Pyometra is a life-threatening uterine infection in intact female dogs requiring emergency surgery, entirely preventable through neutering.
Dogs with pyometra experience rapid deterioration from systemic sepsis. The closed form is particularly dangerous as toxin absorption occurs without obvious discharge as warning. Without emergency surgery, the condition is fatal within days. The welfare suffering from septic shock is extreme. Neutering eliminates pyometra risk entirely. Given that one in four intact female dogs will develop the condition, neutering is a major population-level welfare intervention. Any intact female dog with unexplained illness should prompt pyometra investigation.