Mrs Beech is the director of not-for-profit Just Cats Tasmania and she said she sees the effects of not desexing cats on a daily basis.

Her Evandale-based shelter is home to 57 abandoned, orphaned or feral cats, with a further 52 cats and kittens with foster carers - a number she says is scarily high.

``This week has been my worst week of having to say `we're full' . . . . I probably get 10 or 11 phone calls a day of people wanting to surrender cats. We're just full,'' Mrs Beech said.

This week, Mrs Beech has her hands full bottle-feeding three kittens that came to her with ``cat flu''.

She said cat flu cases were on the rise for two reasons: people not vaccinating their cats and not desexing their cats, therefore enlarging the feral cat population.

``I'm hoping that these guys find homes but they will carry the virus forever, for the rest of their lives,'' Mrs Beech said.

Her message: desex your cat.

Mrs Beech said in one year, a non-desexed female cat could produce 30 kittens.

The end of the current kitten season is nigh, and Mrs Beech said between now and June was the optimum time for people to desex their cats before the next breeding season started.

 Just Cats Tasmania is  grateful for donations, volunteers and foster carers. To find out more visit www.justcats.org.au or visit it at the Evandale Cat Show on Sunday at the Evandale Memorial Hall.