Selective breeding for flat-faced features has created epidemic levels of suffering in bulldogs, pugs, and French bulldogs.
BOAS causes constant respiratory compromise. Affected dogs sleep poorly, overheat easily, and may collapse during exercise. Chronic oxygen deficiency causes fatigue. Eye exposure leads to corneal ulcers and pain. Skin folds trap moisture causing painful bacterial and yeast infections. These conditions are breed-defining and cannot be resolved without changing breeding standards.