Why do little dogs shiver so much? We asked the experts.
When you walk your retriever, he will strut around like he owns the place. But your neighbor’s Chihuahua may be shaking all over for no apparent reason, so much so that you feel the urge to go comfort him.
It’s not just you: Several users on Quora, TikTok, and Reddit are also curious about why dog ​​breeds, especially smaller ones, shiver so much. We asked the experts and the answers go further than expected.
In clinical settings, owners of small dogs tend to report more frequently that their dogs are trembling, says Carlo Siracusa, a veterinary behavior specialist at the University of Pennsylvania School of Veterinary Medicine. Siracusa hasn’t seen a study comparing shivering by dog ​​size, but he sees small dogs shivering quite frequently in his practice.
Small dogs lose to physics
If small dogs really do shake more (which no one has formally studied), Siracusa says, it would likely be to maintain a consistent internal body temperature, regardless of the environment. This process is known as thermoregulation.
Small dogs “dissipate a lot of heat through their small bodies” and have a relatively high surface area relative to their body mass, Siracusa says. Popular science.
Compensating for this heat loss takes energy – and small dogs have to burn off a lot of it. It may seem that a Great Dane expends much more energy than a small breed like the Papillon, but the Great Dane’s relative energy expenditure is lower, says John Speakman, a biology professor at the University of Aberdeen in Scotland. This is a discovery from his seminal work published in 2003. Small dogs burn about 60% more energy per gram of body tissue than large dogs. This is not just a characteristic of dogs, but a lifelong phenomenon, notes Speakman.
Speakman illustrates this by comparing a tennis ball to a basketball: the tennis ball has a much larger surface area relative to its volume, so heat escapes more quickly. This means that keeping your core warm requires more energy. The basketball, on the other hand, with less surface area per volume, retains heat.
The same physics applies to dogs. When dogs begin to lose heat faster than they can produce it, their bodies respond by shivering: their muscles contract rapidly to generate heat.
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While it’s true that small dogs shiver more, Speakman says, “a big dog doesn’t need to start shivering until it gets really cold, whereas a small dog needs to start shivering much sooner.”
Similarly, a 2023 paper found that small dogs lose body heat more quickly and must devote more of their metabolic energy to staying warm — proof that the physics of small size has real physiological consequences.
The temperature you like may not be ideal for your dog
Syracuse thinks small dogs might also shiver more because they live closer to the ground, where cold air settles. “I can’t confirm if there are any numbers,” he says, “but I [would] don’t be surprised.
People don’t always realize that we’re comfortable in temperatures that small dogs find cold, Siracusa says.
The USDA guidelines for dog housing recognize 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 house is dangerously cold: it’s whether the “comfortable” setting on your thermostat is comfortable for a four-pound dog.
To understand if the cold is really what makes your little dog shiver, Siracusa shares some tips. “Make the best guess by observing the environment independent of perceived temperature,” he says. If the environment is very quiet and your dog is just resting, but still shaking, there’s a good chance he’s too cold, unless the shaking is due to a dream, which is usually short-lived.
If people suspect their dog is shivering from the cold, they can provide a heat source, such as heated beds and pillows. If the animal continues to shiver even after the temperature is checked, there could be other causes, Siracusa says.
What if they weren’t cold at all?
Neurological problems can also cause chills, Siracusa says. Tremors could be a side effect of medications like antiallergic medications and serotonergic medications 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,” in which dogs experience tremors throughout their body. The “white” part has always been misleading: dogs of any color can get it. The “small” part is mostly valid, as small breeds like Maltese and West Highland White Terriers are much more commonly affected.
Siracusa says he hasn’t seen any data linking body size to frequency of shivering. Such studies would be difficult. There would need to be cameras in homes, controlled temperatures and willing owners. “But it’s certainly an interesting project to do,” he says.
Besides the cold and medications, interactions with us could also make small dogs tremble, Siracusa says. Small dogs are easier to control and often easier to dismiss. A big dog that lunges is taken seriously, whereas a small dog that growls might just make you laugh. Syracuse has seen embarrassed owners pick up their anxious dogs and let strangers pet them anyway. The dog’s fear signals are ignored and he gets stuck in situations that stress him out.
During fear, stress hormones kick in, muscles contract, and the dog begins to shake.
But do small dogs really shake more than large dogs? There is no shortage of anecdotes, but no one has formally studied the phenomenon.
So the next time you see a small dog shivering, don’t immediately assume you know why. This could be due to the cold, stress, or simply the way they are built. But it’s worth bringing a warm blanket or maybe a trip to the vet if the shivering doesn’t stop.
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