Liz Neporent is a diet and fitness expert and author of 12 fitness bestsellers. She regularly appears on national TV programs and is the president of Wellness 360, a New-York based wellness provider.

The majority of Americans are now considered overweight or obese. Did you know this has also had an effect on our furry friends? Considering that the average house dog is now basically a glorified throw rug with a pulse, it's not surprising that more than 50 percent of the 60 million dogs in the U.S. are considered overweight, and 25 percent of them are considered obese.

Our little Snuffle Pumpkins are overweight for the same reasons we are: Too much food and too much time spent curled up on the couch. They're susceptible to many of the same obesity-related diseases as we are too. Fat dogs are more at risk in surgery, more prone to injury and have more stress on their hearts, lungs, livers, kidneys and joints than their slimmer pack mates. A study done at the University of Pennsylvania found that overfed Labradors had a shortened lifespan of 1.8 years and developed chronic conditions such as osteoarthritis at a younger age than normal-weight Labradors.

Photo: foxypa4/Flickr4

Once a dog is over 15 percent of his ideal weight, he's considered clinically obese. (Same for you, more or less, by the way.) Veterinarians use a 9-point rating system to evaluate a dog's weight with a score of one given to a dog that is extremely thin and a score of nine given to a dog that's a real porker. Ideally, your dog should fall right in the middle with a score of five.

Tell "tail" signs your dog should seriously consider Puppy Chow Lite: Excess fat covering his ribs, hipbones and shoulders; rolls of fat under his neck and the base of his tail; no distinguishable waistline. (Keep in mind that some dog breeds have a genetic tendency towards overly thick waistlines. These include Labrador Retrievers, Beagles, Basset Hounds, Dachshunds, Cocker Spaniels and Shetland Sheepdogs.) For a complete overview of the 9-point weight scale, visit exercisemydog.com.

If you think your dog is overweight, consult your veterinarian to rule out any underlying medical problems before starting the animal on a weight reduction program. And here's an idea -- why not battle the bulge together? Dogs make excellent workout partners. They rarely refuse a chance to take a stroll outside, they prefer to never miss a workout, and they're always overjoyed for the chance at a more active lifestyle.

Start with 20-minute walks nearly every day of the week (factor in five minutes worth of sniffing and leg lifting) and increase by five minutes a session per week until both of you can walk for an hour without too much effort. On the weekends, add a game of catch, fetch or chase. The explosive, high intensity nature of these activities will help both of you build muscle and power. For a quicker result, cut human and canine food portions back by about 5 percent or so per meal and ease up on the doggy and human treats. You should aim for a 1- to 2-pound weight loss per week, and limit his weight loss to no more than 4 percent per week to prevent problems associated with overly rapid loss of weight. If you grab the other end of the leash and start right now, you and your pooch will be noticeably leaner and lighter by Labor Day (or as Dog's like to call it, Labrador Day).

It's time for you to share your stories, concerns and questions about how to shape up with your pup. Oh, and you can now follow me on Twitter, @lizzyfit.