Sure, Boxers and Dobies are both deep chested. That's a different plane, if you will, from barrel-chested. "Deep" refers to, well, the depth - the distance from the bottom of the chest to the ground - in both breeds, the chest should reach the elbows, which should be half-way between the withers and the ground. "Barrel" or the correct "well-sprung" refers to the breadth - the distance from the left side to the right side, if you're looking at the dog from the front or rear, or looking down at it.
Maybe a better way to put it is "deep" means how far down, "well-sprung" means how far out.
Does that make any sense?
Thomas, dogs and wolves are very different in many respects, but they are still the same species. I agree that the dog has a very different behavioral model than the wolf, because they have chosen to align themselves with humans and so had to change some of their ways, but physiologically I think the differences are more similar than not. And while I agree that there are many dogs that would not have been bred without human intervention (and in fact, many breeds - including the Boxer - that never would have come into existence), I wouldn't say there is *no* process of natural selection. Greatly reduced, sure, but puppies still die no matter what lengths the breeder goes to. The very weak most of the time still do not survive. (Although there are many less-weak that do, and probably would not in the wild.)
(Way off-topic, but an interesting discussion to me!)
Also, technically "bloat" and "torsion" are separate things - the term "bloat" generally refers to "Gastric Dilatation-Volvulus" but the bloat part is the dilatation - expansion of the stomach - the torsion is the volvulus (although torsion and volvulus are actually two different things, based upon which axis the stomach twists). But most of the information I have read states that bloat (dilatation) occurs before torsion, not the other way around. I know that there are dogs who bloat without torsing, and sometimes a stomach tube or needle can be used to decompress the stomach before it torses. Of course, the biggest problem with bloat is that no one knows *what* causes it - that's why Purdue has assessed risk factors.