Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Will Sibling Cats Mate? Vet-Reviewed Ethical Issues & Prevention Tips

Two orange kittens standing in hay

Cats are one of the most popular pets around the world. With their cute and cuddly personalities, it is no wonder why people love having cats as part of their families. But when two cats from the same litter live together, will they mate? Yes, cats from the same litter can indiscriminately mate with each other when there is an opportunity. However, there are a few things you can do to prevent this from happening.

In this article, we’ll look at whether sibling cats can mate with each other and if it is a good idea.

divider 2 cats

Will Cats Mate If They Are Related?

When cats are from the same litter, they are considered siblings and may have a close bond. However, unlike humans, cats don’t mate for pleasure. Cats only mate for reproduction, and feline siblings can and do indiscriminately mate with each other if a female comes into heat and a sexually mature male sibling is nearby.

This is undesirable, as you may soon find yourself with more kittens that you can handle. Furthermore, breeding between related cats can produce kittens with genetic defects or traits that may be passed down.

Just as sibling cats can mate with each other, a mother cat can mate with one of her male kittens. Likewise, a female kitten’s biological father can mate with her if she comes into heat. All of these circumstances can lead to an increased risk of genetic risks being passed down to kittens.

persian kittens lying on bench
Image By: Jenni Ferreira-Shutterstock

Health and Ethical Issues With Inbreeding Cats

There are conflicting opinions when it comes to breeding cats from the same litter. Some sources say that it is acceptable to inbreed and register the kittens as purebreds, while others say that it’s not a good idea.

Ultimately, you must consider the evidence that shows the risks of inbreeding cats. If you prefer to play it safe, it’s probably best that you don’t allow your sibling cats to mate.

But given that cats don’t share the same morals as humans, you will have to be the one to prevent them from mating if you don’t want any potentially unhealthy kittens.

Some of the known risks associated with inbreeding in cats include poor immunity of the kittens, with higher neonatal death rates, predisposition for infections, weak kittens, and kittens that are stillborn or born with congenital defects, such as hydrocephalus, improper eye and eyelid development, cleft palate and more. Cats that do live into adulthood may be infertile or. by breeding again. lead to small or sick litters and kitten death.

How to Prevent Sibling Cats From Mating

If you have two cats from the same litter and you want to be vigilant in ensuring they don’t mate, there are a few things you can do.

The most practical option is to spay or neuter both cats. This will prevent unwanted litters, and an early spay or castration (neutering) surgery can offer some health benefits to cats as well. Your vet will be able to give the best advice on when to have this procedure done based on your kittens’ age, health, and other factors.

Another somewhat controversial option is to keep the cats separated and provide them with different litter boxes and food dishes in separate parts of the house. This will make sure they don’t come into contact with each other while they are eating or using the bathroom.

However, all it takes is one moment of carelessness during a heat cycle that allows both individuals to come into contact with each other, and therefore, this option isn’t practical. It is also difficult to keep two cats separated all the time in the same house while ensuring they both get adequate attention, playtime, and interaction from you.

It is also worth noting that even if you do separate your cats successfully, you may still have to endure unwanted behaviors from them. A female in heat will yowl excessively, attempt to escape, and may even spray around the house. Likewise, if a male senses a female in heat nearby, he too will try to escape to mate with her and may resort to spraying around the house. A female in heat can also attract stray or feral males near your house, leading to potential cat fights and unwanted noise.

If you notice that your cats are trying to mate, it’s best to separate them immediately. However, this, too, is easier said than done, as cats can do the deed very quickly whenever you’re not looking.

The use of diapers to prevent mating in cats isn’t considered effective in most cases. Cats can also easily wriggle free out of a diaper, and diapers do have their downsides as well, such as increasing your cat’s risk of urinary tract infections and skin irritation due to urine.

savannah kittens playing
Image By: Kolomenskaya Kseniya, Shutterstock

divider 2 cats

Conclusion

Mating between sibling cats is not recommended, as it can produce kittens with congenital defects or stillborn kittens. The best course of action is to spay or castrate (neuter) both cats before they reach sexual maturity. Other options are theoretically possible but not always practical and very cumbersome. They also don’t offer your pets any health benefits and still come with annoying behaviors, such as spraying and yowling.


Featured Image Credit: Olgaozik, Pixabay

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

4 Responses

  1. Thank you so much for answering my query. I will follow your recommendation and schedule spaying and neutering over the next month.

  2. Hi there! I do intend to have my kittens spayed and neutered (brother and sister), but they are only 3 months old. What should I do for the next 3 months? Actually, I read that it is recommended to wait until the kittens are 1 year old to have them fixed because of lung development in males and hormonal development in both males and females. I don't hve an extra room for one of the kittens. I'm puzzled!

    1. Hi Danielle, thank you for reading us. Kittens can become sexually mature as young as 4 months old. If you are keeping a male and female please schedule their spay and neutering procedure in the next month. These recommendations are supported by veterinary and animal welfare organizations to prevent unwanted litters. Do not worry, lungs are developed in the fetus before the kittens are born. And getting pregnant while still being a kitten is more risky to their health than the procedure. Good luck.

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Foodies vs Picky Eaters: The Wednesday Cats of Catsters’ Food Habits

Welcome to the Wednesday Cats of Catster! Every month, we ask our cat-loving Catsters to weigh in on a new topic. This week,...

Why Does My Cat Smell Like Maple Syrup? 3 Vet-Reviewed Reasons

A cat that smells like maple syrup may sound pleasant, but in reality, it could be an indicator of a medical issue. If...

8 Best Cat Advent Calendars In 2025 – Reviews & Top Picks

What better way to enjoy the days leading up to Christmas than with a cat advent calendar? There are tons of different calendars...

4 Beautiful Egyptian Mau Colors & Patterns (With Pictures)

As one of the oldest domestic breeds, the Egyptian Mau is related to the Siamese and the Abyssinian breeds. Egyptian Mau colors and...

More related

How to Teach Your Kids to Approach Unfamiliar Cats: 8 Vet-Approved Tips

The world is full of unknowns, surprises, and unfamiliar territories to kids. Children do not perceive certain situations as threats unless taught, which...

Never Too Old To Travel: Sully’s Big Adventure

Hi, I’m Dr. Karyn! Read my introduction to learn more about me and meet my five hilarious cats: Clutch, Cyril, Alex, Zelda, and...

Do Abyssinian Cats Shed a Lot? Vet-Reviewed Care Facts

Compared to other cat breeds, the Abyssinian cat does not shed much. They have a short, dense coat, and if you brush them...

Can Cats Get Dizzy? Vet-Reviewed Science & Facts

While dogs are often jokers, cats are the elegant masters of the home. We rarely see cats, especially adult felines, tripping around the...

Keep reading

Cat Brain Anatomy: Vet-Verified Facts & Common Disorders

Anyone who knows a cat is familiar with just how different they act from humans. Sometimes, they do things that leave us feeling puzzled or confused. However, humans share more similarities with cats than they think. In fact, when it...

close up longhaired brown tabby cat

Do Devon Rex Cats Shed a Lot? Tips to Reduce Cat Hair & FAQ

The Devon Rex cat, with its pixie-like appearance and charming personality, is an increasingly popular breed of feline. While these cats are known for their curly hair, endearing nature, and playful antics, one of the most common questions prospective owners...

woman brushing calico tortoiseshell Devon Rex

Why Does My Cat’s Tail Twitch? 6 Vet-Reviewed Reasons

Cat ownership would be a lot easier if our pets could tell us their thoughts. However, until someone develops a cat-to-human translator, we have to use context clues and our pet’s body language to decipher their moods. A cat’s tail...

A-curled-cats-tail-close-up

Are Poppies Toxic To Cats? Vet Approved Facts & FAQ

Cats are intelligent creatures that usually avoid things that can hurt them. However, sometimes curiosity gets the best of them, and if your cat decides to eat some plants, including poppies, they can harm them. Poppies are used to make...

Catster_Are Poppies Toxic to Cats

Do Senior Cats & Kittens Get Along? Vet-Approved Introduction Guide & Tips

Introducing a senior cat to a new kitten can be tricky. Differences in ages, energy levels, and physical conditions can create tension. But it doesn’t mean that your two cats will dislike each other forever. Introducing your cats to one...

Do Senior Cats and Kittens Get Along

Wellness vs Blue Buffalo Cat Food: Our 2025 In-Depth Comparison

If you’ve spent time wandering around your pet food store, you might’ve noticed two brands that are a bit higher-end than normal: Wellness and Blue Buffalo. Each of these brands was started fairly recently, and both have cashed in on...

Wellness VS Blue Buffalo

There’s a Sudden Behavior Change in My Cat, Is It a Medical Issue? Signs to Watch For

Cats are fairly consistent animals and creatures of habit. While their personalities may change when they age from kittenhood to adulthood, most cats will sustain the same personality all throughout their lives. So, sudden behavioral changes don’t usually happen without...

cat scratching owner

How to Treat a Burned Cat Paw Pad: 6 Vet-Approved Tips

Given how curious, fearless, and agile they are, cats have a way of getting into things that they shouldn’t. Add the fact that cats love warmth but cannot distinguish dangerous hot surfaces from safe ones, and you have a recipe...

vet checking up tabby cat