When Is a Dog Considered a Senior? What To Know About Senior Dog Age

Veterinarians often define the senior dog age range to be the last 25% of a dog’s expected lifespan. In other words, if a dog is expected to live to be around 12 years old, they become a senior when they are around 9 years old. These numbers are primarily based on the dog’s size. 

Studies consistently show that smaller dogs live significantly longer than bigger dogs. Why this happens isn’t fully understood, but the pattern is well-established.  

This table outlines when dogs of different sizes are typically classified as seniors. 

Your veterinarian can fine–tune these numbers based on your dog’s breed (some breeds are known to have shorter or longer life expectancies than dogs of similar sizes) and their overall health. 

Certain physical and behavioral changes can show where a dog stands in their aging process, as each pup ages at a different rate and in unique ways. Here are some signs that your dog is approaching their senior years. 

One of the most obvious signs to look for is graying fur. This typically starts around the muzzle before spreading to other parts of the body.  

While some dogs start going gray when they are relatively young, most develop more widespread gray hair during their senior years. This change is completely normal and purely cosmetic. 

Older dogs frequently develop lenticular sclerosis, a normal age-related change that creates a bluish, transparent haze to the lenses of their eyes. But this condition, unlike cataracts, doesn’t significantly impact vision.  

Age-related hearing loss is another common finding in senior dogs. You may notice that your dog seems harder to wake from sleep or appears startled when approached from behind.  

Talk to your veterinarian if you notice changes to your dog’s ability to see or hear. 

Subtle mobility changes are often the first sign you’ll notice as your dog gets older. Pay close attention to how your dog rises from lying positions, navigates stairs, and exercises.  

Arthritis is one of the most common conditions affecting senior dogs, especially large breeds. The good news is many treatment options are available, from anti-inflammatory medications to joint supplements to physical therapy, so schedule a checkup with your veterinarian if your dog appears to be slowing down. 

It’s normal for a dog’s physique to go through changes as they get older. For example, they may experience mild muscle loss if they’re not very active.  

That said, large or abrupt changes should always be evaluated by a veterinarian, as they can be associated with disease. 

Dental wear, tooth loss, and periodontal disease are very common in senior dogs. Regular cleanings and at-home dental care, like brushing your dog’s teeth, become increasingly important as dogs age.  

Schedule an appointment with your veterinarian if your dog has bad breath, red or bleeding gums, loose or missing teeth, or appears to be in pain while eating or being touched around the mouth. 

As senior dogs age, they’re at risk for canine cognitive dysfunction, a condition that is very similar to Alzheimer’s disease in people. Symptoms can include: 

• Wandering aimlessly, especially at night  
• Getting stuck in corners or lost in the house  
• Barking or howling, seemingly at nothing  
• Increased anxiety and panting 
• Forgetting where food and water bowls are  
• Pooping or peeing inside the house 
• Forgetting tricks or training 

As senior dogs age, their needs change. Aging brings metabolic changes and an increased risk for serious diseases. Here’s how to stay on top of your dog’s care. 

Senior dogs need to be seen by a veterinarian at least twice a year—a change from their previous annual visits. More frequent checkups make early detection and treatment of age-related conditions more likely.  

During these visits, your veterinarian will perform a comprehensive physical examination, talk to you about any changes you’re noticing at home, and recommend additional diagnostic tests like blood work or X-rays, if needed. 

While the Association of American Feed Control Officials (AAFCO) hasn’t established specific senior dog nutritional standards, AAFCO adult-compliant senior dog foods that are enriched with antioxidants, omega-3 fatty acids, fiber, and joint protectants are often a good choice.  

Dietary needs can vary significantly from dog to dog, so always talk to your veterinarian about what food is right for your senior pup. 

Senior dogs still need to exercise, but you will probably need to make adjustments to your workout plan as your dog gets older.  

At some point, going for a run or roughhousing at the dog park will stop being fun for most dogs, but an unhurried walk through the neighborhood still provides many of the same benefits. 

Even if your senior dog can no longer join you on all your adventures, it’s still important to include them in as much daily life as possible.

Older dogs need mental stimulation and social interactions just like younger dogs. Enrichment toys, meetups with other older dogs, and simply spending time together are great ways to keep your dog engaged. 

Recognizing how dogs age and when a dog is considered a senior allows for proactive care that helps keep them healthy and happy through their golden years.