SYMPTOM
Rapid breathing
Owners may observe rapid breathing in their pet.
Various conditions
This symptom can occur in multiple conditions and warrants further assessment.
Heat, Exercise and Normal Panting
Dogs increase their respiratory rate to dissipate heat through panting, particularly after exercise, in warm weather, or in overweight or thick-coated breeds. This form of rapid breathing settles once the dog cools down and rests, and the pattern is typically shallow and open-mouthed rather than laboured. It is one of the most frequent reasons an owner notices faster breathing in an otherwise well dog.
Pain and Anxiety
Discomfort from injury, orthopaedic conditions or abdominal pain commonly raises breathing rate as part of a generalised stress response, as does fear or anxiety in unfamiliar situations such as travel. This tachypnoea tends to fluctuate with the dog's emotional state and is often accompanied by pacing or a tense body posture rather than by visible effort on each breath.
Cardiac Disease
Dilated cardiomyopathy reduces the heart's pumping efficiency and can lead to fluid accumulating in or around the lungs, driving a persistently faster resting or sleeping breathing rate. Large and giant breeds, including Dobermanns, Great Danes and Irish Wolfhounds, carry a recognised predisposition, and the rate typically climbs gradually over weeks as underlying heart function declines.
Blood Loss and Anaemia
Internal bleeding, such as from a ruptured splenic mass associated with haemangiosarcoma, lowers the blood's oxygen-carrying capacity and prompts a faster breathing rate as compensation. Middle-aged to older, larger-breed dogs such as Labradors and German Shepherds are more commonly affected, and episodes can appear suddenly or wax and wane if bleeding is intermittent.
Pulmonary and Airway Disease
Infections such as pneumonia, along with fluid or inflammation within the lung tissue, reduce effective gas exchange and lead to a sustained increase in breathing rate. Younger dogs and those with recent kennel or group exposure are more prone to infectious causes, while chronic bronchial disease is more typical of older, smaller-breed dogs.
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
Hemangiosarcoma
Shock from blood loss or pericardial effusion causes increased respiratory rate and effort.
Feline Asthma
Feline asthma involves chronic inflammation and constriction of the airways, which can cause rapid breathing as the cat works harder to move air through narrowed passages. Episodes may occur suddenly or build gradually, often accompanied by wheezing or coughing.
Hyperthyroidism in Cats
Hyperthyroidism in cats accelerates metabolic rate throughout the body, which can increase respiratory rate as tissues demand more oxygen and the cardiovascular system works harder to meet those demands.
Hypertrophic Cardiomyopathy in Cats
Hypertrophic cardiomyopathy can cause rapid breathing when the thickened heart muscle impairs blood flow and fluid begins to accumulate in or around the lungs, reducing the efficiency of oxygen exchange.
Dilated Cardiomyopathy in Dogs
Dilated cardiomyopathy in dogs may lead to rapid breathing when the weakened heart cannot pump effectively, causing fluid to back up into the lungs and prompting compensatory increases in respiratory rate.
Pneumonia
Pneumonia involves infection and inflammation of the lung tissue itself, which impairs oxygen exchange and often triggers rapid, laboured breathing as the animal attempts to compensate for reduced respiratory efficiency.
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