Behavioral traits in dogs and cats have genetic components that influence welfare both positively (breed suitability) and negatively (heritable anxiety and aggression). Understanding these links improves welfare outcomes.
Behavior genetics in companion animals intersects welfare at multiple points. Selective breeding that prioritized working traits historically produced dogs with reliable behavioral profiles suited to specific tasks — but modern breeding focused on appearance has sometimes inadvertently selected behavioral extremes including hypervigilance, reactivity, and fear responses that cause welfare harm throughout life. Heritable anxiety disorders documented in breeds including Lagotto Romagnolo (noise phobia), Cavalier King Charles Spaniels (separation anxiety), and German Shepherds (various anxieties) represent welfare challenges built in at the genetic level. The finding that breed accounts for only 9% of individual behavioral variation underscores the importance of individual assessment rather than breed-based assumptions. Responsible breeding that health-tests for behavioral as well as physical traits can gradually reduce the prevalence of heritable behavioral disorders. Behavioral genetic research is advancing rapidly and will increasingly inform breeding decisions with direct welfare implications.