Dilly Dawg wrote:
The above history I'm familiar with but it still reads like the history of any color registry and still doesn't answer the question for me as to why it's a breed.
I think the simplest answer is this: color prejudice.

The AQHA did not want horses with excessive white to be registered with their association. They closed the door to those horses who, despite quarter horse blood, had more white than they allowed within their guidelines. The association retained those rules until very recently. I'm not intimately familiar with how the change took place, but I imagine AQHA and APHA must have cooperatively agreed that so-called "cropouts" would retain their identity as quarter horses provided their pedigree was AQHA top to bottom. That, of course, requires retroactive registration for many older horses, though first-generation "cropouts" foaled since the rule change can simply register as AQHA with no issues. The one-paint-parent rule will still apply, though, if a horse's ancestors are not retroactively registered AQHA, even if that horse does not express a pinto pattern.

As lopinout mentioned, it has a lot to do with coat pattern, as well. If I understand it correctly, tobiano was not present in early quarter horse blood, so any "paints" with 100% quarter horse ancestry are either solid-bred or some other "overo" pattern like sabino, splash, etc. Tobiano came from other stock (likely mustangs or other horses with Spanish blood), and those horses would be excluded. I think that if AQHA granted registration to all APHA-registered horses with 100% AQHA ancestry, then all that would be left behind are horses with the tobiano gene.

Of course...one could argue that they all go back to common ancestors anyway, so they're all quarter horses. Breeds and breed associations are human inventions. The only way that the division between the paint and quarter horse breeds could ever be solidly explained would be if both associations established a year before which no blood will be considered. If, say, that year were 1850, any ancestor on a pedigree that has tobiano blood would automatically place the horse in the "paint" column regardless of coat pattern, whereas any horse without tobiano blood would be in the "quarter horse" column regardless of coat pattern.

Basically, if a horse has at least ONE of these three things, it would be considered a paint. Only in the absence of all three would the individual be a quarter horse:
Tobiano gene (horse actually tests positive for the gene)
Tobiano expression (horse whose coat pattern clearly expresses as tobiano)
Tobiano ancestry (horse has an ancestor who clearly expressed the tobiano coat pattern* and/or tested positive for the tobiano gene)

*This wouldn't be an exact science, but obviously it's not possible to test all horses and their ancestors for the gene

I know that I'm waaaaaaaaaaaaaay oversimplifying this via a whole lot of hypotheticals, but that's the best way I can think to describe it.

Last Edited By: Timid Wild One Nov 4 11 9:20 AM. Edited 4 times.