The concept of air having weight might be hard to imagine, but science teachers have been demonstrating the fact to us since grade school -- with two empty balloons tied to opposite ends of a stick and balanced like a seesaw: When one balloon is filled with air, that end is heavier. The dog, meanwhile, may not ever understand barometric pressure, at least not without advanced-placement studies. But he can feel barometric pressure changes in his body.
The Barometer's Physical Effects
A barometer is a measuring device that shows the natural fluctuations in air pressure. Moist air is lighter than dry air, counterintuitively, and warm air is lighter than cold; These factors affect the pressure of the air around you, and it affects weather. When the air pressure is high, the weather tends to be tranquil. When it's low, a storm is brewing. Low barometric pressure has physical effects on the body -- for humans and animals.
Low Pressure and Sinuses
Some people get headaches prior to storms because of the relative pressure of the atmosphere on their sinuses, which are filled with air. Whether dogs get headaches has yet to be confirmed, but some vets theorize it’s possible. After all, their sinuses are filled with air, like yours. Theoretically, a dog with a longer snout and a larger sinus cavity would feel the effects of barometric pressure more intensely. But not all humans feel sinus pressure, and whether some dogs do not clear.
Pressure and Joint Pain
Low barometric pressure appears to aggravate joint pain. Low pressure aggravates joint pain because the lower pressure allows the tissues to expand, stiffening or inflaming the joints and sometimes causing nerves to become more sensitive, especially if they’ve been damaged due to injury, scarring or adhesion.
Other Ways Dogs Sense Storms
A dog’s most heightened sense is his sense of smell. Dogs have approximately 200 million olfactory receptors in their noses, while humans have about 5 million. Dogs can smell the effects of nearby rain before you can. Meanwhile, when lightning strikes, even distantly, it ionizes the air with ozone; dogs have the ability to pick up this smell. A dog’s sense of hearing is another heightened sense much greater than ours: They can hear thunder and even rain pelting before you can. Also, according to Dr. Nicholas Dodman of Tufts Cummings School of Veterinary Medicine, dogs are designed to acquire a static charge. After all, they’re “running around on insulated foot pads wearing the equivalent of a big furry angora sweater," Dodman says.