We’re not talking about the “Sit. Shake.” kind of shake. Nor the fun way they shake off water starting from their nose all the way to the end of their tail. (FYI, dogs can shake off 70% of the water on their fur in just four seconds!)
No, we’re talking about that full-body trembling you’ve likely seen your pooch do from time to time. Why do they do it? And is it something you should be worried about? Let’s shake a leg and find out.
A majority of dog owners in an IAMS™ survey* (64%) think dogs shake because they’re cold. Other top responses were because they’re scared (57%) or anxious (54%).
High-fives all around because it turns out there are a number of reasons dogs shake, and all those are possible correct answers.

Just like their owners, dogs will often shiver when cold.
Opens a new windowDr. Tammie King, Applied Behavior Technical Leader at Waltham Petcare Science Institute, says: “Dogs shiver in response to falling temperatures. Dogs with short or no hair are especially susceptible. You should get them warm, put coats on them or bring them inside.” Same goes for you.

“Shaking is a response to epinephrine or adrenaline secretion — a sign of anxiety where the dog is on high alert,” says
Opens a new windowJames Serpell, B.S., Ph.D., Professor of Humane Ethics & Animal Welfare at the University of Pennsylvania School of Veterinary Medicine. You may notice this when you’re at the vet or there’s a situation where they feel threatened. Dr. Serpell also offers a way to help in some cases: “Identify what’s triggering the behavior. Provide them comfort. Going forward, you can gradually desensitize your pet to the thing it’s afraid of.” Unless it’s clowns. Those are always scary.
Trembling can also be a sign of serious issues like injury, poisoning or kidney disease. Opens a new windowDr. Jo Gale, BVetMed CertLAS MRCVS, Senior Manager, Global Science Advocacy at Waltham Petcare Science Institute urges pet owners to be vigilant: “If a pet is unwell in another way, they could be trembling.” If their shaking is accompanied by symptoms like diarrhea, limping or vomiting, you should consult your vet straight away.
*Surveyed U.S. dog owners, age 18+
Sample Size: n=201
Fielded May 8-10, 2020
As your dog matures, his body functions change. He might have decreased immune-system function, deterioration of skin and coat quality, and more frequent intestinal problems. So it makes sense that what a mature dog eats might also need to change.
Throughout a dog's life, a process called peroxidation occurs. This is a normal process the body uses to destroy cells that outlive their usefulness and to kill germs and parasites, but this process also can destroy or damage healthy cells. As a dog ages, the damage caused by peroxidation accumulates and, in turn, increases the risk of certain problems such as infections.
Antioxidants are naturally occurring components in the body (but also can be acquired through diet). They help maintain overall health by neutralizing the peroxidation process of cellular molecules.
Research sponsored by IAMS™ found that dogs fed a diet rich in antioxidants such as vitamin E had improved immune responses and vaccine recognition. This might be especially important for mature/senior dogs, because IAMS research has found that, as dogs age, immune responses can decrease.
Eating a complete and balanced diet with omega-3 fatty acids, such as those found in vitamin-rich fish oils, also helps rejuvenate dry skin and develop a healthy, lustrous coat.
Aging dogs might have higher numbers of unfavorable bacteria and lower numbers of beneficial bacteria in their intestines, which can result in clinical signs of gastrointestinal problems (such as diarrhea). A diet with a moderately fermentable fiber source such as beet pulp can help maintain intestinal health. Beet pulp provides energy for the cells lining the intestine and promotes proper stool formation.
Different dogs show signs of aging at different times, and much of this variation is associated with size. Larger dogs generally appear mature/senior sooner than smaller dogs. The table below can show you when your dog should start a mature diet with a food such as IAMS ProActive Health™ Mature Adult.
Dog Weight and Transition to Mature/Senior Foods
| Weight Range | Age to Begin Transition |
|---|---|
| More than 90 lbs | 5 years |
| 51 to 90 lbs | 6 years |
| 21 to 50 lbs | 7 years |
| Up to 20 lbs | 7 years |