SYMPTOM
Noisy breathing
Audible breathing sounds at rest or during mild activity, including stridor, stertor, or rasping noises.
Upper Airway Obstruction
Noisy breathing frequently originates from turbulent airflow through a partially obstructed upper airway. Conditions affecting the nasal passages, nasopharynx, larynx, or extrathoracic trachea can all produce audible breathing sounds as air is forced through narrowed passages. The character of the sound — whether it is a snore, stertor, stridor, wheeze, or honk — can help localise the level of obstruction. Inspiratory noise typically suggests obstruction above the thoracic inlet, while expiratory noise may suggest lower airway involvement.
Brachycephalic Airway Syndrome
Breeds with shortened skulls face multiple anatomical challenges to normal airflow including stenotic nares, elongated soft palate, hypoplastic trachea, and everted laryngeal saccules. These conformational features produce varying degrees of chronic noisy breathing that may be present from a young age and can worsen with heat, excitement, exercise, or weight gain. Over time, the chronic increased respiratory effort may produce secondary changes including laryngeal collapse that further compromise airway function. The progressive nature of these secondary changes means that breathing noise may gradually worsen even without a new disease process.
Laryngeal Disease
Laryngeal paralysis, laryngeal collapse, and laryngeal masses can all produce noisy breathing by impairing the normal opening of the larynx during inspiration. Laryngeal paralysis is particularly common in older large-breed dogs and produces a characteristic inspiratory stridor that worsens with exercise, excitement, or heat. The condition may progress from mild inspiratory noise to severe respiratory distress, particularly during episodes of increased respiratory demand. Changes in the animal's bark or voice may accompany the respiratory noise.
Tracheal Disease
Tracheal collapse, most commonly seen in small-breed dogs, produces a distinctive honking or goose-honk cough and noisy breathing that may worsen with excitement, tracheal pressure from collars, or environmental irritants. The collapsing tracheal rings create intermittent airway narrowing that produces audible turbulence during breathing. Tracheal masses, foreign bodies, or external compression can similarly restrict airflow through the trachea, producing breathing sounds that may be constant or variable depending on the nature of the obstruction.
Lower Airway or Pulmonary
Conditions affecting the bronchi or lung parenchyma can produce noisy breathing through bronchospasm, mucus accumulation, or consolidation that disrupts normal airflow patterns. Feline asthma produces wheezing through bronchial smooth muscle contraction. Chronic bronchitis produces increased mucus that creates audible crackles and wheezes. Pneumonia or pulmonary oedema may produce crackling sounds as air moves through fluid-filled airways. These lower airway sounds tend to be heard during both inspiration and expiration and may be more apparent during auscultation than audible to the owner at a distance.
Why timing matters
Early observation
When noisy breathing first becomes apparent, it may be situation-specific — occurring only during sleep, after exercise, in warm weather, or during excitement. At this stage, the noise may be intermittent and the animal may not show any distress or limitation in its normal activities. Early noisy breathing in brachycephalic breeds may be so normalised within the breed that it is not recognised as abnormal. Noting the specific circumstances that provoke the noise, its character, and whether it is present during both inspiration and expiration can provide initial characterisation of the level and nature of the airway involvement.
Later presentation
As the underlying condition progresses, noisy breathing may become more constant, louder, and present during lower levels of activity. The animal may begin to show signs of increased respiratory effort — extended neck, abducted elbows, open-mouth breathing, or visible abdominal push during expiration. Exercise tolerance typically declines, and the animal may seek cool surfaces, avoid warm environments, or become reluctant to engage in physical activity. Episodes of acute respiratory distress may occur, particularly during hot weather, excitement, or exertion, representing moments when the airway's capacity is overwhelmed by respiratory demand.
The trajectory of noisy breathing depends on the underlying cause. Brachycephalic airway syndrome tends to worsen gradually as secondary changes develop, with weight gain and ageing contributing to declining airway function. Laryngeal paralysis typically progresses slowly over months, with the contralateral laryngeal fold sometimes compensating temporarily before it too becomes affected. Tracheal collapse may show a more fluctuating course, with periods of relative stability interspersed with worsening triggered by environmental or infectious factors. Understanding whether the breathing noise is stable, gradually worsening, or episodically severe helps characterise the trajectory.
Conditions commonly associated
Laryngeal Paralysis in Dogs
Tracheal Collapse in Dogs
Noisy breathing in tracheal collapse results from turbulent airflow through the narrowed tracheal lumen, producing stridorous sounds that may vary with the phase of breathing and the degree of respiratory effort.
Chronic Upper Respiratory Disease in Cats
Chronic upper respiratory disease can produce noisy breathing through nasal congestion, turbinate destruction, and accumulation of mucus within the nasal passages, resulting in stertor and snuffling sounds particularly during rest.
Chronic Bronchitis in Dogs
Noisy breathing in chronic bronchitis reflects turbulent airflow through airways narrowed by inflammation, mucus accumulation, and bronchial wall remodelling, producing audible wheezes and crackles.
Brachycephalic Obstructive Airway Syndrome (BOAS) in Dogs
Brachycephalic obstructive airway syndrome commonly presents with snoring, snorting, and stertor due to anatomical narrowing of the upper airways.
Nasopharyngeal Polyps
Nasopharyngeal polyps commonly cause noisy breathing as they obstruct the airway behind the nasal passages.
When to explore further
Breathing noise that is progressively worsening over weeks to months, with the sounds becoming louder or occurring during lower levels of activity, may suggest a structural airway change that is advancing rather than a stable condition.
When noisy breathing is accompanied by a change in the animal's bark or voice — becoming hoarse, quieter, or altered in pitch — the combination may suggest laryngeal involvement, as the larynx serves both respiratory and vocal functions.
Episodes where the noisy breathing escalates to visible respiratory distress, with the animal appearing panicked, showing cyanosis, or collapsing, represent acute decompensation of airway function that carries immediate significance regardless of the chronic nature of the underlying condition.
Noisy breathing that is notably worse in warm or humid conditions, and improves in cool environments, may suggest that the airway's reserve capacity is being exceeded during thermoregulation, as panting for heat dissipation places additional demands on an already compromised airway.
When noisy breathing develops alongside exercise intolerance, regurgitation after eating, or recurrent respiratory infections, the combination of signs may suggest a more complex airway or swallowing dysfunction rather than a simple single-level obstruction.
Characterising noisy breathing benefits from careful observation of when and how the sounds occur. Noting whether the noise is primarily during breathing in or breathing out, whether it changes with the animal's position or activity level, and whether specific triggers such as heat, excitement, or eating consistently provoke the sound can help localise and characterise the airway involvement. Recording the sounds — either audio or video — can capture details that may not be reproducible during a clinical setting, as the animal's stress or excitement during examination may alter the breathing pattern from what the owner observes at home.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS