Sweet itch has a strong genetic component in horses, and understanding heritable predisposition supports breeding decisions that reduce the prevalence of this distressing condition.
The genetic component of sweet itch means that breeding decisions have multigenerational welfare consequences. Selecting breeding animals with no history of sweet itch reduces the probability of offspring developing this intensely pruritic and distressing condition. In breeds with high sweet itch prevalence, breed societies that incorporate health recording of sweet itch incidence into stud book data enable breeders to make informed selection decisions. The welfare benefit of reduced sweet itch prevalence accrues to every horse in successive generations that is spared years of seasonal suffering. This is a clear case where breed-level genetic health recording translates directly into population-wide welfare improvement.