SYMPTOM
Breathing with the belly
Owners describe the abdomen or flank pumping visibly in and out with each breath, sometimes as a two-stage or heaving movement, while the chest wall itself appears to move less than expected. It may be seen only at rest or after activity, or as a constant pattern that persists regardless of what the animal is doing.
Normal Variation in Sleep, Heat, or Excitement
In deep sleep the diaphragm becomes the dominant driver of breathing while the chest wall relaxes, producing a smooth, rhythmic abdominal rise and fall that many owners notice for the first time simply because they are watching more closely. The same pattern appears briefly during and after vigorous exercise, in hot weather, or with excitement, when panting recruits abdominal muscles to move air faster. This version is unforced, resolves within minutes once the animal wakes, cools, or settles, and is not paired with open-mouth breathing in a resting cat or a respiratory rate that stays raised once the trigger has passed. Brachycephalic dogs can show a slightly more visible abdominal component as a baseline even when otherwise well, simply because of higher normal airway resistance.
Lower Airway or Bronchial Disease
Narrowed or inflamed small airways, as in feline asthma or chronic bronchitis, make it harder to push air back out, and the abdominal muscles contract to assist this expiratory effort, sometimes producing a visible abdominal push or lift at the end of each breath. This pattern tends to build gradually over weeks to months and is often accompanied by coughing or an intermittent wheeze rather than appearing suddenly. Feline asthma typically affects young to middle-aged cats, while chronic bronchitis follows more of a small-breed, middle-aged to older dog pattern.
Upper Airway Obstruction
Narrowing anywhere from the nose to the trachea forces the diaphragm and abdominal muscles to generate stronger negative pressure to draw air in, which can look like belly breathing even though the underlying problem sits well above the chest. Brachycephalic breeds with BOAS, older large-breed dogs with laryngeal paralysis, and small or toy breeds with a collapsing trachea are the typical patterns, and the effort is often paired with a harsher inspiratory noise or stridor, particularly on excitement or in heat.
Pleural Space or Restrictive Thoracic Disease
Fluid, air, or a mass occupying the space around the lungs prevents the chest wall from expanding normally, so the animal shifts the work of breathing onto the diaphragm and abdominal wall, producing rapid, shallow breaths with a pronounced abdominal component. When the diaphragm itself begins to fatigue under this workload, the pattern can progress toward true paradoxical movement, where the abdomen and chest move in opposite directions. Causes range from pleural effusion and pneumothorax to diaphragmatic rupture, and cats in particular can present this way with a relatively short run-up of preceding signs.
Cardiac Disease
Heart disease that leads to fluid accumulation, either as pulmonary oedema within the lung tissue or as pleural effusion around the lungs, increases the work of breathing in similar ways to primary lung or pleural disease. In dogs this is typically associated with mitral valve disease or dilated cardiomyopathy in older or predisposed breeds, while in cats hypertrophic cardiomyopathy can produce effusion, sometimes as the first visible sign of underlying heart disease. Reduced exercise tolerance and a resting respiratory rate that stays elevated tend to accompany the breathing change.
Abdominal Distension or Pain
A markedly enlarged abdomen, whether from bloat, fluid accumulation, organ enlargement, or late pregnancy, restricts how far the diaphragm can descend, which can make abdominal wall movement look more pronounced as the animal compensates with shallow, rapid breaths. Sudden, painful abdominal distension in a deep-chested dog raises the possibility of gastric dilatation-volvulus, while chronic distension with weight loss points more toward organ enlargement or gradual fluid build-up. Guarding, restlessness, or an inability to settle often accompanies the breathing change in these cases.
Excess Body Condition
Carrying more weight than is ideal adds fat within and around the chest and abdomen, which can restrict how far the diaphragm descends and reduce how easily the chest wall expands, increasing the overall effort of breathing. This often shows as a more pronounced abdominal component to breathing, together with quicker breathing after mild exercise and snoring or snuffling at rest. A large proportion of dogs and cats in the UK carry more weight than is ideal for their frame, making this one of the more everyday contributors to a visibly abdominal breathing pattern, and the pattern typically eases as body condition moves back toward a leaner range over time.
Why timing matters
Early observation
A belly-breathing pattern noticed only intermittently, at rest with a normal respiratory rate, or clearly tied to sleep, heat, or recent activity most often reflects the diaphragm's normal role in relaxed breathing rather than an evolving problem. At this stage the pattern typically resolves within minutes once the trigger passes and is not accompanied by any change in gum colour, appetite, or activity level.
Later presentation
A pattern that is present continuously, worsens with mild activity, or has become paired with a rising resting respiratory rate, open-mouth breathing in a cat, or a reluctance to lie flat suggests the chest wall or lungs are compensating for reduced capacity. By this stage the underlying process, whether airway, pleural, or cardiac, has usually had time to establish itself rather than representing a sudden change.
Many of the conditions that produce this pattern, from bronchial inflammation to gradual pleural fluid accumulation, build slowly enough that owners often adjust to a rising resting respiratory rate without noticing the trend. A same-format record, such as a short video taken at rest on different days, tends to reveal this kind of gradual change more reliably than memory alone, while an onset over hours rather than weeks points toward a more acute process such as pneumothorax or gastric dilatation-volvulus.
Conditions commonly associated
Feline Asthma
Bronchoconstriction narrows the small airways in cats, and the abdominal push required to force air past the narrowing is a recognised part of the breathing pattern this condition produces.
Chronic Bronchitis in Dogs
Chronic airway inflammation increases the effort needed to exhale, producing the expiratory abdominal effort described under lower airway disease.
Brachycephalic Obstructive Airway Syndrome (BOAS) in Dogs
Increased upper airway resistance in brachycephalic breeds means more negative pressure, and therefore more visible abdominal and diaphragmatic effort, is needed to draw each breath in.
Laryngeal Paralysis
Failure of the laryngeal cartilages to open fully on inspiration increases resistance to airflow, producing the exaggerated inspiratory effort described under upper airway obstruction.
Tracheal Collapse
Dynamic narrowing of the trachea increases airway resistance in a way that can produce a similar exaggerated breathing effort, particularly during excitement or activity.
Pleural Effusion
Fluid around the lungs restricts chest wall expansion directly, shifting breathing effort onto the diaphragm and abdominal wall in the pattern described under pleural space disease.
Congestive Heart Failure in Dogs
Fluid accumulation in or around the lungs from underlying heart disease increases the work of breathing in a way that mirrors primary respiratory disease.
Hypertrophic Cardiomyopathy in Cats
This is a common underlying cause of pleural effusion or pulmonary oedema in cats, and can present with an abdominal-breathing pattern as an early visible sign.
Gastric Dilatation-Volvulus (GDV/Bloat)
Rapid gastric distension restricts diaphragm excursion and is one of the acute abdominal causes described under abdominal distension, typically presenting with visible distress and unproductive retching.
When to explore further
A pattern that persists for more than a few minutes after exercise, heat, or excitement have passed, particularly alongside a resting respiratory rate above the high 20s to low 30s breaths per minute, moves the picture away from a normal variant and toward one that may benefit from characterisation.
In cats, open-mouth breathing at rest, or a stance with the neck extended and the elbows held away from the body, reflects a degree of effort that is unusual for the species and may warrant closer evaluation regardless of how settled the cat otherwise appears.
Pale, blue-tinged, or grey gums, a reluctance to lie down or settle in any position, or effortful breathing that continues through rest are accompanying signs that shift a belly-breathing pattern from a background observation toward one benefiting from evaluation rather than observation alone.
A deep-chested, large-breed dog showing sudden abdominal distension together with unproductive retching and distressed breathing, particularly following a large meal or exercise soon afterward, describes a combination that benefits from evaluation rather than continued observation.
A gradual change over weeks, especially in an older cat or a small-breed dog, paired with a persistent cough, reduced exercise tolerance, or weight loss, points toward a chronic process that may warrant characterisation even in the absence of acute distress.
A short video of the animal breathing at rest, ideally lying down and undisturbed, captures the rate and pattern more reliably than a description after the fact and can be compared against a later video to judge whether the pattern is stable or changing. Counting breaths for 30 seconds and doubling the figure, repeated on different days at a similar time and activity level, builds a simple resting respiratory rate log. Noting whether the pattern appears only in specific contexts, such as sleep, heat, or after exercise, versus continuously through the day, helps distinguish a situational pattern from a persistent one.
Last reviewed: 13 September 2026 · Dr Alastair Greenway MRCVS