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Why Is My Dog Panting Heavily? Causes and When to Worry

Dogs pant to regulate their body temperature, but not all panting is benign. Heavy, laboured or unexpected panting can signal pain, overheating, anxiety or serious illness. Knowing the difference between normal and concerning panting could save your dog's life.

Normal Panting vs Concerning Panting

Dogs don't sweat through their skin the way humans do — panting is the primary mechanism for heat dissipation. After exercise, in warm weather or when excited, panting is normal and will resolve as the dog cools down. A relaxed, open-mouthed pant with a normally coloured tongue is generally fine.

Concerning panting looks different: it's heavy and laboured with apparent effort; it occurs at rest or in cool conditions; it's accompanied by restlessness, distress or whimpering; the tongue or gums appear pale, white, blue-tinged or bright red; the dog can't settle.

A dog that suddenly starts panting heavily at night, when it's not hot and they haven't exercised, is telling you something is wrong. Pain, anxiety and various medical conditions all cause this pattern and warrant veterinary assessment.

Heatstroke: The Most Dangerous Cause

Heatstroke is the most immediately life-threatening cause of heavy panting in dogs and kills rapidly without treatment. It occurs when a dog's body temperature rises above 40°C. Signs include heavy, distressed panting, excessive drooling, bright red or blue gums, vomiting, disorientation and collapse.

Risk factors include hot weather, being left in a parked car (temperatures inside a car can reach 60°C within minutes even on a mild day), vigorous exercise in warm conditions, and brachycephalic breeds (French Bulldogs, Pugs, Bulldogs) who cannot pant effectively.

If you suspect heatstroke, move the dog to a cool area, apply cool (not cold) water to their body and contact an emergency vet immediately. Do not use ice — this can cause peripheral vasoconstriction that traps heat in the core. Every minute matters in genuine heatstroke.

Pain and Anxiety as Causes

Pain is a significant and often overlooked cause of panting in dogs. A dog in pain — from any cause — often pants heavily, particularly at night or at rest. Conditions including pancreatitis, spinal pain, abdominal bloat and orthopaedic pain can all present with restless, heavy panting.

GDV (gastric dilatation-volvulus or bloat) is an emergency condition that causes rapid deterioration including heavy panting, restlessness, unproductive retching and a swollen abdomen. Large and giant breeds with deep chests are most at risk. This requires emergency surgery and delay is fatal.

Anxiety — from fireworks, thunderstorms, car travel or separation — causes panting that typically co-occurs with other anxiety signs: trembling, pacing, hiding, drooling. Managing the anxiety trigger is the long-term solution; short-term, removing the dog from the stressor helps.

Medical Conditions Causing Panting

Several systemic conditions cause chronic or episodic panting. Cushing's disease (hyperadrenocorticism) — excessive cortisol production — is a common cause of increased panting in middle-aged to older dogs, often alongside increased thirst, a pot-bellied appearance and skin changes.

Heart and respiratory disease can cause panting as the dog struggles to oxygenate adequately. Anaemia, laryngeal paralysis (common in older Labradors) and tracheal collapse can all cause respiratory distress that presents as heavy, noisy panting.

Steroids — commonly prescribed for allergies, immune conditions and pain — can cause increased panting as a side effect. If your dog is on steroids and has started panting more, mention it to your vet — it may be dose-dependent and manageable.

Brachycephalic Breeds and Panting

Brachycephalic (flat-faced) breeds including French Bulldogs, Pugs, English Bulldogs and Persian cats have anatomical features that compromise their ability to breathe and pant effectively. Narrowed nostrils, elongated soft palates and narrowed tracheas all restrict airflow.

These breeds pant noisily and heavily in conditions that other breeds would handle easily. They are at much higher risk of heat-related illness and respiratory distress. If you own a brachycephalic breed that seems to struggle with even mild temperatures or exercise, discuss BOAS (Brachycephalic Obstructive Airway Syndrome) assessment with your vet.

BOAS surgery — to widen nostrils, shorten the soft palate and remove excess tissue — is increasingly recommended for significantly affected dogs. The RCVS and BVA have called for breeding reforms to reduce the prevalence of extreme conformations in these breeds.

Find a Vet Near You

Persistent or unexplained heavy panting needs a veterinary assessment. For urgent cases such as suspected heatstroke, contact an emergency vet immediately. Use CompareMyVet at app.comparemyvet.uk to find vet practices and out-of-hours emergency services near you.