THE THEORY BEHIND DESIGNER MIXED DOGS
FIRST I WANT TO THANK THE OWNERS OF REGO, the pale cream colored Bologco boy who is featured in all of the pictures on this webpage, for allowing me to use use their pictures of Rego to illustrate this article. Rego was bought from me by a family with three boys from Orlando, Florida, as a 9 week old puppy. And fortunately his family has documented Rego through photography as he has grown up so that I have many consecutive pictures of Rego to illustrate this webpage.
The picture across the top of this page is of Rego's Bologco litter, taken at one day old in the Spring of 2010. There were seven puppies in that litter, and two of Rego's darker colored littermates, and sisters, are also featured on this website--little sable-merle Dixie and black and tan marked Cali--both of whom can be seen on our dark colored Bologcos' page. And the first four pictures of Rego within this article are pictures that I took of him at six weeks old, playing out in some of our "Monkey Grass," which pictures I used in advertising him.
But all of the rest of the pictures of Rego on this webpage are from Rego's family in Orlando. And taken all together, these pictures make a remarkable record of how a Bologco grows up--and also shows a loving family taking excellent care of their precious little pet. And that's what I do here--produce precious companion pet dogs for both individuals and families like Rego's family. And this Theory webpage is an attempt to explain why I have moved from breeding purebred dogs for many decades to now breeding only designer mixes.
I breed designer mixed dogs because I feel that the first generation designer mixes--called F1's--are basically healthier than most purebred dogs due to their having a larger gene pool behind them, as they come from two totally separate breeds. And the so-called "pure" breeds have to be somewhat genetically isolated sub-populations of dogs, or they would not be able to "breed true." But ALL of the modern pure breeds come from the mixing of older breeds at some point in their history, and very few of the modern pure breeds are more than a few hundred years old. And American Cockers for instance, were only officially recognized as a separate breed--separate from English Cockers and Springer Spaniels--by the American Kennel Club in 1946.
However, if anyone had told me as late as only five years ago that I would no longer be breeding purebred dogs--but only designer mixes--I would have told them that they were crazy. But all things change in this world, and unfortunately there have been a lot of things in play in the world of dogs in recent years that finally turned me to only breeding the designer mixes.
In the not too distant past almost all dog breeding was determined by working performance, therefore ensuring that only the healthiest dogs that could move and see and perform their jobs the best were bred. And with "form following function," dogs that had the same job to do usually wound up looking quite a bit alike in form, after being bred to do the same job for generations--except perhaps in their many different colors and markings, even within the same breed--although night guard dogs did tend to be black in color. And brown dogs have been favored as gun dogs, perhaps because they blend more in with the natural brown colors in a landscape. And the old working dog groups were called "land race" breeds, but this did not mean they were not carefully bred by their caretakers. And in the past, before the benefits of modern agriculture freed the majority of people from the backbacking and ever present work of producing their own food, all dogs had to have a job to do in order to pay for their expensive keep, except for smaller companion dogs that were mostly owned by royalty and the very wealthy.
But with the rise of the middle class in developed countries in the past several centuries, many families could afford to keep dogs as pets only. And purebred pet dogs became all of the rage in the Victorian age in England, as Queen Victoria herself was mad for all sorts of dogs and kept huge kennels. And during Victoria's reign the first "dog shows" were held in England, which lead to standardizing the looks of many types of dogs, and the formation of breed clubs and kennel clubs, which began organizing dog shows on a regular basis. And a dog breed can be described as a group of dogs that closely resemble each other in looks, behavior, and
working abilities--if
applicable--and this group of dogs will "breed true" for these traits, meaning that the puppies will eventually both look and act like their parents and grandparents.
And over time many dog owners also became interested in the dog show world--usually called the "dog fancy." And after World War II, and with the great growth of suburbia in the US where people finally had enough yard room to have dogs, there was a great shift in the breeding of show dogs from the huge show kennels of the past to much smaller suburban breeding, often done as a middle class hobby rather than as a full time occupation, or as a hobby by the wealthy who could afford full time kennel help.
Earlier show dogs were bred mostly in the kennels of the very wealthy--who like thoroughbred race horse owners of today with their huge stables, owned huge kennels--with much "help" hired to do all of the kennel work. But the huge old show kennels of the 1920's and 1930's that were so instrumental in developing the show lines of many breeds today, just became too expensive to keep up.
So the dog fancy gradually shifted, until by the 1960's and 1970's it was quite typical for a suburban home to contain several breeding dogs, usually kept as pets, and either bred for the pet market or as potential show prospects. But this shift in breeding from large scale kennels to small scale suburban breeding meant that it was very easy to get into breeding and showing dogs--and just as easy to get out--so that for decades now the average dog fancy breeder who shows has only lasted for about five years, before the combination of the great expense involved in showing dogs, and the stress of never having a "day off" from dogs, finally gets to them. For unlike children, dogs never "grow up," but need continual and unremitting care for all of their lives.
And this continual coming and going of many show breeders has allowed a gradual shift in the "look" of many of the dog breeds, as there are very few kennels that have lasted in showing for many decades. And those kennels that have endured for some time often want to stamp their own particular "look" to their lines, which may or may not be a good example of the breed standard. And over time many of the breed standards have actually been changed in order to incorporate the new "look" that was currently winning in the ring.
But if a dog no longer has a working purpose upon which to base the standard for the breed, then it's very easy for those who have both the time and money to bear the expense of showing to greatly influence what dogs actually win in the ring. And these historical dog pictures show just how differently many dog breeds now look from the dogs that were used to originally establish many of the modern dog breeds.
So with each five year "generation" of small suburban dog breeders a lot of knowledge about breeding was lost--as fewer and fewer people in the dog fancy had been raised in rural areas with farm animals like earlier generations--and thus had little or no experience with the breedng and raising of animals before getting into dogs. And very few had been raised on large estates that kept huge kennels, either as gun dogs or even for riding with the hunt English style, although this tradition goes back to our first President, George Washington.
And although many rural people still kept packs of hounds--of the Southern hunting breeds especially--most of the Southern hunting breeds were not considered suitable for either dog fancy or pet breeding, and most of the Southern hunting breeds are still considered working dogs and kept in packs in outdoor kennels.
So these hunting types of dogs tend to either have their own private registries or to be registered with the United Kennel Club rather than the American Kennel Club, which is the registry that is most associated with "show dogs" in the US. And many a huge breed club fight has been started when a group of breeders decided to seek AKC registration for their working type breed, as many working breeders consider AKC registration to be the "kiss of death" of any working breed.
And thus began the gradual separation of the dog fancy from the more utilitarian working types of dogs that are still kept in rural areas today by people who still live, work, and play on the land with all sorts of utilitarian types of dogs, for instance to either herd other animals or to hunt with. And today most dog fancy purebreds are no longer bred to perform their original jobs, but are bred according to extremely narrow physical "breed standards," based on the current preferences of breed club members for winning at dog shows. And breeding for dog shows often involves line breeding to ensure that puppies are produced with "show type"--with "typiness" connotating that a certain dog has the physical qualities for winning in the show ring. And some breeders still practice inbreeding, which means breeding very close relatives, like sires to their daughters, in order to ensure that these breeders get a certain "look" to their puppies.
But linebreeding is actually still inbreeding, but further back in the pedigree. And a favored breeding strategy for the show ring is to have the sire's sire be the great-grandsire on the dam's side of the pedigree--providing that said dog being linebred on has the desired qualities for winning in the show ring, which means coming very close to meeting the breed standard. And this type of linebreding is done to ensure that the desired qualities come down to puppies from both sides of the pedigree, and so that the puppies all look as alike as possible--as well as all looking as much as possible like the agreed upon breed standard.
But unfortunately this type of line breeding often results in some quite breed specific genetic health problems arising from such close breeding for generations on end--with the same alleles coming down to puppies from both sides of the pedigree--as over time previously buried genetically recessive health problems show up in what are called "affected" puppies. And thus what was once a health problem in just a small number of dogs in a breed can be spread to ever increasing numbers of dogs in the breed, especially with the practice of "frequently used sires"--which are those dogs who win the most in the show ring, and are thus very desirable to breed to many females in the breeding population--which with so many pets being spay/neutered, is the small group of dogs within a breed that are actually bred.
And even if specific recessive genetic health problems are purged from that dog line through repeated linebreedings--then the MHC--the major histocompatibility complex--is narrowed and reduced so much by inbreeding and line breeding that even if puppies do not exhibit a particular genetic defect, puppies often do not thrive, and/or later exhibit auto-immune health problems from having such a narrow and imporvished gene pool behind them.
However, researchers have discovered that when left to their natural devices most species studied will search for unrelated mates. And recent research with mandrills, which are the largest species of monkeys, shows that they "choose mates with genes that are different from their own to guarantee healthy and strong offspring," and that "they (females) will sniff out the males whose body odour is different giving an indication that their genetic make up is likely to be unlike theirs." And this article also states that the "MHC is a cluster of genes which helps build proteins involved in the body's immune system and affects body odour by interacting with bacteria on the skin. According to the scientists, by choosing a partner who is MHC dissimilar, animals can increase their chances of their offspring being better able to resist disease."
And in our extensive research on purebred pedigrees we noticed that purebred pet breeding for the pet market only--usually meaning that the breeder does or did not show their dogs--generally almost always goes back in the pedigree to dogs from the much smaller lines for show breeding--and not the other way around--thus refuting the dog fancy's claims that it is the "pet breeders" for the pet market--often called "puppy mills"--who have brought rampant health disorders into show dog lines. But my extensive pedigree research reflects the fact that most purebred breeders for the pet market do use dogs originally from the dog fancy--or even purchase actual champion dogs, although not as much as in former years--as founder dogs for their kennels--rather than the dog fancy ever bringing in pet lines back into their show dog breeding. In fact I have never seen an instance in my pedigree research where purely pet lines for several generations were brought back and bred to show lines for litters of show prospects. So there is always a "going back" into the show lines for almost all purebred breeding for the pet market in the US every couple of generations, if nothing else but to keep some semblance of purebred breed type in the pet lines.
I spent many years researching health problems in various smaller sized breeds before finally deciding that I wanted to get back into breeding American Cockers, which like many Americans was the breed of my childhood. And my Mother was an American Cocker breeder for almost 20 years, finally stopping in 1958 when she declared that American Cockers were being turned into "hairy little bulldogs" by the dog fancy. And I was aware from breeding other purebreds in the past that all purebred dogs do carry some breed specific health problems. But after much research I finally decided that the American Cocker was still a relatively healthy breed--and I still feel that way today, compared to some breeds which have virtually no members of the breed now unaffected by serious genetic health problems, with up to 30% newborn puppy deaths not uncommon in some breeds. However, I have finally come to feel that mixing my small American Cocker lines with other small breeds that are NOT spaniels can give me healthier litters due to an increase in the diversity of the MHC in my resulting designer mixes.
And I feel that I have proven with my own litters that my designer mixed litters are basically healthier than my previously bred purebred litters, due to the 12% newborn puppy death rate that I experienced with my purebred litters over many years--no matter what my vet and I did to try to improve that number--versus the less than 1% newborn puppy death rate that I have experienced with my designer mixed litters of the past several years. And for this reason alone I can no longer breed any purebred litters, if only to save myself the heartbreak of losing so many little ones!
Now my first designer mixed litters came from the same dams as my American Cocker purebred litters. And my current designer mixed litters come from the same American Cocker lines--as I have retired quite a few of my older Cockers over the years into pet homes. And both my former purebred and my current designer mixed litters are/were raised in exactly the same circumstances, as both types of litters were born within the same whelping crates and with the same amount of cleaning, and are/were raised in the same kennels and dog yards. Thus the ONLY real difference in the two types of litters is that the designer litters have a much more diverse gene pool behind them, coming from two different breeds, thereby giving my designer bred puppies a more diverse MHC, with a much stronger immune system. Plus recessive genetic disease is kept from expressing in my designer mixed litters by the lack of homozygosity--meaning NOT having the same alleles on most gene loci--in the designer mixed litters. Now any dominant genetic health disorder can still be expressed in designer mixed litters, but so far I have not seen any incidence of genetic disease in my designer litters.
Eventually I also researched each pure breed that I mix here now, so that I wouldn't put two breeds together that carry the same health disorders, thus mostly eliminating the possibility that recessive, breed specific health disorders will show up in my designer mixed puppies. And most persistent health disorders in dogs ARE genetically recessive--as dominant genetic health disorders are fairly easy to eliminate, unless they are very "late onset," meaning the dominant health disorder would then only show up when the dog is older and/or past breeding age.
Dominant genetic health disorders only need one parent to produce affected offspring. So dominant health disorders are usually quickly discovered and can be fairly easily eliminated, even when late onset--because if you have a health disorder show up in both a sire and his progeny when they are all about eight or nine years old, then it's not too difficult to figure out what is going on and just stop breeding that line. Of course this assumes that the dominant health disorder has 100% penetrance, but we will get to that shortly.
And studies have proven that most human disease is recessive in small and isolated populations too, as the Finns are considered inbred (for humans) and the population is very homogenous still. And out of the 30-something "breed specific" illnesses considered to be part of Finnish disease heritage, most have been found to be recessive, as out of 29 genes found, only two were dominant. And most genetic diseases within the very inbred Cajun population of the US are also recessive--although a few have proven to be dominant.
Now one of the misconceptions about designer mixed litters is that they are the same as "mutt" litters of unknown origin. But this is not true of a carefully designed mixed litter, with breeder knowledge about the health problems found in each breed. But unfortunately many "mutts" from accidental litters often come from breeds that have similar health problems, such as the prevalence of chronic hip dysplasia in quite a few of the larger sized breeds. So thus some people feel that "mutts" are not really healthier than purebreds, due to bad experiences that they have had with health problems in mixed dogs from rescues and shelters. And I myself had the unfortunate experience of having to put down my first--and only--shelter rescued dog--who was a much loved pet for many years. She was a part German Shepherd and part Chow dog, and made just a lovely pet and was also a good guard dog. But at only nine years old she could no longer walk due to pain and paralysis from chronic hip dysplasia. And I have no doubt that this dog's hip dysplasia was inherited from both of her parents in order for it to be so severe.
And it takes the same alleles--which are variations of genes that are passed along to progeny--from BOTH parents for a recessive health order to actually manifest in a puppy. But neither parent carrying a recessive allele for a genetic health disorder will ever show any sign of having the health disorder themselves, which is why recessive health disorders can be carried along unseen for several generations before "popping up" again in a certain dog line. And many health disorders are not only recessive but breed specific, and thus many genetic tests are only valid for the specific breeds that they have been developed for.
But if two breeds are bred together for designer mixes that do NOT carry the same recessive health disorders, then it becomes highly unlikely that recessive health disorders will show up in the designer mixed puppies--and especially breed specific health disorders. And we definitely believe that a healthy, vigorous, mixed dog is much more desirable as a beloved, long lived pet than a “pure” dog with a higher probability of developing health problems at a much younger age.
And unfortunately, although many purebred breeders do health screenings, there are very few actual breed specific genetic tests available to breeders for the most frequent health problems in many breeds. For example, there is no genetic test for juvenile cataracts in American Cockers, although juvenile cataracts are unfortunately one of the most frequently found health problems in the breed. Ao American Cocker breeders have to rely on waiting until the dog is at least two years old to breed to make sure that the dog is not affected by a double dose of what is considered a recessive eye problem in the breed. Now at two years old the breeder can have the adult dog examined by a canine eye specialist who will declare the dog clear of all visible eye problems such as juvenile cataracts, and then issue the dog a CERF certificate. And then the breeder can seek out a mate for their dog who also has a CERF certificate. And such physical exams given every year can certainly certify that a dog does not manifest eye problems that can be physically seen, like cataracts and some other eye abnormalities.
But CERF exams tell the breeder absolutely nothing about recessive alleles that a dog may carry and for which there is no specific genetic test. For the CERF exam is just an eye examination, much like what a human will get at the optomitrist or opthamologist office, and is not a genetic test that is searching for a genetic marker that indicates the presence of recessive genetic disease. And juvenile cataracts are thought to be a recessive and somewhat breed specific health problem in American Cockers. Thus dogs can appear to have perfectly healthy eyes in their CERF eye exams, but such dogs can still be a "carrier" of the recessive allele for juvenile cataracts. And two such carriers can have CERF exam clearances and can appear to have healthy eyes up to the time that they are well past breeding age--even up until the time that they die--but half of their puppies--or even more--could still become either affected with juvenile cataracts or be carriers themselves.
And this is how recessive, breed specific health problems are perpetuated in the pure breeds, despite rampant "health testing." And if the health problem is thought to be polygenetic--for instance chronic hip dyslpasia, which may involve up to 15 different genes--then breeders face the situation where even two dogs that have both scored "excellent" on their OFA exams can still produce affected puppies with hip dysplasia.
And even when there is a specific genetic test for a health problem in a breed--whether dominant or recessive--if the bad allele(s) does not have total penetrance, then even testing positive for a disease causing allele on a genetic test will not tell the breeder which dogs will eventually be "affecteds." Say if penetrance is only 60% in a breed, then only 60% of the dogs with the bad allele(s) will ever show any sign of this health problem in their lifetime. And in this case it may be that the bad allele only gives a propensity for a health problem, and that it takes something else in the environment to make the health problem active in that particular dog--such as the dog being exposed to a certain virus or becoming extremely overweight. And this is thought to be the action in many autoimmune disorders.
And Von Willebrands is a recessive bleeding disorder, similar to hemophelia in humans, that has become prevalent in several purebreeds--but not any of the breeds that we are mixing--that also has less than 100% penetrance, as not all dogs that have two alleles for the disease--and are thus vWD affected--will have severe bleeding problems. But this is not the sort of thing that one wants to find out about their pet when the pet need to have surgery or if the dog ever has an accident.
And even where there is a quite specific genetic test for a particular health problem, then if during genetic health screenings a quite large percentage of the breed is found to be carrying the allele for a particular genetic health problem, then what is a breeder to do?
If the allele is dominant in that breed, you can't really breed affected dogs because too many puppies would turn out to be "affecteds" too, and this may just be the end line for that breed if the allele is completely widespread within the breed. But if the allele is recessive, and you eliminate every recessive carrier with the unhealthy allele, then you may narrow the gene pool of the entire breed so much that some OTHER recessive health problem is likely to be brought to the fore in the breed, instead of being buried in a wide gene pool and only showing up very occasionally. And this is what has happened in quite a few of the breeds, as the breeding pool of dogs has become so narrowed within a breed, trying to breed out recessive health disorders, that other health problems have appeared in more and more dogs over time.
So often "carriers" have to be included in a purebred breeding program--but only bred to the "clears" who do not carry the allele for the recessive health problem, so that no "affected" puppies with two copies of the bad allele are produced. However, in such breedings other carriers are still produced who will then have to be tested themselves. But the tested carriers can then be bred to other clear dogs--hoping that at some point most all of the carriers will be eliminated--before the breed itself is eliminated through concerns about massive health problems in the breed. And this type of breeding can be quite a successful strategy--if rather expensive due to all of the testing involved--which can greatly reduce the incidence of affected dogs in a breed.
But no one really believes that ALL carriers can be eliminated, and a famous example is that it would take over 900 generations to totally eliminate albinism in humans--which is a very rare affliction in the human genome. So the best that can be hoped for is to get the percentage of carriers down to a lower level, and then the number of affecteds down to an acceptable level.
But then the question becomes, what are acceptable percentages for genetic health disorders in dog breeds? For instance is it acceptable for one third of a breed to be born with either unilateral or bilateral deafness, possibly from too much of the white spotting gene? Or for a breed to have 50% mitral valve disease by the time that dogs in the breed are five years old, and almost 100% by the time that dogs in the breed are ten years old? But at these percentage levels it is virtually impossible to eliminate mitral value disease from this breed. So--is it then better to outbreed to another breed to try to bring in more genetic diversity, or to continue to accept this level of disease in the breed in order to keep it "pure"? I know my answer, but apparently the breed clubs involved with these two breeds disagree.
But this is really a trick question, because all of the major kennel clubs have closed stud books which do not allow cross breeding except under very dire circumstances. And so far in only a few breeds--such as the Besenji African Project--has an AKC stud book been opened to new dogs in order to bring in more genetic diversity. And those dogs were actually of the same breed so really not a crossbreed. However, the Chinook Owners Association, which is affiliated with the UKC here in the US, does have an actual crossbreeding program in order to bring in more genetic diversity to this small in number sled dog breed.
But the number of breed clubs that are attempting to outbreed to improve health is very few in number, and most breed clubs have instead spent a lot of money developing genetic screeing tests, hoping to be able to eventually screen out genetic health problems and still be able to keep their breed "pure." But as I mentioned earlier, there are many pitfalls to genetic screening, the most blatant one being the narrowing of the gene pool even more than before genetic testing began, and the emergence of ever more genetic disease as the gene pool is further imporvished.
And once embarked on massive genetic testing, breeding then becomes more of a matter of breeding to specific genes rather than breeding to certain superior individual dogs. And then there is the worry about other breeders branding those breeders who do breed their carriers as "bad breeders," when in actuality the breeder is trying to maintain genetic diversity while still trying to eventually eliminate the bad alleles.
So then breeding becomes a nightmare, trying to perserve the pure breed in the face of persistent genetic disease, as many breeders in self-preservation of their breeding programs will hide the fact that they have dogs that are either carriers or affecteds--especially if they have champion dogs that are carriers or affecteds--or have such dogs that are the offspring of very famous champions in the past. And many purebred breeders have invested so much time and money into their kennels over the years, and in showing in the conformation ring, that they are very loathe to admit that they have ANY health problems at all, as they feel that then they will come under attack by competitors in their breeds. So it's no wonder that as many as half of breeders for the pet market, who do not show and have no real interest in keeping lines "pure" for the show ring, have said the heck with the whole thing and began breeding the designer mixes instead--to the point that we have seen recent figures that as many as half of the puppies being purposefully bred in the US are now are designer mixes. But of course breeding designer litters has only ignited "breeder wars" between the dog fancy and the more commercial breeders for the pet market, which unfortunately the vegan based, animal rights cult has taken advantage of by dividing the various factions in the dog breeding world. But more about that in another article.
Now some breed clubs do maintain vast health data bases and enforce testing and the publication of test results in an effort to purify their breeds from genetic health problems. But this happens mainly in Europe, and for instance there is a huge Tibetan Terrer health database that is maintained in Europe. But as far as we know the vast majority of breed clubs in the United States do not require testing of breeding stock in order to breed. And again, testing can often only lead to smaller and smaller gene pools, as affected dogs and even carriers are eliminated from breeding, until there are very few lines of dogs left to carry on the breed without some type of other inbreeding health problem starting to appear in a breed in larger and larger numbers. So it all becomes the old conumdrum for purebred breeders of being "damned if you do, or damned if you don't."
There are about three billion base pairs in the canine genome. And the basic idea behind designer mixes is that a cross between two populations (breeds) that have each become relatively homozygous over time--with homozygous meaning the same (homo) genetically across most gene loci--then by crossing the two pure breeds the breeder is much less likely to produce any amount of "affecteds" with recessive health disorders and will instead produce offspring that are quite heterozygous--meaning different (hetero) genetically--at many if not most of the gene loci base pairs. And such F1 cross breeding between two breeds should not produce many--if any--affected puppies with recessive genetic health disorders, as long as the two breeds involved do not carry the same recessive health disorders. And much research has shown that first generation (F1) heterozygous crosses are often much heartier, healthier, and productive than either of the quite homozygous parental lines. And F1 crosses also tend to look alike in litters almost as much as their purebred relatives in many respects, due to the dominance/recessive activity on so many gene loci.
And based on the study of over 23,000 dogs, Gary L. Petronek's 1997 study of vet hospital motrality showed that on average small mixed breed dogs lived longer than small purebred dogs, and that large mixed breed dogs lived longer than large purebred dogs--but that small mixed breed dogs lived longer than large mixed breed dogs. And Patronek's results showed that "The median age at death was 8,5 years for all mixed breed dogs and 6,7 years for all pure breed dogs . . . Mongrels lived 1 – 3 years longer."
I've lost the weblink that I had originally to that above quote, as the abstract that the quote came from was on a webpage that no longer exists--just one of the hazards of internet research as opposed to being able to reference paper published articles. But Patronek's comparison of canine and human life spans, published in a gerontology journal also in 1997, uses his original canine study in the gerontoloty article, within which he states unequivocably that "For each weight group, the age of death of purebred dogs was SIGNIFICANTLY (p = .0001) LESS than that for mixed breed dogs." In other words purebred dogs died earlier than mixed dogs, and at a rate that was statistically significant.
But please note that the "median age" was not the age at which most of the dogs in this study died, but is the statistical mid-point, where half of the dogs died at a younger age and half died at an older age. And many purebreds are noted for their longevity, including Mini-Poodles, Lhasa Apsos, Tibetan Spaniels, and Tibetan Terriers.
Now we still do strongly believe in purposefully bred dogs as pets--whether purebred or designer mixed--which are dogs with a known pedigree and rather predicatable size and appearance--and with much breeder knowledge about the actual dogs behind the litter. And while we do support the adoption of dogs of unknown origin from rescues and shelters, we feel that dog owners should have the CHOICE of where they want to purchase their new canine compannion for their family, especially here in Florida, where even home owners have to deal with crowded suburban conditions, with quite small back yards and or town home patios as the only outdoor areas for their pets, and home owner associations that often make rigorous size limitations for pets.
As to "hybrid vigor" in mixed litters, it has been scientifically proven, and is called heterosis, which is defined in genetics as the tendency of a crossbred organism to have qualities superior to those of either parent. And this is true especially in crossing purebred dogs, because the typical purebred dog has a coefficiency of inbreeding at about 6%, which is the equivalent of a first cousin breeding. But unfortunately there are breeds with much higher COI's, with some breeds regularly producing puppies with COI's in the 30% to 70% range, which means that these breeds are homozygous on the great majority of their gene pairs. And breeds with closed stud books have no choice but to have ever-increasing COI's.
And we ourselves ran into the difficult problem of finding and buying American Cocker breeding dogs who were not closely related in their five generation pedigrees, as unfortunately it has been taught in many purebred breeding seminars that linebreeding or even inbreeding is a very desirable way to breed show dogs in order to "fix desired type." But unfortunately this advice totally ignores the health problems caused by inbreeding depression. And even wild populations of animals have been proven to be negatively affected by inbreeding in the wild, such as happens on islands and in wild animal populations that have lost a lot of their original habitat and/or almost hunted to extinction.
And here's a link to a Labradoodle website in Australia--which country the Labradoodle was developed--that delves into the concept of heterosis in much more detail for those who are interested in this subject. And this article is written by a "country vet" who is also a Labradoodle breeder. And we are really interested in her theory of "three breed rotation" mentioned in this article, which the author states "retain(s) the benefits of hybrid vigour, complementarity and reliable uniformity in the offspring." And in some instances we have more conformation uniformity in our designer mixes than we ever got in our pet lines of purebred breeding, which is due to Mendel's first law, which is the "principle of uniformity." And this Australian breeder and vet explains the way in which hybrid vigour (heterosis) works, and why the F1 progeny are so similar to each other. Of course the degree of similarity in the F1 generation will, as in purebred breeding, entirely depend on how homozygous the two parent breeds are.
And here's a Border Collie blog webpage that has some excellent graphics illustrating the dangers of inbreeding. And this is a blog webpage about a contagious cancer in Tasmanian Devils, that is believed to be due to low genetic diversity, which in term is probably due to earlier extensive hunting and intended extermination of the Tasmanian Devil many decades ago, which almost brought the species to extinction. And the article states "Diversity in the genes in the MHC class I and II in Tasmanian devils is very low."
And this excellent discussion about the MHC in canines is by a sight hound breeder who mixes sight hound breeds here in the US, looking for more genetic diversity in her dogs. And the second part of her mixed sight hound discussion compares inbreeding in canines with certain inbred wild species. And perhaps one of the best websites on the need for canine diversity is the Canine Diversity Project website, which is a wonderful resource for breeders--and pet owners--wanting to educate themselves about the problems with inbreedng and the need for genetic diversity in our modern dog breeds. And closing the links to any of these web pages will bring you back to this point on this webpage. And of course cross breeding cannot guarantee good health. But after reading these articles it becomes obvious that cross breeding canine breeds can make it highly unlikely that breed specific, recessive genetic health disorders will show up in the crossbred, designer mixed puppies, if the breeds to be mixed are chosen with great care and knowledge.
And a good website to read for further understanding about subjects such as the basics of cross breeding purebred strains, Mendalian traits, the principles of independent assortment, and explanations of the concepts of dominant and recessive alleles, is Mendel's Genetics, which webpage has excellent graphics and illustrations, as well as very clear discussions about these concepts. And this list of known Mendelian inheritance in the dog shows that Canis familiaris--the dog--is unfortunately beset with many inherited health disorders. (Online Mendelian Inheritance in Animals, OMIA. Reprogen, Faculty of Veterinary Science, University of Sydney and Australian National Genomic Information Service (ANGIS), University of Sydney. World Wide Web URL: http://omia.angis.org.au/)
Of course no being lives forever on this Earth, and all organisms have genetic weaknesses that ultimately lead to their deaths. But due to such limited gene pools the modern dog has more than its share of inherited genetic disease--especially the purebreds. And the short lifespans of dogs--which they inherited from their wolf ancestors who often only live to about four years old in the wild and average about eight years old in captivity--makes dog health problems all the more apparent to us. Of course some individual wild canids have lived into their teens, but the canids in general are rather short lived animals compared to humans, and especially compared to other pets, such as parrots.
But the domesticated dog has had a special relationship with humans for perhaps as long as 16,000 years according to one article on an archeology webpage, although we have read that some researchers think that dogs were domesticated perhaps as long as over a hundred thousand years ago. However, recent canine mitochondrial studies place domesticated dog development somewhere in East Asia about 15,000 years ago.
But unlike the shorter lived wolves and larger dog breeds, the smaller dog breeds that we have chosen to mix are known for living into their teens. And it's this long association with people, and the great affection with which many people regard their pet dogs, that makes the so called "animal rights" cult so dangerous. This is because these groups are so deceptive in that they are mostly led by vegans who want to break the human-dog (and cat) pet bond because both dogs and cats are true carnivores--yet advertise constantly that they only want to "help" pets so that they can fund their anti-pet legislative efforts. And some of the animal rights cult actually expouses interfering with wild animal hierarchies by eliminating all predator species! These animal rights cultists are nuts, and some of their followers seem to know nothing about evolution or ecology, or the balance that needs to be kept between prey species and predator species in the wild--and seem to have totally accepted a Disneyesque version of "Bambi" as something to be desired in our world. And by much decptive advertising animal rights group shave gained a lot of money and political power in our society, much to the detrmient of our pet dogs.
And the rise of the animal rights cult in both Europe and the United States, under the guise of caring about the "rights" of animals--rather than the welfare of animals--has perhaps done more damage to the domestic dog genome than anything else--perhaps even more than inbreeding and line breeding--as breeders have become personified in the media by the animal rights cult as "greedy and exploitive puppy mills." And many lines of purebreds have been lost to massive spay/neutering, all in the name of "pet overpopulation." And I feel so strongly about this subject that I'm in the process of writing an article totally dedicated to the animal rights menace to our beloved pets.
But in the meantime I hope that you have both enjoyed and learned something from my writing this article about all of the reasons why I've become a designer dog breeder.
CONTACT INFORMATION
WE ARE LOCATED IN THE NORTHCENTRAL FLORIDA AREA just a few miles from the Gulf of Mexico. We can be contacted by E-mail at:
jolie.chiens@gmail.com
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“We are alone, absolutely alone on this chance planet; and amid all the forms of life that surround us, not one, excepting the dog has made an alliance with us.”
Max Depree
