The cat, who has been named Sergeant Harry Tubbs – or Harry for short – weighs a whopping 9.9kg, which is twice the weight of an average cat.
He was signed over into the RSPCA’s care after his previous owner could no longer care for him.
Harry is now with the RSPCA’s South Bedfordshire branch, where he is patiently waiting for someone to adopt him.
Alison Sutton, branch manager, said: “We were told by a vet that he is 80% overweight as a result of being overfed. He’s on a diet now but he will have quite a way to go before he is at his ideal weight, although we have every faith that he will reach his target!
“Harry must be the biggest cat we have ever had in. It is difficult getting him to exercise but in time he will start to have more energy and be able to move easier.
“He is a very sweet cat, he is so lovely and affectionate and he’ll make such a lovely pet for someone. We’re sure he will find his perfect home soon, with owners who will be committed to keeping him on track with his diet.”
Anyone who is interested in rehoming Harry can contact the branch by calling 07510 390872 or by visiting rspca-online
Being overweight can lead to serious health problems for pets, including joint problems, high blood pressure, diabetes and problems with the liver, skin and heat tolerance.
Top tips for keeping your pet at a healthy weight
If you think your pet might be overweight always consult your vet in the first instance.
As a guide – you should be able to see and feel the outline of your pet’s ribs without excess fat covering.
You should be able to see and feel your pet’s waist and it should be clearly visible when viewed from above.
Your pet’s belly should be tucked up when viewed from the side.
Get your pet weighed at the vets regularly if you are concerned.
If your pet is used to treats, give them as part of their daily ration of low-calorie foods. It is advisable to agree to a daily ration of food, weigh it out at the beginning of the day and stick to it.
If you want to give your pet treats, for example, if you are training them, you should incorporate this into their daily food allowance and reduce accordingly.
You could use playful interaction with your pet or a special toy as a reward instead.
Always make sure your pet is getting plenty of exercise.