It’s Kitten Season!
Cats have a unique reproductive system. Intact female cats, which are known as queens, have evolved to be “seasonally polyestrous”. This means that cats only come into heat during one time of the year, but they can have multiple litters during that time. In our area queens begin coming into heat in January, and the peak of the season for litters is in the middle of June.
Cats are also “induced ovulators” which means that the act of mating with a tomcat causes the queen to release an egg, increasing the chances of successful conception. Queens will also breed with multiple toms. It is possible for each kitten in a litter to have a different father.
Once breeding season begins, queens will go into heat approximately every 2 weeks for the entire breeding season. Queens will come into heat shortly after giving birth—before the kittens are weaned.
Queens in heat will vocalize at all hours of the day or night to find a willing tomcat with whom to breed, and indoor only cats will try to run outdoors to seek a mate. With some the breeding drive is so strong with will break through screens to get out. Queens in heat will also be extremely affectionate, constantly underfoot, and will roll around on the ground. They will also lay on their tummy with their tail to one side, inviting breeding.
While it isn’t as common as it is in dogs, cats can also develop an infected uterus called a pyometra if they are not bred, and just as in dogs, this condition is a life-threatening emergency that can only be remedied by spaying the cat. Pyometra surgery carries greater risks than a regular spay, owning to the sickness of the cat and the greatly enlarged size of the infected uterus.
The cat overpopulation problem is extremely serious. Cats are extremely prolific and can become pregnant at 5 months of age. This means that he daughters of a cat who becomes pregnant in January will be able to produce a litter that following July. Allowed to breed naturally, a queen can have 3 litters in a season. With an average of 3-5 kittens in a litter, one female cat can produce up to 150 more cats over its reproductive life.