English Bulldogs Have Reached a Genetic Dead End

[Potoooooooo]

http://gizmodo.com/english-bulldogs-have-reached-a-genetic-dead-end-1784475872

The English Bulldog is one of the most popular dog breeds in the world, but it’s also one of the unhealthiest. An upsetting new analysis now shows that these stocky, wrinkly-faced dogs lack the genetic diversity required to improve the breed, and that their current level of health is as good as it’s ever going to get.

 

[Valjean]

"Purebred" is simply a euphemism for inbred.

 

[zorq]

I never understood the sacrosanct nature of "purebred" dog breeds. If the dogs are unhealthy, then that's BAD. Stop breeding unhealthy dogs! Then again I've always preferred muts anyway so my opinion probably doesn't count.

Still I find it surprising that selective breeding can't start choosing for health and diversity of genes in a population instead of the more arbitrary traits that have been selected for previously. Random mutations can and will still happen in a shallow gene pool. If breeders can identify and select for healthy mutations then there's no reason a closed population of English Bulldogs can't be bred for more health.

But of course selecting for health over wrinkled faces and stubby legs is antithetical to the whole point of having a breed of English Bulldogs. Because if the English bulldog breed starts getting healthier but it ALSO starts looking different then what's the point? You could have just introduced some healthier genes from outside the breed and achieved the same results! It's all nuts!

PS. Dog and Cat breeders suck. (Yes, I'm talking to you, you dirty pet breeder) Don't buy dogs or cats. Go adopt one from your local pet shelter. Every dog or cat bought from a breeder is one more dog or cat needlessly killed in a shelter. Also, take a note from Bob Barker and spay or neuter your pets.

 

[iolo]

Is the bulldog really that popular? I see very little evidence of it as I travel round Britain - in fact, thinking about it, it is years since I've seen one at all. Perhaps they have all gone to Eton with the rich foreigners?

 

[ronburgundy]

Purebred dog breeding is animal cruelty done for the most pretentious of reasons.

Even if its not a purebred, buying a dog or a cat from a professional breeder is dick move.

Peta should spend more time on this issue than on most of the things they waste their efforts on.

 

[laughing dog]

There are responsible breeders and irresponsible breeders (aka puppy mills). Responsible breeders raise healthy dogs and do not over-breed their dogs. There is nothing immoral or unreasonable in wanting or having a healthy animal with specific desired personality traits and/or physical characteristics.

 

[Bronzeage]

I've always found it strange that while the idea that pure bred animal are subject to inherited weakness, due to the fact they only mate with dogs very similar to themselves is widely accepted, racial supremacists will preach that the same practice strengthens their particular race.

 

[fromderinside]

I've always found it strange that while the idea that pure bred animal are subject to inherited weakness, due to the fact they only mate with dogs very similar to themselves is widely accepted, racial supremacists will preach that the same practice strengthens their particular race.

Inbreeding is done for a purpose. Usually its done to maximize an attribute like milk production (Holstein dairy cow), breast size (turkey's), look and behavior (bulldog), etc. The dairy example serves as a template for this post.

How sustainable are the breeding programs of the global main stream dairy breeds? - The Latin-American situation http://lrrd.cipav.org.co/lrrd20/2/mada20019.htm

Selection for high milk yield in first world countries resulted also in a correlated decrease in health and fertility, which was carried over to the Latin-American countries importing genetic materials.
Although the decline in health and fertility was predictable from genetic parameters already known three or four decades ago, most breeding programmes worldwide failed to accommodate the long term consequences of overemphasizing high yield, illustrating the limitations of dairy industry models where the genetic supplier sector is driven solely by short term profits. However, some countries (e.g. Scandinavian countries) did apply the brakes early on and put weight on selection for health and fertility to stop their deterioration, so the interesting question is what made it possible?Hansen(2006) noted that the Scandinavian countries “have practiced more of socialistic approach to breeding their red dairy cattle” rather than “brutal competition” focusing on short term profits.
Crossbreeding, breed substitution and selection on functional traits may all be used to improve health and fertility. In Brazil, the increased popularity of more fertile and adapted breeds indicates that farmers are at least partially aware of the economic set back associated to high yield genetics, although nonetheless more research on the better alternatives, and wide dissemination of the results, are needed to aid farmers to take faster and sounder decisions, properly taking into account unprovoked substantial propaganda. Unfortunately, research and information are too often directed more towards attending vendors’ interests than the farmers’ needs

The issues are known but solutions are usually put on the back burner because, well, we all seem to want the mostest of the bestest, which, when applied to human tribes, results in the worstest.

 

[Tassman]

I've always found it strange that while the idea that pure bred animal are subject to inherited weakness, due to the fact they only mate with dogs very similar to themselves is widely accepted, racial supremacists will preach that the same practice strengthens their particular race.

The same with the royal families of Europe until recently, resulting in e.g. Hemophilia being relatively common among European royalty and which, incidentally, was partially responsible for the Russian revolution.

 

[ronburgundy]

There are responsible breeders and irresponsible breeders (aka puppy mills). Responsible breeders raise healthy dogs and do not over-breed their dogs. There is nothing immoral or unreasonable in wanting or having a healthy animal with specific desired personality traits and/or physical characteristics.

Purebred breeding is pretty much always grossly irresponsible and cruel, and not neccessary even for producing actual working dogs. Other forms of breeding where different breeds are intentionally mixed can be responsible, but few of the people that buy them are acting responsibly.

There are so many perfectly healthy dogs in shelters (and more healthy than most pure breeds) that unless you are only getting the dog to make actual use of it for a specifically bred purpose (e.g., hunting, cattle wrangling), then paying someone to intentionally breed a pet dog for you is a vain, selfish, asshole move.

Given how few bred dogs are actually used for any practical breed-related function, buying bred dogs is as reliable a predictor of being a pretentious asshole as owning an H1 Hummer (IOW, very reliable).

 

[laughing dog]

There are responsible breeders and irresponsible breeders (aka puppy mills). Responsible breeders raise healthy dogs and do not over-breed their dogs. There is nothing immoral or unreasonable in wanting or having a healthy animal with specific desired personality traits and/or physical characteristics.

Purebred breeding is pretty much always grossly irresponsible and cruel, and not neccessary even for producing actual working dogs. Other forms of breeding where different breeds are intentionally mixed can be responsible, but few of the people that buy them are acting responsibly. ...

Dogs are bred for physical characteristics and for temperament. It is responsible to get a dog based on how it will fit in with one's living conditions. It is irresponsible to disregard the temperament when getting a dog.

Puppy mill breeders are irresponsible and cruel. Professional breeders for show and/or for pets are neither grossly irresponsible or cruel. Pet owners who wish to have a dog with a certain temperaments and capabilities are not necessarily cruel or selfish. For example, if you want a dog that does not shed much or a low energy dog or a dog that is likely to be good with children or hunts well or ______, it makes sense to take the breed into account. Unless the local shelters have purebred dogs or dogs with easily identifiable breeds, that is sometimes very difficult to do. It is responsible to have a pet that one can take care of and that will prosper in its new environment. In fact, it is irresponsible and cruel to ignore the temperament and traits of a dog when adopting one. Purebreds are one way (not the only way) to maximize the chance that the adopted dog will prosper.

 

[ronburgundy]

Purebred breeding is pretty much always grossly irresponsible and cruel, and not neccessary even for producing actual working dogs. Other forms of breeding where different breeds are intentionally mixed can be responsible, but few of the people that buy them are acting responsibly. ...

Dogs are bred for physical characteristics and for temperament. It is responsible to get a dog based on how it will fit in with one's living conditions. It is irresponsible to disregard the temperament when getting a dog.

Puppy mill breeders are irresponsible and cruel. Professional breeders for show and/or for pets are neither grossly irresponsible or cruel. Pet owners who wish to have a dog with a certain temperaments and capabilities are not necessarily cruel or selfish. For example, if you want a dog that does not shed much or a low energy dog or a dog that is likely to be good with children or hunts well or ______, it makes sense to take the breed into account.

All those things can be taken into account with shelter dogs. Breed needs to be taken into account mostly because many breeds created by breeders have temperament problems and/or are dangerous around kids. It is more about avoiding particular pure breeds. Outside of very specific working dog contexts, there are few where mixed breed mutts don't don't fair better and aren't more adaptive than any pure breed.

It is responsible to have a pet that one can take care of and that will prosper in its new environment. In fact, it is irresponsible and cruel to ignore the temperament and traits of a dog when adopting one. Purebreds are one way (not the only way) to maximize the chance that the adopted dog will prosper.

Purebreds are the problem, not the solution. A mixed breed mutt maximizes the odds that the dogs will prosper in any caring environment. Breeders are the one's creating the kinds of dogs that are the most problematic and least adaptive to different contexts.

 

[laughing dog]

All those things can be taken into account with shelter dogs. Breed needs to be taken into account mostly because many breeds created by breeders have temperament problems and/or are dangerous around kids.

Do you have any actual evidence to support this claim?

It is more about avoiding particular pure breeds. Outside of very specific working dog contexts, there are few where mixed breed mutts don't don't fair better and aren't more adaptive than any pure breed.

Do you have any actual evidence to support this claim?

Purebreds are the problem, not the solution.

Do you have any actual evidence to support this claim?

A mixed breed mutt maximizes the odds that the dogs will prosper in any caring environment.

Do you have any actual evidence to support this claim?

Breeders are the one's creating the kinds of dogs that are the most problematic and least adaptive to different contexts.

Opinion masquerading as fact.

 

[Toni]

There are responsible breeders and irresponsible breeders (aka puppy mills). Responsible breeders raise healthy dogs and do not over-breed their dogs. There is nothing immoral or unreasonable in wanting or having a healthy animal with specific desired personality traits and/or physical characteristics.

Purebred breeding is pretty much always grossly irresponsible and cruel, and not neccessary even for producing actual working dogs. Other forms of breeding where different breeds are intentionally mixed can be responsible, but few of the people that buy them are acting responsibly.

There are so many perfectly healthy dogs in shelters (and more healthy than most pure breeds) that unless you are only getting the dog to make actual use of it for a specifically bred purpose (e.g., hunting, cattle wrangling), then paying someone to intentionally breed a pet dog for you is a vain, selfish, asshole move.

Given how few bred dogs are actually used for any practical breed-related function, buying bred dogs is as reliable a predictor of being a pretentious asshole as owning an H1 Hummer (IOW, very reliable).

I don't agree at all.

What is irresponsible is not taking care to breed healthy animals. In animal breeding--not just in dog breeding, or purebred breeding, there are often 'trends' or 'fashions' that people--owners, judges at dog shows, breeders, jump on and then try to breed that characteristic, generally something associated with looks rather than intention/function of breed. One example would be tea cup sized dogs of any breed. Pekinese are another. Bulldogs are especially easily identifiable and a primary reason I have always refused to own one is that they are bred such that it impairs their health unnecessarily. Bitches generally cannot birth their litters naturally due to head size; the shortened snout creates serious breathing issues for the animal. I own a particular breed of dog and when I've purchased puppies, it has always been away from what is 'fashionable' and has most recently won best in breed at shows because that particular showy trait is also sometimes associated with deafness. German Shepherd Dogs are now bred so that their shoulder height is far higher than their hips, for another example of a bad breeding scheme that is unrelated to breed purpose or health. It wasn't always like this, even a short while ago:

http://americanbulldog.yuku.com/topic/1929/100-Years-of-Breed-Improvement#.V5_g9KL4GKI


Unfortunately, buying rescue dogs--and you can call a purchase price an adoption fee all you want, it's still the purchase price--does nothing--absolutely nothing to promote or guarantee the health of puppies which are produced from indiscriminate or accidental breeding---although many puppies found at shelters and rescues were in fact, intentionally bred to be sold at rescues and shelters.

I've been wise and purchased puppies from good, ethical breeders who clearly cared deeply about the health and well being of any puppy they produced. And I've been foolish and shortsighted and purchased puppies from breeders I knew had no idea what they were doing but I really really really wanted that specific type of puppy and I felt very sorry for the puppies which were clearly being bred by idiots --and I freely admit: purchased by idiots like me. The dogs--same breed, mind you--from good breeders have had long, healthy lives. The pity purchases--well, I've been lucky that the health problems havent' started too early but after 10 years of age. I don't regret purchasing and owning and caring for and loving my puppies, even the ones with health issues and shortened lifespans. I DO very much regret being stupid and encouraging careless idiots to continue their side incomes of indiscriminate breeding of puppies from unsound breeding stock. I won't do that again.

 

[credoconsolans]

Purebred breeding is pretty much always grossly irresponsible and cruel, and not neccessary even for producing actual working dogs. Other forms of breeding where different breeds are intentionally mixed can be responsible, but few of the people that buy them are acting responsibly. ...

Dogs are bred for physical characteristics and for temperament. It is responsible to get a dog based on how it will fit in with one's living conditions. It is irresponsible to disregard the temperament when getting a dog.

Puppy mill breeders are irresponsible and cruel. Professional breeders for show and/or for pets are neither grossly irresponsible or cruel. Pet owners who wish to have a dog with a certain temperaments and capabilities are not necessarily cruel or selfish. For example, if you want a dog that does not shed much or a low energy dog or a dog that is likely to be good with children or hunts well or ______, it makes sense to take the breed into account. Unless the local shelters have purebred dogs or dogs with easily identifiable breeds, that is sometimes very difficult to do. It is responsible to have a pet that one can take care of and that will prosper in its new environment. In fact, it is irresponsible and cruel to ignore the temperament and traits of a dog when adopting one. Purebreds are one way (not the only way) to maximize the chance that the adopted dog will prosper.

What laughing dog said.

 

[Hickdive]

Breeding for pedigree does not necessarily help however, the biggest culprit, IMO, are breed standards promoted by kennel clubs that are inherently bad for the dog.

When "standards" emphasise nonsense like short muzzles that cause breathing problems, bulging eyes that cause infection, or hip shapes that promote dysplasia, etc. then that is inherently wrong. The standard should be a healthy, happy, example of the breed not grotesque extremes.

If you want a specific breed then you don't have to go to a breeder and get a puppy. Most breeds have their own rescue/re-homing organisations with dogs of all ages available, usually for a small donation and undertaking to have the animal neutered (often at the rescue organisation's expense)

 

[Toni]

Breeding for pedigree does not necessarily help however, the biggest culprit, IMO, are breed standards promoted by kennel clubs that are inherently bad for the dog.

When "standards" emphasise nonsense like short muzzles that cause breathing problems, bulging eyes that cause infection, or hip shapes that promote dysplasia, etc. then that is inherently wrong. The standard should be a healthy, happy, example of the breed not grotesque extremes.

If you want a specific breed then you don't have to go to a breeder and get a puppy. Most breeds have their own rescue/re-homing organisations with dogs of all ages available, usually for a small donation and undertaking to have the animal neutered (often at the rescue organisation's expense)

I don't agree that it is the breed standards. I think that it is the fact that some breeders --and some customers of breeders and rescues! as well as show judges--push for a certain characteristic. If a short snout is good, then an even shorter snout must be better! If shoulders higher than hips is good, then increasing that ratio is better! If white heads are good, then let's breed this even if it is associated with increased risk of deafness! And so on.

A good breeder takes adheres to the breed standards while not pushing the boundaries to get 'more' of whatever, without considering the health implications of 'more.'

As far as breed specific rescues, yes, they can be a wonderful source of pets. However, you are more likely to get dogs--who deserve good homes and who can be wonderful animal companions--who also have some potentially serious medical and/or behavioral issues. There is a reason they ended up in rescue. Also a good--that is an ethical breeder will ALWAYS take back a puppy that doesn't work out because it 'got too big' or the kids are allergic, or the puppy has too much energy or now we're into corgis, sorry labrador puppy! For a good, ethical breeder, breeding puppies is a commitment to the puppies for the puppies' lifetime. A good, ethical breeder will also be very selective about who s/he sells to for these reasons.

 

[ronburgundy]

Do you have any actual evidence to support this claim?

It is more about avoiding particular pure breeds. Outside of very specific working dog contexts, there are few where mixed breed mutts don't don't fair better and aren't more adaptive than any pure breed.

Do you have any actual evidence to support this claim?

Purebreds are the problem, not the solution.

Do you have any actual evidence to support this claim?

A mixed breed mutt maximizes the odds that the dogs will prosper in any caring environment.

Do you have any actual evidence to support this claim?

Breeders are the one's creating the kinds of dogs that are the most problematic and least adaptive to different contexts.

Opinion masquerading as fact.

Your own argument makes the same assumptions from which my claims follow.

"Breeding dogs for specific characteristics and temperament" means that they will only be adaptive to specific contexts and putting them into other contexts will be problematic. When you make a list of dogs to avoid for particular situations or that have known problems or limitations, the list includes various pure breed and does not include mutts, because mutts do not have particular defects and limitations bred into them.

Most problems, physical and behavioral are about being too extreme on some dimension. Pure breeding is entirely about creating dogs that are extreme and various dimensions, but it is impossible to not also make them extreme on unknown or unintended dimensions. That is where the problems arise.

Other problems can occur due to largely random events that can happen to any dog, regardless of breed.

You cannot point to any evidence to support your claim that getting a pure breed rather than a mutt ensures greater odds that the dog will fit into a typical family pet situation (i.e., the situations that make up 99% of those that dogs are currently brought into). The evidence is only that some pure breeds fit better than other pure breeds that are problematic. While some shelter dogs have been abused and thus will have problems that is orthogonal to the pure bred vs. mutt effect.

In addition, any less than perfect fit with an adopted dog is still infinitely better than the one that the adopted dog would be in otherwise. Whereas paying someone to create you a new dog with a specific characteristics, guarantees that all those shelter dogs that would have been good fit are now going to suffer the worst fit possible, a life in a cage or death. Unless you actually abuse the dog, the moment you adopt it, you have engaged in a generous act that is more responsible and less selfish than getting the "best fit" breed from the most responsible breeder possible. Buying a breeder dog is a selfish choice, using so-called "ethical" breeders and selecting your breed carefully only minimizes the harm, it doesn't eliminate it. Every dog bought from any breeder encourages and grows the for-profit industry of manufacturing puppies which guarantees increased suffering of dogs, especially in a world where supply already massively exceeds demand.

Imagine a person who could have biological children, but they didn't like all the defective "uncertain" lineage of the kids up for adoption, so they wanted a specific "breed" of child to match their preferences for white skin, blue eyes, high IQ, and strong athleticism. So, they hand pick the sperm and eggs of strangers based on their traits and have doctors manufacture them a new non-biological child from scratch. Would have any ethical problem with that? Note, the the human vs. dog difference actually makes doing this with dogs worse, because humans are a far greater and more long-term time and cost investment, and your options for dealing with getting a defective one are far more limited. Shelter, dogs can easily and legally be returned to a shelter or put down, either of which is still more ethical than not taking a chance on them in the first place.
So, genetically engineering a non-biologically related child to ensure "fit" while letting orphans languish is arguable less ethically questionable than doing so with dogs.

 

[Toni]

Do you have any actual evidence to support this claim?
Do you have any actual evidence to support this claim?

Purebreds are the problem, not the solution.

Do you have any actual evidence to support this claim?

A mixed breed mutt maximizes the odds that the dogs will prosper in any caring environment.

Do you have any actual evidence to support this claim?

Breeders are the one's creating the kinds of dogs that are the most problematic and least adaptive to different contexts.

Opinion masquerading as fact.

Your own argument makes the same assumptions from which my claims follow.

"Breeding dogs for specific characteristics and temperament" means that they will only be adaptive to specific contexts and putting them into other contexts will be problematic.

No it doesn't. Do you have dogs? I grew up with dogs and have lived with at least one dog most of my life. Some dogs I have lived with were specifically bred as hunting dogs. They were also well adapted to being family dogs. It is very, very common where I live for families to have labs or other retrievers which work as hunting dogs during season and are family dogs the year through.

When you make a list of dogs to avoid for particular situations or that have known problems or limitations, the list includes various pure breed and does not include mutts, because mutts do not have particular defects and limitations bred into them.

Also not true. One would be wise to avoid a 'mutt' with obvious heritage that would include a breed that would be incompatible with your living situation. It would be foolish to get a mutt that is mostly say, a border collie if you live in a small apartment in the city and dislike taking dogs for long walks or training. A dog with a heritage that was mostly from more sedate breeds would be more suitable. Likewise, you should think long and hard about getting a dog with a lot of giant breeds in its heritage if you live in small, confined quarters.

Most problems, physical and behavioral are about being too extreme on some dimension. Pure breeding is entirely about creating dogs that are extreme and various dimensions,

Not, it's not.

but it is impossible to not also make them extreme on unknown or unintended dimensions. That is where the problems arise.

A careful, thoughtful breeder with a good breeding program will select only sound breeding stock and will try to correct for faults in terms of health and temperament as well as breed conformation.

BTW, the unintended, unpredictable --and unhealthy! even dangerous--characteristics are multiplied many times over for dogs of unknown provenance, such as mutts or mixed breeds. Typically, these result from unintentional breeding from parentage of unknown health and inherited health and temperament risks or from deliberate mixing of two dogs because they would 'make such cute puppies' regardless of any health or temperament risks of the parent dogs.

Other problems can occur due to largely random events that can happen to any dog, regardless of breed.

Finally got something right.

You cannot point to any evidence to support your claim that getting a pure breed rather than a mutt ensures greater odds that the dog will fit into a typical family pet situation (i.e., the situations that make up 99% of those that dogs are currently brought into). The evidence is only that some pure breeds fit better than other pure breeds that are problematic. While some shelter dogs have been abused and thus will have problems that is orthogonal to the pure bred vs. mutt effect.

You have just pointed out an advantage of getting a purebred dog. Please note: whenever I write about a purebred dog, I am writing of purebred dogs from careful, thoughtful breeders whose breeding program selects only healthy dogs--physically, temperamentally--from which to create more puppies.

If you know that your living situation would be incompatible with say, a dog with lifelong high energy needs--such as a border collie--you would be wise to avoid getting a border collie. If you know that you have a sedate life style, you would be wise to choose a sedate dog, which is easier to do if you select from a high quality breeding program where the breeder will ask you many questions and make sure you are a good match for her puppy, in terms of lifestyle, temperament, ability and willingness to care for the puppy even as it grows larger and older, etc.

In addition, any less than perfect fit with an adopted dog is still infinitely better than the one that the adopted dog would be in otherwise.

Well, no. Some people 'adopt' dogs specifically for bad purposes, such as dog fighting or animal testing. Or are dog hoarders. Or neglect their dogs. Or worse. This is not better.

Whereas paying someone to create you a new dog with a specific characteristics, guarantees that all those shelter dogs that would have been good fit are now going to suffer the worst fit possible, a life in a cage or death.

No, it doesn't. First of all, there are plenty of dogs which are specifically shipped to shelters in order for the shelter to turn a profit. Yep. Puppy mills dump their puppies somewhere and often, it's a shelter. All of those puppies that are in shelters were not found on the streets or rescued from inhumane conditions. Nope. They were PURCHASED FOR RESALE. From someone who bred them for profit, bypassing any and all medical or breed standards. This is a sad reality.

Unfortunately, shelters often have a profit motive and are not always looking to 'save' dogs so much as they are in running a business that trades on human sympathy for animals.

Not all shelters are like this, but plenty are. The bigger, the more likely that that their primary purpose is to make a buck.

I'm sorry to break that news to you.

Unless you actually abuse the dog, the moment you adopt it, you have engaged in a generous act that is more responsible and less selfish than getting the "best fit" breed from the most responsible breeder possible.

No, it's not. People buy dogs because they want dogs. Calling it 'adoption' ignores the fact that you fork over hundreds of dollars for the dog. Which did not require hundreds of dollars to maintain during it's time in the shelter. Sure, shelters normally will do a spay/neuter before the 'adoption'/sale but they do it early enough that it is not necessarily in the dogs' best health interests to do so. Some states even have or are pushing to have laws mandating spay/neuter as early as 4 months, which might be ok for a small breed animal but is not good for the long term health of a larger breed which will take much longer to reach physical maturity and which benefits from having the whole compliment of hormones to aid its skeleto-musculature growth and maturation.

Buying a breeder dog is a selfish choice, using so-called "ethical" breeders and selecting your breed carefully only minimizes the harm, it doesn't eliminate it.

No it doesn't.

Every dog bought from any breeder encourages and grows the for-profit industry of manufacturing puppies which guarantees increased suffering of dogs, especially in a world where supply already massively exceeds demand.

If you are against the for profit industry of manufacturing puppies which guarantees increased suffering of dogs, you will work against puppy mills and many, many shelters which are supplied by puppy mills. Directly and indirectly.

BTW, some shelters import dogs from other areas and even other countries when their supplies of cute puppies gets too low.

Imagine a person who could have biological children, but they didn't like all the defective "uncertain" lineage of the kids up for adoption, so they wanted a specific "breed" of child to match their preferences for white skin, blue eyes, high IQ, and strong athleticism. So, they hand pick the sperm and eggs of strangers based on their traits and have doctors manufacture them a new non-biological child from scratch. Would have any ethical problem with that?

Actually, this is more analogous to saying that no one should have their own children but should adopt unwanted children from other countries instead. Although that is actually a better argument for adopting children, actually, than it is for 'adopting' i.e. buying from a shelter rather than buying from an ethical breeder.

Note, the the human vs. dog difference actually makes doing this with dogs worse, because humans are a far greater and more long-term time and cost investment,

Actually, you have it turned around. It makes more sense, ethically, to adopt human children than to produce your own biological offspring. Note: I am not adopted nor are my children. Yet, if you are going to take that argument, it applies more to humans precisely because they require so much more than do dogs and the consequences of failing to provide for human children is much more serious than failure to provide 'adoptive' homes for dogs which were 'abandoned.'

and your options for dealing with getting a defective one are far more limited.

Yeah, people aren't defective. Although I am beginning to think maybe some might have defects which are not able to be overcome by say, reason and education.

Shelter, dogs can easily and legally be returned to a shelter or put down, either of which is still more ethical than not taking a chance on them in the first place.
So, genetically engineering a non-biologically related child to ensure "fit" while letting orphans languish is arguable less ethically questionable than doing so with dogs.

Do you know what happens to a dog which is returned to a shelter?

Do you know why dogs are usually returned to shelters?

Do you know at all what you are talking about beyond you read it somewhere?

 

[laughing dog]

Your own argument makes the same assumptions from which my claims follow.....

That was a long winded answer to the questions. A "No, I don't have any evidence" would have been sufficient and accurate.

The rest of your response indicates that you have little actual experience or knowledge about pure breed dogs, mixed breeds (or mutts), breeders and animal shelters. Here is but one example out of many in your response:
"Most problems, physical and behavioral are about being too extreme on some dimension. Pure breeding is entirely about creating dogs that are extreme and various dimensions, but it is impossible to not also make them extreme on unknown or unintended dimensions." Pure breeding is not about creating dogs that are extreme. It is about breeding dogs to a standard. There is nothing extreme about beagles or basset hounds or Old English Sheepdogs or Scottish terriers or most other breeds.