Pyometra When you raise a female dog, you should know about this disease because it is dangerous and can cause our dogs to die. "Pyometra" is a reproductive system disease that is common in dogs and cats. This disease is caused by the hormone progesterone. When a female dog is out of heat, this hormone normally decreases. But in dogs that do not breed, this hormone induces the endometrial gland to enlarge, forming a sac called Cystic endometrial hyperplasia (CEH) and also stimulates the production of more secretions in the uterus. The uterus during this period will contract less...