Genetic solutions for the brachycephalic health and welfare crisis: A way forward in addressing respiratory challenges

Abstract

Historically, aesthetic preferences have been prioritised over welfare in popular brachycephalic dog breeds such as French bulldogs, boxers, and Shih Tzus, contributing to the widespread occurrence of the debilitating condition, brachycephalic obstructive airway syndrome (BOAS). Although education campaigns have effectively raised awareness, the breeding of extreme brachycephalic features persists. In May 2025, a literature search was conducted to assess the extent of research on genetic factors that could help address phenotypes linked to BOAS. The aim was to better inform veterinarians, breeders, and potential legislation on selecting appropriate breeding pairs that retain breed standards while avoiding harmful genotypes associated with BOAS. The search identified five genes with notable genetic variations: DVL2, BMP3, FGF4, SMOC2, and RUNX2. Specifically, homozygous variants of the DVL2, BMP3, and SMOC2 genes have been linked directly to BOAS in brachycephalic breeds. This review highlights the potential of combining genetic testing with phenotypic screening to guide responsible breeding practices. It emphasises the importance of leveraging genetic insights to mitigate health risks and improve the overall welfare of brachycephalic dogs.