death.

How is infectious respiratory disease diagnosed?

A diagnosis of canine infectious respiratory disease can be made by your veterinarian based on the presence of clinical signs consistent with the disease. Diagnosis of the particular pathogen (or pathogens) causing the infection can be made through laboratory tests. In the case of an unusually high number of infections, as with recent canine influenza outbreaks, it may be important to determine a cause. Treatment of the infection can vary with the severity of symptoms and if secondary illnesses, such as pneumonia, are present.

How can I prevent infectious respiratory disease in my dog?

The most important thing you can do for your dog is keep his vaccinations up to date. The core vaccines given to dogs will protect against adenovirus and parainfluenza virus. There are optional vaccines for Bordetella bronchiseptica and canine influenza that you can also request. These vaccines are particularly important if your dog visits places where he will be exposed to other dogs, such as the dog park, groomer, or boarding facility.

Dogs who have a respiratory infection should be kept away from other dogs while sick and for a minimum of 4 weeks after symptoms subside. All surfaces and items the dog may have come into contact with should be disinfected with a cleaner, such as bleach, to prevent the spread of germs.

Questions about canine influenza, canine infectious respiratory disease, or vaccinations for your pet? Call us at 937-866-5949.