Questions about Genetics in Cats

Have you ever gone down into a cave and turned off the flashlight? Your eyes, desperately seeking light which is not there. This impenetrable darkness clung to our eleven-year-old granddaughter at the animal shelter while kittens bounded about the room in play. Huge black pupils with slivers of green surrounding stared intently at her, the kittens arms hugging her neck, refusing to let go. Rumbling purrs filled his chest as he pleaded to go home with her. This granddaughter’s gift is a natural instinct with animals, she takes after her grandma including getting a lighter dose than mine of autism.


Now back and forth from their house to ours goes darkness, named Hugo, as I homeschool our eleven-year-old granddaughter four days a week. After several weeks of doing little more than lounging on laps and purring, Hugo became a six month old kitten last night tearing around the house for hours investigating and this morning is chasing my toes under the bed covers. Our two older cats who live part time in the house and most of the time in the barn pretty much ignore him. The younger of the two presently on another ‘walk about’ which can last up to 7 days in the summer. He was born wild and I guess part of him still is.

IMG_1556I was once called the Cat Lady. The title earned for all the feral cats that came running when I showed up to milk 3/4’s of a mile from our former home. A few would come readily to drink from the bowl of warm, fresh, goat milk and healthy table scraps I’d put out for them, others waited in the shadows. For 28 years I studied them and learned their body language, making friends with some and others respecting their right to distance. Next to the mountain, where we presently live, I’ve seen no feral cats unless you are talking about mountain lions and bobcats of which we have plenty of. I kind of miss them.

Our granddaughter has been asking questions about cats. My brief answers are more than enough information to satisfy her while my brain thirstily seeks more. When she asked if you could breed a long haired cat with a short haired cat and get a medium haired cat. I pointed to the books on plant genetics next to me in the book shelf and said no. Not unless one of the cats had a medium gene in their mix but long and short genes combined don’t make medium.


These are Sue’s kittens. Sue being the male. I mistakenly thought a feral kitten was a female and hence, a boy was named Sue. When he came crawling in as a teenager jaw hanging, belly ripped and dragging a leg hung on by a piece of skin I was reminded of the song by Johnny Cash about a boy named Sue. Barely able to swallow milk he hung in the shadows and miraculously healed. He was tough and there never was Tom that could out fight three legged Sue. (Hence, all yellow kittens.)


Yup, and these aren’t all the cats that came in which included Sue which is in the background drinking with our goat Chicory.

Then our granddaughter thought since a female cat can be bred by several males and have kittens from them all in one litter that the gene pool gets mixed. I drew a picture of eggs and swimming sperm labeled male one, two, and three and explained that an egg is only viable if one sperm enters, if more than one then the egg dies. That meaning only the female and the one male impart genes to the kitten. So the kittens in the litter from different fathers become half siblings.

But exactly how does it all work. I only have the barest of knowledge in genetics so I checked out the Merck Veterinary Manual and


Oestrus cycle begins at around 4 months to 10 months of age depending on genetics and the number of daylight hours when they reach that age; the days becoming longer, the kitten’s weight, age, general health, and their breed all playing a part. A full cycle takes on average three weeks which brings us back to the point when six month old female kittens will begin yowling at the top of their lungs and cower in terror as toms line the windows of the basement yowling back especially in the middle of the night or maybe that has just been our experience.

Cats are seasonally polyestrous meaning they have multiple heat cycles during a season.  Breeding season is practically all year round but in the western hemisphere, because of our lack of light, it is spring through fall. Thankfully if bred, it ends her heat cycle.

Female cats are called queens and are induced ovulators. This means that they do not ovulate (pass an egg) unless they are bred. Most females require three to four matings within a 24-hour period for ovulation to occur and the males are happy to oblige. This greatly increases the chances of conception as does the powerful pheromone that is emitted by the queen which can be picked up to a mile away by the toms. Nothing like an invitation to a cat fight. Yes, the voice of experience. Gestation lasts about two months which is 60 to 63 days.


But yeah! Hugo is male and already neutered along with our other two cats. Now you know about cats, all except of course that all males or all females works best to minimize contention even if neutered or spayed. Yes, the voice of experience and the comments of several vets I’ve asked. So there you have it. The long explanation that our granddaughter could never have sat all the way through.