Kitten season? Sounds magical but it’s totally a thing

Winter, spring, summer, and kitten? Yes, “kitten” is a season! But what does that mean? Kitten season refers to the fact that it seems like more kittens are born during the warmer months of the year. While there’s no scientific basis for this, and the seasons don’t particularly influence a cat’s reproductive system, kitten season was born out of the fact that shelters and rescues typically receive more kittens than usual once the weather warms up.

Kitten season as a concept seems so fun and fluffy, but after connecting with veterinarian Dr. Jo Myers, we realized there is just so much to unpack. Dr. Myers busts myths, clarifies concepts, and provides interesting facts about cats’ reproductive cycles. The best news is, no matter the time of the year, kittens are always in season.

What is kitten season?

Kitten season is a fun concept dreamt up by the media — kind of.

It’s actually more of a climate concept than anything else. During the colder months, people are more likely to provide food and shelter to feral cats because hunting conditions are rough. So when it starts to warm up, these cats are well-fed and ready for reproduction.

And it goes on. In the warmer months, litters of stray kittens are more likely to survive. And rescuers who work with feral colonies are more likely to be out looking for these cuties. The rescuers then bring the litters of kittens to shelters and there’s an influx of adoption-ready kitties.

The media then takes it from there, and thus we have “kitten season”!

When it comes to indoor cats, they can reproduce any time of the year, assuming they’re fertile. Kitten season really only applies to outdoor cats.

What are heat and estrus?

Turns out these two terms are synonyms. “In heat” is just the common term used for estrus (spelled “oestrus” in the U.K.)

“It's the period of time when a cat is preoccupied with mating and can conceive. Several changes happen within a female cat's body to help prepare for breeding and pregnancy, and this occurs over many days, but the stage of the reproductive cycle where the female cat is actually receptive to a male and can become pregnant is estrus,” said Dr. Myers.

A queen’s (unspayed female cat) entire reproductive cycle is called the “estrus cycle,” even though it’s only one stage of the entire cycle. Dr. Myers agrees that this naming system isn’t the most straightforward.

A queen goes through five stages:

1. Proestrus: the period leading up to estrus.
2. Estrus: when the queen will allow the tom (male cat) to mate with her when conditions are right for pregnancy.
3. Interestrus: the time before another proestrus/estrus stage begins, if the queen has not mated yet.
4. Metestrus: after mating occurs and the start of pregnancy.
5. Anestrus: when the body isn’t hormonally ramping up for mating. It occurs during pregnancy and cat menopause.

Human vs. cat reproductive cycles

Humans with a female reproductive system can choose to mate anytime throughout their approximate 28-day cycle, but can only become pregnant during ovulation. Cats also can only become pregnant during a few days of their cycle, and will only be interested in mating during those days.

Female cats also won’t ovulate unless they have intercourse. So when a cat is “in heat,” she’s all about getting pregnant. The queen will roll around and stick her butt in the air. She’ll also be very vocal. And she’ll keep returning to the heat cycle until she is pregnant or spayed. Some people find it very difficult to live with a cat who is in heat, because they are very single-minded and loud about it.

If I have a spayed/neutered cat, do I need to be concerned about kitten season?

Nope! When a cat is spayed, the uterus and the ovaries are removed (at least that’s how it’s performed in the U.S.). Without ovaries, the female cat won’t produce the necessary hormones to be in heat.

When a male cat is neutered, his testicles are removed. So he’ll also be saying goodbye to the hormones necessary for a sex drive.

If I have a cat that isn’t spayed or neutered, do I need to be concerned about kitten season?

Also nope! But for a different reason. If you have a cat that isn’t spayed or neutered, it will try to reproduce whenever it can. So it’s an all-season type of thing you’ll need to be concerned about.

If I’m looking to adopt a kitten, is kitten season the best time to do so?

You’ll likely find more kittens that need homes during the spring and summer months. So check your local shelters and reputable adoption websites for the latest influx of kittens.

When you need help with your new kitten — day or night — don't forget that a friendly, virtual veterinarian is only a few clicks away.