in the severity of the condition. If the cervix is open, the infected material can leave the body, and this is far easier and safer to treat. This is known as open pyometra. If the cervix is fully closed, there is no discharge from the vulva, and like in appendicitis, the uterus may rupture and pus escapes into the abdomen, causing peritonitis and possible rapid death. This is known as closed pyometra. Hormonal influences and mis-mating shots Females that have received estradiol as a mismating shot in diestrus are at risk for more severe disease because estrogen increases the number of progesterone receptors in the endometrium. 25 percent of females receiving estradiol in diestrus develop pyometra. Pyometra is less common in female cats because progesterone is only released by the ovaries after mating. Also in cats, the risk of developing the disease differs depending on breed. Treatment The most important aspect of treatment of pyometra is quick action to provide supportive care. Female dogs are often septic and in shock (see septic shock). Intravenous fluids and antibiotics should be given immediately. Once the female dog has been stabilized, then the treatment of choice is an emergency spay. In livestock the treatment of choice for minor cases is dinoprost tremethamine (lutalyse). Supportive antibiotic treatment may be recommended also. Severe cases require surgery. References External links Pyometra from The Pet Health Library Pyometra Surgery Photos and Description from The Pet Center Cat diseases Dog diseases Inflammatory diseases of female pelvic organs