Dogster is reader-supported. When you buy via links on our site, we may earn a commission at no cost to you. Learn more.

Ask the Vet

Sundowners In Dogs: Signs & Care Guide (Vet Answer)

Dr. Marti Dudley
Written and fact-checked by Dr. Marti DudleyVet Approved
Dr. Marti Dudley
Reviewed & Fact-Checked byDr. Marti DudleyDVM (Veterinarian)
Dr. Marti Dudley is a small animal veterinarian with a strong interest in preventative medicine and pet parent education. She enjoys being a resource for pet owners as she believes that having a team approach leads to the best possible care of pets. Dr. Dudley enjoys writing and has been able to use this skill as another avenue to educate pet owners outside of the traditional office setting.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Learn more
Updated on June 17, 2026
Share
senior dog with arthritis

As our dogs mature and enter their senior years, we commonly recognize behavior changes. For some, it may be that their dog wanders and appears lost at times. Or maybe your companion appears restless in the evenings, unable to settle. These behavior changes may be suggestive of sundowners, or doggie dementia. Continue reading to learn more about this condition and how we can support our canine companions as they age.

Dogster divider_v2_NEW_MAY_24_

What Is Sundowners?

“Sundowners” is a term used to describe people with dementia who experience an onset of signs late in the day, as the sun goes down. This term has been modified to describe our canine companions that show signs of confusion or unusual behavior suggestive of cognitive dysfunction. Other terms for this condition are cognitive dysfunction syndrome and doggie dementia.

This type of brain deterioration can be seen in dogs 9 years and older. One study suggested that 68% of dog owners reported signs of dementia in their dogs between the ages of 15–16 years.1

Image Credit: Amelia Martin, Shutterstock

What Are the Signs of Sundowners?

Signs of cognitive dysfunction syndrome can vary amongst patients and may be difficult to identify in some.

Signs supportive of cognitive dysfunction syndrome are abbreviated as DISHA.

DISHA stands for the following:

  • Disorientation
  • Interaction changes
  • Sleep/wake cycle changes
  • House soiling
  • Activity level changes

What Are the Causes of Sundowners?

The underlying cause of sundowners or cognitive dysfunction syndrome correlates to the deterioration of the brain due to aging. Other conditions, including hearing impairment, blindness, and pain, may resemble sundowners, as patients may behave similarly.

Image Credit: Holly Michele, Shutterstock

Diagnosing Sundowners or Cognitive Dysfunction Syndrome

Other disease processes can have similar signs as cognitive dysfunction syndrome. If cognitive decline is suspected in your pet, a veterinarian will perform a full physical examination and run baseline lab work. Cognitive dysfunction syndrome is more of a diagnosis of exclusion, as there is not a specific test available.

Advanced imaging like an MRI can be done to check for atrophy of the brain. MRIs can also be a way of ruling out other causes of behavior changes, like brain tumors.

How Do I Care for a Dog With Sundowners?

Unfortunately, there is not a specific “cure” for cognitive dysfunction syndrome. The main focus of care is to slow the progression of brain degeneration. However, one of the best things you can do at home is to keep them calm and relaxed. This can include things like offering their own quiet room in the house, playing calming music, avoiding bright lights, keeping their surroundings familiar and safe, and sticking to a regular exercise routine. With that said, care can also include the following, which you should speak to a vet about.

1. Medications/Supplements

Selegiline is a monoamine oxidase B inhibitor that is available in the United States to reduce signs of cognitive decline in dogs. Selegiline may also increase dopamine. Over 70% of pet owners who administered Selegiline to their dogs reported an improvement in clinical signs within 1 month.2

S-adenosylmethionine (SAMe) can also improve signs of cognitive dysfunction in affected dogs. SAMe is considered a nutritional supplement.

Although not yet utilized in the United States, certain medications that increase cerebral perfusion are being used in European countries to combat different signs of cognitive dysfunction syndrome.


2. Modifications to Routines

It is important to create a safe environment for your pet to be in. If you are away from them, it may be helpful to confine them into a space where they are unable to explore or potentially get lost or stuck.

If your senior pup has suddenly forgotten their housetraining, it will be important to offer more bathroom breaks throughout the day.

Remember, patience is key when caring for a pet suffering from sundowners or cognitive dysfunction syndrome.

Image Credit: Annette Shaff, Shutterstock

3. Diets

Some diets are available that have high levels of antioxidants, essential fatty acids, and other nutrients that are beneficial to the brain. A veterinarian will be able to help guide your diet selection, as some are prescription diets, whereas others are over-the-counter.


4. Enrichment

Mental stimulation will help slow cognitive dysfunction syndrome in dogs. This can be in the form of exercise, play, and training. Food puzzles can be great forms of mental stimulation for senior dogs. Alternatively, you could consider teaching your pet a new trick that doesn’t require significant physical strain.


5. Thunder Shirts

Thunder shirts are often used with dogs that suffer from noise phobias and other forms of anxiety, and they may even help dogs with sundowners.


6. Night Light

Use a night light – most older dogs develop nuclear sclerosis (aka lenticular sclerosis), which is a normal sign of aging. The opacity of the lens in the eye increases over time, gradually reducing the amount of light that can reach the back of the eye. This can significantly impact your dog’s night vision, which can be very stressful for your older dog. Leaving just a dim light on at night can make a huge difference.

Dogster divider_v2_NEW_MAY_24_

FAQ (Frequently Asked Questions)

Can I Slow the Cognitive Decline in My Dog?

Fortunately, treatments used in dogs with signs of dementia can slow the progression of cognitive dysfunction. Unfortunately, this is a progressive condition that cannot be reversed or cured.

Are Some Dogs More Predisposed to Cognitive Dysfunction Than Others?

Dogs older than 9 are more likely to develop cognitive dysfunction syndrome. Labrador Retrievers, Staffordshire Terriers, and Cocker Spaniels are among some of the more predisposed breeds. Additionally, spayed females seem to be the most at risk.

Image Credit by Reba Spike, Unsplash
Dogster divider_v2_NEW_MAY_24_

Conclusion

Aging in our pets is not something that can be avoided. Unfortunately, some signs of cognitive dysfunction syndrome may be mistaken for normal aging progression, and intervention may not be immediately pursued.

Cognitive dysfunction syndrome is a progressive disorder and one that cannot be cured. Different modalities can be utilized that may be able to slow the progression of decline and improve clinical signs. If you start noticing changes in your pet, it is a good idea to schedule a consultation with a veterinarian who can perform an evaluation and offer personalized recommendations to benefit your pet.

Sources

Featured Image Credit: Tanya_Terekhina, Shutterstock

The Dogster Newsletter

Expert dog care, straight to your inbox

News, insights, expert advice, and everything dog.

No spam — unsubscribe anytime.

By signing up, you agree to our Terms & Conditions and Privacy & Cookies Policy.

Click a star to rate. You can leave written feedback afterwards. (We read all feedback.)

Dr. Marti Dudley DVM (Veterinarian)
Authored by

Dr. Marti Dudley DVM (Veterinarian)

Dementia in Dogs: Our Vet Explains the Signs, Causes & Treatment

Dementia in Dogs: Our Vet Explains the Signs, Causes & Treatment

It’s normal for dogs to show signs of aging—things like arthritis, loss of hearing, reduced energy levels, and greying of the hair are all fairly common. But w…

Dr. Joe Mallat
By Dr. Joe Mallat · 3 weeks ago
Canine Cognitive Dysfunction Syndrome: Symptoms & Treatment

Canine Cognitive Dysfunction Syndrome: Symptoms & Treatment

Canine Cognitive Dysfunction Syndrome (CDS) is estimated to affect 14% to 35% of all dogs, although it’s difficult to pinpoint the exact prevalence due to the…

Dr. Ernie Ward
By Dr. Ernie Ward · 1 week ago
Senior Dog Behavior Changes: Vet-Approved Care Guide

Senior Dog Behavior Changes: Vet-Approved Care Guide

It’s a beautiful thing to watch your dog grow up and move from puppyhood to adulthood and eventually become a senior dog. Throughout the years, you would’ve se…

Keri-Beth Clur
By Keri-Beth Clur · 3 weeks ago
Why Is My Senior Dog Barking at Night? 3 Vet-Verified Reasons

Why Is My Senior Dog Barking at Night? 3 Vet-Verified Reasons

Barking is perfectly normal for nearly any dog, but unexplained changes to their behavior can be rightfully concerning for owners. Shifts in mood and increased…

Nicole Cosgrove
By Nicole Cosgrove · 3 weeks ago

Liver Disease in Dogs: Our Vet Discusses Signs, Causes & Treatments

The liver is an impressive organ! Not only is it like the body’s oil filter, but it also has the ability to regenerate should it become injured or damaged. How…

Dr. Chyrle Bonk
By Dr. Chyrle Bonk · June 29, 2026
Liver Disease in Dogs: Our Vet Discusses Signs, Causes & Treatments

What Can Trigger a Seizure in a Dog? Our Vet Explains Signs, Causes & Treatment

Seizures can be scary to witness in people and pets alike. Changes in brain activity can trigger a seizure in a dog, though the reasons for those changes vary.…

Dr. Stacie Grannum
By Dr. Stacie Grannum · July 4, 2026
What Can Trigger a Seizure in a Dog? Our Vet Explains Signs, Causes & Treatment

Nuclear Sclerosis in Dogs: Our Vet Explains the Signs, Diagnosis & Treatment

As our pets age, one common ocular change seen in senior and geriatric dogs is a condition called nuclear sclerosis, or lenticular sclerosis. Nuclear sclerosis…

Dr. Marti Dudley
By Dr. Marti Dudley · June 17, 2026
Nuclear Sclerosis in Dogs: Our Vet Explains the Signs, Diagnosis & Treatment

Can Dogs Get Vestibular Disease More Than Once? Our Vet Explains Signs, Diagnosis & Treatment

Vestibular disease in dogs, also known as canine idiopathic vestibular syndrome or "old dog vestibular syndrome," is a relatively common condition that affects…

Dr. Emma Chandley BVM
By Dr. Emma Chandley BVM · June 29, 2026
Can Dogs Get Vestibular Disease More Than Once? Our Vet Explains Signs, Diagnosis & Treatment

Back Pain in Dogs: Our Vet Explains Signs, Causes & Treatment

You probably know that back pain is common in us two-legged humans. Many people don’t know, however, that back pain is also relatively common in their four-leg…

Dr. Joe Mallat
By Dr. Joe Mallat · June 17, 2026
Back Pain in Dogs: Our Vet Explains Signs, Causes & Treatment

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.

You may opt-out at any time. View our Privacy Policy for more information.

The Dogster app on a phone