By Dr. Marty Becker for Vetstreet.com

I've always been an active person, so I admit I never felt I had to exercise. I didn't need a gym; we live on a ranch, and I happily tackle my chores, which has always given me both a mental and physical break from sitting in my home office.

While I'm outside breathing the fresh air, I haul out the Chuckit and help our dogs get moving too. An active mind in an active body is the ideal, for pets and people both.

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A few months ago, though, I decided that although I was doing OK, I knew I could feel even better. Fortunately for me, my wife, Teresa, is an expert on diet and exercise, and she has long practiced what she preaches. I took my wife's advice (and my doctor's) and joined her for workouts in our home gym. It was one of the best decisions I've ever made.

See, I thought I had my fitness under control, but I needed to take a fresh look at what I was doing and make some changes. The same is often true when it comes to your dog: No one form of exercise fits every dog, and even then, what worked at one time might need changing now and then.

Start With A Conversation With Your Veterinarian
No matter what age, size, shape, breed or mix of dog you have, you can't just push him into an exercise program until you know he is healthy. That has long been the advice for people wanting to improve their diet and physical condition, and it makes just as much sense for dogs. So see your veterinarian before you start adding new activities to your dog's day.

Once your veterinarian gives you the go-ahead, look at your dog. For some dogs, the true multi-sport athletes in fur, almost any kind of exercise is great and more of it is even better. With other dogs, however, you have be careful: Some kinds of exercise are just not suitable for certain types of dogs. Two kinds of dogs in particular are likely to be intolerant of some kinds of exercise: Dogs with short faces, and dogs with short legs and long backs.

Exaggerated Features Need Special Care
Dogs with short noses such as Pekingese and Bulldogs are often exercise-intolerant. Because they have been bred for an appearance that's adorable but not efficient for breathing, they can overheat and even die very easily when exerting themselves, especially when it's warmer. Swimming might seem to be a good exercise for keeping these dogs cool, except that they typically don't swim well, either -- and in fact some Bulldogs can't swim at all; they just sink.

For these brachycephalic dogs, walking at a slow pace when it's cool is the best exercise, working up to increased distance very gradually. If you want to try some indoor exercise in the air-conditioning, a canine treadmill isn't a bad idea. My daughter, Vetstreet dog trainer Mikkel Becker, has trained her Pug Willy to use one. He does great!

The other dogs who need special consideration are those with long backs and short legs, such as Welsh Corgis and Dachshunds. These dogs are, not surprisingly, prone to back injuries, which means activities that demand leaping and twisting movements (such as chasing a flying disk) are not a good idea. These are active dogs, however, so if you come up with activities that keep all four on the floor, you'll be making your dog happy -- and keeping him healthy.

A Dog With A Name To Match An Activity
While some dogs have activities that need to be ruled out for safety's sake, when it comes to retrievers, fetching and swimming seem to beg to be ruled in. Retrievers are water dogs, and although not all of them like to swim, the ones who don't are likely the minority. And not many breeds share their names with an activity, either, which tells you that retrieving simply has to be in the playbook for these dogs. One of our dogs, our Golden Retriever Shakira, is so crazy about retrieving a tennis ball that she still plays fetch even though she can't see. And I'm happy to oblige her.

Thinking about what your dog's breed or mix of breeds were developed for is likewise key to choosing the perfect activity for other kinds of dogs. Those developed to work all day in constant motion such as herding dogs, sled dogs and gun dogs are likely to be perfect running companions, or would do well (once trained not to pull) in accompanying you on bike rides. Dogs who were developed for short bursts of speed such as Whippets and Greyhounds would prefer a shorter, faster, more intense workout, followed by a long nap. Dogs with strong neck and chest muscles such as American Pit Bull Terriers and similar breeds enjoy the challenge of weight-pulling, and it's a huge improvement over squaring off against another dog in what is now a thankfully illegal activity.

When you consider what a dog was developed for, you'll look beyond size to guide you. Consider the Pug and Jack Russell Terrier, who are roughly the same size. While the Pug was developed mostly to be a companion, a JRT was meant to spend every waking minute as an in-home pest-control service. Today, that means while light, regular exercise will suit your Pug, no amount of exercise would be enough for your Jack Russell.

Need more ideas? Check out our breed profiles. And if your dog has been a couch potato, don't worry: Even old(er) dogs can learn new tricks and feel better for it. I'm living proof of that!

For more on pet health, click here.

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