TL;DR: Stridor is a high-pitched breathing sound that indicates a partial upper airway obstruction in cats and constitutes a high-priority veterinary emergency.
What is stridor in cats and what does it sound like?
Stridor is a harsh, high-pitched, vibrating sound produced when your cat breathes. Unlike a purr or a soft snore, stridor is typically loud and indicates that the upper airway—specifically the larynx (voice box) or trachea (windpipe)—is partially obstructed or narrowed. This physical blockage forces air through a smaller space, creating the distinct, alarming sound you are hearing.
Is sudden onset stridor in my cat considered a medical emergency?
- Urgency Level: High. Sudden stridor indicates your cat is struggling to move enough oxygen into their lungs.
- Cats are masters at hiding respiratory distress; the presence of loud stridor suggests your cat is in immediate danger of a total airway obstruction.
- Immediate Action: Contact your nearest emergency veterinarian immediately.
How can providing photos or videos of my cat’s breathing help with veterinary triage?
- If it is safe and does not delay your trip to the clinic, capture a photo or a 5-second video of your cat breathing.
- Photos allow veterinarians to see "orthopneic" posture, such as an outstretched neck or open-mouth breathing.
- Videos capture the specific rhythm and sound of the stridor, which helps differentiate the cause.
- These visuals help the medical team prepare life-saving equipment, such as oxygen tanks or sedation, before you arrive.
Clinical Context (Merck Veterinary Manual)
Partial large airway obstruction in cats causes noisy breathing (stridor or stertor), heard without the aid of a stethoscope, and is often accompanied by cyanosis and anxiety. Compromise of the extrathoracic airway (nasal passages, pharynx, larynx, or cervical trachea) causes similar signs. Definitive diagnosis of laryngeal involvement requires laryngoscopy, typically under anesthesia or analgesia in cats. In cases of laryngeal obstruction, a tracheotomy tube should be placed immediately; if this is not possible, airway patency may be established by passage of a pliable tube through the glottis. Corticosteroids should be administered to reduce obstructive swelling of the larynx or pharyngeal tissues.
Chapter: Respiratory, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 1420)