Sundowning in Dogs: Symptoms & What to Do

Is your dog wandering, getting stuck, pacing or barking for no reason more often in the evening / nighttime? These could all signal sundowning in dogs.

A gray senior dog.
A gray senior dog. Photography ©Akchamczuk | Thinkstock.
Last Updated on November 18, 2023 by Dogster Team

Just like us humans, as our four-legged friends grow older, they may experience health issues ranging from arthritis to cancer. But what many pet owners aren’t prepared for are the behavioral changes that often arise in their elderly dogs. A component of canine cognitive dysfunction or dog dementia, sundowning (or sundowner’s syndrome) is one such condition that impacts many dogs as they age. And sundowning in dogs presents itself much like Alzheimer’s disease in humans.

“Just like with humans, sundowning in dogs is believed to be caused by age-related issues such as the breakdown of the central nervous system, oxidative stress and brain cell death,” explains Dr. Stephen Katz, a veterinarian practicing more than 30 years and founder of the Bronx Veterinary Center in New York. “Unfortunately, it’s often all just a part of the aging process for both dogs and people.”

Symptoms of Sundowning in Dogs

Senior dogs give a whole lot of love. Celebrate Adopt a Senior Dog Month.
Is your dog getting lost in the yard? Could it be sundowning? Photography ©CatLane | Getty Images.

According to Dr. Adrienne Pincetl, associate veterinarian at University Veterinary Hospital and Diagnostic Center in Salt Lake City, Utah, recent studies have shown that both dogs and cats experience physiologic changes to their brains and central nervous systems as they age, which may account for behavioral changes and symptoms of cognitive dysfunction.

“These symptoms can include wandering, getting lost in the house or yard, or getting stuck places, such as behind furniture. They may also exhibit pacing, restlessness or other repetitive behavior … and there can also be a regression in learned behaviors, including house training, so more accidents may be observed,” she adds. “Anecdotally, many people report that there’s an increase in this type of behavior in the evening and night-time hours, similar to the ‘sundowner’s syndrome’ observed in humans.”

Dr. Katz adds that sundowning in dogs may also exhibit as barking for seemingly no reason, becoming clingy to owners or demonstrating anxiety-related behaviors like panting. “Quite often, there’s also an increase in irritability, and some dogs may even become aggressive,” he warns.

Is It Sundowner Syndrome or Something Else?

However, another common side effect of getting older — loss of vision and/or hearing — can also cause similar symptoms. “It can be difficult to determine whether an animal is scared and confused at night because of cognitive dysfunction, or because their limited vision is impacted by the lack of light … or they may just be acting differently because they are arthritic and uncomfortable,” Dr. Pincetl adds.

Managing Sundowner Syndrome in Dogs

According to Dr. Katz, while there’s no known cure for the symptoms of sundowning in dogs, there are strategies to help your dog manage these changes in behavior, including medications like Selegiline to help increase dopamine levels in the brain, a change in diet to improve digestive health and limit accidents, or anything that might help improve your dog’s cognitive performance, such as puzzle toys or even certain brands of dog food. “It has been shown that dogs that get regular mental stimulation as they age, like new toys or learning new tricks, maintain a better ability to learn — and may even experience a delay in mental decline,” Dr. Pincetl agrees.

Scott R. Sheaffer, a certified canine behavior consultant and owner of USA Dog Behavior, LLC in Texas, notes that one of the best things you can do for your dog during this stage of life is reduce the number of triggers that might cause anxiety to keep your pet as comfortable and relaxed as possible. “For starters, you’ll want to provide plenty of structure in your dog’s day and keep his daily routine predictable for him … so he should be fed or walked or go to bed in the same order and around the same time every single day,” he advises.

What Not to Do

One thing you shouldn’t do when it comes to sundowning in dogs, however, is attempt to discipline or punish your dog for undesirable behaviors like suddenly having accidents in the house.

“Canine cognitive dysfunction is under-diagnosed and misdiagnosed in a lot of dogs … and while we’ve made great strides in understanding how Alzheimer’s affects humans, we’re just now starting to understand how dogs are impacted by similar issues as they age,” Scott notes. “As a result, sometimes people think their dog needs to start a new obedience training regimen in order to improve his behavior — but the only thing that’s going to do is make your dog even more anxious.”

Some Final Thoughts

When it comes to sundowning in dogs, experts agree the best thing to do for your dog in his later years is to continue to provide him with a healthy diet and ample exercise, a predictable routine and mental stimulation, and medication when appropriate to keep him as comfortable as possible — particularly in the evening hours. “Although it’s not possible to completely reverse the clinical signs associated with this condition, it is possible to maintain a good quality of life — for both the animal and the owner — as your pet experiences his “golden years,’” Dr. Pincetl concludes.

Read more about senior dogs and aging in dogs on

About the author

Jennifer Lesser is a New Jersey-based freelance writer. A marathoner, triathlete, and Taekwondo black belt, she specializes in health and wellness — for people and canines — and has written for magazines and websites including Whole Dog Journal, Health, The Spruce Pets, Weight Watchers and Animal Sheltering. She is the proud pet parent of a rescued Cocker Spaniel/Shih Tzu mix named Miles, who has become her favorite running partner. Visit her online at

Featured Image Credit: Akchamczuk | Thinkstock.

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