Just because your dog isn't a puppy anymore doesn't mean they should stop learning. In fact, you should never stop training your dog, "especially as they get older as it can help work out their mind as well as their bodies," Russell Hartstein, CDBC, CPDT-KA, founder of Fun Paw Care, tells Bustle. "As a dog ages, it might not be possible to work out their bodies as much as they used to, [but] dog training will keep your senior dog fulfilled and sharp throughout their lives."

While puppies are energetic and need calories to burn, that's just not the case for older dogs who won't be exercising as much, Harstein says. So have a chat with your vet about the right amount of food to give your dog, based on their age and weight.

The right amount of calories will also help prevent them from getting overweight, which is a major issues for older dogs, Harstein says. Not only does extra weight put strain on their joints, but it can also lead other age-related health issues.

Dogs of any age need lots of company, but hanging out with yours — just like you always have — will also help you spot health issues as they arise.

"If you can notice when your dog is just a bit slower during a hike, you’ve got a better chance of helping her feel better than if you waited until she was full-on limping," Kayla Fratt, certified dog behavior consultant at Journey Dog Training, tells Bustle.

By pointing these issues out to your vet, you can start figuring out ways to make your dog feel more comfortable.

Joint health is super important for older dogs, so you might want to consider giving them a few supplements like turmeric or milk thistle, which "helps to support even young dogs, and keep them healthy in their senior years," Reel says. Ask your vet about which ones might be best.

"Keeping active is also important," Reel says. "As dogs age and slow down, they tend to lose muscle mass. This can have a detrimental effect on their joints and cause difficulty with mobility. If your senior pet seems to have trouble with exercise, try a low impact activity like swimming to help build and maintain muscle mass."

It might be necessary to switch up your dog's food as they get older, especially since their teeth may not be able to chew through their usual hard grain, pet expert Kelly Meister-Yetter, tells Bustle. That, and their digestive tract may not be able to handle their usual foods. If you're not sure what to give them, ask a vet for advice.

"As dogs get older, they aren’t able to cope with stressful things as well as they could when they were younger," Dr. Todd says, which is why you'll want to do whatever you can to keep their stress to a minimum.

This can include changing up how you train them in favor of a more low-key version, Dr. Todd says, to taking care of them during nerve-racking times.

"For example, if they are afraid of fireworks, they may find them harder to cope with than when they were younger," she says, "and this is something you could speak to your vet about."

Even if your dog knows every trick in the book, teach them something new to help keep their brain sharp. "It’s important to keep your dog’s brain active as they get older," Dr. Todd says. "Of course, senior pets don’t usually need to learn obedience, but teaching tricks can be great fun for you and the dog. There are some great tricks videos on the internet. Use small pieces of food that your dog really likes as a reward, and count it as part of their daily calorie allowance."

Another way to keep your dog's brain active is through "enrichment" activities, like ones that involve their sense of smell.

"Snuffle mats allow you to hide treats for your dog to find with their nose, or you could simply scatter treats in the grass for them to find," Dr. Todd says. "Or take them on [...] a smell-walk in which they get to follow their nose wherever they like (within reason)."

You might expect your dog to change a bit as they get older. But that doesn't mean all changes are normal.

"If you see changes in your dog’s behavior, don’t just assume it is because of old age," Dr. Todd says. "For example, if your dog suddenly does not like to be touched, is not keen to jump into your car, is having accidents in the house, or is suddenly afraid of loud noises when they weren’t before, it’s time to schedule a visit with your vet."

There are a number of things that could be going on, including underlying medical issues that need to be treated.

If your dog is getting up there in years, make sure they can still reach their food and water bowl, without having to walk too far or strain.

"Multiple water bowls around the house will help your pet make shorter trips to get a drink," Dr. Dani McVety, co-founder of Lap of Love, tells Bustle. "Dehydration is very common and dangerous in older pets. Easy access to water is essential."

Older dogs tend to have a tough time walking on wood and tile floors, which is why you may want to lay down a few rugs. "Use rug runners, bath mats, or yoga mats to give them a nice ‘runway’ to walk on," Dr. McVety says. "Use something that is easy to move (but doesn't slide) and easy to clean."

There are so many things you can do to make sure your older dog is having a good time. By giving them nutritious food, keeping their mind active, and adjusting their surroundings, they can be happy, healthy, and comfortable for years to come.