BOAS is the most significant welfare issue associated with current dog breeding practices, affecting millions of flat-faced dogs globally and causing lifelong respiratory suffering that is partly preventable through breeding reform.
BOAS represents a welfare crisis of extraordinary scale — millions of dogs are bred with anatomical features that make normal breathing impossible. Dogs with severe BOAS cannot run, play, or exercise without respiratory distress; many experience sleep apnoea; and extreme heat can be rapidly life-threatening. The welfare suffering is chronic and continuous throughout these dogs' lives. The fundamental cause is consumer demand for extreme flat-faced features that breeders have amplified through selective breeding. Welfare improvement requires both breeding reform (selecting for longer muzzles within affected breeds) and consumer education about the welfare consequences of flat-face features. The Cambridge Respiratory Function Grading system provides a validated tool for identifying BOAS-free individuals suitable for breeding.