Bacterial Infection of the Uterus in Cats

The bacteria that cause metritis to occur can spread into the bloodstream, causing sterility and septic shock if left untreated. Cats with metritis need to be seen by a veterinarian as soon as possible in order to prevent the condition from becoming lethal.

Metritis is a bacterial infection of the uterus that normally occurs within a week after the cat gives birth. Symptoms occur when the lining of the uterus, or endometrium, becomes inflamed. Though it most often occurs after a natural birth, the condition can also be caused by a miscarriage, a natural or medical abortion or artificial insemination. The condition differs from pyometra, an infection of the uterus caused by hormones, as it is typically caused by bacteria such as Escherichia coli.

Symptoms normally appear 12 to 96 hours following birth.

• Swollen abdomen
• Foul-smelling discharge from the vulva
• Dark green- or dark brown-colored discharge or discharge that is mixed with pus and/or blood from the vulva
• Lethargy
• Fever
• Vomiting
• Diarrhea
• Dark red gums
• Dehydration
• Reduced milk production
• Depression
• Loss of appetite
• Neglecting kittens

The condition occurs when bacteria enter the uterus through the vagina. This occurs when the uterus is most susceptible in the following circumstances:

• Artificial insemination
• Difficult birth
• Long birth from a large litter
• Obstetric manipulation
• Natural or medical abortion
• Miscarriage
• Retained placentas or fetuses

The veterinarian will ask for the cat's complete health history, including details of the most recent birth. A physical examination will then be performed to look for the symptoms of metritis. The veterinarian will then order labs, which include a complete blood count, a chemical blood profile, an electrolyte panel and a urinalysis. The complete blood count will show the number of white blood cells in the cat's blood that is indicative of an infection. The chemical blood profile will show if the infection has spread to the bloodstream and where it originated from. A urinalysis and electrolyte panel help the veterinarian know how the kidneys are functioning and how dehydrated the cat is due to the infection.

An ultrasound or x-ray may also be performed, which will help the veterinarian to look at the uterus to do a visual exam to look for retained placentas, fetuses or birth material and excess fluid that may have accumulated due to swelling or uterine rupture. The vaginal discharge may also be examined under a microscope to determine the type of bacteria and what antibiotic will be most effective at treating it.

• Fluid Therapy: The cat will be hospitalized upon diagnosis of metritis. Fluids will be administered via an IV in order to help the cat recover from fluid loss and dehydration. The fluids will also help to correct the electrolyte imbalances that can result in reduced kidney function.
• Antibiotics: The bacterial culture and sensitivity tests on the cat's discharge require that the bacteria grow in order to be examined. Until the bacteria and proper antibiotic can be identified, broad-spectrum antibiotics will be administered to the cat in order to kill the bacteria. Once the tests are back, the antibiotic best suited for killing the specific bacteria that caused the metritis will be administered.
• Treatment for Septic Shock: If the bacterial infection has reached the bloodstream and the cat is in septic shock, the cat will be treated to prevent it from becoming lethal. Large amounts of fluid will be administered via an IV to raise the cat's blood pressure and medications will be given to increase the flow of blood to the heart, brain, and other organs. Oxygen will also be administered.
• Surgery: Cats who do not respond to medical treatment risk uterine rupture and abdominal infection. This risk is increased if retained fetuses or placentas are in the uterus. Spaying the cat is often the best solution to prevent complications. Cleaning of the uterus to remove any retained fetuses or placentas is an option if future breeding is planned. In severe cases, an ovariohysterectomy may need to occur where the ovaries and uterus are removed.

Nursing kittens will need to be hand-fed in order to prevent the antibiotics and infected milk from reaching them. The cat will need to continue the antibiotics until the infection has cleared from their body. Cats who receive prompt treatment normally respond well but typically have a decreased chance of fertility in the future.