Longevity and major causes of death are heritable in Irish Wolfhound

Irish Wolfhound (IW) is a large dog breed developed several centuries ago with an average longevity of 7 years The genetics behind the short lifespan is poorly understood. Based on data from the Irish Wolfhound database (IWDB) on 118,095 pedigreed IW and data from the IW Longevity Study including 10,122 dogs with known longevity and 6,057 of these having a known cause of death (COD), longevity and the two most common COD were analysed. Heritability, maternal effects, and correlations were estimated accounting for sex, birthyear, country of origin and inbreeding coefficient. Both longevity (0.27) and COD (0.17-0.20) were moderately heritable. Longevity and COD showed low correlations, both genetic and residual correlations. We argue that this is likely due to short longevity being caused by early aging and COD being specific expressions of early aging. In addition, inbreeding was found to significantly reduce longevity. Implications for increasing longevity in IW are discussed