Why are bull terriers so inbred?

According to one study of the pedigrees of AKC breeds, the bull terrier is the most inbred dog.

Of all the dog breeds currently being “improved,”  none is more inbred than the bull terrier. It is also one of the earliest breeds introduced into to the institutionalized dog fancy. In fact, but for dog shows and the institutionalized fancy, this breed would not exist at all. (The study that found the bull terrier to be so inbred can be found here , and another analysis can be found at terrierman, where the breed of choice is the Jack Russell, the least inbred dog.)

I know this breed best from the Alby Mangels “World Safari” series, in which several of these dogs and crosses of them, accompanied the Dutch-born Australian filmmaker across the world. Some of you may know them from the “Spuds MacKenzie” dog that was used to advertise beer. I once wanted one of these dogs badly, but now that I’ve found out about how inbred they are, I’m really not so keen on them.

Why is this breed so inbred? The answer lies in its history.

In the early to mid-nineteenth century, old- type bull dogs were losing their gameness, and bull and bear baiting was made illegal after the passage of the Cruelty of Animals Act in 1835.  Dog-fighting and ratting continued on as the main bloodsports. (By ratting, I mean rat-killing contests in which dogs were judged by how many rats they could dispatch in a timed killing event).

Ratting terriers were developed, often with adding either Italian greyhound or whippet blood. Two standardized dogs developed from these ratting dogs, the Manchester (the black and tan– not be confused with the black and tan fell terrier) and the English white terrier (not to be confused with the white terrier used to bolt foxes during hunts).  These dogs soon became refined and standardized as pets, and toy versions were bred for fashionable pets.  The English white terrier that is ancestral to the bull terrier is a refined dog from the 1860’s, not mean to be a working ratter at all.

These ratting terriers were crossed with bulldogs to make the bull-and-terrier, which became the preferred breed of he fighting ring. These dogs are the ancestors of the pit bull and Staffordshire bull terrier breeds.

"Dustman," depicted here in 1812, was a celebrated fighting bull-and-terrier.

In the 1860’s, a dog dealer, who sold dogs to people wanting “valuable” purebred  dogs for pets, named James Hinks began crossing the pet white terrier with a white bulldog. These dogs were called “bull terriers,” and they were an instant hit with the people. These dogs had the refined lines of the pet English white terrier with the muscles of  bulldog. It was meant to be a gentleman’s dog, a dog that wouldn’t start a fight but would finish one if attacked. (This is, of course, nonsense.) The white dogs were called “white cavaliers” because of this reputation.

Dalmatian blood was added to further refine this breed. Some lines were crossed with the toy version of the pet white terrier to make smaller dogs, even toy versions of the breed. Many of these dogs had apple heads, just like the toy white terriers. The bigger ones and the smaller ones were kept in their own distinctive lines, but the toy bull terrier died out by World War I.

These dogs were the ultimate fad dogs, and mass-production of so many similar dogs certainly required a great deal of inbreeding.  Little did most breeders realize it, but breeding for the white color locked in a related gene for deafness.  Splitting the dogs into different sizes further Balkanized the gene pool, as did the breeding for the white color exclusively.

By 1890’s, the English white terrier fell out of favor as the amount of deafness found in the breed. It was worthless as a terrier, and this breed died out. This deafness characteristic would later become a major issue in the bull terrier.

Whippet and perhaps other sight hounds were also crossed into the Bull terrier, creating the egg-shaped head that so much a trademark of the breed. However, the breeders did a great deal of inbreeding to fix that head type. The eyes were also bred triangular as part of the head piece.

Then in 1895, cropping was banned in Britain. Before then, ears of virtually all terriers were cropped. This ban could have proved the death knell for the bull terrier. However, its breeders soon began breeding dogs with erect ears. Breeding erect ears also meant that a certain amount of inbreeding had to happen, because erect ears are a recessive trait. It happens to be one of the harder recessive traits to select for, and as a result, the bull terrier lost popularity. Fewer dogs meant that genetic diversity would be a bit truncated, and this narrowing of the gene pool was fed back with the selective breeding for the erect ear.

"Patsy Ann" was a bull terrier that greeted ships at Juneau, Alaska in the 1930's. She had the egg-shaped head of the breed, but her ear carriage was typical of early bull terriers.

In 1917, the first modern bull terrier was born, “Lord Gladiator.” He added another fad characteristic to the breed. He had no stop. Soon, all bull terriers were bred without stops, very often using dogs related to Gladiator or Gladiator himself. This would be an example of the most-used sire effect.

At some point after this, it was decided as caprice of the fancy to breed for a downward pointing muzzle (“downface.”) Today’s bull terrier standard doesn’t require it, but it is so common that large numbers of them still have it. The standard does allow for a “downface.” The changes in the breed’s skull that came from breeding this feature are commonly pointed out. It is a rather drastic shift in the bull terrier’s conformation.

Changes in the bull terrier skull:

By the 1930’s, breeders began to see that breeding for the white color was creating many deaf dogs. The white color was associated with deafness,  so it was then decided to add color to the lines to reduce the chances of deafness. The mandarins in the breed were not necessarily happy with this decision, but they eventually compromised. They would allow the colored dogs to exist within the breed, but only as a separate variety. A separate variety, as we have seen in the golden retriever, can easily be culled off and made another breed. Thus, the bull terrier’s lineage became even more Balkanized. The colored bull terriers were  the result of adding Staffordshire bull terrier to the bloodline, which did decrease inbreeding. But the staffie’s eyes were inherited in the offspring. To make these colored dogs become more of a bull terrier type, they had to inbreed again. It took several decades to create colored bull terriers that could be shown at the same level as the white ones.

As I said earlier, bull terriers originally came in a wide range of sizes, mainly because this was one of the few breeds that did not have a size requirement in its standard. The current AKC standard lacks a size requirement. However, the larger sizes tended to do better in the ring than the smaller ones. So the breeders of the smaller size formed their own breed, the Miniature Bull terrier. This breed was recognized as a separate breed by the AKC in 1992.

This continuous punctuated fad breeding and the continuous aggregation of different traits into different strains of this dog created a narrow gene pool in th breed. It has had a far longer time period of continuous ”fancy breeding” than virtually any other breed in existence. That is why it is so inbred.

Now, I’m sure I’ll get a response like this: “We can’t breed bull terriers for their original purpose, so why should we care about the original type?”  Well, the original purpose of the bull terrier is to be a pet and a plaything of the upper middle class and the wealthy. It was not designed primarily to be a fighting breed, although some individuals did partake in fights. The primary purpose of this breed was to be a pet, marketed to gentlemen and men who thought themselves gentlemen.

Update: If you think I’m making this stuff up, please pull your head out of your anus.