4 Behavior Changes in Senior Dogs: Common Signs and How to Help

When it comes to aging, every dog follows their own timeline — larger breeds reach their senior years sooner than smaller ones. Still, all senior dogs experience physical and cognitive changes as the years add up—just like us.  

As dogs age, their organs, joints, and muscles become less efficient, making them less eager for a game of fetch or roughhousing. 

Their metabolism slows, too, which may mean having to switch your dog to a senior diet, to help prevent weight gain and support their joints. These changes are all part of growing older, and they often bring a gentler pace that’s good for lingering cuddles and unhurried walks. 

However, not all new behaviors are signs of normal aging. Canine cognitive decline (CCD) affects an estimated 14 to 35% of senior dogs and can cause confusion, changes in sleep, increased anxiety, or even sudden aggression in senior dogs.  

Pain, illness, and medication side effects can also cause changes in behavior. 

Keep an eye out for anything that feels “off” with your dog, because even small changes are worth checking out with your vet. 

Senior pups tend to take more daytime naps, topping out around a whopping 16 to 18 hours of sleep a day. More sleep is normal, as senior pups get tuckered out easily and have less energy overall, but it’s still important to encourage gentle play and mental stimulation. Boredom can also cause dogs to oversleep. Gentle play and mental stimulation can be achieved through the use of plush toys, a KONG filled with peanut butter, or a doggy puzzle game. 

And speaking of oversleeping, if your dog suddenly starts sleeping more than 18 hours a day, seems unusually tired, or doesn’t have enough energy to enjoy their favorite activities, schedule a checkup with your veterinarian.  

On the other hand, some senior dogs suddenly start sleeping less at night, which is one of the most common reasons pet parents of senior dogs see Dr. Lena Provoost, DVM, DACVB, a veterinary behaviorist and University of Pennsylvania School of Veterinary Medicine assistant professor of small animal behavior.  

“This can manifest as pacing, panting, and overall restlessness with intensities that can range from mild to severe—think panic attack,” she explains. While it’s a frequent complaint, Dr. Provoost stresses that it’s not a normal part of the aging process. She quickly gets to work uncovering the root cause, starting with a complete checkup and, in many cases, prescribing pain medication. 

Just like with people, a dog’s physical and functional aspects of the brain change as we age. In dogs, areas of the brain responsible for memory and problem-solving gradually shrink, which can make learning new tricks a little harder or cause them to respond more slowly to cues they’ve known for years. 

In dogs with CCD, memory loss is more pronounced and can occur rapidly. “What owners tend to notice is disorientation, such as their pet walking into a room or going outside and just standing there as if they have forgotten what they intended to do,” Dr. Provoost says.  

Has your senior pup started losing patience with a new puppy, or do they seem less interested in hanging out with guests? “It’s not unusual, but it still deserves attention,” says Dion Studinski, head trainer and founder of Ancillary K9 Dog Training. “Senior dogs may become less tolerant of puppies or chaos simply due to fatigue, pain, or sensory decline.”   

A bigger red flag is a sudden increase in aggression. “A dog with a stiff body posture, direct stare, and a high, rigid wagging tail is likely one who is ready to lunge forward and react with aggression,” says Dr. Meghan Herron, DVM, DACVB, a veterinary behaviorist and senior director of behavior, research, education, and outreach at Gigi’s, an Ohio-based dog shelter. While aggression can be a normal way for a dog to ask for space, in senior dogs it can also signal pain or CCD. 

If you thought the days of house-soiling by your pet were long gone after puppyhood, it can be worrisome—and a little frustrating—when your house-trained senior pup starts peeing in the house. Don’t ​​just chalk it up to normal aging, Dr. Herron says.  

These accidents can stem from memory issues, medical conditions that affect bladder control, or joint pain that makes going outdoors uncomfortable. Whatever the cause, your veterinarian can help figure out what’s going on and recommend ways to make doing their business more comfortable for your dog.  

Your vet may recommend dog diapers, such as CuteBone’s  Reusable Female Dog Diapers, or the use of pee pads to help make cleanup easier.  

The best thing you can do for your dog’s cognitive and physical health is keep them active. “What we don’t use, we lose,” Dr. Provoost says. Gentle walks, short play sessions, and swimming are fantastic low-impact ways to stay active with your senior dog. Engaging their noses with scent games or puzzle toys is another great way to challenge them not just physically, but mentally.  

Keep in mind that this list of common behavioral changes in senior dogs isn’t comprehensive because every dog ages differently, and CCD is known to cause unpredictable behavior.  

Changes in your dog’s behavior might look like clinginess or increased vocalizations, while a friend’s senior dog might become more withdrawn or irritable. You know what’s normal for your dog, so trust your gut. ​​At the first sign of a behavior change, schedule a visit with your veterinarian. 

During the appointment, they may perform a wellness exam, blood tests, urinalysis, or other diagnostic tests to rule out medical issues such as pain, thyroid problems, or urinary tract infections.  

Once the underlying cause is identified your vet can recommend solutions, which may include medications, supplements, therapeutic diets, or small adjustments at home that can make senior dogs more comfortable.  

What are the behavioral changes in elderly dogs? 

As dogs age, certain changes are a normal part of the aging process. Senior dogs may sleep up to 18 hours a day, tire more easily, or not have interest in physically demanding activities. However, rapid or severe behavior changes, such as house-soiling, disorientation, nighttime restlessness, or increased anxiety or aggression should be taken seriously and be checked out by your veterinarian. 

What is sundowning in senior dogs?

Sundowning in dogs is often used to describe canine cognitive dysfunction (CCD), sometimes called “doggie dementia,” which is similar to Alzheimer’s in humans. Specifically, sundowning refers to increased restlessness or confusion some senior dogs experience in the evenings or overnight.  

Why is my senior dog becoming aggressive? 

Aggression is a normal way for dogs to communicate, but sudden aggression or aggression in situations where your dog was previously calm calls for a chat with your veterinarian. Aggression in senior dogs isn’t just “grumpiness” or a normal part of aging. Rather, sudden aggression often signals an underlying issue, such as pain, CCD, illness, stress, or a side effect from a medication.