A 30-pound feline thought to be Britain's fattest cat is entering a pet fitness competition in an attempt to lose weight, his owner said.

Jan Mitchell, 68, of Dorchester, England, said her Norwegian Forest cat, Ulric, is one of 21 overweight pets being put on a strict diet and exercise regimen for six months by a veterinary charity, the People's Dispensary for Sick Animals, the New York Daily News reported Friday.

"He just kept getting bigger and bigger and when he hit the two stones [28 pound] mark that's when the alarm bells started ringing," Mitchell said.

The PDSA said Ulric is the fattest cat ever to participate in their program.