SPAY FEMALE CATS IN LATE FALL TO PREVENT SPRING (AND SUMMER) LITTERS

FORT COLLINS - If you have a female cat born this year, you may be surprised by her litter of kittens as early as February.
"Cats are seasonally polyestrus," said Dr. Lynne Kesel, associate professor of clinical sciences at Colorado State University's Veterinary Teaching Hospital. "That means there's a certain season of the year when they come into heat, and that's usually sometime in December. The majority stop coming into heat in May or June."

Probably 90 percent of domesticated cats demonstrate polyestrous behavior, said Kesel, who oversees the Veterinary Teaching Hospital's spaying and neutering program. A cat born as late as August could mate in December and give birth in February (cats gestate for 64 days).

Polyestrous behavior has been observed in big cats in the wild.

"We don't do a lot of selective breeding on cats the way we do with dogs," Kesel said. "Essentially, most cats are still mutts and close to the wild." Spring births have survival value, she notes, ensuring that kittens are born when their prey (mice, birds, etc.) are providing a good supply of food for the nursing mother and eventually for the young cats.

It's always a good idea to have dogs and cats spayed or neutered, Kesel said, but it's easy to overlook those female kittens born late in summer. Don't, she warned. Pounds and shelters are full of overlooked animals, most of them destined for destruction.