symptom-respiratory 9 min read

Why Is My Dog Breathing Noisily? Stertor vs Stridor Explained

Breed: All Dogs | Published: July 7, 2026 | Source: allpets.ai

Noisy breathing in dogs can be benign or life‑threatening. Learn how to tell stertor from stridor, common causes, when it's an emergency, and next steps.

Introduction

Hearing unusual sounds when your dog breathes is alarming. Noisy breathing can be caused by many conditions ranging from mild (nasal congestion, sleeping sounds) to life‑threatening (airway obstruction or laryngeal paralysis). This guide explains the difference between stertor and stridor, the most likely causes, how veterinarians evaluate noisy breathing, safe home care steps, and when to seek immediate veterinary care.

Important: Do not attempt to diagnose or treat potentially serious airway problems at home. If your dog is struggling to breathe, weak, or has blue/pale gums, seek emergency care now.

Stertor vs Stridor — What’s the Difference?

Stertor: A low‑pitched, snoring or snuffling noise. It originates from the nose, nasopharynx, or back of the throat (upper airway). Often worse when the dog is relaxed or sleeping, or during inhalation.
Stridor: A high‑pitched, harsh wheeze occurring on inspiration (sometimes both phases). It indicates narrowing at the level of the larynx (voicebox) or trachea and can be more alarming because it often reflects a more significant obstruction to airflow.

You can sometimes tell by watching: stertor is usually audible with the mouth closed and sounds like snoring; stridor is louder during active inhalation, may be heard with the mouth open, and often accompanies obvious respiratory effort.

When to See a Vet Immediately

Seek emergency veterinary care right away if your dog has any of the following:

Marked difficulty breathing, using abdominal or chest muscles to breathe, or rapid shallow breaths
Blue, gray, very pale, or brick‑red gums or tongue (poor oxygenation)
Collapse, fainting, or severe weakness
Severe coughing, gagging, choking, or repeated retching
Sudden onset of noisy breathing after a bite, swelling, or suspected allergic reaction

These signs suggest a potentially life‑threatening airway problem that needs immediate stabilization and advanced treatment (oxygen, airway support, emergency procedures).

Differential Diagnosis — Common Causes (Ranked by Likelihood)

The list below summarizes common causes of noisy breathing in dogs, ordered roughly from most to less likely in general practice. Breed, age, and clinical history change the likelihood for any individual dog.

Brachycephalic Obstructive Airway Syndrome (BOAS) — Very likely in short‑muzzled breeds (pugs, bulldogs, Boston terriers). Includes elongated soft palate, stenotic nares, everted laryngeal saccules; produces stertor and exercise intolerance.

Nasal disease and rhinitis — Infections, foreign bodies, fungal disease, or allergies cause snuffling, sneezing, and stertor.

Tracheal collapse — Common in small, middle‑aged to older toy breeds (Yorkshire terriers, pomeranians). Produces a honking cough and inspiratory/expiratory noise; may cause stridor when severe.

Laryngeal paralysis — Typical in older, large breeds (labs, golden retrievers). Causes stridor, exercise intolerance, gagging, and risk of aspiration pneumonia.

Infectious kennel cough (canine infectious respiratory disease) — Causes loud, hacking cough and sometimes harsh inspiratory noises.

Foreign body lodged in nose, throat, or trachea — Sudden noisy breathing, pawing at mouth/face, sneezing, or coughing often present.

Allergic reaction (angioedema, anaphylaxis) — Rapid swelling of the face/throat leads to stridor and urgent airway compromise.

Neoplasia (nasal or laryngeal tumors) — More gradual onset; may cause persistent unilateral nasal discharge, stertor, or progressive stridor.

Congenital malformations or acquired masses (polyps, granulomas) — Cause chronic noisy breathing depending on location.

Pulmonary disease (less commonly causes upper airway sounds) — Wheezes and crackles originate from lower airways rather than stertor/stridor.

(Source references: Merck Veterinary Manual; VCA Hospitals.)

What Your Vet Will Do — Diagnostics and Typical Treatments

Veterinarians take a careful history (onset, breed, exercise tolerance, sudden vs gradual), perform an exam including airway auscultation, and assess oxygenation. Diagnostics may include:

Pulse oximetry and blood gas analysis (oxygenation)
Sedated oral and laryngeal examination (laryngoscopy)
Thoracic and cervical radiographs (chest and airway structure)
Endoscopy/rhinoscopy (look inside nose, larynx, trachea)
CT scan for nasal tumors or complex anatomy
Cytology, cultures, or biopsy for infectious or neoplastic causes

Treatment depends on cause:

BOAS: Surgical correction (staphylectomy, nares widening, removal of everted saccules) plus weight management and environmental modifications.
Laryngeal paralysis: Surgery (tie‑back procedure) in moderate‑severe cases; management of concurrent aspiration pneumonia if present.
Tracheal collapse: Medical management (cough suppressants, weigh loss, bronchodilators) or stenting/surgical options for severe cases.
Infections/allergies: Medical therapy (antibiotics, antifungals, anti‑inflammatories, antihistamines, corticosteroids) as appropriate.
Foreign body: Removal under sedation or anesthesia.
Emergency airway obstruction: Oxygen therapy, endotracheal intubation, or surgical tracheostomy in critical cases.

Never attempt invasive procedures or give prescription drugs without veterinary direction.

Home Care and Safe Steps to Try (When Not an Emergency)

If your dog is breathing quietly but has intermittent noisy breathing, try these safe measures while arranging veterinary evaluation when needed:

Keep your dog calm and rested. Stress and exercise worsen noisy breathing.
Keep them cool and in a well‑ventilated area; heat can worsen upper airway disease.
Avoid pulling on collars — use a harness to reduce airway compression in brachycephalic breeds.
Remove potential irritants (smoke, strong perfumes, household chemicals) from the environment.
Offer water if the dog is alert and swallowing normally. Do not force food or water if the dog is coughing, gagging, or having trouble breathing.
Note and record frequency, triggers, and any change in color of gums or behavior to share with the vet.

Do not give over‑the‑counter human medications (e.g., decongestants, antihistamines) without veterinary advice. Do not attempt to syringe medications into the mouth of a dog that is breathing poorly — this risks aspiration.

Red Flags — Seek Emergency Care

Sudden onset noisy breathing after a known bite, sting, or exposure to allergen
Progressive worsening over minutes to hours
Inability to stand, collapse, fainting
Severe coughing with blood, or persistent choking
Open‑mouth breathing with exaggerated abdominal effort
Pale, bluish, or muddy mucous membranes

These signs require immediate transport to an emergency veterinary hospital. Emergency teams can provide oxygen, establish an airway, and perform life‑saving interventions.

Prognosis

Prognosis varies by cause and how quickly treatment begins. Mild nasal allergies or seasonal rhinitis have a good prognosis. Brachycephalic dogs often improve significantly after corrective surgery. Conditions like laryngeal paralysis can be managed successfully in many dogs but carry risks, especially with aspiration pneumonia. Sudden, severe airway obstructions have a guarded to poor prognosis without prompt treatment.

Preventive Measures

For brachycephalic breeds: maintain ideal weight, avoid overheating and strenuous exercise, consider early consultation with a surgeon or your regular vet about airway surgery if signs develop.
Keep foreign objects, small toys, and plant materials out of reach of curious dogs.
Maintain vaccinations to reduce risk of infectious respiratory disease (kennel cough complex).
Regular dental care — severe dental disease can contribute to oropharyngeal inflammation and infection.

Key Takeaways

Stertor (snoring/snuffling) is low‑pitched and usually from the nose or back of the throat; stridor is high‑pitched and points to laryngeal or tracheal narrowing.
Breed, age, and history help narrow likely causes — BOAS in brachycephalic breeds, laryngeal paralysis in older large dogs, tracheal collapse in small breeds.
Immediate veterinary care is essential for difficulty breathing, pale/blue gums, collapse, or rapidly worsening signs.
Do not attempt invasive or prescription treatments at home; safe supportive care includes keeping your dog calm, cool, and avoiding stress until a vet evaluates them.

References

Merck Veterinary Manual — Respiratory System: https://www.merckvetmanual.com/respiratory-system
VCA Hospitals — Noisy Breathing in Dogs: https://vcahospitals.com/know-your-pet/noisy-breathing-in-dogs

Frequently Asked Questions

How can I tell if the noise is stertor or stridor?

Stertor is a low‑pitched, snoring or snuffling sound from the nose or back of the throat and often occurs with the mouth closed. Stridor is a high‑pitched, harsh noise typically heard during inhalation and indicates narrowing at the larynx or trachea.

Is noisy breathing always an emergency?

No. Intermittent mild snuffling or snoring while sleeping may be benign. However, sudden or worsening noisy breathing, open‑mouth effort, pale/blue gums, collapse, or severe coughing are emergencies and require immediate veterinary care.

Can I use antihistamines or decongestants from my medicine cabinet?

Do not give human medications without veterinary guidance. Some over‑the‑counter drugs are unsafe for dogs or may mask important symptoms. Contact your veterinarian before giving any medication.

Will surgery fix noisy breathing in brachycephalic dogs?

Many brachycephalic dogs improve significantly after corrective surgery (e.g., nares widening, staphylectomy, removal of everted saccules). Surgery reduces but may not completely eliminate breathing noise; weight control and environmental management remain important.

References & Citations

Parts of this article reference data from Merck Veterinary Manual.

Tags: dog-healthrespiratoryemergencybrachycephalic