07/10/2015 3:59 PM AEDT | Updated 15/07/2016 12:50 PM AEST

Fat Pets Are A Result Of Human Behaviour -- Yes, That Means You

Reggie Casagrande via Getty Images
Two Pug dogs sitting against animal print background

Do you have a fat cat? A tubby puppy? A heavy hamster? Chances are you might need to consider putting your pet on a diet.

Though some pets can look cute carrying those extra kg's, it's probably not good for their health (or yours).

October 7 is National Pet Obesity Day in the US (Australia is yet to have a similar official day) and Queensland veterinarian and dog weight loss coach Dr Charlotte Williamson is using the occasion to urge pet owners to take a long, hard look at their animal companions and ask the tough question -- does their butt look big in that?

"Obesity in pets -- and particularly in dogs -- is a growing issue in Australia," Williamson told The Huffington Post Australia.

"Basically, it's to do with lifestyle changes and the way people view their pets now. Over the past couple of decades, dogs have gone from being in the yard and in the kennel, to having dogs in the home and part of the family unit."

"It means there is an increased opportunity for food interaction. While you're preparing a meal, the dog is there. While you're eating dinner, the dog is there. Whatever the kids drop on the floor, the dog is there to lick it up.

"There is just so much more opportunity for dogs to get extra calories. We also tend to associate love with giving their dogs treats and extra food."

Other factors contributing to the kibble mix include the fact many of us are time poor and find it hard to fit in walking or pet exercise time, as well as the trend of downsizing yards due to an increase in apartment living.

"None of that helps, of course, but when it comes to weight gain and dogs, it is really 90 percent through eating."

Williamson's rescue dog Maxo before and after his doggie diet.

After seeing more and more overweight pooches waddle through her practice door -- as well as adopting an overweight rescue dog, Maxo -- Williamson decided to do something about it, and created an online dog weight loss program called the K9 Weight Challenge.

"I guess I’ve always had a passion for helping dogs lose weight, and when you see the difference, it's incredible," Williamson said.

"It enhances quality of life by so much. While you think you are being kind to your dog by giving him extra treats, obesity in dogs actually causes really nasty health affects such as arthritis, tumours and diabetes.

"Overweight dogs suffer-- they overheat, they are lethargic, they lack energy. They get ache and pains and pant and snore heaps as well as experience disturbed sleep patterns.

"It's not just about putting your dog on a diet -- it's about changing your owner mindset and learning to manage that owner/dog bond.

"It's a strong bond but often that love can be doing untold harm, unintentionally. People want to help their dogs -- but instead of providing love and food, give them time and attention, and use treats responsibly."

If you think your pet is overweight, consult your local veterinarian for advice.