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

Why Do Cats Like Ice Cubes? 5 Vet-Reviewed Reasons

If you give ice cubes to your cats, you may be surprised by how much they like playing with them, nibbling on them,...

120 Brother and Sister Cat Names for Feline Sibling Pairs

Bringing a new cat into your home is an exciting adventure. It’s even better when your heart is snatched up by two kitties...

Can Cats Eat Canned Salmon? Vet-Reviewed Facts & FAQ

Cats are notorious for their love of fish, so feeding them a bit of canned salmon should be a no-brainer. What could be...

How to Identify and Stop Food Aggression in Cats: Vet-Reviewed Advice

Cats are in touch with their wild side. You’ll see examples in their behavior, which may seem inappropriate in the home setting, but...

More related

Don’t Panic Yet: What Happens When Cats Eat Silica Gel Packs

If your cat just chewed on a “DO NOT EAT” packet, take a breath. This is one of the most common pet-parent panics,...

The Terminal Purr: When Purring Isn’t A Sign of Happiness

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

Can Cats See Ghosts, Spirits, & the Supernatural? (Vet-Reviewed)

It’s happened to every cat owner at one point or another: Your cat suddenly stops and freezes, staring off into the distance at...

What Kind of Cat Breed Is Stryker? Feline Celebrity Facts

Stryker is an internet-famous cat that was rescued by his owners, Shlomo and Joe, when they found him kept captive in a cage....

Keep reading

Iris Melanosis in Cats: Vet-Verified Signs, Causes & Treatment

A cat’s eyes are often their most striking feature. We all know whether our cats have amber or green irises and are fairly familiar with the shape of their eyes and pupils. Iris melanosis in cats is a condition of...

cute orange tabby cat

12 Best Cat Foods in 2026: Vet-Approved Reviews & Guide

Proper nutrition is just as essential for your cat as it is for you. Like with humans, a poor diet for cats can lead to issues like malnutrition, weight gain, and certain diseases. It can also have a negative effect...

siamese kitten eating from a stainless bowl

Cat Whimpering & Whining: Why, What to Do & When to Worry (Vet-Approved)

Cats vary in how talkative they are. Some always seem to have something to say, while others aren’t nearly as vocal. You may be used to your kitty’s repertoire of sounds and even understand what your pet is trying to...

abyssinian-cat-meowing-at-the-sofa

How to Shave a Cat’s Bum: 6 Vet-Approved Steps

If you’re starting to notice an unpleasant odor following your cat, and if you’re starting to see unpleasant remnants in their nether regions, it might be time for a sanitary trim. It’s not a fun process for anyone, but when...

cat being groomed and shaved at a salon

Do Cats Really Play With Their Prey Before Killing Them? Vet-Approved Behavior Explanation

We easily forget that our cute, fluffy cats are natural-born killers. Perfectly evolved to chase, stalk, and hunt small animals to devour them, even our domestic cats can often bring home their prey. Cats are often thought to be malicious...

cat hunting mouse outdoor

Do Cats Eat Less in Summer? Vet-Approved Seasonal Feeding Guide

Have you ever noticed that when winter comes, you start to eat more and crave heartier foods, while when summer rolls around, you move more and eat less? Believe it or not, cats may also eat less food in the...

Bengal cat beside food

How to Help a Cat Give Birth: 5 Vet-Reviewed Tips

Giving birth can be a very stressful situation for cats. We are used to seeing cats being independent animals, but even for them, giving birth is a challenging task. This period is very stressful for cats and also the owners....

mother cat gave birth to kitten

What Are Cat Paws Made Of? 5 Vet-Reviewed Facts & FAQ

Cats’ paws are incredible and are used for a host of different things. Paws help with balance and carrying the load of the cat, and they also provide protection, offer grip, and even dissipate energy, which is how cats can...

close up paws of orange cat

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.