Why Is My Dog Panting So Much? Causes and Warning Signs

Dogs do not sweat the way we do. They lose heat by moving air rapidly over the moist surfaces of the mouth and upper airway, and panting is that mechanism running. So panting on a warm day or after a run is the system working, not a symptom. The useful question is narrower: does the panting match what the dog has just been doing?

The Distinction That Matters Most

Before working through causes, establish whether you are watching panting or laboured breathing. They look superficially similar and mean very different things.

Panting is open-mouthed, fast and relaxed. The dog can stop when something interesting happens, close its mouth, swallow, and settle. Laboured breathing takes visible work: the abdomen heaves with each breath, the neck extends forward, the elbows push away from the chest to open it up, and the dog resists lying down because upright is easier.

Effort matters more than speed. A dog breathing quickly but easily is in a different situation from a dog breathing at a normal rate but working for every breath. The second is an emergency.

Heatstroke: The One That Cannot Wait

Heatstroke kills quickly and the early signs are easy to rationalise. Rapid panting, hot skin, drooling, vomiting, distress, uncoordinated movement, then collapse and unconsciousness. It does not require a heatwave — a parked car, a walk at the wrong time of day, or hard play in humidity will do it, and flat-faced breeds cool themselves poorly enough to be at risk in conditions other dogs tolerate. Begin cooling on the way to the vet rather than waiting to see whether it settles.

When There Is No Heat to Explain It

Panting in a cool room, at rest, or at three in the morning is the pattern worth taking seriously. The common explanations:

• Pain. Dogs rarely vocalise pain; they pant and cannot settle. Night-time panting with repeated position changes in an older dog is often arthritis.
• Anxiety or fear. Fireworks, travel, a vet waiting room. Usually obvious from context and it resolves when the trigger does.
• Fever. Panting is one way a dog sheds heat it should not have.
• Medications. Steroids and opioid painkillers both cause it. Worth reviewing anything recently started.
• Anaemia. Fewer red cells means the dog moves more air to compensate.
• Heart disease. Reduced output and fluid on the lungs both drive up respiratory effort.
• Airway problems. Laryngeal paralysis in older large breeds, and brachycephalic airway syndrome in flat-faced dogs.

The One That Gets Missed: Cushing's Disease

Hyperadrenocorticism — too much cortisol — is a recognised cause of excessive panting, and it is worth knowing because owners rarely connect the two. The panting arrives alongside a cluster: drinking more, urinating more, a noticeably bigger appetite, a pot-bellied outline, thinning coat and reduced stamina. Individually each looks like ageing. Together they are a pattern.

Cushing's frequently announces itself on routine bloodwork before anyone suspects it, as a raised alkaline phosphatase. If your dog has a high ALP and pants at rest, Cushing's is a reasonable thing to raise with your vet.

What to Tell Your Vet

Three things make the appointment much more productive. When it happens — at rest, at night, after exertion. Whether the dog can settle and stop, or cannot. And what else has changed in recent months, particularly thirst, appetite, urination, weight and exercise tolerance. A video of the breathing at home is genuinely useful, since dogs frequently pant in the consult room from stress alone and mask the pattern you came about.

Frequently Asked Questions

Sources

• Merck Veterinary Manual — Clinical Signs of Respiratory Disease in Animals
• Merck Veterinary Manual — What to Do in a Dog or Cat Emergency