The RSPCA in Stoke-on-Trent and Staffordshire says it is struggling to cope with the number of cats that are being abandoned.
In the latest incident, six kittens were found dumped in Whiston, near Alton, Inspector Julie Lyons said.
She said the animals had been found under bushes, in shoe boxes and even in a suitcase.
The charity's cattery in north Staffordshire which can house 30 cats, has been full since April.
"I just dread going to cat call now because there is just no where to put them," she said.
She added she had been relying on support and help from other charities in neighbouring areas.
"Every cat charity is struggling, services are stretched everywhere," she added.
"I just think it is down to people being irresponsible and not thinking about what is involved.
"There's the financial climate of course but I think that's more of an excuse than a reason."