The East Lincolnshire branch of the RSPCA is calling for the public to bring the cat population under control through neutering.
The branch is struggling for space, with too many cats in its care.
A spokesman for the branch said: “This year, we have already rehomed over 150 cats and kittens and have 30 more in care at this time.”
“It makes us very sad that, in 2016, people still don’t understand how vital neutering their cat is.”
Becky Harper, a Lincolnshire inspector said: “Sadly, 2016 has been a massive step backwards with regard to cat numbers, especially in the Boston area, and all local charities and vets are struggling to cope.”
Pet owners are being encouraged to neuter their cats in order to try to control the growing population across Lincolnshire.
Cats Protection Sleaford and District is experiencing similar problems, with too many cats and kittens currently in its care.
A spokesman said: “At the Sleaford branch alone, we have already rehomed 280 cats and kittens this year and, despite it being autumn, the problem is not slowing down.
“We have cat neutering schemes running all over the country and would urge people to neuter rather than add to the cat crisis.”