Fat cat Bailey (6) from Dagenham, Essex, tips the scales at 8.8kg making him double the weight of a healthy cat.

The bulging black cat has a passion for food, food and more food and even out-muscles his canine companions – Ozzie and Ellie – when it comes to feeding time.

Janet Searle, Bailey’s owner, worries that he has an unhealthy obsession with food. In fact the mega moggie’s appetite has become so monstrous he’s even been known to make light work of a pig’s ear - a treat more often associated with dogs.

Janet said: “Bailey likes his food and I’ve seen him eat dog treats before. He dwarfs my one dog Ellie and I’ve even caught him tucking into a pig’s ear before. I’m not sure if he thinks he’s actually a dog because he will often join us on walks!”

Meanwhile, bulky Boxer Diesel, from Poole, has been big since a puppy, but his love of treats has led to the pounds piling on. He now weighs a staggering 58kg – making him around double his ideal weight.

Custard creams were a particular favourite, but his owner, Suzanne Fox (56) has now banned the sweet treat, as he can no longer squeeze through the dog flap.

Suzanne said: “Diesel used to chew the furniture when he was a puppy, so to help him grow out of this destructive habit, we started giving him a little treat. I have another Boxer, Tia, who is a healthy weight, so I was really shocked when I found out just how heavy Diesel was after talking to the PDSA vet. He loves going to the beach, so I hadn’t considered that his weight could cause him to have health problems in the future.”

Both pet owners are now following advice from PDSA vets and will be putting their pets forward to try and secure a place in the six-month slimming contest.