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Female Infertility

What is infertility in female dogs and cats?

Infertility is the inability to conceive or to carry a pregnancy to term. Infertility in female dogs (bitches) and cats (queens) includes abnormalities of the heat cycle (estrus), failure of breeding (copulation), failure of becoming pregnant (conception), and pregnancy loss.

What causes infertility in female dogs and cats?

The most common cause of infertility in bitches is insemination at an improper time in the estrous cycle. Previous ovariohysterectomy (spay) of female dogs and cats acquired as strays or adults should be considered a possible cause of infertility. Problems with the female reproductive tract (anatomic abnormalities), chromosomal abnormalities, or abnormal ovarian function may lead to infertility. Other causes include uterine infection, male infertility, thyroid gland insufficiency, and hyperadrenocorticism (Cushing's disease, the overproduction of adrenal hormone by the adrenal gland). Infection with Brucella canis should be considered and eliminated as a cause in all infertile bitches.
The causes of infertility in queens are similar. Cats are induced ovulators. This means that they must be stimulated to release eggs from the ovaries. If the queen lacks enough stimulation to induce ovulation, she will be infertile. Problems with the female reproductive tract (anatomic abnormalities), chromosomal abnormalities, or abnormal ovarian function may lead to infertility. Other causes include uterine infection, male infertility, and systemic infections (viral or protozoal infection).

How is infertility diagnosed in female dogs and cats?

Infertility in female dogs (bitches) and cats (queens) is diagnosed by a good medical history, including breeding management, and a physical examination. The serum progesterone concentration is an important diagnostic tool. Progesterone is a female hormone that readies the uterus for pregnancy and maintains the pregnancy. In dogs, measurement during the pre-heat and heat cycles (estrous cycle) can predict ovulation time and optimize breeding management. In cats, measurement after breeding determines whether ovulation was induced. The progesterone concentration should remain high throughout pregnancy (gestation) in dogs and cats.
The veterinarian may perform a serologic test for Brucella canis in dogs. Bacterial cultures of the reproductive tract may be taken to determine if the animal has an infection of the uterus. Other tests include adrenal gland hormone or thyroid hormone testing to determine hyperadrenocorticism or hypothyroidism (dogs) and serologic testing for canine herpesvirus (dogs) and Toxoplasma (dogs and cats). Additional diagnostics for cats include feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing. Some animals may have genetic studies performed, including karyotyping to determine chromosomal abnormalities.

The normal ovaries and uterus are not visible on radiographs (X-rays); therefore, large ovaries and a visible uterus on a radiograph indicate some type of abnormality in the infertile female. Ultrasound may reveal disease of the ovaries or uterus. Ultrasound also is used for diagnosing pregnancy as early as 2 to 24 days after ovulation and for documenting pregnancy loss.

Exploratory surgery in dogs and cats allows assessment of the anatomy of the reproductive tract. It also allows the veterinarian to obtain a biopsy (removal and examination of a specimen) of the uterus or ovaries.

How is infertility treated in female dogs and cats?

First, the veterinarian will eliminate improper breeding management from the diagnosis. Improper breeding often is at the root of perceived infertility. If improper breeding techniques are not the problem, the veterinarian will treat the underlying cause of the infertility. Antibiotics may be given for infection of the uterus. Thyroid hormone is given to dogs with hypothyroidism. A hormone (called "gonadotropin") can be given to induce ovulation in dogs and cats with ovulation problems.
Surgical considerations include surgical correction of abnormalities of the vagina (dogs), surgical repair of an obstructed reproductive tract, surgical drainage of ovarian cysts, and removal of a cancerous ovary.

What is the prognosis for infertility in female dogs and cats?

The prognosis (outcome) for infertility in female dogs and cats varies, depending on the underlying cause. Since the most common cause of infertility is improper breeding management, the initial prognosis is good. However, if improper breeding is ruled out, the prognosis for future breeding worsens. Problems that can be resolved by medical management have a fair to good prognosis, whereas those that must be corrected by surgery have a guarded to poor prognosis.




The information on this page was obtained from the site www.VetMedCenter.com

For more information, go to the pages for:
Abortion and Pregnancy Loss in Cats
Abortion and Pregnancy Loss in Dogs.