Download Chronic Coughing in Dogs and Cats

Chronic Coughing in Dogs and Cats
Nick Schroeder, DVM DACVIM (cardiology)
Dogs and cats may suffer from a variety of ailments that lead to chronic coughing. Coughing is the forcible exhalation
of air against a closed glottis. This may be soft/wet sounding, hacking/dry/harsh sounding or have a honking
component. Coughing that has been present on a daily basis for over a few weeks in duration is generally considered
to be chronic. Dogs frequently will have a gagging activity following a spell of coughing, which may be confused with
“having something stuck in the throat,” and is the result of an attempt to clear mucus from the airways. Coughing
cats are frequently mistaken for having hairballs or retching/vomiting. Coughing is almost always exacerbated by
obesity, and weight loss alone in many pets may markedly improve or even resolve a chronic cough. Coughing must
be differentiated from reverse sneezing – which is a forcible inhalation of air through the nose/open mouth associated
with loud, snorting noises. It is important for the owners of animals with a chronic cough to understand the often
multiple reasons for the coughing, how medication can help, and to have realistic expectations regarding therapy.
Patients with a chronic cough rarely quit coughing altogether, even on life-long medications. The goals of medical
therapy are to improve quality of life and minimize the frequency and duration of the coughing. Chronic coughing
dogs typically cough a bit first thing when rising from sleep, when eating or drinking water, when excited and/or
barking. Cats tend to cough sporadically. As long as the coughing spell lasts less than a minute or so, intervention is
generally not indicated. If coughing spells last for more than 5 minutes at a time, are unprovoked and occur
frequently throughout the day, especially if difficult or labored breathing occurs simultaneously, then medical therapy
is warranted. Such patients often need lifelong medication with the goal to wean to the lowest effective dose in most
cases.
Congestive heart failure typically leads to coughing as the blood pressure in the lungs builds, leading to congestion
and even fluid in the lungs. Dogs commonly cough when they have congestive heart failure. Most of the time, the
coughing that ensues is soft, possibly wet-sounding and may be associated with terminal gagging, exercise
intolerance, difficult or labored breathing, or fainting or seizure-like activity. Classically, the coughing associated
with congestive heart failure tends to be worse at night. This is thought to be from increased venous return being
exacerbated in the failing heart in pets that are trying to lay down. However, most pet owners are going to naturally
be more aware of any nocturnal coughing as that is when most people are trying to sleep! Coughing that is the result
of congestive heart failure tends to respond best to diuretic administration (i.e. furosemide) in addition to other
therapies to support heart function. Be aware that diuretics will also tend to help any pet that is coughing to some
extent, as the airway secretions will tend to thicken up (and this may not necessarily be a good thing if the pet has
airway infection or pneumonia, and high doses of diuretic can promote dehydration). Many dogs with congestive
heart failure also suffer from airway collapse at the base of the heart, necessitating additional medication (i.e. cough
suppressant) to help control symptoms. Cats actually rarely cough as the result of congestive heart failure, and much
more commonly may be inappetant, inactive, with shallow/rapid or even open-mouthed breathing. Cats at home
should not pant like a dog, even after activity. Keep in mind it is not uncommon for stressed cats to have openmouthed breathing in association with a car ride.
Airway diseases may lead to chronic coughing in dogs and cats. Upper airway disorders include brachycephalic
syndrome (squished faced breeds with overlong soft palates, narrowed nostrils, etc.), laryngeal paralysis, cervical
tracheal collapse (collapse of the windpipe in the neck region), mainstem bronchus collapse (collapse of the main
airway branches over the base of the heart), or infectious tracheitis. Lower airway disorders include chronic
bronchitis/bronchiectasis, infectious bronchitis, chronic obstructive pulmonary disease (COPD), and feline
asthma/bronchitis complex (FAC, FABC). Classically, patients with upper airway problems tend to have noisy (snorty)
breathing, a honking cough, and wheezing (high-pitched inspiratory noises). Patients with lower airway issues on the
other hand usually have hacking and dry coughing with or without wheezing and labored breathing. Cough
suppressants may help patients with either upper or lower airway issues. Corticosteroids may also be useful to help
suppress airway inflammation. Pets with severe laryngeal paralysis may require surgery and those with severe
tracheal collapse refractory to medical therapy may require stent implantation. Patients with a superimposed airway
infection (tracheitis/tracheobronchitis) may need antibiotic therapy. Parasitic airway diseases are a rare cause of
chronic coughing and may require parasiticide (anthelmintic) and corticosteroid medications.
Pulmonary parenchymal disease (lung disease) may also lead to chronic coughing in our pets. Pneumonia is the
accumulation of pus, which has bacteria and inflammatory cells, in the lung tissue. Productive coughing with
terminal gagging with or without difficulty breathing is common in these patients. Occasionally, older pets may suffer
from abnormal growths of tissue (granulomas, tumors, cancer) in the lungs. Pulmonary fibrosis occurs when scar
tissue develops in the lung tissue. This frequently is associated with COPD and is marked by the presence of loud,
coarse crackles (like scrunching up plastic wrap) on auscultation of the lungs with a stethoscope in patients with no
obvious fluid in the lungs on chest x-rays. Chronic, dry and hacking coughing that is usually unproductive is common
in these cases. Those pets with pneumonia generally need antibiotic therapy, should be encouraged to cough, and
may benefit from airway hydration with a nebulizer. Corticosteroids and cough suppressants are generally
contraindicated in patients with pneumonia. Surgical removal of any growths in the lungs may or may not be
possible, and these patients may benefit from other therapies (antifungal medication, chemotherapy or radiation
therapy for cancer, or empirical corticosteroid/cough suppressant administration). Patients with pulmonary fibrosis
generally require long-term corticosteroid and cough suppressant administration.
It is important for owners of pets with chronic coughing to know that the vast majority of the conditions that lead to a
chronic cough are ultimately incurable and require life-long medical therapy. Most pets will have good days and bad
days. Those with conditions associated with airborne allergen exposure may have seasonal flare-ups. Sudden and
marked worsening of the frequency and duration of coughing or a distinct change in the character (the sound
wet/dry/honking/hacking, whether it’s now productive/non-productive, etc.) of the cough are signs that something
new may be exacerbating the pet’s underlying condition and warrant a trip to the veterinarian for reevaluation. It is
generally recommended that pets with chronic coughing get recheck chest x-rays at least every 4-6 months to
monitor for any changes.