How Many Times Could my Cat Become Pregnant in a Year?

Mother and kitten
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A reader asked: "If I don't neuter my female and have another cat of the opposite gender in the house how many times could my cat get pregnant over the course of a year?"

Assuming your cat is past puberty, she could bear as many as five litters in 52 weeks, which at an average of 5 kittens per litter, would be 25 kittens. I calculated that by assuming a standard gestation period of nine weeks, and an average gap of two weeks between pregnancies:

  • Weeks 1-9: Litter 1
  • Weeks 11-20: Litter 2
  • Weeks 22-31: Litter 3
  • Weeks 33-42: Litter 4
  • Weeks 44-53: Litter 5

Let's carry our calculations a bit further: Those kittens are going to mature, and if left whole, will start reproducing during that year. Kittens can reach puberty (sexual maturity) as early as four months, but for the sake of argument, I will use five months. Assuming conservatively that each litter has 5 kittens and that two of them are female. (The females may mate with either or both their littermates or the original male.) Using the same average periods as the first example Litter 1 can start mating on the 29th week.

  • Litter 1: 2 Females
    Mate 29th week, give birth Week 38. Total Kittens to Date: Original 25 plus Litter 1's 10 kittens = 35 kittens
  • Litter 1's 2 females then go on to mate on week 40 and give birth on week 49. Total count now: Original 25 + Litter 1's 20 kittens = 45 kittens
  • Litter 2: 2 Females
    Mate 40th Week, give birth Week 49. Total Kittens to date: Original 25 plus Litter 1's 20 Kittens, plus Litter Two's 10 Kittens = 55 kittens.

Allowing for a 15% loss with stillborns, that would leave 47 kittens during a one year period.

I don't know of anyone who could give responsible care to that many cats in a single home.

These are the kinds of situations we read about in stories about cat collectors and backyard breeders aka kitten mills. They are also the situations that lead to feral cat colonies, as people dump their unwanted cats out into the street.

As horrible as those stories can be to contemplate, some people do fall into that trap by way of failure to spay and neuter pet cats.