Significant Differences – A Tale of So Many Breeds

Let’s state this fact right up front: Breeds are man made. There is no natural genetic definition, no line within which a dog is a member of a breed and outside of which a dog is not a member of that breed. In reality, there is only similarity and lack thereof – and human beings decide what’s similar enough to be the same breed and what’s not. This similarity can be by look (phenotype) or by genes (genotype) but, in fact, a dog is a dog is a dog.

“What?!” you say.  “How can that be?!”

It’s not that breeds don’t exist –  they obviously do – it’s that breed definitions vary. They are defined at different times in different ways by different people and institutions. Nature, however, is arranged in species – and dogs are a singular species. In cats and horses and various other purposely bred animals, breeds are often less stringent in definition, and crossbreeding isn’t necessarily as shocking.  In dogs, we don’t do that. And that’s fine – it’s our tradition, and since cross breeding is usually done purely to sell lower quality dogs for high prices to unsuspecting families, it’s understandable that there is considerable hostility for the practice.

This tradition of purebred dogs, however, requires careful management, because when we isolate populations, which is what we’ve done by creating highly specified breeds with no new influx of genetics, there are both positives and negative consequences. The positive ones are the ones we talk most about – predictable type and temperament. We get very excited about specific colors and coat qualities, ear sets and tail sets and angles of fronts and rears. It’s also a huge benefit to have predictable temperaments, sizes and energy levels, even today when many dog jobs are no longer necessities. We want our dogs the way we want them and we tend to see too much variety as a negative. However, when all breeders want the same thing, which is what breed standards require, we often create popular sires without realizing it, we breed too close too often, and we hope it won’t be a problem in our program. And most times it’s not a problem – not for us.

What we don’t realize is that it IS most often eventually a problem for the breed – especially for breeds with small populations. Only on very rare occasions is a breed with low diversity levels also a generally healthy breed. How much of a problem there is – or if there’s a problem at all depends on the breed. Some breeds have small numbers of founders, and not much diversity, but the founders were healthy, breeders selected for health more than type, and were careful to outcross. Some breeds had founders with a certain look that was highly preferred, but which also harbored certain genetic diseases that quietly became common in the breed until one day, they seemed to be everywhere. Some breeds have pockets of highly bottlenecked dogs but overall enough variation so that breeders can always find a different enough dog to breed out and away from a health issue, or a fault. Because breeds have different traits, histories, purposes, founders and population sizes, they have different genetic population structures. Breeders need to know their breed’s genetic population structure to know what’s best for the breed as a whole.

In the following posts, we are going to take a look at the breeds we have so far in the BetterBred database from different angles. You can preview some of the statistics for yourself on the breed page.

Natalie Green Tessier