Canis lupus hominis

Sometimes the issues discussed on this blog suddenly pop up in the mainstream media, and when they do, it gets very interesting to see how journalists frame the issues. I was very impressed with a recent article on golden retrievers and their cancer risk.

When Melinda Beck at the Wall Street Journal was confronted with an aggressive cancer in her seven-year-old golden retriever, Cody, she  began to research why goldens have such a high cancer risk.

She found that some of this problem comes from some institutionalized problems inherent in the fancy:

All purebred dogs are essentially inbred. And the genes become more concentrated with each generation, because most pet dogs aren’t bred and breeders select only a few dogs with the most desirable traits to reproduce.

Since cancer is found in goldens all over the world, experts theorize that the genetic predisposition goes back to the early founder dogs—in their case, a yellow flat-coated retriever and a now-extinct type of water spaniel—that were bred in the 1860s by a Scottish land baron who was seeking a superior sporting dog. After several generations of refinements, the breed was officially recognized by the U.K.’s Kennel Club in 1911, and the “studbook” was closed, meaning that henceforth, all purebred goldens would be descended from the existing dogs.

“It’s possible that some trait that we desire in goldens is linked to something that puts them at risk for cancer. We just don’t know what it is,” says Ms. Hovan, who has also bred goldens in Akron, Ohio, for the past 30 years.

Contrary to rumors in dog-runs and on the Internet, there’s no evidence that cancer is more prevalent in any particular line of golden or puppies by popular sires, Mr. Hovan and other experts say. Cancer has been found in “field” goldens with lean faces and dark coats as well as “show” goldens with bigger builds, blocky heads and light coats.

I’m getting the impression in that last paragraph that the last paragraph that people might be misunderstanding the most-used stud effect. Yes, the genes that cause goldens to get cancer are probably deep within the gene pool of this breed, and they have been there since the beginning.

However, this effect can make such a problem worse, because reduced genetic diversity in any gene pool is associated with a weakened immune system. All organisms will get some cancer, if they live long enough. However, the immune system helps fight these cancers. When the immune system is compromised as the result of decreased genetic diversity, you can see how this can be a problem for a breed that already has a genetic tendency towards developing various forms of cancer.

Cancer itself cannot be traced to one stud or one line.  Cancer is systemic in the breed, which is why we need some reforms at the institutional level.

Think of it as something like the problem that now exists in Portuguese water dogs. We now know the genes that produce the “improper coat” in the PWD. However, if we stop breeding from carriers of that coat, that particular breed will be in a lot of trouble.

My problem is not that we shouldn’t be breeding away from genetic disorders, including these cancers. I’m saying that we should be doing this while also worrying about how diverse the gene pool is.

The article seems to think that identifying the cancer genes is going to solve this problem, and if those were discovered, they would help reduce the risk of those cancers. However, to do that, there would be aggressive culling. Culling does what to the genetic diversity? Indeed, you might breed out those cancers but you might make the breed predisposed to something else. In fact, at some point, you are almost guaranteed to do this. Most-used sires make any genetic tendencies toward certain diseases worse.

The other thing that makes this problem worse is we have giant splits in this breed to the point that the golden retriever might as well be four or five different breeds. The dogs are bred for different standards and for different functions that are so specific that the breeders of each type are often very cautious about adding blood from different lines.

There is also some (rather weak) evidence to suggests that English golden retrievers (as in the “white” ones) have a little bit lower incidence of cancer.  The KC has performed surveys on their purebred dogs, and they have found that the only 38% of the dogs in the survey died of cancer. Of course, this survey has some interesting methodological flaws. The response rate to that survey is actually quite low. So we must have some caution about making some statements about these surveys. The cancer rate in European line show goldens could be quite a bit higher, but the fact that we have this survey means that we should at least be willing to look at their lines. When I was “white” golden retriever bashing, I got this thrown at me in one of the comments, and to be honest, I was a bit surprised.

I have read websites that sell these “white” dogs that talk about their lower incidence of cancer. I have never owned a “white” one, but I do know the breed’s longevity record holder is a British “white” golden.

(Please note that I don’t actually much like the white ones.)

So take that evidence how you will.

I do know that the GRCA has done its own (much better) survey.

And it is from that study that we have an understanding that various forms of cancer are systemic in the breed.

***

If my blog is the source for some of these rumors, I apologize. I research everything that is on here, and I do not put deliberate falsehoods on here.

I do write a lot about the most-used sire effect in the breed. The problem with the most-used sires is that they wind up reducing genetic diversity int he breed. Reduced genetic diversity is bad for increasing the tendency to develop many genetic disorders (especially those that are the result of simple recessive genes).

It also results in a weakened immune system, and then there’s the whole inbreeding depression problem. Problems that come from those issues cannot be solved through “breeding them out.”

I don’t often write about goldens and cancer, but I can say that it is systemic. I don’t see reasonable way to “breed out” cancer. The only thing that can happen there is institutional reforms.

It is very illusory to believe that anyone can breed out any genetic disorder by using the same methods that we breed conformation or working ability. In the short run, it will work. In the long run, intense culling for anything that systemic is going to have some sort of consequence. We might breed out hemangiosarcoma and  find out that we doubled down on something else that is even worse.

Albert Einstein once said, “No problem can be solved from the same level of consciousness that created it.”

And that’s what we’re discussing here. What created the golden retriever’s cancer problem is what is called the founder effect. The dogs that gave us the cancer genes were in those early dogs. What we need is a new consciousness that allows to carefully add new blood to the lines. That will not solve the problem entirely, and it certainly won’t solve it short term. It could also introduce something new. However, unless we start paying attention to genetic diversity problems, the cancer issue is going continue and may get worse.

Of course, even saying we have “cancer genes” is not accurate. We are saying that the dogs have a tendency to develop the cancer because of genes that predispose them to getting cancer. Cancer itself is not inherited– just the predisposition for certain cancers. And that’s what makes some of this research an absolute mess.

So keep in mind, I am not saying the most-used sire problem gave goldens an increased risk of cancer. I am saying that the founder effect did, and although those things are similar, they are not the same thing.

The high cancer rate in goldens is not something that should be accepted as normalcy. This breed is not exaggerated in its conformation. Indeed, I think that if you wanted to describe the “generic Western dog” to anyone, it would be something like a golden retriever.  It should be a very healthy breed that lives well into its teens. I have yet to find a breeder or fancier in this breed who thinks this breed’s health has improved over the years.

These cancers in golden retrievers are the result of systemic problems, and the only way to solve them is for some kind of systemic change.

***

I want to thank Doug Westfall (Willie’s dad) and Jeannine Lalonde for sending me that article.

It was a very good piece.

But it did get me a little worried.

I don’t know if my blog is the resource for some of the rumors, but if it is, I take full responsibility. I am responsible for what I write and for how people interpret what I have written. If something gets distorted for the sake of clarity, I am also sorry, but clarity is one of the main goals I have for anything I write.

Keep in mind that I am writing about two different issues when I write about most-used studs and the founder effect. They are two different problems. The two things can exist within the same population, but they are distinct.

And I also never said anywhere that field line golden are healthier than the show dogs.  If anything,  they are probably a little worse off in terms of genetic diversity. I happen to like them a whole lot better, and I find the way they move and behave closer to what I enjoy in a dog.