The big argument I hear people saying is that designer mixes, or mix breeds are healthier. Its usually the people selling these dogs, or those hell-bent on buyng one saying it however.
I felt this warranted discussion.
Purebred dogs are believed to have MORE health problems, which, is simply a misunderstood untruth - they are not any healthier per se, but they are not any worse off - due to the breeders dutifully health testing, and clearing dogs prior to breeding. Health and longevity in many breeds HAS improved, and usually health problems can be narrowed down to usually a few prime suspects per breed.
Now... when it comes to the myth of hybrid vigor, why would someone think that breeding two breeds together would eliminate any of the health problems within those two breeds?
Lets also consider, that most pet store, or BYB puppies are the ones that people complain about the most health problems in purchased dogs, sad, yet true... and responsible breeders, do NOT allow people to breed their dogs to just anything - so we have to assume, correctly, that the dogs used to 'create' designer breeds are not the best bred animals themselves. (No Ch lines, no health testing for several generations, etc..)
Now, you take two dogs of two different breeds, and whelp a litter. Knowing how genetics works - why would ANYONE claim OR believe that breeding two breeds WITH health problems would ELIMINATE those problems?
What REALLY happens, is the resulting offspring are more prone to the health problems associated with BOTH breeds. With puggles, you get the risks of elongated soft palates, to Pug Dog Encephalitis, heart problems Megaaesophagus, Mastosarcoma Vestibular Disease and MANY MANY more.
Not to mention the conflicting temperament traits... that adds another whole nightmare scenario.
But, genetics tells us that breeding ANY two animals is about combining genes, and possibly doubling up on recessives - which can and DOES happen in ANY breeding - pure or mixed. The merit in buying a wellbred dog from a reputable breeder is in that those breeders are trying to ELIMINATE any of those negative traits from their breeding programs through testing, knowledge and diligence.
The mix breed designer dog breeders just breed two dogs. With little to no concern for the study of recessives, and the fact that HYBRID VIGOR in canines IS A MYTH.
Bottom line - combine two breeds, and you combine the health problems for those two breeds.
Now, you take two dogs of two different breeds, and whelp a litter. Knowing how genetics works - why would ANYONE claim OR believe that breeding two breeds WITH health problems would ELIMINATE those problems? ...
Cinemaboxers, when people write that "hybrid vigor is a myth" where dogs are concerned, they're mostly coming from the point that all dogs are the same species so that crosses between two different breeds of the same species can't strictly be called hybrids, not in the same sense that a dog-wolf mix would be, or a lion-tiger mix. But some of what you're saying flies in the face of intuitive sense. It's hard to buy into your sweeping statements when every dog I've ever known to live more than 15 years has been a cross, and every dog I've ever known to succumb to an inherited ailment has been a purebred, sometimes a costly purebred with show parents. And no, that doesn't constitute research, but it is a point of view borne of decades of experience and observation.
Disclaimer: I'm not a geneticist in any sense but I have worked in epidemiology, including some work trying to sort out familial versus acquired cases of diseases like ALS in military service veterans. But back to dogs: Most ailments known to dog have expressed themselves in just about every known breed of dog. It's a matter of prevalence: whether a particular breed has a high or low incidence of it. If you breed a lab to a toy poodle, presumably their puppies will have a smaller chance of inheriting hip displasia than labs in general, and higher than toy poodles in general. And on down the line of known and unknown problems. If the two breeds have very different lists of most common ailments, of course their progeny will have an excellent shot at good health, since so few of the dangerous recessive genes will have a chance to express themselves. A responsible breeder would start out with specimens of both breeds that are healthy themselves and have clean (perfect doesn't exist)bloodlines. But if you start out from the ironclad conviction that responsible breeders wouldn't mix different breeds in the first place, it's impossible to continue the dialogue. By my definition, there are responsible breeders out there doing just that. And they can't rightly be discredited by pointing to the shoddy practices of bad breeders; it's really two separate issues that shouldn't be confused.
Joan, I'm glad that you have had such luck with your mixes, but I don't know about anyone else on this list but I own 10 dogs, 6 purebred (3 from top of the line breeders, 1 from a show breeder, 1 from a Byb and one from a rescue) and 4 mixes, all rescues. This is not including all of my past dogs, both pure and mix. After years of learning and oberserving all the different breeds and mixes my family have owned, I have found that I have had by far more health problems in the mix breed dogs compared to my purebred dogs. I have had only one purebred that has any major health issues, and that is the one from a show breeder, other than that one purebred, all the rest of the dogs that I have had that have had health issues have been mix breeds. In a couple of years I will let everyone know what I have learned, since I am heading back to college to finish my degree in genetics so I can improve my breeding program. But again this has been my experience with both the purebred and the mixes.
I wasn't just talking about dogs I've owned, but dogs owned by neighbors, friends, relatives, co-workers and other acquaintances. I've never owned a mix myself, though I'd probably go that way next time. And I'd look first at the Pound.
No way you are going to tell me that mixes are healthier. That is just BS. ...
Obviously, our beliefs are influenced by our own experience and observations. Just because my own lead me to different conclusions than yours doesn't mean that I consider yours to be BS. But you've responded with that twice now to my posts. If you can write civilly only to people who already agree with you, whatever. And good luck with that.
Also, people who breed purebreds tend to be more responsible breeders, doing these health clearences and such. Don't believe me... look in your local newpaper, I can almost promise about 2/3 of purebred pups in there will say something along the lines of "hips checked, OFA, CERF," look at any mixed breed it NEVER says anything...
I as well have found my well bred purebred to be more healthy then any other dog I've owned, be they purebred puppy mill rescues, mutts from the pound or rehomed dogs.
Hybrid vigour is a term used in bringing in new blood to a gene pool that has been all but depleted to ensure survival. It does not have to do with purebred dogs vs crossbreeds. When you have only a few animals in a given situation, whether it be geographical, a limited subspecies or otherwise you risk losing all the animals because they will all be so closely related that if something affects one animal adversely it will affect all of them the same way. The introduction of new blood will increase the survivability of that particular group.
Everyone has an agenda, and a reason to take their opinion with a grain of salt. Sometimes the agenda is just defending our own difficult choices. Here's a quote from one locale's SPCA home page. Obviously they have a lot of mixes they'd like to see homed, and if that makes you disbelieve them. so be it. But they've also seen and helped more purebreds and mixes combined than has everyone on this board, combined:
"A 1994 Time magazine article on the effects of overbreeding reported that as many as 25 percent of the 20 million purebred dogs in the US are afflicted with a serious genetic problem. "Mixed breeds, on the other hand, have something called hybrid vigor. When you mix two or more separate gene pools, the recessive genes that carry the health problems are buried. As a result, you get a healthier animal. Simply put, mixed-breed dogs are, in general, healthier than their purebred cousins and typically require fewer visits to the veterinarian."
I haven't had a mixed-breed dog yet, or made a dog purchase in 11 years. Of cats I've had both kinds, and the mixes were much healthier, FWIW, which probably isn't worth much on a Dog board. My purebred lab has cost me thousands over the years just for her Addison's. Her lipomas probably have more to do with old age than being a purebred, but over a thousand just to have 2 of them removed that were interfering with her mobility. When Camilla dies, I hope she comes back as a mix so I can adopt her.
***Edited By: JoanEK on 11/26/2006 6:38:15 PM*** Reason: typo
joan, you are right on. your words flew over the rest of this groups heads... the true definition of hybrid is a mating or breeding between two different speices... thus a pure bred dog x a diff pure bred dog is NOT a hybrid. there fore the term "hybrid vigor" doesnt apply to the mixing of breeds and thus cinemaboxer or what ever her/his name is and has no clue to what she is talking about proven not by me but by the use of her words.
this is a term that very few understand. hybrid...i find very few people that understand as you have joan...
as far as mixing breeds that is a diff. topic.. one i am sure you all know is close to my heart.
the statement that "mixed breeds are healthier than pure breds.... " came into the canine world of the art of breeding dogs by the public themselves... as it is them (the vast majority) who have voted this to be so.
it is also true that the pure bred dogs are vastly improving in thier breeding and health of their dogs. twenty years ago the mutt was healthier than the purebred as i live to tell what i have seen.
with the cry from the public who holds the power of purchase... the breeders of purebreds have stood up and started to pay attention. many do an excellent job (now a days) to do the best job they can in their breeding of pure breds.
also i read someone mentioned the fact that some breeders are out crossing... oh , for sure! and lieing on pedigrees. this is not a new thing. that has been going on for a very long time, before you all were born... people will be people...
Trust me, most members do have an understanding of what the term hybrid means. But we also understood what the OP was trying to say, and instead of going on a rant and rave about the incorrect use of the term hybrid, we responded to her topic. So please do not believe that people are below your abilities of understanding, because you would be greatly mistaken.
***Edited By: GSDgirl on 11/26/2006 9:40:17 PM*** Reason: add
I am glad you posted that! I have seen way too many hybrid breeder websites acting like their hybrids will never be sick and have no chance of genetic defects. I think that is very misleading to the majority of people looking for a dog.
You brought up some very strong points. Thank you for posting that.
Eh, shepalute, I think the beginning of your post towards Cinema was pretty pointless, since they clearly stated that hybrid vigor IS a myth, and you only stated a piece of what we all, including Cinema, already knew. No need to put them down, check back, we know what a hybrid is, there's even threads on it's definition, and how it is taken.
As far as this myth going on health, from personal experience, my purebreds have had the same health as my mixes. Maybe I just got lucky, or maybe I just have dogs who were bred right. Either way, that's what I know to be true.
I breed mixes. I breed Alaskan Huskies/Eurohounds (whichever you like to know them as, which is most likely just "sled dog"). As I said before, their health is the same as my purebreds. However, they tend to be more drivey, lighter, faster, and they can generally run for longer periods of time (mine do anyway). That's about the only difference (aside from appearance and general dog things) between my mixes of husky and hound/setter/etc, to my Chinooks, Inuits and Siberians (as well as my indoor dogs, Pomeranian and Chow Chow).