Fertility Problems in Female Dogs
Failure to conceive does not necessarily mean that a bitch is infertile. Incorrect breeding dates and reduced fertility in the stud dog are among the first possibilities to consider. Problems within the bitch may also prevent conception or cause a pregnancy to be lost.
What Is Needed for a Successful Pregnancy?
Successful breeding requires a normal season and ovulation, healthy eggs, good-quality semen, accurate breeding dates and a healthy reproductive tract. The embryos must implant and develop normally, and the pregnancy must then be maintained until delivery.
A problem at any stage may result in failure to mate, failure to conceive, resorption, abortion, stillbirth or a small litter.
Signs of a Possible Fertility Problem
- No seasons, irregular seasons or unusually frequent seasons
- A season that is difficult to recognise
- Repeated refusal or inability to mate
- No pregnancy after apparently successful matings
- Repeatedly small litters
- Pregnancy loss, abortion or stillborn puppies
- Abnormal, unpleasant-smelling or persistent vaginal discharge
- General illness, fever, increased thirst or loss of appetite
Common Reasons a Bitch Does Not Conceive
Incorrect breeding dates
The visible start of a season does not reliably reveal the day of ovulation. Some bitches ovulate earlier or later than expected. Behaviour, vulval swelling and the colour of the discharge are not accurate enough on their own when timing is important.
Reduced fertility in the stud dog
Both dogs must be considered. A male may mate normally but have poor semen quality or another reproductive problem. Previous litters do not guarantee that his fertility is currently normal.
Age and reproductive-tract changes
Fertility commonly declines with age. Changes within the lining of the uterus, including cystic endometrial hyperplasia, inflammation, fibrosis and scarring, may interfere with implantation or pregnancy.
Abnormal seasons or ovulation
Silent seasons, split seasons, failure to ovulate and ovarian disorders can cause breeding failure. Dogs ovulate spontaneously; mating is not required to trigger ovulation.
Illness or hormonal disease
Poor general health can affect fertility. Depending on the individual dog, the veterinary surgeon may investigate thyroid disease, adrenal disease or another systemic illness. These conditions should not be diagnosed from reproductive signs alone.
Structural problems
Abnormalities of the vulva, vagina, cervix, uterus or ovaries may make mating difficult or interfere with conception and pregnancy.
Infection and Brucella Canis
Brucella canis can cause infertility, abortion and stillbirth in bitches, as well as infertility and inflammation of the reproductive organs in male dogs. Some infected dogs show few or no obvious signs.
Infection can spread through mating and through contact with semen, urine, vaginal discharge, placentas, aborted material and birth fluids. It can also infect people, although human infection is uncommon.
Breeding dogs should be tested in accordance with current veterinary guidance, particularly before introducing a new or imported dog into a breeding household. If infection is suspected, isolate the dog and contact a veterinary surgeon promptly. Avoid direct contact with reproductive fluids and do not breed the dog while investigations are taking place.
Other infections and inflammation of the uterus may also cause reproductive failure. Testing should be selected by the veterinary surgeon according to the history and clinical findings.
How Fertility Problems Are Investigated
The veterinary surgeon will need a detailed breeding history, including the bitch's age, previous seasons and litters, breeding dates, pregnancy losses, medication and general health. The stud dog's fertility and health history are also important.
Investigations may include:
- A full physical and reproductive examination
- Vaginal cytology and vaginoscopy
- Serial progesterone tests to identify the fertile period
- LH testing when particularly precise timing is required
- Semen examination of the stud dog
- Blood and urine tests selected for the individual dog
- Testing both dogs for Brucella canis
- Ultrasound examination of the reproductive tract
- Culture, biopsy or other specialist tests where indicated
A single progesterone result may not provide enough information. Serial measurements interpreted by a veterinary surgeon are normally more useful for identifying the rise associated with ovulation and planning the correct breeding dates.
Before Breeding
- Arrange a pre-breeding health examination for both dogs.
- Complete relevant breed health and DNA tests.
- Discuss current Brucella canis testing guidance with your vet.
- Confirm the stud dog's current fertility where there is any doubt.
- Use progesterone testing rather than relying only on calendar days.
- Do not breed a bitch that is unwell or has abnormal discharge.
- Seek veterinary advice after repeated empty matings or any pregnancy loss.