Every year thousands of stray cats and kittens enter shelters throughout the Unites States and are sterilized before being adopted out or returned to the colony in which they reside. Despite aggressive spay/neuter services provided by all these organizations, there are still hundreds of thousands of cats reproducing every year.
Why does it seem like headway is not made?
One big reason is that cats are very good at procreating. The female cat can have multiple heat cycles a year and cats are referred to as spontaneous ovulators. This means that upon mating, the female cat is stimulated by the male and ovulates on penetration. Unlike humans and dogs who have a very narrow “fertile window” that can be difficult to pinpoint during their cycle, a cat getting pregnant with each mating is almost a sure thing!
In addition, the average litter size is 4 kittens and sexual maturity can be reached as early as 6 months of age. Once a litter is weaned by the mom cat, she can re-enter a heat cycle and procreate again. Some cats may have as many as three litters in one year, potentially adding another 12-15 cats to the world.