Does cross breeding eliminate/tend to lessen genetic problems that are inherent to either parent breed?

I was in the same course you were... perhaps I paid attention a bit more.. lol.

In theory, if you had exhaustively tested both parent purebreds, and they both checked out as good, healthy specimens then you could create a mixed breed line that holds the same quality of traits, or better.

The process by which this occurs is called Allelic Drift.

Read up on it a bit with your old genetics textbook, (you know it's upstairs somewhere!lol).

Interbreeding foreseen problems notwithstanding, (ie. anything related to breeding the god damn english bulldog and it's nightmarish genetic pool and C-sections) It is pretty accurate to say that offspring would be healthier and probably genetically superior over a few generations.

Seb, there are other unforseeable factors that will in some way contribute to a healthier generation of offspring. Somatic and de novo mutations would play a role in optimizing the offspring. (aka Muller's neomorph)

Also, in the case of a breeder breeding 2 separate purebreds, one would not be inclined to agree with Hardy-Weinberg principle about population health remaining constant. This is because the field is limited.

ADD: I CAN NOT BELIEVE THE TONE OF WOLF FEMME... and her profile says she's 16. What the hell does she know about biological sciences past Sophomore year of HS? So you've dedicated your life to Canidae huh? still doesnt mean you've progressed to possess a bachelors or Ph.D in the subject. Go ahead and be pretentious when you do get that BS or MS, or Ph.D NOT BEFORE. How was your Prom? lol Stay in school young one. The confidence of youth is no substitute for wisdom and formal training/a degree in the subject! lol

A. Wolf Femme is assuming that all "mutt breeders" wouldnt take the same care to exhaustively genetically test their offspring to ensure line optimization. One has problems arise when one assumes ALL or NONE, as Wolf Femme so often does.

B. Wolf Femme: perhaps Seb wrote "hybrid" because he's appealing to the idiot masses on the dog section who don't have a degree in biology and wouldn't respond to a question which they didn't understand. The tone you take when you tell Seb to "go do research about what a puppy mill is", is an insult. What an arrogant little thing you are!

C. Here is some of the "current research" that denotes exactly what SebScola is saying Wolf Femme (see link below)... again with the nasty comments of "By whom, unknowledgeable high school chem students?" WTF, why would chem students do research on a biogical/genetics paper?

Anyways, perhaps you should read this paper- If the scientific vernacular isn't above your Sophomore HS education! http://www.naiaonline.org/pdfs/LongTermHealthEffec...

FYI, NAIA is a reputable Animal Welfare group and the paper answered every checklisted question you ranted on and on about at the end of your posting. So, Go do YOUR research, cause Im not gonna do it for YOU!

D.Grow up and learn to treat people with respect; you are interrupting while scientists are talking.

(Seb, AMAG got a new FTIR Spectrophotometer the other day... and yours truly will be conducting the IQ/OQ/PQ and method development and optimization. This means padding of the resume for Bristol Myers Squibb position.)

Yes and no. It depends on the genetics of the parents. If, in your example of 2 hip dysplasia prone breeds, neither has hip dysplasia, the puppies would be unlikely to have it. However, if one has it and the other doesn't, there's a good chance of having it in at least some of the puppies. If both parents have it, it's almost certain that the puppies will as well.

Some of the most popular combinations people try to advertise involves breeding a non-shedding dog (like a poodle) with one who sheds (like a lab). They say the puppies will not shed (like the poodle), but will have the more easy going personality of the lab. This isn't true. Most of the puppies still shed to some degree. Some shed very little, some shed a lot. Some are more easy going, some are not. Crossing breeds does not mean the best traits of each breed are being brought together. It simply means some traits from each breed are being brought together, whether they are good or bad. It is impossible to predict which puppies will inherit what genes.

Compare it to a child born to a parent with blue eyes and the other with green. The child could get either the blue or the green, but there's no way to know which until they are born.

If you were trying to make a dog, say a labradoodle as in our last example, that does not shed, is easy going, doesn't have hip dysplasia problems, and is not prone to allergies, you would have to find parents in each breed who didn't have hip dysplasia, didn't have allergies, had the right personality, and (in the case of the poodle, does not shed) and breed them. Then you would have to take the puppies and find the ones who showed the qualities you were looking for (none are likely to have all of them-you'd find the best examples of each for now), and breed them together. Then you choose the best examples in those puppies and breed them, and so on. This is how breeds are developed. You can probably see that this kind of breeding leads to inbreeding, which tends to bring out recessive traits over time. This leads to the new breed you created having other specific problems based on whatever was in the original parents' genetics, but didn't show up because they were recessive. These may include good traits or bad (liver shunts, knee problems, heart problems, etc.)

not necessarily. In cross breeds(what people refer to as hybrids) the dogs have just as much of a chance of inheriting the bad as they do the good. However in a true Mongrel where you have no clue what the dog is, then yes, these dogs are in general healthier because the genetic pool has been diluted so much. However, a well bred purebreed dog can be just as healthy as a mongrel because these breeders work very hard at whelping healthy dogs via genetic testing and the right breeding program.

edit: Hip dysplasa is not related to early neutering. What is confirmed is the growth plates don't close on times and the limbs will grow longer but there is nothing to prove that will cause any issues. The paper that everyone seems to refer to was written by a woman who has never identified her credentials at being able to analyze medical papers. the other dr, Dr. Zink has had a number of rebuttals questioning the conclusions reached.

You need to work to eliminate the bad trait. Genetics does not care if you are breeding a mutt or a purebred. It takes a basic understanding of genetics. A dominate gene will be evident and will pass this gene on to 1/2 of its offspring who will also show the gene. If the dog has 2 copies of the dominate gene 100 % of the puppies will have that gene. A recessive gene may not be evident but will be passed on to 1/2 of the offspring and not show up in the offspring until it is matched up with another of that recessive gene. If the dog that is showing the recessive gene is bred to a dog that shows the recessive gene then 100 % of the puppies will have that trait. If a dog showing the recessive trait is bred to a dog without that gene, then none of the pups will have that trait but be carriers.

So to answer your question. If two dogs with hip displaysia of different breeds are bred then the pups have an equal chance of having hip displaysia as if breeding two affected dogs of the same breed. In fact, you are now introducing the bad genes from both breeds on top of it.

Hybrid vigor within the same species (dog to dog) is a myth. (they are not Hybrids as you know) It is a marketing phrase by the BYBs.

Hybrids are the offspring of separate species. All dogs are the same species.Breeds are like human races, in the end all the same and fully capable of successful interbreeding.

No crossbreeding does NOT eliminate or even lessen genetic problems.

If you take two dogs who hips have been OFA'd as fair or poor they will produce pups some will have fair hips but most will more than likely have POOR hip ratings.

This is why the myth that cross breeds are healthier is just that a myth.

Healthy pups come from healthy stock that have been genetically screened.

1 to less than 1% of mutts breeders have stock that have been genetically screened and come back with acceptable results not to mention having the appropriate temperaments for their breeds

That means the majority of cross breeds will either be genetically or temperamentally unsound.

The same of course goes for purebreds who if owned by reputable breeders would NEVER be allowed to pass their genes on.

Yes they may have been 'hybrids' (completely improper term) in the beginning, but they where created for a reason. We have enough breeds to serve a variety of purposes, why do we need more? I have yet to fine ANY mixed breed breeders who are ethical and responsible. they don't do health tests on their breeding stock. They have no idea what health defects they are breeding into their dogs. Hence why they often end up with severe health defects. There is no standard for them to breed to, no set size, appearance, temperaments. How can they call them a breed.

As for the whole breeding two breeds together to reduce health issues that is rather silly. Every breed has health issues, so you breed a german Shepherd who is prone to hip dysplasia and mix it with a Golden Retriever who is less prone to dysplasia. Now you have a mutt with the chance of having hip dysplasia and lymphoma ( a major issue in golden's.) What is the point?

ADD: many issues are now starting to be traced back to early neutering and spaying. I dont agree with the shelter dogs are healthier bit. I have purebreds and shelter/stray dogs who where mixed. One of my rescues had cancer, another hip dysplasia and epilepsy

Labrador breeders are struggling to eliminate hip problems through intensive breeding programs based on female and male Labs that do NOT have the hip problem. The breed originally did not have this problem, it is something that popped up in the 20th century due to puppy mills grinding out "bad" pups. Enough "bad" pups survived long enough to breed and carry their problems into the gene pool. ("bad" as in unhealthy, deformed, otherwise defective) This is something that is happening with other breeds as well, and for the same reason.

A Labrador crossed with a Golden Retriever may make a great hunting companion, but it's true name is "Mixed Breed." That is why breeders do not cross breeds with breeds as a normal part of business.

Not all dog breeds are mixed way back when, and by "far enough" you'd have to look at some point B.C. for some breeds.

Being different breeds does not nullify the fact that they can produce offspring that have hip dysplasia. Very few traits are carried by one gene alone, but cross-breeding is not a panacea.

"Does one need to try to eliminate the bad trait or does this take care of itself with the mixed genetics"

Every case of a mixed-breed litter is the result of an irresponsible or plain ole' ignorant owner. The dogs bred had no health tests, and there it's a pure guessing game when it comes to genetic disorders.

No mutt breeder would even THINK of testing each dog for diseases - and then comparing and studying the two to see if they would produce healthy offspring.

It's NECESSARY for us - the creators of the species - to eliminate problems we've brought about. This is through testing, studying, and consultations -- NOT through throwing two dogs together and hoping for a big litter [cause that's where the money is!!].

"two hip dysplasia prone breeds being less likely of having dysplasia prone puppies by the mere fact that they aren't of the same breed"

That makes absolutely no sense.

If you take two dogs that have a high chance of Hip Dysplasia - there's no way the litter will turn out to not have any chance of HD at all.

That's the same thing as saying "if these two ethnic people with coarse black hair and dark brown eyes have children, their children will come out caucasian with soft blond hair and bright blue eyes".

"isn't every breed known today just a hybrid if you look back far enough"

In many cases, yes. The difference being that these breeds were NOT created overnight like these designer dogs we see in everyone's purses.

These breeds were created over CENTURIES and have taken DECADES upon DECADES of "perfection" - just to get them at such a good point as that that they are in now.

NOW do you understand?

"dog breeder sense it is loosely used now like cockerpoos or labradoodles"

The only "breeder" that would use the word Hybrid while talking of a MUTT -- is a BYB/Puppy Mill. Don't know what they are? Go do some research - I'm not gonna do it for you.

"pound puppies do not suffer many of the maladies of purebreds"

This is purely for the reason that any dog with any disease or disorder that effects their life is euthanized because of it. This keeps runs open for dogs that are healthier and more able to be adopted out to families.

"current research is beginning to show many cases of hip dysplasia can be traced to neutering too young"

By whom? Unknowledgeable high school Chem students?

With what standard for testing? None? So they could each test the dogs as extensively or as in-extensively as wanted? So they could each use different HD tests to get the results they wanted?

And these were dogs that were urged to be altered at what age? Before 6 months? A general downfall to only listening to your "oh so knowledgeable" veterinarian 24/7.

In what breed of dog? One that's naturally prone to HD, or one that has few cases?

Dogs from what "supplier"? BYBs? Puppy Mills [most likely]? Reputable breeders?

I know some of the breeders involved with a vet school project studying hip dysplasia. they crossed a very low incidence Hip dysplasia breed dog (with good hips) with a high incidence HD breed dog who ALSO had good hips and no close relatives with bad hips. GOT HORRID hips on the pups - they think cause the good hips on each parent came by different genetic routes...

second scenario I spent many years on a support list for owners of dogs with a chronic health problem believed probably hereditary (preliminary statics indicate it may be over 3x MORE hereditary than HD) -the #1 breed on it -the MIx!!!