The effects of inbreeding are not the same in all breeds. Remember, it is inbreeding and then rigorous selection process that causes gene loss. Different inbred breeds have experienced the loss of different genes, and this is why we get some variance on the effects of inbreeding between different breeds. Some breeds handle it relatively well. Others come very close to extinction. (And many have actually become extinct.)
To illustrate these differences, it will be necessary to look at some case studies. I deliberately chose two breeds that have origins in the very recent past; both of these dogs were developed after the Second World War. Both were developed in Central Europe– one in capitalist West Germany and the other in communist Czechoslovakia. Both are the result of crossing established kennel club breed, and both were intensely inbred to establish type.
The two breeds are the Cesky terrier and the wolf-chow. As we shall see, the two breeds have very different experiences as they have been inbred. Because inbreeding almost killed it, one of them had to have the infusion of another breed to save it. And when that other breed was added, it became a new breed. The other still exists as it does, although there have been outcrosses with one of the parent breeds, it still has high levels of inbreeding.
The Cesky terrier was founded in 1949 in communist Czechoslovakia. The communists took control over the country 1948, and the breed founder, František Horák,wanted to create a hunting terrier that the “new socialist people” could take hunting the forest. He wanted a small dog that could fit down nicely down
Horák began with a cross between a Sealyham dog named Buganier Urquelle and a Scottish terrier bitch named Scotch Rose. Only one puppy survived to adulthood, Adam Lovu zdar. That dog was trained as a hunting dog, but he was accidentally shot before he could produce any puppies. So Horák repeated the breeding, and six puppies were produced. One of these was Balda Lovu zdar, who was bred back to his mother, Scotch Rose.
And that began a long period of intense line and inbreeding with the Scottish terrier/Sealyham crosses. Horák had worked as an assistant with geneticists at the Czech Academy of Sciences, so he was well-versed in Mendelian genetics. He rigorously selected for conformation and working characteristics, and the result was the only working terrier to develop in the Eastern Bloc.
Of course, we can criticize Horák for inbreeding, but Czechoslovakia at the time was not a place that was full Scottish terriers and Sealyhams for breeding. Many of the dogs that were in the country before the war dead, and during the war, no one was breeding from them. And to make matters worse, Czechoslovakia, as a communist country, was now cut off from the West, where most of the terrier blood was. Horák had to establish his breed with a smaller number of dogs than he might have liked, and to establish his line, he had to inbreed.
Today’s Csesky terrier is quite inbred. Many individuals have COI’s above 80 percent. However, the breed has no known genetic disorders, although the dogs are slightly susceptible to Scottie cramps. However, the breed does appear to have issues with cancer and has a median lifespan of 8 years, 5 months. (One should be careful about that one study. It has an n=9. For the purposes of this post, let’s assume they do have issues with cancer.)
This breed is a good example of what rigorous selection can do to an inbred population. Because Horák and his successors were likely engaging in something very similar to natural selection upon this population. These dogs were selected for their health, vigor, size, floppy ears, and pack mentality. It is a sort of cheetah-lite selection process. Many working dog breeders who swear by breeding close and rigorously selecting are engaging in similar process.
And over time, the dogs were bred away from certain deleterious recessives. That is why the breed has no obvious genetic disorders.
However, continuous inbreeding still had an effect upon the breed. The high cancer rate in the breed is very likely the result of inbreeding depression. The breed likely has little diversity in the MHC.
Now, in the 1980’s, a Sealyham was crossed into increase genetic diversity in the Cesky. Dogs that have this influx of Sealyham blood are called “Line 2″dogs, which differentiate them from Horák’s dogs, which are designated as “Line 1” dogs.
Although this breed has been selected against genetic disorders, it still has experienced the effects of inbreeding depression. It was only because of that rigorous selection process that genetic disorders were selected against.
One should not use the case of the Cesky terrier to assume that very tight breeding is okay. In that one instance, a very tight breeding program was able to work because of the selection process– and because the breeders miraculously did not select away or select for genetic diseases.
But even with that luck, they still have issues with cancer.
That is why many Cesky terrier breeders are trying to find ways to reduce COI’s in their breed. Even if the breed has survived and has thrived (in a relative sense) through very tight breeding, it does not mean that it will work in every case or even the majority of cases.
Dogs have not evolved inbreeding tolerance. The only wild dog population that has been able to survive exteme inbreeding has been the San Nicolas Island fox, which was able to survive and maintain a diverse MHC through balancing selection. The wolves of Isle Royale were once touted as being a great example of a thriving inbred population. That is no longer the case.
Generally, dogs do not do well in inbred populatons. As a wonderful counter-example to the Cesky terrier. the story of the wolf-chow is more indicative of what happens when domestic dogs are very tightly inbred.
A German named Julius Wipfel had always been fascinated by northern sled dogs. He settled in Weinheim, Baden-Württemberg, after the Second World War with his young wife. He then went looking for a dog. When he found a spitz-type dog at the local shelter, he jumped at the chance to take him home. The shelter said the dog had accompanied Canadian troops that had been occupying Mannheim. Maybe this was a ploy to get Wipfel to adopt the dog. Maybe this dog actually was a Canadian Eskimo dog. But whatever he was, the dog, who was named “The Canadian, ” had a profound influence on Wipfel. In Wipfel’s mind, he was the ideal sled dog of the northern type. He had very a “primitive” characteristics. He bonded very strongly with his family and was quite aggressive toward strangers.
When the Canadian died, Wipfel purchased a wolfspitz (keeshond) bitch. Like many of her breed, she was sweet and gentle– not at all what Wipfel wanted.
It was only after reading about a Chow-Chow/German shepherd dog cross in Konrad Lorenz’s books that Wipfel got the idea to breed Chows to wolfspitz.
He began breeding chows to wolfspitz and trying to build a club around these dogs. He called the breed the “wolf-chow.” However, he had a very hard time getting people to want to breed from them, and it became difficult to set traits.
His original breeding program required a rotation of different mating combinations of different wolfspitz and chow crosses and setting traits through selective breeding.
However, such a breeding program required lots of different dogs to be bred, and because West Germany was a mostly densely populated urban society, not many people wanted their dogs to be part of the breeding program.
Wipfel then came in contact with Charlotte Baldamus. She was a refugee from East Prussia who had many years of experience breeding poultry strains. Now, in breeding animals for agriculture, the metric is very different from breeding pets. The metric for productive animals is the market for meat, eggs, or milk. Inbreeding to produce these animals is fine, simply because no one expects a chicken or a dairy goat to live out its full life. With dogs, we expect so much more. We want them to live out their full lives, and in doing so, we allow them have the potential of experiencing different genetic disorders.
Baldamus began an inbreeding program for wolf-chows. It required fewer breeding dogs and fewer generations to set type, and the results were very much what she was expecting.
However, as the program continued, COI’s got higher. This was exacerbated when the whole breed was essentially built upon one red stud dog.
The dogs looked like what they wanted, but they were of no use as sled dogs. They also begant os show signs of an inbreeding depression and hip dysplasia showed up for the first time. Wipfel wanted to cross in Samoyed dogs, but Baldamus did not want any new blood.
It was only when Konrad Lorenz, who had admired this breeding program because it was based upon his own work, suggested that Samoyed be added into the breed. Wipfel did so, producing a litter of black puppies– and Lorenz purchased one. Black puppies shouldn’t have been a surprise. Samoyeds are black-skinned e/e’s. For some reason, the e/e genotype makes the Samoyed white instead of cream or gold, as we see in golden retrievers.
But when the Samoyed was crossed in, the primitive temperament that Wipfel wanted to hold onto disappeared. The Chow’s strong bonding tendencies were swamped with the friendly and gentle natures of both Samoyeds and keeshonds/wolfspitzes.
When the breed was officially recongized, the Chow fanciers club refused to allow them to register the dogs as “wolf -chows.” So it was decided to incorporate the Samoyed influence in the breed’s name, calling them Eurasiers to reflect the origins of their ancestors in Europe, Siberia, and China.
The wolf-chow was not selected for working characteristics as the Cesky terrier was. It was selected for appearance only. And the selection process for the wolf-chow did not select against disease. Without an understanding of which genes are associated with which disorders, selective breeding at this time was a crap shoot. The Cesky terrier breeders had been lucky that they selected against genetic disorders. The wolf-chow breeders were unlucky in their roll of the dice.
And they were not rigorously selecting for health. They were breeding dogs as if they were poultry.
And the results were not good.
Most dog breeding in Western countries would involve the selection pressures in the wolf-chow. Very few breeders are engaging in rigorous selection that would produce a dog like Cesky. Even if they are breeding for health, the dogs are not going to undergo that selection process.
Many working dog breeders use something like the Cesky breeding strategy. They even make their bitches whelp outside in doghouses or steel barrels so that natural selection also acts upon their breeding programs.
And that is one way to select against genetic disorders.
But over time, inbreeding is inbreeding, and some effects of an inbreeding depression still pop up, such as the Cesky terrier cancer rate.
Now, most modern dogs are not bred in the same way that wolf-chows and Cesky terriers were. Most dog breeders use line breeding techniques, but the results can be similar, though far less dramatic in the short run.
The truth is that inbreeding and the selection process can cause no problems in terms of the health of a dog breed or line. It can also cause very real problems for a breed. Our understanding of dog genetics is still not complete enough to understand why it causes problems in some cases and not in others. And even if our understanding is better than it is now, we can still have surprises. The genome has many surprises for us, especially when we think we know it all.
For that reason, as a precautionary measure, it is best to see inbreeding as something to avoid and genetic diversity something to promote. And even if things wind up being okay for a time, it does not mean that something might go wrong someday. (See the Tasmanian devil’s story to see why.)
One can use stories in which animals, including other domestic dog breeds, have done relatively well through inbreeding. However, the only dog I have found that has an even half-way good outcome from inbreeding is still experiencing what appears to be an inbreeding depression. We cannot base our whole model for dog breeding off of this one case. History has shown that when dog loose genetic diversity, the have experienced more like that of the wolf-chow than the Cesky terrier.
The risks are just too high to ignore the COI and diversity within the MHC/DLA genes in domestic dogs. And just because it worked out once (kind of) does not mean that it will work in every case or even the majority of cases.
And just as it appears to work at one point does not mean that there are no long-term consequences.
Both of these breeds were founded from small numbers of dogs out of necessity. The were both created in social and economic situations in having large kennels was simply impractical.
Most of our kennel club breeds are actually derived from breeders who did have many, many dogs to choose from and the founding populations were actually quite large. And very tight breeding was not often pursued without using outcrosses, which often came from lines produced in the same kennels.
Inbreeding was a way of establishing a breed quickly with just small numbers of dogs.
Because of these factors, most modern dogs have gone this same direction but at a much slower pace.
But the story of these two breeds should tell us what could potentially happen with genetic bottlenecks– even when things appear to be going fine.
Did the wolf-chow become the Eurasier, or is that another chow/keesie/sam-based breed?
Wolf-chows became Eurasiers.
Samoyeds used to come in black as well: http://smg.photobucket.com/home/Pietoro/tag/samoyed
They used to come in black and white, too.
I have been trying to find a connection between this breed and the Swedish and Finnish lapphunds. They are very similar in appearance and function– reindeer herders.
But I’ve found no genetic evidence.
Have you asked the lapphund research folks? :)
Goign to a Lapphund education seminar on Friday. Will ask for you. :)
I wouldn’t be nearly as generous to the Cesky as you are. This is a breed that had to have an infusion only 40 years after it was founded. That’s a huge red flag, especially since we’ve seen how reticent anyone is to bring in new blood.
It got so bad after only 40 years… what was the issue at that time? Why did they do this? I doubt it was a forward looking precaution.
And the low N on that study is a sign of another problem, not that we don’t have enough data…. that we don’t have enough Ceskys to maintain a healthy breed. Jemima posted that there were 64 surveys sent out. Is that the total number of breeders? Psh, this breed is done for.
You can’t save such a small breed.
As for the lack of documented inbred diseases… that’s no indication. Absence of Evidence is NOT evidence of absence, especially with the facts we have here. There are simply too few dogs to have any significant data.
And those life spans? Those are already worse than what would be caused by any number of diseases.
I’d say we don’t have much of a contrast here. Both are pathetic.
They didn’t always have problems, though.
In the short-term, they were okay. Until everyone in the Communist bloc wanted them…
Ceskys are a very good example of a breed that was selected for function in the way that many working dog breeders do it. Breed and rigorously select.
But it’s the only one I can find that has no serious genetic disorders but has the inbreeding depression syndromes. Most breeds have both.
They got lucky with their founder population.
And with the selection process.
Human can’t figure this out. It is all luck.
Considering we live in a disposable society, the inbreeding depression syndromes might not be a bad thing for materialistic Westerners.
http://www.ceskyterrier.co.uk/section213947.html
The only ones that are significant are cancer and Scottie cramp.
This is actually where border collies are likely headed. Few genetic disorders but inbreeding depression problems.
I don’t know how rare they are. Apparently, they are pretty common in former communist countries, because they were virtually the only terrier they could easily procure.
actually there is more than one “island fox” in CA:
Urocyon littoralis littoralis of San Miguel Island,
Urocyon littoralis santarosae of Santa Rosa Island,
Urocyon littoralis santacruzae of Santa Cruz Island,
Urocyon littoralis dickeyi of San Nicolas Island,
Urocyon littoralis catalinae of Santa Catalina and,
Urocyon littoralis clementae of San Clemente Island
Unlike “Isle Royale wolves” these foxes have had a chance to seriously develop over a minimum of 800 to possibly a max of about 16,000 years. And because they were foxes, there could be more of them than wolves on Isle Royale, meaning there was a bigger “base” gene pool once the islands became isolated. They are very susceptible to canine Distemper — not because of inbreeding but because they evolved without this disease being present until modern times. I was priveldged to see the Santa Cruz foxes when I worked for the Navy. One of the things the Navy did, quietly and effectively, was to save the Santa Cruz fox.
Regarding the Cesky terrier, I find it hard to believe that there were so few “terriers” available that a better breeding pool couldn’t have been used, even given the effects of WWII and being behind the “iron curtain”. I tend to believe that, given the tendency of the Soviet bloc to dissemble about their accomplishments, that the real background of the Cesky may not be exactly as it’s presented. It would be interesting to see if the DNA shows the claimed decent. I’ve always thought the “black Russian Terrier” probably has a good dose of Bouvier in there despite assertions that it doesn’t.
Peggy Richter.
The one that is most inbred is the San Nicolas subspecies.
That’s why I referenced it, not because I’m an idiot who doesn’t know about the other species.
The distemper susceptibility thing is genus-wide. Mainland gray foxes are particularly susceptible to it: http://www.jwildlifedis.org/cgi/content/abstract/28/1/28
But island foxes would likely be more so.
San Nicolas foxes are those that have had balancing selection. That is why I referenced them:
http://www.nature.com/hdy/journal/v93/n3/full/6800539a.html
Thank you Retrieverman, for a far more balanced appraisal of the Cesky Terrier than is often seen.
The health survey that seemed to suggest a very high incidence of cancer was seriously flawed, as it was done at a time when the breed was fairly newly imported to the UK. Those dogs that went on to live long, healthy lives were still young, and many owners felt that they had nothing to contribute to the survey as their terriers had never visited a vet, apart from for routine shots.
Evidence over the last few years seems to suggest that Cesky Terriers have no higher incidence of cancers than any other breed. Fertility can be a problem – but it does seem that introducing a slightly unrelated dog into a breeding programme can increase litter size quite markedly, even if the numbers drop again after a couple of generations – so those breeders working to lower COIs are seeing a rapid improvement.
Just a couple of small corrections to your excellent piece. The first mating was between Buganier Urquelle and the Scottie Donka Lovu zdar. Scotch Rose produced the second litter some six months later.
The re-generation of the breed, by the introduction of the Sealyham, Andra z Rastamoru, is usually given the nomenclature Line 1A, not Line 2. Likewise, dogs descending from the litter born in 1972, supposedly by Trysk Lovu zdar ex Bellis Solor (but of questionable parentage) are designated Line 1B.
One of Horak’s stated aims was that he wished to see if it was possible to create a distinct new breed from a very limited number of individuals. If he had had the benefit of modern understanding of population genetics, maybe he would have approached the task slightly differently.
Sheila Atter
Ridley Cesky Terriers
What’s interesting to me is that you can get dogs like Cesky terriers that don’t have as many health issues, despite their low genetic diversity, but you can have others where the diversity is higher and have all sorts of issues. Nova Scotia duck-tolling retrievers come to mind. Sussex spaniels were largely doomed from the start because they were founded upon inbred individuals that were inbred again.
It often is just luck about which genes are actually lost.
Exceptions to the rule, as Cesky terriers are, are worth examining, because we can look at why they are exceptional.
I am willing to forgive Horak for two reasons: post-war Czechoslovakia was largely cut off from the West and our large number of dog breeds– and was forced to do some close breeding– and secondly he was living at a time when our understanding of population genetics was not what it is now. I don’t know how prevalent Lysenkoism was in other communist countries– I know it was big in China– but not having a good grasp of Mendel would be a very big problem in founding any strain.
I think that, officially, Lysenko’s theories were in force in communist Czechoslovakia – but Horak was both widely read and pretty non-conformist. There are a few inconsistencies in his breeding programme that make me believe that he managed to do as much as he did partly by justifying his ‘experiment’ with the authorities. For example, why would you choose a Scottie that must have been a carrier for Scottie Cramp (I can’t believe that he didn’t know) except that the P.I.S. was researching epilepsy.
He told me that he developed his breeding programe according to the ‘English’ method – by which he meant the closed stud system outlined in Roy Robinson’s ‘Genetics for Dog Breeders’ – he and Robinson corresponded quite frequently, although the letters from the latter were always opened and read by the StB who were very suspicious of Horak’s activities and correspondence with breeders in other countries.
Thank you for writing. I rescued a dog I have determined is a “wolf-chow”. You hit spot on with the temperament and primitive traits. I want to breed her because she is the best dog, but after reading this I see the danger of doing so without a better understanding of genetics. I don’t want to repeat history like the original breeder did with inbreeding.
[…] And it looks like the America bully is going to race down it– just as the Eurasier and the Cesky terrier have done before. […]