Those of us on the human end of the leash are well aware of the variety of contagious respiratory viruses that seem to be ready to pounce on us as we innocently go about our daily lives. Unfortunately, our dogs are subject to their own array of respiratory illnesses. While many respiratory conditions might be considered seasonal or isolated to specific circumstances, it is now wise to be on the lookout and in protective mode throughout the year. Recent outbreaks of canine influenza across the United States serve as a good reminder of the need to raise our caution levels a bit more.
Most dog owners are familiar with “kennel cough.” There are a
number of different organisms that can cause a cough and respiratory condition including an array
of bacteria and viruses. Because of the complexity of these infections this
condition sometimes is referred to as Canine Infectious Respiratory Disease
Complex (CIRDC). One of the more common
causative agents is Bordetella bronchiseptica and there is a specific
vaccine available for that particular organism. Because other organisms can be
responsible, the Bordetella vaccine does not offer complete protection, although it does offer a considerable decrease in the likelihood of infection with this agent. Other vaccinations are available for additional protection, particularly parainfluenza and adenovirus.
Distemper also has a respiratory component and is one of the recommended
core vaccines but is significantly distinct from what we usually think of as “kennel cough.”
In the last year or so, outbreaks of canine influenza have led to
serious illnesses and the closure of a number of shelters and other facilities
for dogs in order to control the spread of this dangerous disease. Several of these have been in the mid-Atlantic
area including D.C., Virginia, and North Carolina. Canine influenza is viral in
origin with two specific subtypes of the Canine Influenza virus being responsible
for outbreaks in the US so far. Canine
influenza gained considerable attention in 2004 when a number of racing greyhounds
were affected. The causative agent for that outbreak was identified as Canine H3N8
influenza virus which is thought to have originated in horses. In 2015 another
subtype (H3N2) was found in association with some severe cases during an outbreak
in Chicago. The H3N2 strain also has
been found in cats who were presumed to have been infected by transmission from
dogs.
Illnesses associated with CIRDC are highly contagious.
Similar to how respiratory disease spread among humans, dogs can spread infection before there are obvious signs of illness. This makes it much more difficult to control and, for us trying to keep our dogs safe, also to avoid exposure. In most cases an infected dog will show signs of illness, particularly an obvious cough. In addition to the cough, other signs that are easy to observe in other animals are noisy or labored breathing and nasal or
eye discharge. Infection is spread through the close contact including sharing
toys or water bowls, close play, or any close contact that enables a dog to inhale
or ingest droplets from the cough or sneeze or saliva of an infected dog. A dog
who is showing any signs of respiratory disease should be kept apart from other
dogs. For the most part, we humans are safe from these particular pathogens.
Only one of the causative organisms, Bordetella, is known to spread to humans but that
is very rare and more of a concern for people with compromised immune status.
A hallmark sign of CIRDC is the sudden onset of coughing. It
is common for the cough to have a loud honking sound, although this is not
essential for diagnosis. Nasal and eye discharge may be present as well. The cough and other symptoms tend to appear
suddenly, often within 2-3 days of exposure. Kennel cough can be self-limiting
provided the lungs are not involved; similar to our cold viruses, the dog might
recover on its own within about 10 days or so.
Canine influenza has the potential to be more serious with dogs in poor health otherwise or those very young or very senior being at greater risk. Since the owner
cannot tell what organism has infected the dog or if the
lungs are involved, it is best to have a veterinary examination to determine
an appropriate plan for each dog. The
veterinarian will be interested not only in the examination of the dog but the
dog's recent activities which gives a clue to possible exposure.
Any upper respiratory condition (the pathway that carries air prior
to reaching the actual lungs) can progress to a more severe state if the lungs become involved (pneumonia). As with most illnesses, this is a greater risk for debilitated
animals. The dog may seem distressed and
uncomfortable from coughing and some symptomatic relief can ease the process
for the dog and concerned owner as well. Typically a cough suppressant is prescribed
which can help the dog be more comfortable. Occasionally antibiotics are prescribed
if there is suspected or bacterial infection or concern or developing a secondary
infection beyond the initial cause. Antibiotics are not effective against viruses
and should be used judiciously. In addition to these measures, supportive care can help the dog be more comfortable and
make good progress through the disease. Supportive care includes ensuring adequate rest and maintaining good nutrition and drinking plenty of water.
CIRDC, including kennel cough and influenza, are ongoing concerns
for our dogs. The dedicated caretaker or pet parent should be aware of the
widespread nature of these diseases and the potential for outbreaks and take steps
to protect dogs from becoming ill. An
important starting point is to ensure the dog is up to date with core vaccines (or
titers) which offer some protection against several of the causative agents.
Discuss with your veterinarian your dog’s lifestyle, including potential for
exposure and risks associated with respiratory illness, to determine if any
additional vaccinations are appropriate.
Stay alert to any news about outbreaks in your area or locations where
you may travel with your dog. Minimize exposure to other dogs during times of
high disease activity. This is especially relevant for dogs of unknown history
such as at a public dog park. It may be safer for your dog to visit a dog play
group or day care where someone supervising the dogs is likely to notice a
cough or other signs of illness. Check what vaccinations are required for a dog
to attend that facility. Consider your own dog’s health and risk profile to
determine best ways for exercise and socialization. Of course, a healthy dog is
better able to recover from any illness, so good nutrition, weight management,
and exercise are beneficial for any dog.
If your dog does develop a cough, contact your veterinarian for an
appointment. Be sure to tell the office personnel that your dog is
coughing. They will have specific
directions for how you can bring your dog for examination while minimizing
exposing other animals to a respiratory illness. Keeping your dog fit and
healthy and taking just a few precautions can help you and your dog enjoy activities without interruption from a respiratory infection.
