Just call it Biggest Loser: Pet Edition. One Bay Area vet clinic is launching a weight-loss contest for your dog or cat, and it’s free!

Cornerstone Integrative Veterinary Hospital in Marin County was inspired to start this weight-loss challenge due to a startling trend in pet ownership: roughly 50 percent of our furry friends are now overweight, which is leading to a number of health issues.

“Most don’t realize their pets are overweight, they just think they are a bit chubby,” Cornerstone owner Dr. Kristina Hansson says. “But when explained all the problems associated with obesity, they tend to take it very seriously.”

To enter the contest, schedule a free consultation with the office in September, where they will assess your pet and do a weigh-in. All overweight cats and dogs are eligible and the winner will receive a one-year wellness plan valued at over $2,000.

Weigh-ins start October 1 and run through March, 2015. The dog or cat that drops the greatest percentage of body fat will win the grand prize.

The clinic says they have seen an enthusiastic response thus far from clients wanting to get their pet back into shape.

Pet obesity has become a nationwide epidemic, mainly due to lack of exercise and overfeeding. Most dogs aren’t getting at least 30 minutes of exercise a day and are taking in too many calories from kibble and treats.

“Eliminating table scraps and high-calorie treats is a must,” Dr. Hansson says. “For pet treats, try carrot slices, apple slices, unseasoned rice cakes, or plain popcorn with no salt or butter.”

If you don’t have time to take your dog for 30-minute walks or the resources to pay a dog walker, try games and training in the house.

“Playing fetch, teaching and running through commands, playing games like hide-and-seek, and even puzzle toys are good ways to keep your dog occupied,” Bay Area trainer Beverly Ulbrich says.

For cats, try stimulating games or toys they can chase around the room.

When it comes to kibble, make sure you are feeding a high-quality food.

“The brands we recommend are brands that do extensive scientific research and testing and have never had any food recalls,” Dr. Hansson says. “Many brands at pet food stores spend way more on advertising than product development or research and use lesser quality ingredients and fillers.”

Yellow Dog Blog chronicled the scary truth about commercial dog food and we suggested some things to look out for when choosing your kibble. If you have any other concerns about your pet’s food, it’s best to talk to your vet.

Also keep in mind the recommended serving sizes on kibble bags are crude estimates.

“The recommended amount on the back of food bags is always overestimated,” Dr. Hansson says. “They do this so you buy more food!”

If you aren’t sure how much kibble you should be feeding your dog, try this calculator which takes activity and your kibble’s nutritional content into account.

Remember to adjust your pet’s food intake based on their activity level. If they aren’t getting daily exercise, it’s unlikely they will need the amount of recommended food.

“Most people just feed their dog the same amount every day,” Ulbrich says. “If your dog goes on a long hike or plays an extra hour at the park, he needs more food that day. If he doesn’t get out or isn’t feeling well, then he’ll need less food than usual.”