Dispelling myths about dog breeding

Discussion in 'Labrador breeding & genetics' started by pippa@labforumHQ, Jul 11, 2019.

  1. pippa@labforumHQ

    pippa@labforumHQ Administrator

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  2. J.D

    J.D Supporting Member Forum Supporter

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    Hi Pippa
    This was a bit too technical for me but I have been doing some research of my own into why Toby(18 months old) is battling cancer.

    I came across an article on here about coefficient of inbreeding and looked up Toby’s. It is 8.8% so higher than the ideal 6. something or below. His parents share a great grandfather and great great grandfather. My conclusion from that is that he may have a double dose of the gene for mast cell tumours and maybe the breeder should have considered the COI more closely. Please correct me if I am barking up the wrong tree here.
    I went from that to see if there was any research being done and came across the Animal Health Trust.
    They are researching a test for mast cell tumours which will help identify those more likely to metastasise and therefore those more likely to benefit from chemo.
    They are also looking specifically at genetics in labradors. The article is below.
    There are several ways we can help with the research. With Toby specifically I can arrange for his biopsies to be sent to them and with regards to the genetics a mouth swab.
    Hope this is of some interest.

    https://www.aht.org.uk/news/new-res...t-thousands-of-labrador-and-golden-retrievers
     
  3. pippa@labforumHQ

    pippa@labforumHQ Administrator

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    Very sorry to hear your dog has cancer, especially at such a young age. It's good that you are able and willing to help with research to combat this horrible disease. The susceptibility to cancer has been shown to be greater in some breeds than others but there is still so much we don't know. I sincerely hope your lovely young dog pulls through.
     
  4. Jo Laurens

    Jo Laurens Registered Users

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    8.8% is not really that high. Many dogs and breeds have COIs around 15%. My Weimaraner was 12%. Yes, the breed average for labs is 6.5%, but that is quite low when compared to other breeds. It's great that it is low for labs and we should all be striving to keep it that way, and 8.8% is above average - but that's unlikely to explain his cancer. It would be good to find out if any other relatives of his have experienced MCTs, though. I hope he is doing ok.
     
  5. J.D

    J.D Supporting Member Forum Supporter

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    Hi Jo
    Toby is doing ok as far as I know. He has had 5/8 chemo sessions. They haven’t been able to get him up to the maximum dose as his stomach won’t take it. Will know more when he has tests again at the end.
    The breeder has said she hasn’t heard of any other problems but also said they didn’t all reply and she may not have up to date details(there have been two large litters with the same pairing) Toby was one of 10.

    One of the reasons I looked at his COI was an article on here from last year on
    “Coefficient of Inbreeding”
    In that conversation you said :-

    “The average COI for labs is 6.5%. You should be looking for a breeder producing pups at or below average. Our last litter had COIs of 5.9% in 2016. This year, we are slightly higher at 6.9% - but that's the very highest I would ever consider going”

    So I’m quite surprised you don’t think 8.8 is high.
    His mother’s COI was 3.2 so she could have kept it well below the average if she had chosen another father.
    I’m not trying to find someone to blame but if anything can be done to prevent other owners going through the horrible time we are at the moment a bit more care/research must be worth it.
    I’ll keep the group posted if I hear anything else about the Animal Trust research.
     
  6. Jo Laurens

    Jo Laurens Registered Users

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    It's all relative - it is a bit higher than ideal, but it's not shockingly high. It is probably about average for a working/field bred Lab, going by litters I've seen advertising and by spending ages with Mate Select looking for stud dogs myself, it is commonly what comes out when different working combos are put into Mate Select... 6.5% is the average for the breed as a whole, which will include show bred Labs, and labs that have some blood from both show and working in there.

    Lastly, really COIs are pretty meaningless although they are all we have most of the time to go by. The reason being that COIs assume the same genetic material is inherited by all puppies in a litter. Whereas actually that's not the case. Some puppies in a litter can inherit a lot of genetic material from one parent and not very much from the other - and vice versa - and the same for grandparents... The genetic makeup of puppies in the same litter, therefore varies considerably. We know this from Embark and BetterBred, which work by DNA testing to determine the exact genetic level of inbreeding of individuals and are therefore way more preferable to COI.

    You can read more about COIs and why they are pretty much meaningless - although all many of us have at the moment - here: https://www.betterbred.com/2019/01/...rbred-and-uc-davis-vgl-canine-diversity-test/

    Embark and BetterBred will be very useful but require more people to DNA test their dogs and get them on the databases. The databases are only as useful as the number of dogs recorded.
     

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