WE are supposed to be a nation of animal lovers.

Yet it seems we may be doing our furry friends an injustice. By feeding them too many titbits and treats we are effectively turning them into portly pets.

It is hard to comprehend some owners are feeding their four-legged friends takeaway leftovers and even booze but according to the veterinary charity, the PDSA, this combination, along with snacks and scraps is fuelling an obesity crisis among our pets.

New data reveals 5.5 million cats, dogs and rabbits in the UK are being fed treats every day and now the charity's vets are warning owners they could be drastically shortening their pet's life expectancy.

Owners have admitted to indulging their pets by giving them fatty, sugary and, in some cases, dangerous foods. These include cake, chocolate, biscuits, crisps, chips, takeaway and even alcohol.

According to the charity a third of dogs and a quarter of cats are now classed as overweight or obese and vet professionals predict the problem will increase with 80 per cent believing there will be more overweight pets than healthy ones by 2019.

To help portly pets fight the flab the PDSA has launched its annual Pet Fit Club competition and is inviting owners of overweight and obese pets to participate in the pet slimming competition.

Kirsty Warren, veterinary clinical team leader and pet well-being rep at the PDSA's PetAid Hospital, The Jeanne Marchig Centre in Bradford, says she has seen pet obesity steadily increasing mainly in the last four or five years. "I think a lot of it is people just not reading the packets of food properly, with a lot of dry foods it is easy to over-feed."

Pet treat calculators, produced as part of the Pet Fit Club competition, are aimed at raising awareness. For example, feeding a can of tuna to a cat is the equivalent of a human eating 35 chicken nuggets and a packet of crisps to a dog is the equivalent of two steak pies.

Obesity can impact significantly on a pet's health. "We have seen a lot of obesity related problems and one of the biggest is arthritis," says Kirsty.

"With older pets it is a real concern and if we can tackle it when they are younger it will make such a difference to animal wellbeing."

Over the past 11 years, PDSA Pet Fit Club has helped transform the lives of some of the UK’s most obese pets. The competition has helped more than 100 animals lose more than 63 stone and encouraged thousands more owners to make positive changes to their pet's lifestyle.

Vicky Wood mistakenly believed Lucy, the cat she adopted six months ago, was pregnant and had fed her double portions leading her to put on weight.

Tipping the scales at 18.5lbs (8.4kg) Lucy, from Low Moor, was almost 70 per cent more than she should be,

“Because I was told she was pregnant I kept her indoors and gave her extra food," says Vicky.

“However, when the time came for her to give birth nothing happened.

“I took her to the vets and they said she wasn’t pregnant. The PDSA advised me to put Lucy on a diet.”

Lucy's case was highlighted as part of the study revealing an obesity crisis among pets in Yorkshire and the Humber.

Natasha Sangherra, a veterinary surgeon at White Cross Vets, Guiseley, says they are noticing an increase in overweight pets.

She explains some of their owners are now feeding their dogs special dietary foods with reduced calories. They also run free weight loss programmes.

However, when it comes to cats, curbing treat feeding can be difficult for owners whose feline friends are popping into other people's homes, but Natasha suggests owners can invest in collar tags stipulating the cat is on a special veterinary diet.

Lack of exercise can also impact on pets becoming too portly. "It depends how much people can get their pet out on walks so exercise may be a big part of it. If people have a busy work lifestyle pets will go out for fewer walks," says Natasha.

Her advice to owners is to be sensible when feeding your pet; cut out human food which tends to contain more calories and cut down on the number of treats.

The PDSA's Pet Fit Club is a six-month diet and exercise programme tailored and overseen by expert PDSA vets and nurses. Entry forms are available from PDSA Pet Hospitals and the deadline for entries is Sunday March 6. For more information visit pdsa.org.uk