Panting is how dogs cool down and it’s usually completely normal — after exercise, in warm weather, or when excited. But heavy panting at rest can signal heat, pain, stress or illness.
Dogs barely sweat, so they regulate their temperature mainly by panting — rapid, shallow breathing that evaporates moisture from the tongue and airways and carries heat away. That is why a dog pants after a run, on a warm day, or when worked up with excitement, and it is entirely normal. Flat-faced breeds pant less efficiently and so may pant more and overheat more easily.
Normal panting eases off once your dog rests, cools down or calms down. Be more watchful when panting is heavy and out of context — your dog is panting hard while lying quietly in a cool room, or the panting seems frantic and will not settle. This can point to overheating, pain, anxiety, or a problem with the heart, lungs or hormones.
On warm days, escalating panting is the early warning sign of heatstroke, which can become life-threatening fast. If panting is paired with drooling, bright red gums, wobbliness or distress in the heat, cool your dog and seek help immediately — see our heatstroke first aid and check the live walk-safety tool before going out.
Contact your vet if your dog pants heavily at rest, pants more than usual without an obvious reason, or the panting comes with coughing, weakness, pale or blue gums, restlessness, a swollen belly or collapse. Sudden, severe or unexplained panting deserves prompt attention, as it can be the first clue to pain or a heart or breathing problem.
Keep exploring: Heatstroke first aid · Can I walk my dog now? · Why does my dog shake?
Most quirks are perfectly normal. If a behaviour changes suddenly or comes with other signs of illness, check with your vet. Full disclaimer.