The average weight of cats has ballooned by 25 per cent over the last 10 years and they are now four times more likely to become diabetic than 30 years ago.
More than 50 per cent of cats kept indoors are dangerously overweight compared with 25 per cent of those that go outdoors and cats have the same problems that are driving the enormous increase in human diabetes.
Cats get tasty, rich foods from us which thousands of years ago were not available but they are much the same genetically as they were when they hunted for their prey.
Thousands of years ago, in times of famine, those who were greedy and could store glucose survived the longest but now they get diabetes.
Burmese cats are particularly prone to diabetes but domestic short-haired and long-haired are high on the list and old cats are particularly prone.
Being overweight and diabetic causes multiple problems for cats.
The excessive weight puts a strain on their bodies, while the fat circulating in their blood inflames joints.
They have to be given insulin injections and have their diets strictly controlled and their glucose levels monitored.
Last month Battersea Dogs and Cats Home admitted the fattest cat in its history.
For example, Titan was 10kg – more than twice his healthy weight – when he arrived after his elderly owner died.
His excessive weight had left him struggling to walk and he was unable to climb steps.
Just by putting him on a sensible diet he lost 1kg in less than a month .
Daniel, a cat with diabetes reached a weight of 12kg – almost three times his healthy weight.
He had been fed two pouches of meat a day and as he was a lazy cat he really piled on the weight.
He originally went on to insulin but has now gone into remission which can often happen with cats on the correct diet.
People giving their cats too much or the wrong type of food as an expression of their love is in fact a form of cruelty.