# Inbreeding



## Oliyks (May 4, 2021)

Hey fellow breeders! I'd like to have your opinions on one matter. 

I have my eye on a female kitten I'd like to purchase for my cattery. The issue is that she has several ancestors common with my male, making the inbreeding coefficient of their potential kittens 15,7%. I know these ancestors in question, the offsprings they have produced, all healthy and of good quality. In my understanding inbreeding enhances all the positives and also the negatives, but I have not seen any negatives to write home about in these lines over multiple years. I have asked around for opinions on the matter and have got conflicting ones - one breeder saying that she would never work with anything over 0%, the other saying that if I am confident about the health of those lines then she wouldn't see any issue whatsoever. Needless to say, I really like that female, huge potential, good pedigree and the offspring in combination with my male could be amazing. I have a possibility to use an outside stud with her but I would probably not buy her if I wouldn't be able to use her with my male. 

So please give me your opinions and help me reach to the decision. Have you worked with the lines so close together? Would you do it considering the above?


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## Lunarags (Jan 16, 2021)

I dont know what breed you are interested in but with ragdolls the gene pool is very small and im not even sure its possible to get a 0% inbreeding coefficient with them, never mind how hard it would be to even get a very low coeffecient. I would breed with them if they tested negative for breed related congenital conditions and are otherwise in great health, especially since she sounds like a great match for your male. My ragdolls share several ancestors im their 4th and 5th generations and i dont think my stud has ever found a queen who doesnt share at least 2 or 3 ancestors in the 4th and 5th generations, many of whom were carefully inbred. 99% of the time the kittens he produces are the picture of health

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.gccfcats.org/Portals/0/Outcrossing%20Policy%202017.pdf?ver=2017-03-29-143710-263#:~:text=First%20degree%20inbreeding%20is%20now,risk%20of%20genetic%20health%20issues.&ved=2ahUKEwiA1uD-vK_wAhXFRxUIHf32DSEQFjABegQIBBAG&usg=AOvVaw2fRMlEORmaKNWqgXL2H5jW

Gccf info on inbreeding coefficient found on page 4


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## Oliyks (May 4, 2021)

Lunarags said:


> I dont know what breed you are interested in but with ragdolls the gene pool is very small and im not even sure its possible to get a 0% inbreeding coefficient with them, never mind how hard it would be to even get a very low coeffecient.


Thank you for your opinion and the reference! I work with Maine Coons - bigger gene pool and 0% is very achievable. As I see from the policy, 10-20% is considered fair. I have never had to deal with it, so in my opinion everything over 10% was already unacceptable


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## OrientalSlave (Jan 26, 2012)

Oliyks said:


> Thank you for your opinion and the reference! I work with Maine Coons - bigger gene pool and 0% is very achievable. As I see from the policy, 10-20% is considered fair. I have never had to deal with it, so in my opinion everything over 10% was already unacceptable


Personally I think 10% is fine but 20% is not. The boundary in-between is blurry but my feeling is that 15.7% is probably near or on it.

The common cats in the pedigree - any sign of HCM? Being negative for the MCO HCM gene doesn't rule it out. How old are the common cats? How many generations is the inbreeding over? If you keep a kitten for breeding, can you provide a complete outcross for a mate? And most importantly, does this kitten bring anything you can't get in a less related cat?

In my breed there are a lot of cats heavily inbred 20-30 years ago, and a lot of people bemoaning they now aren't as long lived and robust as they used to be. Personally I think the two are connected.


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## spotty cats (Jul 24, 2012)

OrientalSlave said:


> The boundary in-between is blurry but my feeling is that 15.7% is probably near or on it.


Agree. That would be getting much too high for me if you're only looking at 5 generations and not back to foundation.

Some breeds are becoming much too high and will cease to exist in years to come if they carry on that way.


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## QOTN (Jan 3, 2014)

This is a very tricky problem. I have done complete outcrosses and got something less than ideal into the line and I have done some closer matings and had kittens who lived well into their teens. Obviously, from the point of vigour, it is always better to outcross, but I have more than once added the only testable gene for our breeds into my line even with an 0% coefficient.

I have just checked a boy of mine who I only allowed other people to use because he was out of two quite closely related cats of mine and his percentage was 3.12 on Pawpeds.

You have to bear in mind that the results of the mating you are considering cannot be completely known until you actually do it. Personally I would think twice but, if you decide to risk it, I do hope you will test for recessives like Pkdef to try to eliminate at least some of the risk.


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## OrientalSlave (Jan 26, 2012)

From the GCCF website:

"Breeders are encouraged to work towards a low inbreeding co-efficient level, and to refer to the pawpeds program available on line to draw up planned matings, in order to assess such levels. (http://pawpeds.com/userguide/) It is not recommended that an inbreeding COI of more than 6.25% should be allowed, and ideally, should be as low as possible. This is equivalent to the breeding together of first cousins. More information is available on the link given. In addition, the MCBAC would strongly advise that current gene tests for HCM are undertaken to identify the status of cats before breeding. This can be followed up with later scanning and work is currently underway to arrange this facility in the UK at a cost that would make it more advantageous to breeders. There are other genetic tests, for SMA (Spinal Muscular Atrophy) and for PKD (Polycystic Kidney Disease) that breeders may well consider advantageous to have done. Neither of these diseases have been much evidenced in the UK, but are known to exist in Europe, and may well be worth considering, particularly for cats imported from European lines. For further information on health issues, see the section on page 14 on Genetic defects."

https://www.gccfcats.org/Portals/0/MaineCoon.BP.pdf

Remember that if you belong to a breed club in the Langford scheme you get 20% discount on DNA tests. Langford advise testing MCO for MCO HCM, PKDef and SMA.

https://www.langfordvets.co.uk/media/2166/genetic-diseases-by-breed.pdf


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## Maurey (Nov 18, 2019)

Oliyks said:


> Thank you for your opinion and the reference! I work with Maine Coons - bigger gene pool and 0% is very achievable. As I see from the policy, 10-20% is considered fair. I have never had to deal with it, so in my opinion everything over 10% was already unacceptable


My female MC neuter was product of a carefully planned and researched brother-sister breeding - the father, who is now a show neuter, and who I also currently own, has perfect temperament (very gentle, people oriented, social), and near perfect conformation (short tail for his huge frame, slightly small chin, smaller lynx tips than the breeder was aiming for), so he was paired with his littermate, who had complementary features to him with a huge tail, good chin, thick lynx tips. That said, breeder knew ancestry 10+ generations back and there was nothing in common with their ancestors, and none had any serious breed related issues like HCM or PK def surface. They were also both extensively tested for everything under the sun.

While none of their offspring went onto be quite what the breeder was looking for in terms of line continuation, so they were never crossed again, nothing has occurred health-wise in the litter that could be related to the inbreeding. Jum has a congenital issue where the buds of 3 of her adult canine teeth were improperly developed, so she never grew them in, but she was the only kitten in a litter of 7 who had the issue, so there's no reason to believe it's genetic. I'm in touch with most of the other owners of Jum's litter, and none of them have had health problems other than some sniffles :> they're young, of course (just over 2), but I've no reason to believe that anything is likely to surface, though both my cats have HCM screening before their dentals, as it's a requirement of my vet dentist before elective anesthesia of breeds that have propensity to HCM.

That said, personally, wouldn't endorse breeding to heighten coefficient, if it's avoidable. Had I known Jum was inbred prior to meeting her and getting attached to her wonderfully personality, I'd never have taken her, I think.


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## QOTN (Jan 3, 2014)

Mother-son, father-daughter or sibling matings are not allowed to be registered active on GCCF.


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## Maurey (Nov 18, 2019)

QOTN said:


> Mother-son, father-daughter or sibling matings are not allowed to be registered active on GCCF.


GCCF isn't a registry that's present where I live. We only have WCF and TICA.


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## QOTN (Jan 3, 2014)

I think it is one of the reasons why, whatever we say about the GCCF, it is not all bad.


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## Maurey (Nov 18, 2019)

Disallowing close breedings is one of the best things about GCCF, though I have my reservations about showing in it over TICA after I move, even if TICA shows are rare in the UK. There’s just no good reason to risk heightening inbreeding coefficient in established breeds that have good genetic diversity.


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## Tigermoon (Apr 2, 2013)

Oliyks said:


> The issue is that she has several ancestors common with my male, making the inbreeding coefficient of their potential kittens 15,7%.


Over how many generations is this?? If it's only back to Great Grandparents, then I would be seriously unhappy about that sort of %. You'll also need to plan the next generation carefully to drag that coefficient down whilst maintaining the type you've built up over time, and that is not at all easy.



Maurey said:


> Disallowing close breedings is one of the best things about GCCF, though I have my reservations about showing in it over TICA after I move, even if TICA shows are rare in the UK.


I'm surprised you'd bother switching codes to be honest, especially as they are run so very differently.


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## Maurey (Nov 18, 2019)

Tigermoon said:


> I'm surprised you'd bother switching codes to be honest, especially as they are run so very differently.


I'm vaguely considering GCCF over TICA only because my show boy isn't currently dual registered - the breeder passed before she could get it sorted for him, with COVID delaying showing anyway, it wasn't priority. I'll have to register him if I want to continue showing once we move, anyway, so it's worth at least considering both.
That said, as he's a neuter, and I'm unlikely to take up breeding in the next 5-10 years, I may just stick to casual TICA showing - he doesn't really "need" premiership titles. Chips really enjoys WCF showing, and he preens when he hears guests marveling at how gorgeous he is haha. He'll strut when someone who finds him particularly gorgeous stop by


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## OrientalSlave (Jan 26, 2012)

Maurey said:


> I'm vaguely considering GCCF over TICA only because my show boy isn't currently dual registered - the breeder passed before she could get it sorted for him, with COVID delaying showing anyway, it wasn't priority. I'll have to register him if I want to continue showing once we move, anyway, so it's worth at least considering both.
> That said, as he's a neuter, and I'm unlikely to take up breeding in the next 5-10 years, I may just stick to casual TICA showing - he doesn't really "need" premiership titles. Chips really enjoys WCF showing, and he preens when he hears guests marveling at how gorgeous he is haha. He'll strut when someone who finds him particularly gorgeous stop by


Where you end up living might determine who you show with. TICA shows are all fine if you live in the right bits of the UK but many parts would need a lot of travelling to get to them.


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## Lunarags (Jan 16, 2021)

@Oliyks more conflicting opinions for you then :Hilarious


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## Oliyks (May 4, 2021)

OrientalSlave said:


> The common cats in the pedigree - any sign of HCM? Being negative for the MCO HCM gene doesn't rule it out. How old are the common cats? How many generations is the inbreeding over? If you keep a kitten for breeding, can you provide a complete outcross for a mate? And most importantly, does this kitten bring anything you can't get in a less related cat?


I am not worried about hereditary diseases that much - three full generations of both the named male and female have been all tested for HCM, PKdef, SMA at least. Probably the earlier generations as well, but I can't claim that since I have not seen the test results myself. But all from breeders who don't work with carriers. Before using a cat in my breeding program I always do HCM screening as well, as I don't want to rely on genetic tests only. The common ancestors are 9, 7 and 6, all with completely clear track record for themselves and their other offsprings.

Yes, the traits that I'm looking for would be also possibly available in some other cats. But I wouldn't have such deep knowledge of other lines and full visibility of previous offsprings of the parents. I have a bit of a trust issue and not every breeder is willing to admit that their cats might have had some problems.

GCCF doesn't apply to me, I belong to Fife system. And yes, this mating has to be approved by the club beforehand so I will definitely discuss it with my club as well.


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## lillytheunicorn (Nov 17, 2012)

FIFe doesn’t have any specific rules about COI of inbreeding. 

What are your plans for any offspring? If you are to keep any for breeding, will you be happy to bring in a new breeding line for any you keep? If you are looking at a pool of cats with similar relatives again you will only be increasing the COI for the next generation.


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## Oliyks (May 4, 2021)

lillytheunicorn said:


> FIFe doesn't have any specific rules about COI of inbreeding.
> 
> What are your plans for any offspring? If you are to keep any for breeding, will you be happy to bring in a new breeding line for any you keep? If you are looking at a pool of cats with similar relatives again you will only be increasing the COI for the next generation.


The only inbred mating would be with my current male and this new female. If I would accomplish what I'm looking for from this breeding, then I will keep a female from there indeed, but then I will use an outside stud for her. Mating the outside stud I currently have in mind with the potential offspring would give a nice clean 0% again. If my plans for this mating will not give the desired result then those kittens will be sold only as pets.


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## lillytheunicorn (Nov 17, 2012)

@Oliyks i have done closeish matings same cat twice in 3rd generation. Her COI was only 4.95% as her grandfather was an import. However it meant that I would have to have imported a cat to breed from her as I was limited in the cats I could use as she is an almagation of lot of very nice cats who are in a lot of pedigrees.


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## Lunarags (Jan 16, 2021)

@Oliyks clearly you've thought carefully about it and considered matings for kittens with litter COIs, and you're doing it to further the breed I think it's a perfectly good plan


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## lenanowa (Apr 15, 2019)

The most important thing to remember with inbreeding / line breeding is that yes, you’re locking in good traits (and tbh, the few breeders I know with very consistent “look” to their cats, achieved it through line breeding), but you’re also locking in faults, and that can be difficult if not impossible to come back from. That’s why, IMO, only very experienced breeders should ever attempt it. Good luck whatever you decide


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