Mating Siblings

by Zee

It may be a dumb question, but, can you mate siblings with each other?

*Moderator's Response:*
No, this is definitely not a dumb question, as the rabbit community has no consistent answer for it.

We think *Yes* ... maybe! Here's the genetics of our opinion, and see our Rabbit Genetics page for a refresher on the basics, if needed:

For every trait, the rabbit inherits two copies of a gene. These traits can be dominant or recessive. If the dominant gene copy is a healthy normal gene, but the recessive copy is flawed or damaged, you have no way of knowing about the presence of the flawed gene, because the normal dominant gene will completely override the flaw, and keep the animal healthy.

The more related the animal, the greater the chance that two flawed genes for a trait, already present recessively in both siblings, will match up and be unable to prevent an outwardly flawed or damaged offspring. A pairing of recessives is what causes albinism and various other recessive traits like color and size. No problem there. But it's very bad if that flaw is structural or metabolic, like buck teeth, a propensity to cancer or cataracts, or polycystic kidneys.

The inbreeding itself doesn't 'cause' these problems -- it is the pairing of already pre-existing genetic flaws that creates the problems, and inbreeding is the fastest way to reveal IF there are flaws hiding in the genetic code.

So... If you breed siblings together that are excellent genetically, you'll be pleased with the results. If you get 'freaks of nature,' well, now you know that you better not match that set of siblings again. :-)

--Breeding siblings results in offspring that carry 50% of the genetic material of each of the original parents.
--Breeding offspring with a parent results in a 75% - 25% split in genetic material of the original parents, and is a much closer pairing.

That was probably way more than you hoped to hear, but we at least hope it helps.

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Aug 31, 2021
Brother and sister got together
by: jim pita

Okay, my bunnies are 100 days old. They have different pens but I woke up today and the boy bunny was in with the girl bunny. I am sure they have done the thing bunnies do.

Is there a day after pill I can give the girl bunny? Or some kind of birth control I can use while waiting on an appointment with the vet to have them taken care of? Or do I just have to wait and see if she is pregnant?

They are from the same litter of 5; 2 are white with red eyes, 2 are brown, and one is brown and white. They are mini lionheads, it was a white boy and a brown girl. Someone said to me that they are from the same mother but different dads. Can this be true? When I got the mommy bunny I had no idea she was pregnant.

***** Karen Sez *****
First, sadly, there is no day-after pill, lol. You should probably assume your girl is pregnant, and get ready to put a nestbox in her cage on day 28. Expect babies on day 31-32.

Second, how did Mister Brother manage to leave his pen and get into her pen? Unless you like surprise litters, you'll need to fix this little glitch in your set up.

Third, about the genetics of your rabbits: the brown coloration is dominant, and the white coloration is very recessive. It is very possible for the bunnies to all have the same parents, if both parents carried the recessive white albino gene. See Click here for more details on rabbit genetics. Best of luck with everything!

Jan 17, 2021
Breeder Beginner
by: Micah Bun

I am beginning my research in breeding. Just to clarify, it is safer to mate a bunny to a parent or cousin instead of its sibling? Also, for "half-siblings" would you recommend breeding them? In a previous comment you mentioned it would be a "half-risk." I assume instead of mating siblings and half-sibling, I should choose to mate offspring with parents? I have 3 bunnies (not siblings or related in any way) and I would like to begin breeding them and then their further generation. Thank you.

***** Karen Sez *****
Hi Micah,
Good for doing your research! Experienced breeders do clos(er) breedings all the time (line breeding). The attention is placed on finding and multiplying the excellent traits in a herd, while eliminating the presence of negative traits. Breed together two rabbits that BOTH carry the needed positive trait. But, if they both ALSO have a negative trait, their offspring will also inherit a double dose of the negative.

While you are striving toward the good traits, you must not also inadvertently fix into your herd the negative ones.

Know also that in breeding related animals, you are likely to eventually REVEAL various hidden defects. Which can be a good thing, if you then eliminate those negative traits.

Good luck with your own breeding program!

Oct 20, 2020
by: Pat

Hi. So I'm a teen and a few months ago my mom handed me two baby bunnies. They're five months currently. Well the lady that sold them to us said they were brothers. Turns out one of them was a girl. She had 4 babies. We separated them and everything but all four babies died. We were really surprised. I cried a lot. My mom says we can let them try in spring. I was wondering if this was a good idea or if we could do anything to keep these ones from dying.

***** Karen Sez *****
Hi Pat, My guess is that the bunnies may not have died of a too-close breeding, but from other causes. Do some research on reasons why bunnies die (tons of info on the Raising-Rabbits website), and then ask the question: what do you plan on doing with the offspring when you let your rabbits rebreed? If you like the idea of breeding your rabbits, you might could get an unrelated rabbit with which to do a breeding...? Enjoy your rabbits!

Jul 16, 2020
by: Aalyiah

My rabbits share a cage. Well, they did, but we just thought that they couldn’t have babies together since they are brother and sister.

I don’t know their breed; I got them from someone who didn’t really care for them and I’ve had them for 6 months. I got home today and took them out of their cage to run around and have play time and clean the cage also. Well I saw a baby and it was dead then we saw just a baby head and she started bleeding again.

Now she’s in the clean cage by herself in the dark and quiet and I keep checking in her but I’m not seeing any signs of any more babies but I know they have like around 6 or more with their first litter they are about 9 months and this is the first litter ever and going to be the last but I just want to know what could be wrong with her not having anymore yet and how long is it safe for the babies to stay in there if so?

***** Karen Sez *****
Hey there Aalyiah,
A litter of 6 is actually quite a sizeable litter, so, nothing wrong with the rabbit on the surface of things. What is kind of surprising is that it took until 9 months of age to to actually kindle the first litter. Because yes, siblings have no problem mating and reproducing.

You need to separate the boy from its sister, and keep him in its own cage. As it is, your girl rabbit might have her second litter in roughly 31 days after this first one.

If you have him fixed, don't put them back together until 8 weeks have passed (to prevent litter #3).

About the babies, make sure the mom has pulled some fur to cover them with. I don't know what kind of a cage you have, but it would be helpful for the babies' safety and warmth if they have some kind of a nest box. You might could use a cardboard box temporarily (the doe is likely to chew on it so be prepared to replace it in a few days).

Tons of information in one of these resources:
Rabbit Reproduction E-Book
Rabbit Raising Problem Solver

Enjoy your rabbits!

May 31, 2020
Wanting to keep a bunny from brother-sister breeding
by: Anonymous

When I bought my rabbits I didn't know the girls were bred. They were 5 months old and bred to the full brother only a couple months older. I just had one of them drop babies and the other is huge (not fat from food); she looks like she is going to have a lot of babies. I contacted the guy that sold them to me to find out why he didn't tell me and he said he forgot.

My question is the new mom is doing great - 7 babies none dead. I am selling her brother and kit's dad, but my daughter wants to keep one of the kits. I have other does and bucks that are no relation to the baby. Could we keep the baby and breed it to a different line and be okay or should we just eat all these babies? We normally eat most of what we produce.

***** Karen Sez *****
You sound very observant, Anon, and you have a good plan for diversifying the genetics of the offspring of a line-bred rabbit. Keeping and breeding the baby should be fine. Keep and work with good examples of meat rabbit genetics, and eat the rest. Best of luck with everything!

Feb 06, 2018
Are they siblings?
by: Anonymous

Are two rabbits who have the same dam but different sires still considered siblings? We are looking to breed our doe and there are few choices for our breed of bunny in the area but we can get a nice buck from the same breed but it has the same dam as our doe.....would this be a risky match? No obvious flaws on either bunny so far.

***** Karen Sez *****
Well, they're certainly half-siblings, eh?

Given the circumstances you describe in brief, and given good stock with no obvious flaws, it sounds like a "half-risk" you may need to take. Just be prepared for the possibility of low vigor or other unforeseen issues. You will know not to use affected animals in your breeding program. And in the meantime, you have time to search for worthy, unrelated animals which will improve your herd. Best of luck!

Oct 19, 2017
by: Anonymous

I had a similar situation that happened to me. I had sibling rabbits get out of their cages at the same time and about a month later unexpectedly found babies born in the cardboard box that I had in her cage. I had a total of 7 rabbits born, yet 2 died but the other 5 were fine and healthy and made great social, loving pets. This was my experience, so it should be okay.

Sep 06, 2017
by: Anonymous

I have a question. If I mate a father with a daughter, can I then mate a buck from that litter with a previous litter where the father that was bred also fathered the doe from the previous litter with a different doe? (i.e. the mother of the daughter that mated with the father.)

***** Karen Sez *****
So, if I followed your descriptions, you're interested in mating a buck which has 75% of his genes from his sire to a doe which has 50% of the same sire's genes AND 50% of the genes of her mate's mother's genes?

If so, I'd simply ask: Are these excellent quality purebred animals that conform well to their standards of perfection? And, how much additional line-breeding or in-breeding exists deeper in the pedigree? Because, it isn't the inbreeding that causes problems. Inbreeding reveals any flaws in the gene pool by exponentially increasing the chances of pairing flawed recessive genes, thereby exposing the existing flaws which were hiding behind normal dominant genes.

You're proposing breeding very tightly on two separate individuals: especially on the sire, but also on the dam of the sire.

Many very capable breeders may decide to conduct such "tight" breedings if they feel the two animals will complement each other. These same breeders will then observe the results of the breedings (any loss of size or vigor or poor health or deformities, etc.), and then enter the offspring in rabbit shows to get opinions from rabbit judges to help them direct their breeding program. There is nothing at all wrong with these choices when done wisely.

So, you'll have to find the ultimate answer to your question. Can you? Of course you can. Should you?? This will depend on the animals you are working with, which I cannot see and with whose pedigrees I am unfamiliar.

Hope this helps!

Aug 18, 2017
by: Chubby bunny

I have two siblings large breed rabbits which started mating at 4 months I'm scared the kits will be ill and not formed properly.

***** Karen Sez *****

Easy solution - separate the rabbits immediately. If what you thought was mating was just dominance humping, there may not be any bunnies. But keep them together, and bunnies will certainly follow.

Whether or not inbred bunnies are deformed depends on the underlying genetics. Better to separate the male and female, but if it is too late, time will tell if the babies are healthy or not.

Apr 21, 2017
Bloody hell!!!!!
by: Anxious bunny owner

So my 2 "female" siblings created a litter!!! I went to go feed them one morning and noticed blood and fur in their hutch on the bottom level! I initially thought they had been fighting so quickly grabbed one to check "her" over and then noticed movement in the corner where they toilet! I was scared at what I might find, thinking something had got into the cage and expecting a dying mouse or rat so grabbed the grooming brush and discovered 4 live kits and 1 dead! I separated dad straight away but obviously not soon enough!

All that litter died...I think from the low temperature so when she started to make another nest I bought an indoor hutch as I was scared of loosing them! Something more horrible happened and she gave birth to 5 stillborns on the cage floor and ate them!! I thought that was it, all gone but she was still protective over a hidden bed compartment so when cleaning her out I left it! 5 days later I heard noises and had a sneaky peak and there were 2 Netherlands dwarf babies!!

They have defied all I've googled, they were 7 months when they mated, they have been with me in the same cage from 8 weeks old! I've read that they don't move young but how has she had stillborn babies on the cage floor but live ones in the nest?! I'm proud of my little rabbit! The babies are now 14 days old and she will leave a tunnel open for them to come out of the nest when she wants them to or will block the door off with shavings to keep them safe inside! I love being a bunny granny!!

***** Karen Sez *****
Good job, Bunny Granny! No, I know of no instances where a doe moves a litter, but sometimes they DO end up with 2 separate nests. Then they will ignore one nest and care well for the other one. When this happens, it is probably smart to put all the kits in the nest that is being cared for. Except, of course, when the other kits don't make it.

Jan 07, 2017
Breeding Rabbits
by: Anonymous

I am wanting to start breeding rabbits. I am looking at rabbits that are around 10 weeks old. Do you recommend separating them in different cages from the very beginning until the doe is 6 months old? I don't want to put them together if the buck will try and mate with the doe before that 6 month mark? Naturally will they try and mate earlier than that?

***** Karen Sez *****
Yes, bucks and does will naturally mate with each other at the earliest possible moment. This is why caging them separately after 10-11 weeks is smart.

For the record, separate cages doesn't emotionally cripple a rabbit.

Nov 15, 2016
Consequences of rabbits mating too young?
by: Anonymous

I have recently gotten two mini satin bunnies. They are siblings and are both 7 weeks. I do not have the heart to separate them when they are 12 weeks. Will the doe be ok if she mates too early? Will she die because she is too young?

***** Karen Sez *****
Well, on the one hand, wild rabbits don't cage themselves in the wild when they reach a particular age. (But a community of wild rabbits does have checks and balances that prevent tight inbreeding, and the predators take care of the stupid rabbits.)

On the other hand, and I know you love them dearly and you want them to live happily ever after, why don't you have the heart to separate them? These are SIBLINGS. Willy nilly sibling breedings are not good for the offspring. I wonder if you are not familiar with rabbit reality? Have you been listening to the House Rabbit Society schpiel that rabbits can’t possibly live happy lives apart from one another? We all need a reality check on the HRS.

If you don't have the heart to separate them, why did you purchase them? Do you have the heart to neuter the male? (No, not you, the vet.)

Finally, to answer your question: Early mating is not typically fatal, but an immature mini-satin trying to birth a litter of dwarf-gene-influenced, large-headed kits might run into trouble if her birth canal is still undersized. If there are 6 in the litter, the kits will be more likely smaller and able to birth successfully. But if she has only one or two, the chance is greater that the kits could grow too large in the womb, and the first kit could get stuck.

Having said that, each rabbit, each litter, and each pregnancy is unique, and these words should not be taken as a dire prophesy. They do describe a possibility, but the chance of dangerous events actually happening in the case of your rabbits is unknown.

Mar 06, 2016
by: Megan

I have siblings that recently mated by accident since I let them free in the yard. They are 6 months old each and I was wondering if the kits will be fine and the other can safely kindle since the parents are siblings!!😂😍🐰🐰💖💖

***** Karen Sez *****
If you've seen other posts on this topic on this website, you will have seen that mating siblings is not by itself a problem. Sibling matings however can easily reveal IF there are underlying genetic problems with these rabbits by uncovering negative recessive traits.

Time will tell! Feel free to check back in and let us know how it goes, and thanks. :-)

After this litter, you'd be super-wise to figure out how NOT to keep breeding siblings to siblings. Once might be fine, but the following doubly-inbred generation may create a disaster. It just depends on the underlying genetics (and the wisdom of the rabbit owner).

Feb 20, 2016
Same age
by: Katie

I have two 6 month only rabbits and they mated earlier I was wondering if since the rabbits are the same age would it still be ok for the mother rabbit easily to kindle because in another article I read if the father is bigger than the mother the mother would have trouble kindling. Is this true for the same size rabbits as well?🐰💖🙃

***** Karen Sez *****

6 months old is very likely adult age for your rabbits (as long as yours aren't a giant breed). Adult rabbits of the same size breed and kindle successfully every day. :-)

Feb 18, 2016
Same age rabbits
by: Nikki

Hi, my bunnies are the same age, 4 months. I was wondering that they are allowed to be the same age when breeding or will that cause the mother trouble kindling? Thanks for your help. BTW: this article was very helpful. You did a nice job!!!😊🐰💖

***** Karen Sez *****
4 months old is really young for intentional breeding. (And I'm assuming these are small breed rabbits?) How about waiting until they are at least 5 or 6 months old? This will be better because it gives the doe a chance to get some adult wits about her, reducing the chance she'll be an airhead during kindling and forget to mother the kits. Good luck and enjoy your rabbits!

Nov 25, 2012
Dwarf rabbits mating
by: Anonymous

We have 2 dwarf rabbits male and female 18 months old. They had been together in the same cage since they were approximately 2 months old. For the last six months the male rabbit was trying to mate her but she's not letting him. Any advice on what we can do?
Thank you.

Oct 23, 2011
by: Anonymous

If a sibling male and female were caged together would they mate or should we keep males and females separated?

****Karen Sez****
Siblings WILL mate. You have until they're roughly 12 weeks old max, and then you'd best find separate housing for females and males. Additionally, as males mature, they tend to start fighting as they would in the wild - the dominance thing. So males should get their own cages.

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