How do kittens prevent my cats from going into heat?

Question

I have two indoor cats who're sisters. One of them got pregnant and had kittens, and the sister did not go in heat once during the 3 months we had the kittens. Do kittens prevent a cat from going in to heat? If so, how?

Answer 1

1. Sister went in heat the same time mamma did and although she mated she didn't get pregnant, this will cause the cat to enter a pseudopregnancy state, the cat will think it's pregnant and won't go into heat for another several months.
2. Sister might have a hormonal(ovaries) problem/defect, I can't elaborate much on this, but one of my cats had ovaries with defects(low hormone production) which would cause her to only go into heat one or two(pushing it) times a year, also if you're really worried, I'd take her to the vet since it could be tumors in the ovaries as well(worst case)
3. If she didn't go in heat when mamma did(or at all), don't worry... Some cats just bloom later than others. It's called an average for a reason, there's no rule as to when a cat should start going into heat, only approximations.

Answer 2

In humans, the mother will usually not begin to be fertile until the body fat ratio returns to a region where the new fetus can be amply supplied for growth. A breast feeding mother will usually remain comfortably below that threshold, so there is a general barring of a new child until the old is out and about.

As mammals, mother cats probably have a similar mechanism to avoid overlapping litters.

Answer 3

Cats don't actually go into "heat." A mature female cat can be receptive of a male at any time.

The way to fix all of these problems is very simple-- Get The Cats Spayed!

SimonT