Spontaneous Abortion in the Cat

Spontaneous Abortion in the Cat

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Overview of Abortion in Cats

Spontaneous abortion is the death and resorption or expulsion of a fetus before the pregnancy has come to term. Some people choose to abort unwanted pregnancies intentionally, but abortion can also occur in planned pregnancies. Be aware that it is possible for the dam to abort one or more kittens and still maintain and deliver healthy full term kittens later. Since early pregnancy is difficult to confirm before 16 days post fertilization, abortions early in pregnancy may be diagnosed as infertility.

Abortion after confirmation of pregnancy can occur without any signs of illness. You may not know the dam has aborted until you realize it is past her due date and there are no kittens. Subsequent examination reveals that she is no longer pregnant. In these situations, the kittens were probably aborted early enough to result in reabsorption.

In late stage abortion, you may see:

  • Abdominal contractions
  • Vaginal discharge
  • Expulsion of the premature fetus (live or dead)

    Causes of abortion can be divided into maternal causes and fetal causes. Maternal causes include:

  • Severe illness from preexisting disease
  • Brucella infection
  • Herpes infection
  • Uterine disease
  • Ovarian disorder leading to low progesterone levels

    Fetal causes are primarily related to abnormal development and early fetal death.

  • Diagnosis of Spontaneous Abortions in Cats 

    Diagnosing spontaneous abortion can be difficult. Pregnancy in the dam can be confirmed 16 days post fertilization. If the abortion occurs before this, there is no way to determine if the dam aborted or was never pregnant.

    After 16 days, ultrasound can confirm the presence of kittens. If future ultrasounds or x-ray examinations reveal fewer kittens or no kittens, abortion is diagnosed.

    Determining the cause of the abortion can also be tricky. The best way to find out why your dam aborted and to help prevent future abortions, post mortem (necropsy) examination of the aborted puppy is highly recommended. If the puppy is not available or was absorbed by the mother, specific tests on the dam may help determine the cause.

    Prior to breeding, all cats should be tested for Brucellosis. This is a bacterial infection that is easily spread from cat to cat and can infect people. It is difficult to treat and there is no vaccine to prevent transmission. All cats found to be Brucella positive should be excluded from any breeding program.

    Brucella infection typically results in abortion at about 45-55 days of pregnancy.

    Other tests that can be done on the mother include:

  • Blood tests to determine overall health
  • Uterine biopsies can help determine if there is any uterine disease present
  • Blood progesterone levels can help diagnose an ovarian problem related to sustaining a pregnancy.
  • Treatment of Spontaneous Abortions in Cats 

    There is no treatment to stop abortion. Treatment is aimed at helping to reduce abortion in future litters. The treatment, if possible, is specific for the cause of the abortion. If no cause is found, no treatment will be available and future pregnancies may be normal or result in abortion again.

    Home Care and Prevention

    There is no home care for abortion. Save any aborted kittens for examination by a pathologist to help determine the cause and prevent future abortions.

    Without knowing the cause of abortion, there is no preventative care. For certain diseases or conditions, preventative treatment is available for future litters.


    In-depth Information on Abortion in Cats

    Abortion in cats can be the result of maternal causes, fetal causes or related to medications.

    Maternal Causes

    The most common maternal causes of abortion are infection with Brucella or herpes virus.

  • Brucella is a bacteria that is contagious among cats and can be contagious to people. All cats in a breeding program should be tested for Brucellosis before ever being bred. Those cats testing positive should be removed immediately from the breeding program. There is no effective treatment nor vaccine to prevent the spread of Brucellosis.

    Those infected with Brucella usually abort the kittens around 45 to 55 days of the pregnancy. If strict rules regarding the removal of Brucella-positive cats are not adhered to, Brucella infection can have a devastating effect on a breeding program.

  • Herpes virus is difficult to test for in the mother but can be detected in aborted kittens. Herpes can result in late stage abortions. It can also cause infertility and is a primary cause of fading puppy syndrome.
  • Other less common infectious causes of abortion include Campylobacter, Streptococcus, Leptospira, E. coli, toxoplasmosis, distemper and mycoplasma. The mother can be tested for some of these bacteria if abortion has occurred.
  • Fetal Causes of Abortion

    The fetus may have developmental abnormalities that are not consistent with life. Severely deformed or improperly developing kittens are usually aborted early in the pregnancy. A cause for these abortions is rarely found and may be related to genetic disease or birth defects.

    Other causes of spontaneous abortion include administration of glucocorticoids or Chloramphenicol during pregnancy. For this reason, medication administration during pregnancy should be done with extreme caution and only under your veterinarian’s advice.

    In-depth Information on Diagnosis of Abortions in Cats

    Evaluation and examination of the aborted kitten is the best way to diagnose the cause of abortion. This will give you and your veterinarian the best chance of finding the cause of the abortion and help avoid future abortions.

    If the kitten is not available, some tests can be done on the mother.

  • Serology is done to determine the presence of feline leukemia, FIV or toxoplasmosis. These can result in abortion.
  • Complete blood cell count (CBC), biochemistry profile and urinalysis will help determine the overall health of the queen.
  • Abdominal radiographs (x-ray) or ultrasound can help determine any masses, tumors or abnormalities within the uterus.
  • Bacterial cultures of the vagina and culture of any vaginal discharge can help diagnosis a bacterial problem.
  • Testing of blood progesterone levels can help determine ovarian abnormalities.
  • In-depth Information on Treatment of Abortions in Cats

    Once abortion has begun, it is nearly impossible to stop. Frequently, you are unaware that abortion has occurred. The goal is to determine the cause of the abortion, treat for any underlying disease and help prevent abortion in future litters.

    Some causes of abortion have potential corrective measures:

  • Feline leukemia. There is no treatment for feline leukemia and these cats should not be bred.
  • Feline immunodeficiency virus. There is no treatment for FIV and these cats should not be bred.
  • Feline infectious peritonitis virus. There is no treatment for FIP and these cats should not be bred.
  • Low progesterone levels. For future litters, progesterone supplements are given throughout the pregnancy to help bring the kittens to term.
  • Follow Up Care 

    Queens that have been diagnosed with abortion in the past may have repeated problems. Even with treatment, these cats may continue to abort some, if not all, of the future litters. You may want to consider removing queens prone to abortion from your breeding program.

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