Why does my dog pant so much?

Usually. Panting is a dog's primary way of losing heat (VCA), and the more a dog pants, the hotter it is (RSPCA). Normal cooling panting:

• matches the trigger: a run, a warm room, a car journey, visitors;
• slows after a short rest in the shade with water;
• comes with a bright, steady, interested dog.

Hot walks are the bigger risk: the RSPCA says dogs are 10 times more likely to get heat-related illness on hot walks than from overheating in cars (RSPCA). See is it too hot to walk my dog.

Dogs pant when hot, excited or stressed, and panting without exercise may be stress (VCA). Look for yawning, pacing, or wide eyes showing the whites, and move your dog away from the trigger to somewhere quiet (VCA).

Panting as you get ready to leave can be separation distress: see why your dog follows you everywhere. Panting with trembling is covered in why is my dog shaking.

It can be. VCA lists excessive panting, even at rest, as a pain sign (VCA). Other clues:

• Restlessness, unable to get comfortable lying down (VCA).
• Groaning when lying down or getting up, a grimace, trembling back legs (VCA).
• In older dogs, restlessness at night, often from arthritis (VCA).

Yes. Heart disease signs include rapid or difficult breathing, cough, tiring on walks and collapse. Mitral valve disease is very common in ageing small breeds, and Cavalier King Charles Spaniels are at particularly high risk (Cornell). Laryngeal paralysis, mostly in older Labradors, Golden Retrievers and St Bernards, causes excessive panting, noisy breathing and a changed bark (VCA).

Count the resting breathing rate

With your dog asleep, count breaths for 30 seconds and double it. Repeat over a couple of hours if it is high (VCA).

Cushing's disease (hyperadrenocorticism) is a common hormonal disease of adult and older dogs (Merck). Signs include panting, more thirst and urination, a bigger appetite, a pot belly, hair loss and heat intolerance. It tends to occur in middle-aged to older dogs, and in 85 to 90% of cases the cause is a small, benign pituitary tumour (Merck).

• Higher risk: Miniature Poodles, Dachshunds, Boxers, Boston Terriers, Beagles (Merck).
• Long-term steroid medicine can cause the same signs (Merck).

Brachycephalic obstructive airway syndrome (BOAS) affects Bulldogs, Pugs, Boxers, Boston Terriers, Pekingese and Shih Tzus. Narrow nostrils and a long soft palate make panting less effective, so they overheat easily, especially in humid weather. Severe cases can collapse after exercise, and obesity makes it worse (VCA). For a growing puppy, the puppy weight calculator shows the expected adult weight.

New panting at rest or at night in an older dog deserves a vet visit. Likely causes:

1. Pain, especially arthritis (VCA).
2. Cushing's disease (Merck).
3. Heart disease: count sleeping breaths (Cornell, VCA).
4. Laryngeal paralysis in large breeds (VCA).
5. Cognitive dysfunction, which disturbs sleep and brings anxiety (Merck).

Vets rule out pain before calling it behaviour (Merck). The dog behaviour checker hub covers other senior changes.

Heatstroke is an immediate emergency. A temperature above 103°F (39.4°C) is abnormal, and organ failure becomes likely around 107°F to 109°F (VCA). Signs: heavy panting, drooling, red gums, vomiting, diarrhoea, weakness, confusion, collapse (RSPCA).

1. Stop exercise and move your dog into shade (RSPCA).
2. Pour cool, not cold, water over the stomach, armpits and feet; no ice packs (VCA).
3. Do not cover your dog with a wet towel, which can trap heat (VCA, RSPCA).
4. Cool first, then go: call ahead and drive to the vet straight away (RSPCA).

If your dog may have swallowed something toxic, call the ASPCA Animal Poison Control Center on (888) 426-4435; a fee may apply (ASPCA).

Go now for heatstroke signs, bluish gums, struggling to breathe or collapse (VCA, Merck). Contact your vet soon if the sleeping rate stays above 30 a minute (VCA). For recurring panting at rest or new panting in a senior, no source gives a fixed number of days, so call your vet to be safe.

Every figure and threshold on this page comes from the veterinary sources below, and each one is linked where it is used. Where no source gives a cut-off, we say call your vet rather than invent one.