SYMPTOM
Persistent cough
Owners may observe persistent cough in their pet.
Various conditions
This symptom can occur in multiple conditions and warrants further assessment.
Airway Collapse (Tracheobronchomalacia)
Progressive weakening of the cartilage supporting the trachea and bronchi allows the airway to narrow during breathing, producing a chronic, non-productive cough that worsens with excitement or exercise. Small-breed, overweight, and older dogs are most typically affected.
Chronic Bronchitis
Long-standing inflammation of the airway lining, not attributable to active infection, leads to a persistent cough that tends to worsen with exercise or excitement and is more common in middle-aged and older dogs. Diagnosis usually follows exclusion of infectious and cardiac causes.
Cardiac Disease
Heart enlargement from mitral valve disease or dilated cardiomyopathy can compress the left mainstem bronchus or lead to fluid accumulation around the lungs, both of which produce a persistent cough. Small breeds such as Cavalier King Charles Spaniels are prone to mitral valve disease, while larger breeds including Dobermanns are more associated with dilated cardiomyopathy.
Lungworm Infection (Angiostrongylus vasorum)
Larvae migrating to the pulmonary vessels and airways cause chronic coughing, reduced exercise tolerance, and occasionally clotting abnormalities. Dogs acquire the parasite by ingesting slugs or snails, and cases cluster in known UK hotspots including South Wales and parts of South East England.
Eosinophilic Bronchopneumopathy
An immune-mediated infiltration of eosinophils into the airway lining produces chronic, often productive coughing with variable exercise intolerance. It typically affects young to middle-aged large-breed dogs, most often between four and six years old. An association with Siberian Huskies and Alaskan Malamutes has been reported in some studies, though later research has not consistently confirmed a true breed predisposition, so this should be treated as a possible rather than established link.
Why timing matters
Early observation
Early recognition allows prompt assessment and intervention if needed.
Later presentation
Persistent or worsening signs may indicate progression requiring attention.
The significance of this symptom depends on its context, duration, and associated findings.
Conditions commonly associated
Angiostrongylus (Lungworm)
Coughing results from larval migration through lung tissue and associated inflammation.
Dilated Cardiomyopathy in Dogs
In dilated cardiomyopathy, the weakened heart muscle can lead to fluid accumulation in or around the lungs, triggering a persistent cough that often worsens at night or during rest. This cough reflects the heart's reduced ability to manage circulatory volume effectively.
Hypertrophic Cardiomyopathy in Cats
Hypertrophic cardiomyopathy in cats can cause persistent cough when thickened heart muscle impairs blood flow and leads to fluid build-up affecting the lungs. The cough may appear alongside breathing changes as the condition progresses.
Feline Asthma
Feline asthma involves chronic airway inflammation that often manifests as persistent coughing, typically with a characteristic hunched posture and extended neck. The cough reflects underlying bronchial constriction and mucus accumulation in the airways.
Pneumonia
Pneumonia causes persistent cough as the lungs respond to inflammation and infection, often producing mucus or fluid that the body attempts to clear. The cough in pneumonia tends to appear alongside other signs of respiratory distress and systemic illness.
Laryngeal Paralysis in Dogs
Laryngeal paralysis can trigger a persistent cough as the incompletely opening larynx irritates the airway and disrupts normal breathing patterns. The cough may accompany characteristic voice changes and increased respiratory effort, particularly during exertion or heat.
Eosinophilic Bronchopneumopathy
Eosinophils infiltrating the airway lining in this condition irritate the bronchi, producing a cough that persists for weeks rather than clearing.
When to explore further
When the symptom is persistent or worsening
When other signs are present alongside
When daily activities or quality of life are affected
When there is uncertainty about the cause
Noting when this symptom occurs, any triggers, and how it changes over time can provide useful information for veterinary discussions.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS