Greater Shepparton residents are being urged to desex their cats, with breeding season running from spring through to autumn — and longer if temperatures stay warm.
Cats can start breeding from as young as 16 weeks old and have very little difficulty conceiving and giving birth.
This means nearly every undesexed female cat who is exposed to an undesexed male during the warmer months will become pregnant.
Goulburn Valley Pet Adoption and Rehoming founder Tilliah Brooks said Greater Shepparton had a "massive" kitten and cat overpopulation problem.
"If you’re thinking about getting your cat or kitten desexed, now is a great time to do so,” she said.
In addition to preventing unwanted litters, Ms Brooks said desexing could have many health benefits.
"Desexing reduces the likelihood your cats or dogs will get certain types of cancer, uterus and mammary infections,” she said.
"Desexing can also reduce aggression, wandering and urinary marking."
Ms Brooks said her rescue service had adopted out more cats than dogs.
"We’ve found in our local area that more people are needing to rehome kittens from unwanted litters, or adult cats, than puppies and dogs,” she said."We’re very lucky to have been able to find amazing homes for all of our fur babies we’ve had in foster care.”
According to RSPCA, cats and kittens are adopted at a much slower rate than dogs, and are six times less likely to be reclaimed than dogs.
Shepparton Animal Rescue and Rehoming adopts out up to 300 cats and kittens each year.
"With our amazing network of foster carers we can take in more and rehome more,” a spokesperson said.
“Before they leave the rescue, all cats and kittens are desexed, vaccinated and microchipped.
“They stay in care for as long as needed until they find their forever homes.”
The local organisation said desexing cats was a "must".
"Young cats who have litters often don’t know what to do and abandon their young,” the spokesperson said.
"This is where rescues, shelters and pounds get lumped with kittens.”