What I mean by that is, how much worse would current morph breeding issues be if they happened further back in time when animal well-being wasn't considered nearly as important? To give an idea I've thought of parallels with other current day "breeds." Most of these are more ball python-related than anything else since those are what I'm most familiar with, but they could be generalized since who knows what selective breeding could cause in other species.
Snakes with bug eyes would be considered cute and bred to make them absurdly massive (celestial and bubble-eye goldfish).
The wobble issue wouldn't be thought of as much of a deal and simply treated as a mere quirk until eventually there would be swaths of individuals that can barely move properly (fainting goats).
"Duckbilling" would be a desired appearance and the trait would become grossly exaggerated until some snakes had perpetual breathing issues (any given smush-faced dog/cat breed).
Kinking would also possibly be seen as desirable, leading to generations with horrific skeletal deformations (balloon mollies).