Brother And Sister Cat Mating - Problem For Kittens?

by Tammy Moxley
(Temple, TX USA)

Question:
I have two kittens, one male, one female. They are brother and sister. They are 9 months old. She just began being in heat and I think the male has already gotten to her. Will she continue her heat cycle and if she is pregnant, will something be wrong with the kittens?

Answer:
I can't say anything about the heat cycle (much depends on the cat) but statistically there's a higher chance of birth defects and diseases when your breed a brother and sister. Inbreeding, as it is called, exposes both the good and bad qualities in a cat. That doesn’t mean you’ll always get an unhealthy litter - there are many cases where everything turns out fine. But there are more risks.

Read all about pregnancy in cats in How To Take Care Of Your Pregnant Cat