Pyometra is a potentially fatal uterine infection in intact female dogs that requires emergency surgical or medical treatment, making recognition of signs and urgent care the most critical welfare factors.
Pyometra is a welfare emergency where hours matter: toxins from the infected uterus cause progressive organ damage and septic shock that is rapidly fatal without intervention. Open pyometra cases may be identified from vaginal discharge while still in earlier stages; closed pyometra can progress to critical illness before owners recognize severity. The welfare argument for elective spaying before the first heat is compelling - it eliminates not only pyometra risk but also mammary tumor risk and the welfare burden of repeated estrus cycles in intact females.