Mixed breed VS purebred health

Discussion in 'Dogs - General Dog Chat' started by milos_mommy, Mar 13, 2013.

  1. milos_mommy

    milos_mommy Active Member

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    Spin-off of the GSD thread:

    Regarding genetic issues, are there any concrete reasons to believe purebred dogs or mixed breed dogs are less predisposed to them? I'm talking specifically about unhealth tested dogs, from unknown backgrounds.

    What about other issues, like issues that may stem from physical conformation? Or environmental factors? Does breed, or rather purebred/mixed breed, have an influence on how a dog develops environment influenced disorders?

    Here is what I was going to put into the other thread, before I decided we needed a new one:

    "I'm fairly certain that mixed breeds are less predisposed to genetic illnesses...it's not that one parent has or carries a disorder, so it's likely for offspring to have it, and therefore opens up a large pool of genetic disorders for mixes. Usually (at least for many disorders) BOTH parents need to be a carrier of the disorder. So if you're breeding two dogs who's genetic issues don't generally overlap, you have a better chance of the dog not developing that specific issue. It's the same in people - if two people of an ethnic group known for carrying a specific gene for a disease, for example, Tay Sachs, reproduce, the child has a higher chance of being unhealthy. If someone of that ethnic group reproduces with someone of another ethnic group with a DIFFERENT prevalent disorder (sickle cell anemia), the child has a much less chance, or no chance at all, of having those disorders. It's not that they're now predisposed to both disorders."

    But, as I mentioned in the other thread, I don't know THAT much about genetic disorders, and I'm not entirely sure that's accurate. There are obviously way too many factors to state "mixed breeds are healthier" or "purebred dogs are healthier", but is it safe to say that generally (discounting two breeds who are often carriers of the same disorder) that genetic issues are less common in mixes than untested purebreds?
     
  2. Saeleofu

    Saeleofu Active Member

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    Without health testing? It's a crapshoot either way.
     
  3. sassafras

    sassafras mushinois

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    Well IMO all dogs may be predisposed to certain health problems based on their genetics. But with purebreds, you generally have a better idea what problems you might be in for (particularly for poorly bred dogs).

    It doesn't mean mixed breed dogs don't have genetic predispositions to diseases or are healthier overall, it's just that your radar may not be up as much for specific problems as much as with a purebred. Maybe people perceive that as meaning that mixed breeds are healthier?
     
  4. Beanie

    Beanie Clicker Cult Coordinator

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    Agreed.

    What you're talking about as far as both parents being carriers is any disease that follows the Mendelian pattern - there are tons of genetic disorders that do not follow that pattern and, even among those often believed to follow the pattern, still cases where oddities pop up.

    Even WITH health testing, you still have oddities pop up.

    Genetics. Not that simple.
     
  5. milos_mommy

    milos_mommy Active Member

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    Yes, true, but would you argue there is the same probability of the mixed breed dog having a genetic issue as there is the purebred?

    Lets say you have two groups of dogs of two different breeds. They aren't predisposed to any of the same genetic issues...let's say the first group carries for X disorder, and the second group carries for Y disorder.

    Say there are 50 dogs of each breed in each group.
    Say 30 of each breed is carrier for their given disorder (X in group 1, Y in group 2).
    Say 5 of each breed is a carrier for the other disorder.

    If you breed the dogs in group 1 together, there is a much, much higher chance that they will have X disorder. If you're mixing them, there isn't an equal chance the dog will have X OR Y disorder, or MORE of a chance for them to have a genetic disease. It's much less of a chance.

    Or is there something wrong with my highly scientific evaluation? :rofl1:

    Aside from the fact it doesn't consider that most genetic disorders are prevalent in a number of popular breeds.
     
  6. milos_mommy

    milos_mommy Active Member

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    Right - but do mixed breeds have a higher chance of developing a genetic or non-genetic disorder that doesn't follow that pattern?
    And if they don't, wouldn't the probability of a mixed breed being "healthy" go up, just because you're ruling out a plethora of issues? There's still a high chance they'll have a different type of disorder, without health testing, but wouldn't the probability be lowered?
     
  7. sassafras

    sassafras mushinois

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    Also, it's likely that few genetically-predisposed disorders have a simple, one-gene pattern of inheritance.

    The famous example of one that IS really simple is the LUA dalmatians - one pointer in the mix and subsequent careful breeding affected the incidence of that disorder tremendously in those lines.

    But most diseases with a genetic component are probably not only controlled by multiple genes, but the expression of those genes is probably affected by environmental factors.
     
  8. release the hounds

    release the hounds Active Member

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    I really don't know :)

    I've had more than a few shepherds here and I have not had one with dysplasia or bad elbows. The biggest issue has been allergies of some sort. Not any hair falls out, skin is about to type allergies, but enough to get them itching and scratching at times.

    I've known a few shepherds that weren't mine to have dysplasia, heard of others with pancreatic issues, but have never met one and Mega E as well, again never met one, but i know they are out there.

    That said, I run into mixed breed dogs all the time that have problems. Genetic? I don't know, but severe allergies, skin conditions, eye problems and things that send them to the vet that cost thousands.

    I don't really buy that one is any more healthy than the other. I know if I go to breeders I like, my chances of getting a puppy that will grow to a healthy adult is pretty high.

    I feel that if I went to a shelter and just picked any dog, i'd get health issues a lot of the time.

    By the same token, if I went to a shelter looking for a specific type dog, I bet I could get a healthy one a lot of the time too.

    of course I have no science to back me up, other than I am always right.. So there :)
     
  9. AdrianneIsabel

    AdrianneIsabel Glutton for Crazy

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    I have no faith that mixed breeds retain any better health than casually pet bred UNtested purebreds, let alone carefully bred, proven and or tested purebreds.
     
  10. Beanie

    Beanie Clicker Cult Coordinator

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    No, a mixed breed is not more at risk of developing any disorder, Mendelian or not. And no, the fact that they are not MORE at risk of developing a disorder does not thereby make them LESS at risk. Your risk is basically the same - a dog of unknown health history, carrying who knows what, prone to throwing who knows what, potentially going to produce a dog who might end up with who knows what genetic mutations. If the dog is a mix or our definition of a "purebreed" it doesn't really matter.


    Can you explain how you think a mixed breed rules out a plethora of issues?
     
  11. Romy

    Romy Taxiderpy

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    A lot of health problems common to non health tested stock are inherited the same way across breed lines.

    Hip dysplasia is not uncommon in labs, GSDs, and a plethora of other breeds. It's much MORE common in lines that aren't health tested and selected against that defect.

    So when you start mixing non health tested individuals of breeds that share the same disorder, you're still going to get affected puppies.

    Out of all the dogs I know, the majority are purebreds. Out of all the dogs I know that have died of cancer, 3 were purebreds and 11 were mixes. In my own personal experience that is a hugely disproportionate number. I have no idea of that's representative of anything bigger, but I don't believe mixes are inherently healthier by virtue of being a mix.
     
  12. milos_mommy

    milos_mommy Active Member

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    I didn't mean rule out - but for at least some disorders, they're going to be very reduced. One example might be Basset Hounds and Thromopathia. A basset hound mixed with any other breed would not (barring any unusual or unheard of anomaly) have thromopathia, even if the basset parent was a carrier.

    There are lots of other diseases like that. Many of them might be found in multiple breeds, so that's something to consider (a dobe X GSD wouldn't be less likely to have Von Willebrand than a purebred dobe or GSD...but a dobe X husky would be less likely to have it).
     
  13. Flyinsbt

    Flyinsbt New Member

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    Even with an unusual condition which is limited to one breed, it only takes one crossbred to spread it into the mixed breed population.

    Take L-2-hydroxyglutaric aciduria (L2-HGA), which is a very unpleasant neurological disorder in Staffords. It's an autosomal recessive, so it's method of inheritance is simple, you just need to have 2 carriers match up. We have a test for it, so we can identify the carriers.

    On a Stafford forum, one poster told us that a dog of his breeding which tested as a carrier had been used in a cross-breeding. I don't know why, but what that means is that the pups of that breeding will not have L2-HGA, but there's a 50/50 chance that they carry it. If they carry it, there's a 50/50 chance their progeny would also carry it. And so on, until one of those carriers breeds with another carrier. Could be that they're related several generations back, or it could be a separate incidence of the condition entering the mixed breed genepool. Either way, it's entirely possible that a mixed breed dog could have that condition.

    Now of course, any other purebred will not have that condition. The worst bred GSD in the world, with no health testing done, ever, is not going to have L2-HGA (except in the extremely unlikely case of a spontaneous mutation). The condition isn't in that genepool. But in a non-isolated genepool, you can't rule anything out. All conditions are possible.
     
  14. OwnedByBCs

    OwnedByBCs Will Creep For Sheep

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    Funny, I was just discussing this with my mom yesterday.

    I think the main reason that people believe mix breed dogs are healthier than purebreds is because you don't hear about health problems in mix breed dogs. Shelters don't go out and OFA every dog they get in- and if someone's rescue dog passes away young, it isn't reported- who would you report it to?

    I think the problem is that saying "purebred dogs" and "mix bred dogs" is so completely vague- there is so much more to it than that. Redneck Joe breeding his two coonhounds together because he wants to make some cash is not going to health test his dogs, and so you can have absolutely no guarantees as to their health. If those dogs have health problems, it is not because they are purebred, it is because they were BADLY bred. Same with mix breeds.

    It simply is not cut and dry as you want it to be.
     
  15. sassafras

    sassafras mushinois

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    Well and you don't hear about consistent health problems in mixed breed dogs. 100 mixed breed dogs are probably (in my experience anyway) going to have a different distribution of health problems than 100 golden retrievers, or 100 westies, or 100 bichons, or 100 whatevers.
     
  16. Red Chrome

    Red Chrome New Member

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    Von Willebrands is not common on GSD. Just want to clear that up.
     
  17. Laurelin

    Laurelin I'm All Ears

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    First thoughts. 1. What kind of mixed breed? F1 cross? Unknown multi mix? Island type population where the dogs are mixes but probably all related? Which breeds?it makes a difference. Many of the issues you see most often are found across breeds. Ex being my gsdx golden wih hip dysplasia. Another issue is that often purebred owners may know about an issue that is common in he breed therefore they may keep an eye out for it. Ex being Mia's knees. She is totally a asymptomatic at this point. If you weren't looking for luxatong patellar you would never have known. I know many dogs that are dysplasia, etc that live quite fine in a normal life. How many mixes have an issue no one knows about? Now I certainly think mixes can be healthier but it depends on the mix or the purebred you are comparing to. it's not cut and dried.
     
  18. Saeleofu

    Saeleofu Active Member

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    If hybrid vigor is what you're trying to get at, it doesn't work like that. That's hybrid vigor when species are crossed. All breeds of dog are the same species. It's not like breeding a horse and a donkey and getting a mule that can outperform both its parents.
     
  19. Miakoda

    Miakoda New Member

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    This.

    In my life, it's been my mixed breeds with myriad health issues.
     
  20. Psyfalcon

    Psyfalcon Fishies!

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    You do start to escape some of the purposely bred extremes though.

    Mixes of GSD tend not to have the extreme and sometimes weak rear end common to the show and pet lines. A mix with a Lab will be very unlikely to have that problem even though common disorders aren't ruled out.

    In many cases its not a problem of a line carrying a problem, but the breed having one or two major goals. Bassets are short and wrinkled. Both have some incidence of causing problems. You can find short dogs that are probably Basset mixes that lack the wrinkles.
     

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