Common Causes of Coughing in Dogs

1 What to watch for alongside the cough

Pay attention if any of these are present: loss of appetite, low energy, something in the home gone missing (a swallowed object), or a strong recent impact or blow. Also note whether the dog still wants to eat and whether there is fever or nasal discharge – these clues help decide which disease is involved.

2 Types of cough and what they suggest

A wet cough with phlegm usually points to a disease of the breathing organs. A continuous, harsh dry cough with no other complications often suggests kennel cough. A weak, repeated mild cough raises the possibility of pneumonia. A persistent dry cough can be caused by heart disease, and heartworm infection can also produce a dry cough.

3 Conditions that can cause coughing

Roundworm: worms lodge in the small intestine and cause poor appetite, vomiting, coughing, and diarrhea; a heavy load can even block the gut. Heart-related causes include mitral valve insufficiency (blood flows backward in the heart, common in older small breeds) and heart failure.

Airway problems: tracheal collapse brings a chronic cough that worsens after exercise with labored breathing and bluish lips and gums; bronchial stenosis narrows the airway; nasal stenosis is often congenital; sinusitis and rhinitis cause bloody or thick nasal discharge and blocked, noisy breathing.

Serious infections and illness: pulmonary edema (cough plus blood-tinged nasal discharge and purple tongue – seek a vet at once), pneumonia (constant cough with high fever, labored breathing, and a stretched-forward head posture; it advances fast), heartworm (spread by mosquitoes, with lethargy, cough, and later fluid in the belly), and distemper, canine adenovirus II, infectious hepatitis, and rabies – all of which can include coughing among their signs.