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

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

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

How to Choose the Right Cat Carrier in 2025: 7 Vet-Approved Steps

Cat carriers are a convenient way to transport your cat both short and long distances. Cat owners might feel overwhelmed when looking for...

What to Say to Someone That Has Lost Their Cat: Helping Through Grieving Process

Every pet owner understands the gut-wrenching pain and grief that threaten to overwhelm their emotions when they lose a cat. They are keenly...

My Washing Machine Smells Like Cat Pee! How to Remove the Odor & Useful Tips

If you’ve ever owned a feline friend, you know that accidents happen, especially when they’re kittens. And whether it’s a new kitten who...

Can Cats Eat Fish Bones? Vet-Reviewed Feeding Facts

Cats are obligate carnivores. In the wild, they eat a good variety of small prey, depending on availability, and they make the most...

More related

Aphrodite (Cyprus) Cat Breed: Info, Pictures, Temperament & Traits

Also called the Aphrodite Giant or Cyprus cat, the Aphrodite cat is a large, friendly feline who has helped humans for hundreds of...

Remember Me Thursday 2025: When It Is & How to Celebrate

If you spend a lot of time around other pet lovers, there is a good chance you’ve heard about Remember Me Thursday. Remember...

Pretzel is Blind, Deformed and Inspiring People on Facebook

Carmen Bernard and her husband were driving down a country lane just outside of Jacksonville, FL, when they spotted something fuzzy moving in...

Can Cats Be Allergic to Their Own Teeth? Our Vet Explains Feline Dental Health Facts

Feline chronic gingivostomatitis (FCGS) is a condition in which cats develop inflammation of the gums and oral cavity. Although understanding of this disease...

Keep reading

Heart Murmurs in Cats: Signs, Causes, and Care (Vet Approved)

The last thing that anyone wants, is to worry about the health of their pet. But cats are talented at hiding injuries or health problems until it might be too late. When it comes to the cat’s heart, various conditions...

Veterinarian doctor holds cat

Is Baby’s Breath Toxic to Cats? Vet-Reviewed Houseplants Examined

Baby’s breath is an extremely common flower in arrangements. The small, white flowers are especially useful at bringing out the colors of other flowers and make a good “background” flower for arrangements. Less commonly, you can also find this flower...

Catster_Is Baby’s Breath Toxic to Cats

Can Cats Eat Dill? Vet-Reviewed Facts & FAQ

Are you looking for a cheap and effective treat for your cat? Or are you worried because you just caught your cat chowing down on your dill plant? Either way, you’ve come to the right place. Dill is safe for...

Can Cats Eat Dill

My Cat Isn’t Affectionate Anymore: 7 Vet-Reviewed Possible Reasons

If your cat has suddenly stopped being affectionate, it can be unsettling. However, it likely isn’t because of anything you did. Cats can be sensitive creatures and may react negatively to things that we don’t even realize happened, changing their...

hand touching cat's paw

How to Get Rid of Cat Dandruff: 6 Vet-Approved Tips and Tricks

Dandruff is common in cats and is generally a sign that your pet has dry skin. But the causes of dry skin can vary from a simple lack of sufficient humidity in the air to more serious conditions such as...

cat fur with dandruff

Why Do I Need to Clean My Cat’s Litter Box? 10 Vet Reviewed Reasons & Cleaning Tips

As a cat owner, you know that cleaning the litter box is definitely the least pleasant chore associated with caring for your feline friend. However, keeping your cat’s litter box clean is also one of the most important things you...

cat-pooping-outside-the-litter-box

How Often Do I Need to Bathe My Cat? Facts & 7 Vet-Approved Reasons Why

Bathing your cat is not something most owners think about. Cats are notorious for being self-grooming animals. For the most part, they do a darn good job of keeping themselves clean. Most cats don’t need frequent baths. However, there are...

cat bath

Can Cats Eat Mint? Vet-Verified Facts & Advice

The mint genus is a broad category of plants containing multiple species that cats will react to differently. If you’re confused about the difference between catnip and catmint or catmint and wild mint, you’ve come to the right place as...

Can Cats Eat Mint