Pyometra is an infection of the uterus and is more commonly seen in older dogs but has occurred in young and middle age dogs as well. The cause of Pyometra is subsequent heat cycles where the dog does not become pregnant, causing the lining to build up, cyst and bacteria to grow. This disease can be avoided if you spay you dog. Treatment for this infection is an ovariohysterectomy, also known as a spay. If the dog is a breeding bitch, some infections can be treated with medications but there are statistics that the owner should be aware of. These are a higher rate of the Pyometra reoccurring, depending upon whether the cervix is open or closed the success of treatment is between 25%-90%, and finally the dog only has a 50%-75% chance of becoming pregnant after the infection.