Metritis in Queens

July 2, 2026

Labor is Over, So Why Do I Still Feel Bad?

Nancy Kerr

Your cat has recently given birth and everything seems to be going fine, then you notice that the kittens are crying nonstop and that their mom has stopped taking care of them. While it looks like she is being is bad mom, she may have something called metritis, “a uterine infection that usually occurs within a week after a cat gives birth. It can also develop after a natural or medical abortion, miscarriage, or after a non-sterile artificial insemination. It is symptomized by an inflammation of the endometrium (lining) of the uterus due to a bacterial infection. The bacteria that are most often responsible for infection of the uterus are gram-negative bacteria like Escherichia coli, which often spreads into the blood, causing a blood infection. The infection may lead to sterility, and if left untreated, septic shock – a lethal condition – may follow.”¹

Causes

Metritis normally occurs shortly after the kittens are born, typically within the first week postpartum. A bacterial infection called Escherichia coli, commonly known as E. coli, is usually present; however other bacteria can also be involved. “Inflammation of the endometrium and myometrium characterized by postpartum vaginal discharge is a classic sign of metritis.”² Contributing factors for metritis “are prolonged or difficult delivery and retained fetuses or placentas.”³ Other factors include “obstetric manipulation, natural or medical abortion, miscarriage or in rare cases natural or artificial insemination.”¹

Symptoms

Symptoms can include “anorexia, lethargy, vomiting, decreased maternal instincts, fever, and decreased or absent milk production”², “dark red gums, lack of appetite”¹, and “increased thirst.”⁴ The mother cat may neglect her kittens, resulting in them becoming restless and crying continually. There will be “a purulent, foul-smelling discharge from the cat’s vagina. On palpation, the abdomen is tender, and the uterus is thickened.”⁴ There will be “increased heart rate if the bacterial infection has become systemic.”¹

Diagnosing

It is vital to determine if this is actually metritis or another serious disease that can cause postpartum vaginal discharge. These include “normal postpartum lochia, subinvolution of placental sites (SIPS), vaginal or uterine trauma, and pyometra.”² Gathering the cat’s history along with a physical examination by a veterinarian should help in ruling out other diseases that can cause postpartum vaginal discharge.

The infection is diagnosed through abdominal physical examination, x-rays, ultrasonography, and laboratory tests. Diagnostic tools, like “radiograph and ultrasound imaging, will allow your veterinarian to visually examine the interior of the uterus for any retained fetuses or birth matter, excess fluid accumulation, and/or abnormal amounts of abdominal fluid production due to uterine rupture.”¹

“A sample of the vaginal discharge will also be taken for cytologic (microscopic) examination. A culture of both aerobic and anaerobic bacteria (bacteria that lives with oxygen, or without oxygen, respectively) will be used for identifying the bacterial populations present in the blood, and a sensitivity of the isolated bacteria will be performed so that the most appropriate antibiotic treatments can be prescribed.”¹

Additional further diagnostic testing can include “CBC, serum biochemical analysis, urinalysis, and diagnostic imaging. Changes in clinicopathologic parameters usually reflect septicemia, inflammatory reactions, and endotoxemia. This can be represented by either increased or decreased WBC [white blood] count, with or without anemia, increased or decreased protein concentration, signs of dehydration, or elevations in kidney and liver enzyme activity.”²

Treatment

Treatment options depend on severity of the disease. In simple cases, “antimicrobial treatment based on microbial culture and antimicrobial susceptibility testing may be enough. If systemic disease is present, then fluid therapy and supportive care may be necessary to stabilize the patient’s condition.”² The veterinarian may begin “broad-spectrum antibiotic therapy (e.g., cephalosporins) while awaiting culture and sensitivity results.”⁵

This may include administering intravenous fluids, antibiotics and supportive care. “Severely ill cats may need to be spayed once they are stable enough for anesthesia. If future litters are not desired and the infection is not severe, the mother can be spayed after she finishes nursing her kittens.”³ If the metritis is not in an advanced stage, a cat should most likely respond to treatment.

“However, medical treatment does not always prevent the infection from progressing to a generalized abdominal infection and ruptured uterus. If future breeding is not planned, having your cat spayed is the treatment of choice. This solution is especially appropriate when retained fetuses or placentas are present in the uterus, when the uterus has ruptured, or when it is severely infected. Patients suffering from a long-term infection that is not responding to medical treatment may improve with a surgical cleaning of the uterus.”¹

“If the infection has reached sepsis, your cat will also be treated for shock. Your cat will also need to be placed on broad-spectrum antibiotics until the bacterial culture and sensitivity results return from the lab. Then, depending on the results, your veterinarian may switch your pet to the antibiotic best suited for eliminating the bacteria that are causing the infection.”¹

Prognosis

The mother cat may be unable to care for kittens during serious illness, so temporary foster care or supplementing for the kittens may be necessary. “If your cat is nursing and has been diagnosed with a bacterial blood infection, it will be better to hand-raise her kittens so that transmission of the infection through her milk can be prevented. This can also prevent possible harm to the kittens from exposure to the prescribed antibiotics in their mother’s bloodstream.”¹

“While subsequent fertility is expected to be normal following prompt and successful resolution of the disease, studies to document future fertility are lacking.”⁵ “Even without spaying, animals that have been treated for a uterine infection have a chance of becoming less fertile, or even infertile, making future breeding difficult or impossible.”¹

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