Why do little dogs shiver so much? We asked the experts.

When you take your retriever out for a walk, they will strut around as if they own the place. But your neighbor’s Chihuahua might be shaking all over for no apparent reason, so much so that you get the urge to go comfort them.  

It’s not just you—several Quora, TikTok, and Reddit users are also curious why dog breeds, particularly tiny ones—shiver so much. We asked the experts, and the answers go deeper than you’d expect.   

In a clinical setting, owners of small dogs tend to more frequently report their dogs trembling, says Carlo Siracusa, a veterinary behavior specialist at University of Pennsylvania School of Veterinary Medicine. Siracusa hasn’t seen a study comparing shivering across dog sizes, but he quite frequently sees tiny dogs shiver in his practice. 

Small dogs are losing to physics

If small dogs really tremble more (which no one’s formally studied), Siracusa says, it’d likely be to maintain a consistent internal body temperature, no matter the environment. This process is known as thermoregulation. 

Small dogs “dissipate a lot of heat through their tiny bodies,” and have relatively high surface area compared to their body mass, Siracusa tells Popular Science. 

Compensating for that heat loss takes energy—and small dogs have to burn through a lot of it. It might appear as if a Great Dane expends much more energy than a small breed such as the Papillon, but the Great Dane’s relative energy expenditure is lower, explains John Speakman, a biology professor at the University of Aberdeen in Scotland. This was a finding from his foundational work published in 2003. Small dogs burn about 60 percent more energy per gram of body tissue than large dogs do. This is not only a feature of just dogs, but a phenomenon that exists across the scale of life, Speakman notes. 

Speakman illustrates this by comparing a tennis ball to a basketball: The tennis ball has far more surface area relative to its volume, so heat escapes faster. This means keeping its core warm takes more energy. The basketball, on the other hand, with less surface area per volume, holds on to heat. 

The same physics applies to dogs. When dogs start losing heat faster than they can produce it, their bodies fight back by shivering—muscles contracting rapidly to generate warmth. 

If it’s true that small dogs shiver more, Speakman says, “a big dog doesn’t have to start shivering until it gets really cold, whereas a small dog has to start shivering much, much earlier.”

Similarly, a 2023 paper found that smaller dogs lose body heat more rapidly and must dedicate a larger share of their metabolic energy to staying warm—evidence that the physics of being tiny has real physiological consequences.

The temperature you like might not be ideal for your dog

Siracusa thinks small dogs could also shiver more because they live closer to the floor, where cold air settles. “I cannot confirm if there are numbers,” he says, “but I [would] not be surprised.”

People don’t always realize that we’re comfortable at temperatures that small sized dogs find cold, says Siracusa.

USDA guidelines for housing dogs acknowledges that toy breeds are more sensitive to cold, requiring temperatures no lower than 50 degrees Fahrenheit—warmer than the threshold for larger dogs. The question isn’t whether your home is dangerously cold: It’s whether your “comfortable” thermostat setting is comfortable for a four-pound dog. 

To understand if cold temperature is really what causes your tiny dog to shiver, Siracusa shares a few tips. “Take the best guess by observing the environment independent of the perceived temperature,” he says. If the environment is very quiet, and your dog is simply resting, but still trembling, there is a good chance that the dog is feeling too cold, unless that trembling is because of a dream, which is usually short-lived. 

If people suspect their dog is shivering because of the cold, they can provide their dogs with a heat source, such as heated beds and pillows. If the animal continues to shiver even after temperature control, there could be other causes, Siracusa says. 

What if they aren’t cold at all?

Neurological problems can also cause shivering, Siracusa says. Trembling could be a side effect of medications like anti-allergic drugs and serotonergic drugs that help manage anxiety and aggression. 

There is even a condition called “little white shaker syndrome,” now more often known as “idiopathic generalized tremor syndrome,” where dogs experience full body tremors. The “white” part was always misleading—dogs of any color can get it. The “little” part mostly holds as small breeds like Maltese and West Highland White Terriers are far more commonly affected. 

Siracusa says he hasn’t seen any data linking body size to shivering frequency. Such studies would be tricky. You’d need cameras in homes, controlled temperatures, willing owners. “But it definitely is an interesting project to do,” he says. 

Apart from cold and medications, interactions with us could also make tiny dogs tremble, Siracusa says. Small dogs are easier to restrain and often easier to dismiss. A large dog that lunges gets taken seriously, whereas a tiny dog that growls might just get laughs. Siracusa has seen embarrassed owners pick up their anxious dogs and let strangers pet it anyway. The dog’s fear signals get ignored, and it ends up stuck in situations that stress it out. 

During fear, stress hormones kick in, muscles contract, and the dog starts to tremble. 

But do small dogs actually shiver more than big ones? There are plenty of anecdotes, yet no one’s formally studied the phenomenon. 

So, the next time you see a tiny dog shivering, don’t immediately assume you know why. It could be the cold, the stress, or simply the way they’re built. But it’s worth a warm blanket or maybe a vet visit if the shivering doesn’t stop. 

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