How many days or months can dog pyometra last? It depends on whether the dog’s condition is serious when it is discovered and whether the treatment is timely. There are two types of dog pyometra, one is open, and the other is open. In one case, the dog can hold on for a longer time. The other is atretic. This situation is more critical and can hold on for a shorter time. Timely treatment is required to avoid damage to the dog's body. If your dog is found to be in low spirits, has no appetite, vomits, has a fever, etc., it may be pyometra, and you need to go to the hospital for examination and treatment in time.