SYMPTOM
Retching after coughing
A bout of coughing ends in a gag or retch, which can look like an attempt to vomit. Retching that brings up nothing and does not follow a cough is a different sign.
Infectious Tracheobronchitis (Kennel Cough)
Inflammation of the airway lining from Bordetella bronchiseptica or associated viruses produces a harsh, honking cough that may be followed by retching and gagging. It spreads readily where dogs mix closely, such as boarding kennels, daycare, or training classes, and most cases are mild and self-limiting, lasting 10 to 20 days. Puppies are more prone to severe disease.
Tracheal Collapse
Weakening of the cartilage rings supporting the windpipe allows it to flatten during breathing, producing a distinctive dry, honking cough that may end in a gag, particularly with excitement, exercise, or pulling against a collar. This is strongly associated with small and toy breeds, including Yorkshire Terriers, Pomeranians, and Chihuahuas, and tends to develop gradually in middle-aged to older dogs. Severe cases cause laboured breathing, exercise intolerance, fainting, or turning blue when excited.
Cardiac-Related Cough
In dogs with mitral valve disease, coughing can be linked to an enlarged left atrium and to disease of the airways themselves. In a study of 206 dogs with this disease, left atrial enlargement and an abnormal airway pattern on X-rays were associated with coughing, while congestive heart failure was not. Heart failure can still cause coughing, along with difficulty breathing, faster breathing at rest and tiring on exercise. In a bronchoscopy study of 16 coughing dogs with the disease and no heart failure, collapsed airways were found whether or not the left atrium was enlarged. The disease is most recognised in small breeds such as Cavalier King Charles Spaniels, about half of which have a mitral murmur by 6 to 7 years of age.
Environmental And Mechanical Airway Irritation
Pulling against a collar and exposure to smoke, dust or cold air can mechanically irritate the trachea enough to trigger a cough-retch sequence. Collar pressure is also a typical trigger of the cough in tracheal collapse, so a link to the collar does not on its own show that the airway is healthy.
Lungworm (Angiostrongylus Vasorum)
This parasite is endemic in the UK. Dogs pick it up from slugs and snails, and the adult worms live in the blood vessels of the lungs and the right side of the heart. Signs include coughing, difficulty breathing, spontaneous or uncontrolled bleeding, weight loss, vomiting and neurological signs, and some infected dogs show no signs. The same signs occur in many other conditions, so testing is needed to confirm it.
Chronic Bronchitis And Eosinophilic Bronchopneumopathy
Chronic bronchitis is a cough lasting at least 2 months that is not due to another respiratory disease, and it most often affects middle-aged and older small-breed dogs. In eosinophilic bronchopneumopathy, a published series of 23 dogs found cough, gagging and retching in every dog and breathing difficulty in 21.
Why timing matters
Early observation
A cough with retching that starts suddenly 5 to 10 days after mixing with other dogs fits kennel cough, which usually eases over the first 5 days.
Later presentation
Coughing that continues for weeks or months points away from kennel cough and towards long-term airway disease such as chronic bronchitis or tracheal collapse, which is chronic and progressive.
The cause cannot be told from the sound of the cough at home. Kennel cough, tracheal collapse, heart disease, lungworm and chronic bronchitis can all cause coughing, and telling them apart relies on examination and tests such as chest X-rays.
Conditions commonly associated
Infectious Tracheobronchitis (Kennel Cough)
The harsh, honking cough of kennel cough may be followed by retching and gagging.
Pneumonia
Pneumonia can cause retching after coughing when inflammatory exudate and mucus accumulation in the airways provoke forceful coughing that stimulates the pharyngeal gag reflex. The productive nature of coughing in pneumonia often brings material into the pharynx, which may trigger retching as the body attempts to clear it.
Laryngeal Paralysis in Dogs
Laryngeal paralysis can produce retching after coughing when airway obstruction and aspiration risk lead to episodes of forceful coughing that irritate the pharynx. Dogs with laryngeal dysfunction may experience repeated cycles of coughing and gagging as they attempt to clear the airway or respond to food or water entering the larynx.
Tracheal Collapse in Dogs
Gives a harsh, dry, goose-honk cough brought on by excitement, exercise or pressure from a collar.
Mitral Valve Disease in Dogs
In one study of 206 dogs with this disease, coughing was linked to left atrial enlargement and airway disease rather than to heart failure, but coughing with difficulty breathing is also a common sign of heart failure.
Chronic Bronchitis in Dogs
A long-term cough that most often affects middle-aged and older small-breed dogs.
Eosinophilic Bronchopneumopathy
In a published series of 23 dogs, cough, gagging and retching were present in every dog.
Angiostrongylus (Lungworm)
A UK-endemic parasite whose signs include coughing, difficulty breathing and spontaneous or uncontrolled bleeding.
When to explore further
When breathing is laboured, or noisy breathing is getting worse, the tongue or gums turn blue, or the dog faints or collapses: in tracheal collapse and laryngeal paralysis these are signs of a breathing crisis
When fever, dullness, loss of appetite, nasal discharge or a moist, productive cough develops during kennel cough, signs that point to bronchopneumonia
When there is spontaneous or uncontrolled bleeding alongside the cough, as can occur with lungworm
When the cough has lasted beyond the 10 to 20 days that kennel cough usually runs
When retching brings up nothing or only a little foam and does not follow a cough, especially in a large, deep-chested dog with a swollen belly: this can be a sign of gastric dilatation-volvulus (bloat), which gets rapidly worse and kills about 15% of dogs even with treatment
When breathing is faster than usual at rest or during sleep, or is laboured, alongside the cough in a dog with a heart murmur or mitral valve disease: these can be signs of heart failure
Noting when this symptom occurs, any triggers, and how it changes over time can provide useful information for veterinary discussions.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS