There are many reproductive diseases that can affect the female cat. The most common of these diseases are discussed below.
Abnormal or Difficult Birth (Dystocia)
Many factors can cause a difficult birth, including uterine problems, a too small birth canal, an oversized fetus, or abnormal position of the fetus during birth. One of the more common situations in cats is a partially delivered kitten. Unless the head of the kitten is sticking out (so that the kitten can breathe), it must be delivered within 10 to 20 minutes or the kitten will die.
Dystocia should be considered in any of the following situations: 1) cats that have a history of dystocia; 2) strong contractions for more than 1 to 2 hours with no birth; 3) a resting period during labor that lasts more than 2 to 4 hours; 4) obvious illness in the mother; or 5) abnormal discharge from the vulvar area. Once the cause is determined, the appropriate treatment can be selected. X-rays or ultrasonography can show how many fetuses are present. Medication can sometimes help the labor progress if the mother is still in stable condition. Surgery (cesarean section) is performed if the mother or kittens are not stable or the fetuses are not able to be delivered naturally.
False Pregnancy (Pseudopregnancy)
False pregnancy occurs in cats when they have been induced to ovulate but did not conceive. The ovary will produce progesterone for about 40 days. There may be mammary development. When it does occur, treatment is often not recommended because the condition usually ends on its own in 1 to 3 weeks (see Reproductive Disorders of Dogs: False Pregnancy (Pseudopregnancy)).
These fluid-filled structures develop within the ovary and result in prolonged secretion of estrogen and continuous signs of estrus (heat) and attractiveness to males. Ovulation may not occur during this abnormal estrous cycle. Follicular cysts should be suspected in any female cat continuously showing signs of estrus (heat) for more than 21 days. This can sometimes be difficult to differentiate from normal, frequent cycles. The condition is diagnosed through laboratory tests or ultrasonography. The most commonly recommended treatment is removal of the ovaries and uterus. If the cat is to be bred, administration of drugs that affect ovulation might resolve the condition.
Overgrowth of Mammary Tissue (Mammary Hypertrophy)
This benign condition is characterized by rapid abnormal growth of the breasts. There are 2 types of breast swelling in cats. It occurs most often in young, cycling, or pregnant cats, but it can be seen in older, non-neutered females and in neutered males after treatment with progesterone. This condition is due to the effects of progesterone and is not cancerous. The most commonly recommended treatment is surgical removal of ovaries and uterus, although spontaneous remission can occur.
Mastitis is inflammation of the mammary gland(s) after giving birth. It is usually caused by a bacterial infection and can be treated with appropriate antibiotics; however, mastitis is uncommon in female cats (see Reproductive Disorders of Dogs: Mastitis).
Metritis is inflammation of the uterus that may occur after pregnancy. Factors such as prolonged delivery and retained fetuses or placentas might lead to metritis. Bacteria such as Escherichia coli can also cause an infection of the uterus. The primary sign of the bacterial infection is pus-like discharge from the vulva. Female cats with metritis are usually depressed, have a fever, and may neglect their offspring. Kittens may become restless and cry incessantly. The infection is diagnosed through abdominal physical examination, ultrasonography, and laboratory tests. Treatment includes administering fluids, supportive care, and appropriate antibiotics.
Ovarian Remnant Syndrome
Ovarian remnant syndrome is caused by ovarian tissue that was left behind in a cat that has been spayed. Affected cats resume estrous cycles at variable lengths of time after surgery. This is a complication of the surgery. To diagnose this disorder, the veterinarian should see the cat when it is showing signs of heat. The remaining ovarian tissue must be surgically removed.
Pyometra is a bacterial infection of the uterus due to hormonal changes in unspayed cats. The signs are variable and include lethargy, poor appetite, and vomiting. When the cervix is open, a discharge of pus, often containing blood, is present. When the cervix is closed there is no discharge and the enlarged uterus may cause abdominal enlargement. Signs can progress rapidly to shock and death. The infection is diagnosed by physical examination, determination of the nature of the discharge, ultrasonography, and laboratory and blood tests. Removal of the ovaries and uterus is the recommended treatment in most cases. Medical treatment may be considered for valuable breeding females that have an open cervix (see Reproductive Disorders of Dogs: Pyometra).
Last full review/revision July 2011 by Cheri A. Johnson, DVM, MS, DACVIM (Small Animal); James A. Flanders, DVM, DACVS; Autumn P. Davidson, DVM, MS, DACVIM; Fabio Del Piero, DVM, DACVP, PhD; Mushtaq A. Memon, BVSc, MS, PhD, DACT; Robert C. Rosenthal, DVM, PhD, DACVIM (Small Animal, Oncology), DACVR (Radiation Oncology); Brad E. Seguin, DVM, MS, PhD DACT