Almost all dog lovers know why their furry friends pant after taking a stroll in the stifling Texas summer heat, but have you ever wondered why panting is the primary way our canine companions cool down? Or why they only sweat through their paws and noses? And have you ever asked why your dog would start panting in the middle of the night for no reason? If you said yes to any of the above questions, keep reading.

What Is Panting?

Panting is a key mechanism for heat reduction. The movement of air during panting is strictly limited to the upper airway, which ends where the trachea (windpipe) begins branching. As a result, cool outside air absorbs heat from the body during panting and allows for evaporation of saliva in the mouth and airway, thus slowly lowering body temperature¹ (Goldberg et al., 1981). Panting is an inefficient way to cool down, especially in the stifling heat so common in Texas. A primary reason panting is inefficient is because dogs evolved to retain as much of their body heat as possible, which is the main reason why dogs only sweat through their paw pads and noses.

Pain and Anxiety-Induced Panting

If your dog is randomly panting in the middle of the night in your perfectly air-conditioned home, what could possibly cause such a behavior? The three most common reasons for panting when there is not an obvious temperature-related cause are from pain, anxiety and disease.

When dogs show signs of stress or pain like during a Texas summer thunderstorm or from aching joints, their bodies rapidly increase cortisol production, leading to excessive panting. Cortisol is a steroid hormone produced by the adrenal glandsendocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol that is helpful in dealing with normal amounts of stress. Under usual circumstances, cortisol is helpful in regulating metabolism, salt and water balance and blood sugar, just to name a few functions. If produced in excess, the additional cortisol will increase metabolism, thus leading to an internal rise in body temperature and excessive panting² (Dresche and Granger, 2005). Any source of stress, fear or pain for your dog can cause the same effect. In addition to elevations in cortisol, medications such as prednisone that mimic cortisol can cause panting as well.

Disease-Related Panting

In cases of disease, any process that causes an increase in the respiratory rate (number of breaths per minute) often will give the appearance of panting once breathing is rapid enough. Such disease processes include heart failure, lung ailments and metabolic abnormalities just to name a few. One disease that increases cortisol levels is Cushing’s disease. Not only will dogs affected with this condition experience excess panting but they also will develop a pot-bellied appearance, have excessive thirst and urination, and their skin and coat will look unthrifty.

How To Identify Panting

The best way to know if your dog is experiencing panting or rapid breathing is to first know the normal breathing rate, which at rest is between 10 to 40 breaths per minute. If at any point you are unsure if the breathing is abnormal, call your veterinarian.

Whenever you see your four-legged family member starting to pant, remember that it could be a possible sign of discomfort, overheating or disease. Your veterinarian can provide insight on why your dog may pant with no obvious explanation, so be sure to discuss any questions about panting during your next visit with your other family doctor.

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References:

1. Goldberg, Marcia B.; Langman, V.A.; Taylor, Richard C. “Panting in Dogs: Paths of Airflow in Response to Heat and Exercise.” Rspiration Physiology. March 1981, Vol 43, Issue 3, 327-338.

2. Dresche, Nancy A. and Douglas A. Granger. “Physiological and Behavioral Reactivity to Stress in Thunderstorm-Phobic Dogs and Their Caregivers.” Applied Animal Behaviour Science. December 2005, Volume 95, Issues 3-4, 153-168.