Keeping dogs fit is actually easier than keeping yourself fit, because the person feeding the dog isn’t the one feeling the dog’s cravings for something yummy and fattening. Figure out how much food, and what kind, you should be feeding your dog — if you’re not sure (I wouldn’t trust the “help” you get from dog food manufacturers) ask your vet for advice. Then feed your dog that food, and that much, every day.
Exercise is important for dogs, and no only for health reasons. If your dog tears up your house, it’s probably because he’s bored and has extra energy and no way to burn it. Take your dog for a walk every day. (It’ll help you get your own daily exercise in too.) An active dog might actually need a bit more food, once she works up to a significant amount of exercise per day.
If you’re not up to as much exercise as your dog needs, throwing a ball or other toy can get your dog running while you stay mainly in one place. Teaching your dog tricks, like jumping through a hoop, will also give the dog more exercise than you.
Getting your dog into a doggy sport can be fun for both of you and give your dog a great way to exercise. Flyball is a great team sport that gets your dog running, jumping and fetching balls. Lure coursing will get your dog running if she has a strong instinct to chase prey. Agility training will get your dog (and you) moving while also training communication and teamwork and some puzzle solving. Frisbee dog sports, whether for fun or in competition, is a great activity you can do with your dog, that’ll get your dog burning a lot of calories.
If your dog is too fat to walk much, and you have some money to spend, check around your area and see if there’s a doggy gym nearby. (Ask your vet; they should know.) Some places have small infinity pools where they can get your dog swimming in a flotation jacket. This lets the dog exercise without putting a lot of strain on her joints, so she can work up to being able to go for walks, or even runs eventually. I’ll admit this isn’t available to most folks, for lack of facilities or lack of money, but if you can afford it and there’s one near you, and your dog is seriously overweight and largely disabled because of it, it’s an option.
If you need to give your dog treats while training, use lower calorie treats that your dog will see as high value. Break dog cookies in half if they’re bigger than a small bite size. A small piece of white meat chicken has fewer calories than most dog cookies, and your dog will probably prefer it. Heat it up in the microwave just until it’s warm, and it’ll smell even better, which makes it even more attractive to your dog. Most dogs prefer chicken over regular (for people) cookies or bits of cake, which too many dog owners give their pets regularly. If you feel you have to give your dog people food, don’t give them sugary food.
Bottom line, your dog can only eat what you (or another human — get your family and friends in line!) give him. You should be able to control your dog’s diet completely, and if your dog is fat, you need to do so, and do it carefully. You can also control how much exercise your dog gets. If you have a family, get them involved in taking the dog for walks, throwing balls or frisbees or sticks, etc. You can get your dog slimmer and healthy; it’s a matter of making a plan and sticking with it, and ignoring the begging puppy eyes when they want something they shouldn’t have.