Purebred vs. Mutt
 

So, I'm in biology, and we have been studying genetics. And I have actually come to found that purebreds are more prone to diseases (digestive problems, etc) than mutts. It was a very intriguing fact that I thought I would share with you guys and get your experiences on.

Why do you think that is?

Ahem..

When different breeds mix. The genes of both parents go to the puppies. .. Those puppies could get EVERY genetic defect from every breed it is mixed with. And maybe only get the genetic defects from one of the breeds, Or 1 defect from each of the breeds.. etc etc.

Neither are better. But that "a mutt has less chance of getting genetic defects" is a load of bull.

Health wise, mutts have no back round, same goes for agression and temperment. Ussually with a mutt, you cant even tell which breeds are there. It could look like a half lab half German shepherd and guess what, there might be 20 other breeds in there. Genes are passed down from dog to dog. just because you have a black mixed breed mixed wit another black mixed breed, doesnt mean your not gonna get white puppies, red puppies, fawn puppies and brown puppies.. Right?;)

you could get a truly aggressive dog mate with a friendly dog and it has non aggresive pups with great temperments.

A female from that litter could have a litter of pups with great temperments.

A female from HER litter could have pups with great temperments.

But uh-oh. a female from her litter, mixed with another stable dog, could have a litter full of truly agrresive (not just reactive) dogs.


Niether is better. Things can happen with mutts so well as they can with purebreds.

IMO, getting a pure bred from a reputable breeder,stacks the deck in your favour.

Purebreds are bred just between their breed right? Their genetic diversity is very limited, because if you trace back their parents, and parents' parents, they are all connected in some way. Just like if you were to marry your second cousin or something. Mutts, and I'm talking about any two crossing of breeds, have more genetic variability, meaning healthier systems, etc.

A cross between 2 breeds is not considered a "Mutt" A cross between 2 breeds, is a mixed breed.

A mutt, is a mongrel.. It is a dog of unknown origins.

Ahem.. It could also have the COMPLETE opposite effect;)

Could you explain to me what studies you did to come to this conclusion?

What kinds of tests did you run?

I think that this is both interesting and true. I have two yorkies and I have an 11 year old high percent wolf and husky mix. I have never ever had any sort of health problem with my mix Kalaya and I think that wolf makes her about as far from a purebred dog as you can get. Her teeth are perfectly white. She still plays like a puppy and spends her days digging up mice and eating berries and apples from our orchard. She is unlike any dog I have ever known and most of her ancestors that I know of lived between 16 and 19 years, which is very old for a large breed dog. In nature there is a variety of potential mates and the sick ones do not make it long enough to reproduce and pass on the bad genes.

When you breed within a limited gene pool, like in the case of a pure bred dog, you are bound to turn up genetic problems. There are also far less breeders out there that do all the necessary testing for the breed than there are ones that do. And not always a test for every problem. I think that this is a big reason why when searching for a breeder you find someone that is breeding responsibly with knowelge of their breed and lines. And who's first priority is health. This will greatly reduce the risk of ending up with a sick purebred.

So, how many health tests do you think are put into the dogs that are producing mutts?A person that lets there little mixed breed dogs breed just for the sake of it, do ya really think tyhey get health tests done? Alot of mutts out there, have yet to even see a vet (There are more owners out there that do not take there animals to vets, then there are owners who do) Most mutts that are out there, are there because somebody just didnt care.. they didnt plan a breeding, they just let there dog get pregnant and figured why not just let the dog have puppies.

That is too simplistic of a statement to be truly factual. While it is true that dogs closely bred are more inclined to pass on some genetic problems, purebreds wisely bred, will also be free of many genetic problems. I took genetics too and your statement is a favorite thing the profs like to pass on but it is not completely accurate. It comes from the fact that if 2 same breed dogs carry a recessive and a dominant gene for a disease state it can result in them each being carriers but not exhibiting the disease/defect. If they mate with other breed dogs that do not carry the recessive genes, no problem -- disease free mutts. But if they do mate with each other, then you could get two recessive genes together that would result in a diseased pure bred (you could also get two of the dominant genes, or a recessive/dominant combo that would be disease free).

I am not aware of any genetic digestive problems that yorkies are more prone to than mutts, but let's take a condition like luxating patella. Yorkies (and other toy breeds) are more prone to this condition. If yorkies with this condition in their history are bred, they have a high liklihood to pass it on. But if a wise breeder spays and neuters any dogs who have produced offspring that have shown this condition, their breeding program will be less likely to produce the problem.

It is impossible to say purebreds will have more of any kind of problem than a mutt when a mutt by virtue of its definition is a dog of mixed parentage. If that mix is even partially the same as the purebred, then they will both be passing on many of the same genetic traits. See what I mean? The mutts may also be passing on traits that a purebred breeding program would have bred out by selective breeding and spaying and neutering any dogs they feel will pass along poor gentics.

As you get into the genetics course you will find there are so many factors that can affect diseases that have a genetic component, that simply saying purebreds are more likely to have digestive problems than mutts is impossible. It is not even just a simple matter of recessive and dominant genes. There are also modifiers to contend with and not all diseases are single gene defects, so it can really become complicated. More complicated than my memory could dredge up! LOL!

I really wish I could retake a genetics class now that I have something I could relate it to. I hope you enjoy the class and maybe you will be able to apply it to Yorkie breeding. But don't let your professor over-simplify to the point he is diminishing the purebred breeding initiatives.

Actually I think I should be talking alleles instead of genes......but that was another chapter....:)

The theory your prof is talking about is hybrid vigor. But... it does not take in to account a breeder that makes wise decisions and there are other things to consider such as: ...."However, some deleterious recessives are common across many seemingly unrelated breeds, and therefore merely mixing breeds is no guarantee of genetic health. The declining overall health of many purebreds is also leading to a decline in the mixed-breed population, especially with the "designer dog" fads. Breeding two poor specimens together does not guarantee the resulting offspring will be healthier than the parents and in fact, due to simple genetics law, the offspring actually stand to inherent the worst of both parents. This is most commonly seen in "pet store puppies". Not all damaging genes are recessive, and there are relatively few single-gene traits. Purebred and mixed-breed dogs are equally susceptible to non-genetic ailments, such as rabies, distemper, injury, and infestation by parasites." from wikipedia..... but there are some genetic predispositions that are going to show up more when closely bred. Have to admit it.

If man did not have anything to do with the reproduction of animals, then animals would experience true natural selection. Only the strongest of the species will survive. If two animals happened to mate, but their offspring were not healthy, the offspring would die. Only the strongest of the offspring would go on to produce more offspring, thus strengthening the species. Also the size of the mother, the father, etc, etc...

so many BYBs and millers nowadays want to breed the smallest, unhealthiest, weakest pups with their wallets in mind. Not strengthening the breed, but strengthening their own greed. So just b/c a pup is a mixed breed or a mutt doesn't mean his bad genes will negate themselves if mixed. If there is an unfavorable gene in their "pedigree" it can and will come out sometime. It is the responsibility of the good reputable breeder to be able to s/n the dogs that have unfavorable genes, and pass on the ones that have favorable ones.

PS. I'm just saying, if you want a "designer dog", that does not mean your dog will be impervious from disease. A bad breeder will pass on bad genes, no matter what dog. A designer dog is sold in much the same manner as a "teacup" yorkie, or worse yet, a "MICRO" yorkie, as one of my customers have told me. *and as a YTer asked me, "Why not a nano?!"*

I don't know anything factual as I haven't done any research on this... however, I have definitely found in my experience with family and friends who own mutts and have no idea what they are mixed with... have zero to very little health problems. Sheer luck? I don't know. But my uncle owns a mutt who went to the vet for the first time in like 4 years a few weeks ago. She's 13 years old right now, a large mixed breed, and perfectly healthy besides a little pain in her joints. My friend owns a 17 year old Black Lab looking mutt. My step-dad owned a total unknown mutt named Judy for 18 years, towards the last year of her life she began becoming blind and deaf but 18 years! Among many others. So... who knows.

This is a very interesting thread. Thanks for posting!

I have to say I'm sure we can all point out different dogs that we've known that are both healthy or unhealthy and mixed or pure breed. I've owned both in my life time and have had the same issues with either dog. We had a large mixed breed that had hip dysplasia at 3 yrs of age. He lived to be 10. Now we have a large Great Pyrenees who is bow legged and is likely to have hip problems. I've got family members and friends who have both mixed and pure breed dogs and it's the same.

I'm just saying that you have to look at the individual dog and it's family tree (so to speak). Personally if I'm purchasing a puppy from a breeder like to know it's line's genetic history with health problems. Otherwise it's a roll of the dice and with so many dogs needed loving homes why not rescue one instead? IMO I'd chose a rescue dog any day of the week:D

Sounds like interesting research, but so much of it depends on how the two groups were chosen. There are many purebreds, and many purebred breeders, and the majority of breeders are not that good, and no better than those breeders who breed mixes. I think if the study just included dogs found at the pound, the results would probably be accurate.

And if Capt Noonie was a nano -- would that be "Nano noonie" or "Noonie Nano?" :D I kinda like the ring of it! My mom had Yorkie that she named Chip way back when PCs were just becoming "the thing." It was short for Micro-chip -- but I supposed today, he could have been a Nano-Chip!

You will probably find certain breeds within the purebred category that are "sicklier" than other breeds. On the surface, it would look like there is something wrong with the breed itself, but with a little more investigation you will learn that the breed is too popular for it own good. When a breed is extremely popular, you get breeders who are breeding only for profit, and not to produce a beautiful healthy dog. Yorkies would be considered one of the most popular, and most genetically at risk breeds. That's why it's extremely important to find a great breeder when you are looking for a dog that's in the top five in popularity. Breeders, who breed lower rated dogs in popularity, are probably on the whole, doing it primarily because they themselves love the breed, and want to do right by it.

I also believe this to be true. I think the clincher is that dogs live significantly shorter lives than wolves, despite the fact that they live pampered lives with optimum nutrition and health care. All dogs come from recessive wolf genes, and it's clear that these are not the best genes for longevity.

Pet insurance also indicates that research confirms mutts are generally healthier, because it's cheaper to insure a mutt. Insurance companies don't have any agenda other than making money, and it is in their favor to price their product properly.

Finally, it's well known that breeders have often bred close relatives, even parent to child to "set" their line. This is bad for species, period. It is never good. It's very clear with inbred humans and it's clear with dogs. There's a reason that nature drives most animals to seek outside mates.

It seems to me that breeding is a dicey business - leaving it up to nature guarantees that you won't have specific breeds, and of course, nature mercilessly culls the weak. On the other hand, we humans with our limited knowledge and varying motives cannot make perfect breeding choices.

I've read that some breeds of dogs can literally be traced back to as few as a dozen ancestors. That blows me away.


(Disclaimer: I'm not saying all breeders are evil or anything like that. Breeding is like the economy - a lot of factors we don't fully understand come into play, and try as we might, we can't really control it.)

Wowza! Ha ha, a lot of replies! I don't think I can answer to every single one! We didn't do any tests in our lab involving dogs. Only plants. My TA was the one who was telling us about genes (and yes, alleles), and how she has a purebred dog that is in the vet every other week, and a mutt (which is the SAME THING as a mixed breed) who is always healthy. (We also took a survey of the class, and all purebred owners took their pet to the vet more than the mutts) Then she showed us why, that when mixing two, true purebred dogs, you are getting only a limited possible amount of genes that could be expressed in the pups.

Don't get me wrong here folks! When breeders do genetic testing to make sure their dog is healthy, that is great! And also expected! It usually makes for healtheir dogs! But if none of that was done, and you were just to mate two, purebred dogs, the likelihood that the pups would be sickly is very high! With a mutt, you have a variety of mixtures of genes, and they are usually healthy dogs with no genetic defects. Of course, there are those some rare occassions where a disease is passed down, etc. etc.

Also, I'm not just talking about digestive problems. It was simply an example. All I was trying to say was that when you keep the breed just in the breed, there is limited genetic diversity. :)

I don't know, I just thought it was interesting and something I never really thought about. We are going to get more into it on Monday, so I will let you guys know what comes up. ;)

You are a genious .

I have also heard that this was true . However, having two purebred dogs myself, so far, they have been healthy . Knock on wood ! i don't have to take them to the vet every other week , nor have they been sick . If this were always true then I would suspect people would not be buying purebreds all the time, and not be wanting them either. It would not be preferred , AND we would also be seeing a LOT of pure breds in the dog pounds and put to sleep in greater numbers then the mixed breeds , overall , in great numbers , then the mixed breeds combined . This is just my opinion , of course. I do feel strongly about buying from reputable breeders and staying away from BYB's puppy miller's and puppy stores . No designer breeds puppy brokers, internet puppy sales , either. Education , education and more education is the key to knowing the propper way to to bring home a healthy sound, puppy for life, no matter pure bred or mixed breed. :thumbup:

I like the sound of Noonie Nano! (We sometimes call her Noonie Nunez) But Uni is DEF not a nano! She's 5 1/2 pounds, perfect size for me! :D

I think you may be thinking of something called Hybrid vigor, but this works only if natural selection is in operation.


"Don't be duped into thinking that mixing breeds will result in healthier offspring. The truth is that puppies, whether purebred or mixed, inherit genes from each parent. If the parents pass along the genes for a hereditary disease, the pups stand a good chance of having that disease. Hybrid vigor—the idea that unrelated parents produce healthier offspring—works only if natural selection is in operation. In the wild, a dog with clinical symptoms of a debilitating disease such as hip dysphasia or epilepsy would not be able to survive, and so would not pass on its genes. But in the modern world, with reasonable veterinary care and a constant food source, dogs with serious, even deadly, problems do survive long enough to produce lots of pups. "

Purebred vs. Mixed Breed and other pet resources - FamilyEducation.com

Wow, thats really rude


I don't have any facts or research to add to the debate, I do have personal experience with both mutts and purebred dogs though. Growing up we had a mutt, he was large breed and had lab and ??? in him. He was as healthy as could be while we had him but my mother was a big animal rehomer and I don't know how old he lived to be. I myself have always had purebred labs, and now a boston terrier and yorkie. My labs have all had no medical issues at all, 2 of them came from BYB and 3 from very reputable breeders that do do all the testing and know their bloodlines. I really feel like it was a gamble with the 2 that came from byb's though, I just go lucky. Anyway, I'm very interested in everyone's thoughts on this (whether they are backed up by research or not) :)

And, a mixed breed and mutt are the same thing.

Haha, just thought it was funny. Look who is talking, genius :p. No need to be mean.

But almost by definition, mutts are driven by natural selection (ie, random mate selection / stronger males more likely to woo females and healthy females more likely to birth pups), whereas purebreeds are planned, no? Natural selection still operates on humans, despite the fact that our lives are significantly easier than they were in the Stone Ages - it's just different pressures, that's all.

In cases where humans are severely inbred, many undesirable traits crop up, and not necessarily related to disease. Intelligence is severely affected, as is height and general health. This was very obvious in western Europe with arranged marriages of royalty (ie, PEDIGREE), when a few too many cousins got into the mix.

I read some interesting cases of breeding gone wrong in Temple Grandin's work. Specifically, she mentions chickens, which are bred for white feathers and large breasts (I think this was a specific line of chickens). Apparently roosters need to do a little dance to get a hen in the mood. Somehow, by breeding for what humans wanted out of chickens, farmers unintentionally bred this courting ritual out of rooster instincts, and these roosters actually rape and kill hens, which is clearly bad for species continuation - it's never a good idea to kill the mother of your eggs.

It depends how you define the word "mutts". I'm not sure what we call a mutt is really natural selection. A large part of natural selection is that only the healthiest can survive to reproduce, as stated earlier, a dog with joint problems, or Liver Shunt wouldn't live long in the wild, so he couldn't pass these traits on.

I agree with you about inbreeding, it can produce extremes in either direction though, but this is different than breeding purebreds, and this is why I recommend breeders study up on breeding and genetics before they hook up their pair.

I have heard the same thing. Thanks for your post. I am interested in hearing more on Monday.

Great minds must think alike. ..... LOL! See my post #10 in this thread....."The theory your prof is talking about is hybrid vigor. But... it does not take in to account a breeder that makes wise decisions and there are other things to consider such as.....:"

PS -- I am JK here and not calling either of us a genius. Wanted to make that clear before .... well you know.....:D