Stridor & Stertor (Harsh Upper Airway Breathing)
Abnormal, loud, harsh respiratory sounds caused by turbulent airflow through narrowed or obstructed upper airways.
💬 In Plain English
Stridor and stertor are medical terms for loud, noisy breathing caused by a partial obstruction or narrowing in the upper airways. Stertor is a low-pitched, heavy snoring or snorting sound that originates in the nose or back of the throat, very common in flat-faced (brachycephalic) breeds like Bulldogs and Pugs with elongated soft palates. Stridor, on the other hand, is a higher-pitched, harsh, raspy, or wheezing sound produced when air struggles to pass through a narrowed voice box (larynx) or windpipe (trachea). Stridor is a classic hallmark of laryngeal paralysis—a condition in older large-breed dogs where the vocal cords fail to open during breathing, putting the dog at high risk of heatstroke and asphyxiation.
🔬 Clinical & Technical Depth
For Vets & TechniciansFormal Clinical Definition
Turbulent inspiratory acoustics resulting from anatomical narrowing of the upper respiratory tract: stertor designates vibrations of relaxed pharyngeal/nasopharyngeal soft tissues, whereas stridor designates high-frequency acoustics from rigid laryngeal or tracheal stenosis.
Why Veterinarians Use It
Veterinarians auscultate stridor vs. stertor over the larynx and trachea to localize upper airway disease and identify pets needing laryngeal tie-back surgery (lateralization).
Clinical Context Encountered
Seen in older Labs panting heavily with a raspy "roaring" noise or Bulldogs struggling to breathe on hot summer days.
Clinical Reference Guide (Clinical Symptom)
Tongue turning dark purple or blue, panic pacing, vomiting white foam, or body temperature > 103.5°F.
What to Look For
- Harsh raspy roaring panting, change in bark sound ("whisper bark"), snorting, exercise intolerance, reluctance to go for walks in the heat
Home Care Do’s & Don’ts
- DO keep pet strictly in air-conditioned environments; DO NOT use neck collars (switch immediately to a chest harness)
- •Loud, raspy breathing accompanied by high body temperature (> 104°F) and a blue or purple tongue is an acute respiratory emergency: seek emergency oxygen and cooling care immediately.
❓ Questions to Ask Your Veterinarian
Take these actionable questions with you to your next clinic visit or appointment:
- 1Is the sound a high-pitched laryngeal rasp (stridor) or a low-pitched pharyngeal snore (stertor)?
- 2Has my dog been sedated and examined for laryngeal paralysis (failure of the vocal folds to abduct on inspiration)?
- 3Why is hot, humid weather or vigorous exercise life-threatening for a dog with stridor?
Academic & Clinical References
- ACVS Clinical Guide: Laryngeal Paralysis and Brachycephalic Airway Syndrome in DogsOrganization: American College of Veterinary Surgeons (ACVS) • Accessed: 2026-01-10https://www.acvs.org