TL;DR: If your cat’s sides are heaving, they are in respiratory distress and require immediate emergency veterinary care to address potential life-threatening conditions like heart failure or asthma.
What does it mean if my cat's sides are heaving while they breathe?
When a cat's sides or abdomen move significantly in and out with every breath, it is a clinical sign known as dyspnea, or labored breathing. Unlike humans, healthy cats breathe primarily with their ribcage, and their breathing should be nearly silent and effortless. If you can see the 'flanks' or sides of the belly pumping hard, your cat is using their abdominal muscles to force air in and out of the lungs.
Is my cat having a medical emergency if their breathing is labored?
Urgency Level: High. Yes, this is an immediate medical emergency. Because cats are experts at masking illness, by the time they show visible signs of struggling to breathe, they are often in a critical state.
- Respiratory distress can be caused by heart failure, asthma, fluid in the chest, or severe infection.
- Contact an emergency veterinarian immediately.
- Transport your cat to the clinic without delay.
How does taking a video of my cat's breathing help the veterinarian triage the situation?
While you should never delay your departure to the clinic, having a brief 10-to-15 second video of your cat's breathing can be incredibly helpful for the veterinary team.
- A video allows the vet to see the 'respiratory effort' and rhythm while the cat was in a resting state.
- This visual information helps them categorize the type of distress (upper vs. lower airway).
- A video allows for faster stabilization once you arrive at the hospital.
Clinical Context (Merck Veterinary Manual)
Compromised breathing in cats manifests as increased respiratory rate and effort, followed by changes in respiratory pattern. Cats may sit crouched on all four limbs with the sternum slightly elevated. Obvious labored, open-mouth breathing, and changes in mucous membrane color (gray and/or blue [cyanosis]) indicate significant loss of pulmonary function and impending pulmonary arrest. Pleural space disease causes asynchronous breathing, where the chest expands on inspiration as the abdomen is pulled inward, then the chest moves inward on expiration as the abdomen expands. Lung parenchymal disease causes quiet, smooth breathing, with the chest and abdominal wall moving in the same direction; inspiration and expiration are equally labored unless concurrent small airway constriction is present. Cats may present with forced abdominal expiratory effort. The location of the pathology, pleural space or parenchymal disease, can be determined by careful observation of the breathing pattern and auscultation of the thorax, which will direct resuscitative efforts. Taking radiographs or performing stressful diagnostic procedures before the animal has been stabilized can lead to rapid decompensation.
Chapter: Emergency, Respiratory
Source: The Merck Veterinary Manual, 11th Edition (Page 1663)