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Posts Tagged ‘homozygous bobtail’

This is a homozygous natural bobtail Pembroke corgi that was born alive. You can tell from its profile that it has something very wrong with its back end.

Over at BorderWars, Christopher Landauer has taken down one of the great myths that breeders of dogs with a certain type of natural bobtail often like to perpetuate.  (I should warn you that the images on this post are quite graphic. Reader discretion advised.)

The myth is that although this trait is a considered lethal when inherited in a homozygous manner, these homozygous natural bobtails are never born.

This myth has gained certain currency in Europe, where tail docking is becoming illegal in country after country. If docking is illegal, then many breeds are going to have to breed for a consistent tail type and carriage. When breeds have been docked for generation after generation, no one has selected for any kind of consistency in the tail, which makes the dogs harder to show. If a breed has a wide variety in phenotypes, it’s very difficult for judges to make a selection about which dog is truly meets the standards.

So it might be a good idea to produce lines of dogs that don’t produce any tails at all.  Dogs that are born pre-docked.

Sounds like a wonderful idea, eh?

The first breed to undergo an experiment to produce natural bobtails was the boxer.  Dr. Bruce Cattanach bred a white boxer to a Pembroke corgi with a natural bobtail. After just a few generations of breeding back to the boxer breed, he was able to produce naturally bob-tailed dogs that were virtually indistinguishable from high quality conformation boxer in the UK.

This particular outcross was performed without any consultation of the German Boxer Club. Germany is the patron country of the boxer in the FCI, and the German Boxer Club refused to accept any dogs that are naturally bobtailed. The German and FCI standard now disqualifies any dog that is naturally bob-tailed, and all the boxers I saw in Germany had long, whip-like tails.

This particular outcross is essentially a failure on breed politics grounds. The majority of boxer clubs in the world will not accept these dogs. And there is really no health or working reason to dock a boxer. Most boxers are family pets. They aren’t running over fields covered in thorn bushes that might damage their tails, as would be the case for a German short-haired pointer, and they aren’t guarding flocks of sheep from wolves that might try to catch them by the tail, as would be the case for a Central Asian ovtcharka. Boxers look fine with tails. The only downside to a boxer with a tail is that it might be mistaken for a pit bull and result in some bizarre hysteria.

But even if this natural bobtail didn’t totally fail breed politics, there are actual health and welfare reasons to be skeptical of it.

Cattanach contends that natural bobtails are not a problem in terms of health.

However, as you will see in Chris’s post, there are risks of breeding natural bobtails together.

Although homozygous natural bobtails are rarely born, they still are born on occasion.

And when they are born, they have severe deformities.

The dog pictured above was a homozygous natural bobtail that was born in a natural bobtail to natural bobtail breeding.  It was euthanized shortly after birth. It was born with no anus, no tail, and an open hernia that leads into the spinal canal. This animal simply could not have survived.

This is the photo of the back end. I should warn you that this image is quite graphic, and it may be disturbing to some readers.

No anus. No tail. And an open hernia into the spinal canal.

Another homozygous natural bobtail corgi was also born. This one also had no tail and no anus. Its intestines and lungs were full of gas, and it had severely wasted muscles in its hindquarters. It also had a kinked spine.

Any breeding can produce dogs with deformities. My uncle bred a puddin’  Jack Russell that was half puddin’/ half JRTCA to a bitch that was derived English farm stock that likely included some border terrier or Patterdale ancestry. The two dogs produced three litters. The first one had two healthy puppies.  The next had three.  The fourth had five, but one of these had spina bifida and had to be euthanized. This was an entirely outbred litter, and neither parent had any defects or disease.  But a birth defect still happened.

However, when one breeds natural bobtail to natural bobtail one is accepting a relatively higher risk that a truly deformed puppy might be born, and in this situation, we have to consider the ethical implications.

Now, we do have lethal traits that are inherited in a somewhat similar way to this form of natural bobtail. The dominant hairless dogs– the xoloitzcuintli, the so-called Chinese crested dog, and the Peruvian Inca orchid–are hairless because of a mutation that in theory is inherited the way it is often claimed that natural bobtails are.  These hairless dogs do not produce solely hairless offspring when bred together. That’s because homozygous hairless puppies are never born. They die before they ever develop into puppies. All of these hairless dogs are heterzyous hairless, and they all carry the recessive coated trait. In every hairless breed of this type, there will be coated puppies born. It’s very simple.

Cattanach claims that the natural bobtail is just like this hairless trait.

But the two corgi pups show that it is not.

If it were just like the hairless dogs, these two puppies would never have been born.

And because they were born alive, there is a real welfare consideration that has to be made.

The German Boxer Club made the right decision. As Europe pushes harder against tail docking, the future is going to be with long-tailed boxers, not gimmicks with natural bobtails.

***

I find it particularly interesting that Cattanach has come out against the Australian shepherd/Nova Scotia duck-tolling retriever cross-breeding program.

This particularly program is controversial, and it is totally failing breed politics. But it is an outcross for an entirely different reason.

Nova Scotia duck-tolling retrievers have low MHC/DLA haplotype diversity. These MHC/DLA genes control immune response, and because tollers have such low diversity, they have very real issues with autoimmune disorders.

The only way to increase diversity in haplotypes is to outcross or bring in unregistered dogs from Nova Scotia– which may or may not have diverse MHC haplotypes.

This crossbreeding has been criticized for using an Australian shepherd, a breed that comes in merle and is sometimes more reserved in temperament than toller people might like.

Also, one person in Germany is doing the crossbreeding, and one person doing the crossbreeding on his own cannot save the entire breed. His dogs likely won’t be included in the bloodlines of the breed.

However, he is doing something.  And its for the health of the breed. Maybe the breed clubs will accept his dogs one of these days.

However, this is a beautiful example of cognitive dissonance within the dog fancy.

Cattanach claims that it’s okay to outcross to a corgi to introduce a cosmetic trait into boxers– even if this cosmetic trait can result in severely deformed puppies.  And even if this outcross winds up failing totally when it comes to the politics of the boxer fancy, he still promotes it as a sucess.

But if anyone tries to outcross another breed for health reasons, it’s a bad idea.

It’s really interesting the amount of cognitive dissonance that exists within the dog fancy at large.

It’s everywhere.

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