What is it?
•Pyometra is defined as an infection in the uterus
•It occurs more often in dogs than in cats
•The severity of the disease is determined by whether or not the cervix is open and actively draining fluids and pus
•Some cases are caused by leftover ovarian tissue from a spay (known as stump pyometra) 

What causes it?
•The hormone progesterone usually causes the uterus lining to produce a secretion
•Pyometra is a secondary infection that occurs as a result of hormonal changes in the female reproductive tract
•Following estrus (“heat”) in the dog, progesterone hormone levels remain elevated up to two months and cause thickening of the lining of the uterus
•The thickened, cystic lining secretes fluids that create an ideal environment for bacteria to grow
•Progesterone causes the cervix to relax
•If the cervix is open or relaxed, bacteria that are normally found in the vagina can enter the uterus and cause infection
•Animals may have vaginal discharge, decreased appetite, depression, vomiting, diarrhea, lethargy, fever, and excessive drinking or urination 

What tests are needed?
•Because a Pyometra infection often affects other organs as well, routine laboratory tests are recommended to look for signs of infection elsewhere
•Typically the white blood cell count spikes
•X-rays will likely show fluid-filled structures in the uterus
•An ultrasound or bacterial culture of uterine fluid may be needed 

How is it treated?
•The typical treatment of choice is surgery to remove the uterus and ovaries
•Prior to surgery, most animals require aggressive fluid therapy and antibiotics
•For a stump pyometra, the ovarian remains must be removed 

What follow up care is needed?
•Antibiotics are usually given and blood tests may be repeated until clinical signs disappear
•Medically treated animals are monitored for any side effects