The Coughing Pet
This information is not meant to be a substitute for veterinary care.
Always follow the instructions provided by your veterinarian.
Cough is a common problem in dogs but occurs less frequently in cats. Cough
is caused by irritation of the throat, airways or the lungs. The main airway
to the lungs known as the windpipe or trachea branches into smaller airways
called bronchi which branch several more times as they travel to the deeper
parts of the lung. (Anatomy of the lungs and airways:
dog /
cat)
There are many causes of cough. A thorough history and physical examination
help the veterinarian decide which causes of cough are most likely in your
pet and helps him or her decide which diagnostic tests to recommend and
which therapies are most likely to be effective. Cough originating from the
trachea may be stimulated by lightly squeezing the trachea. Cough due to
heart disease may be accompanied by a murmur or abnormal heart rate or
rhythm.
Your description of the nature of the cough, when the cough occurs, and
if anything brings on coughing can be very helpful in pinpointing the cause
of coughing in your pet. Some causes of cough result in difficulty breathing
between coughing episodes whereas with other diseases, the pet breathes
normally between coughing episodes. Some types of cough occur more commonly
at night when the animal (and human family members) are trying to rest.
Animals with heart failure, collapsing trachea and lung edema cough more at
night than during the day.
Cough caused by tracheal irritation or tracheal collapse often occurs
when the pet is excited or is tugging on its collar. Cough caused by heart
disease may follow exercise or excitement. Cough due to tracheal collapse
may be stimulated by drinking water. Coughing that occurs during or shortly
after eating may be due to disease of the larynx or esophagus. The larynx
normally closes when food is swallowed to prevent food from entering the
trachea. If the larynx is diseased it may not close when food is swallowed
resulting in food entering the trachea. Food may pool in an abnormally
dilated esophagus. The food then may pass to the mouth and down the airways
into the lungs causing pneumonia and cough.
Some coughs sound moist and others are harsh and dry. Moist coughs
indicate the accumulation of fluid (water, blood or pus) in the airways or
lungs. The environment and habits of the pet can influence which causes of
cough are more likely. Dogs that hunt or spend time outdoors may inhale
grasses, seeds or other foreign materials through the nose into the airways.
In addition to causing coughing, foreign materials can travel down the
airways and through the lung causing an infection with a large amount of pus
to develop in the space surrounding the lung. This disease is called
pyothorax. Animals that have exposure to other animals in a shelter or
boarding facility are more likely to have an infectious cause for coughing.
The region of the country in which you live or to which you and your pet
have traveled, influences the likelihood of some diseases like heartworm
disease and fungal infections of the lung (histoplasmosis, coccidiomycosis
and blastomycosis). Heartworm disease occurs in both dogs and cats and is
most common in parts of the country that have lots of mosquitoes.
The age
and breed of the pet also influences what causes of cough are most likely.
Young animals are more likely to develop a cough due to infections with
bacteria or viruses. Young to middle aged cats may develop wheezing and
cough due to asthma. Cats with asthma have sudden episodes of wheezing and
coughing but are normal in between episodes. Middle aged to older, small
breed dogs are more likely to have heart disease due to leaky valves. Middle
aged to older, large breed dogs are more likely to develop paralysis of the
larynx.
Tracheal collapse occurs most commonly in middle to aged overweight small
breed dogs . Tracheal collapse is rare in cats. The cough is often described
as sounding like a goose honking. Treatment for tracheal collapse includes
weight reduction and intermittent use of cough suppressants and sedatives.
Surgery can be performed in dogs with severe collapse that don't respond to
weight reduction and cough suppressants but often surgery is not effective.
Kennel cough or infectious tracheobronchitis is caused by several
infectious organisms, including bacteria and viruses. Vaccinations are not
100% protective against the agents of kennel cough. Coughing due to kennel
cough usually becomes apparent within a few weeks of exposure of your dog to
other dogs in a kennel or show environment. Kennel cough usually resolves
itself without any treatment. If the cough is severe enough that the pet
has difficulty sleeping or people in the house have difficulty sleeping,
cough suppressants can be given to suppress the frequency of cough, allowing
the pet and human members of the household to get rest while the disease
runs its course. If the cough does not subside in a week to ten days, your
pet should be evaluated for other diseases of the lungs or airways.
Cough can be caused by heart disease, which is diagnosed by a chest x-ray,
an electrocardiogram which measures the electrical activity of the heart,
and often by a heart ultrasound which allows the veterinarian to view the
inside of the heart, including the valves and the thickness of the walls of
the heart muscle. Heart disease may cause heart enlargement that puts
pressure on the airways causing cough or the heart may fail and lead to
edema of the lungs. (Anatomy of the
dog /
cat heart)
Allergies to particles in the air including dust, pollens, and smoke can
cause allergic lung disease and coughing.
In older patients, lung cancer has to be considered. The lungs receives a
large amount of blood that flows through the rest of the body. Lung cancers
in dogs and cats most often originate from other organs and are transferred
from those organs through the blood to the lung. Some cancers may be
controllable with anticancer medication. Single lung tumors that originate
within the lung may be surgically removed in some cases.Tests that may be
recommended to identify the cause of a cough include a blood profile to
screen multiple organs, a stool exam to look for parasites or their eggs
that are coughed up and swallowed, chest x-rays or x-rays of the trachea.
The larger airways can be examined using a flexible scope called a
bronchoscope in a procedure called bronchcoscopy. Sterile fluid can be
flushed into the airways to collect samples for culture or microscopic
exam. Large foreign bodies in the airways can be removed by bronchoscopy.
Specific tests may be performed if heart worm disease or an infectious
cause for the cough are suspected.
Treatment of coughing patients depends
upon the disease diagnosed and may include cough suppressants, antibiotics
for bacterial infections, and steroids for allergic lung disease. Avoid self
medicating your pet as the treatment for one cause of cough may be very
wrong for the treatment of another type of cough.
Washington State University assumes no liability for injury to you or
your pet incurred by following these descriptions or procedures.
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