42. Infertility of the bitch - infertility after apparently normal mating

What is the most common cause of failed breeding in bitches despite apparently normal mating?

Mating at the incorrect time (too long before or after ovulation)

What is the period of maximum fertility in relation to ovulation in bitches?

Day 1-4 after ovulation

When do most bitches typically ovulate after the onset of pro-oestrus?

Between 9-14 days (but can range from 5-30 days)

What is one method used to time breeding by monitoring hormone levels?

Serum progesterone levels, which increase rapidly about 2 days before ovulation

What vaginal cytology finding suggests a fertile period in a bitch?

Presence of stratified squamous epithelium

What is another vaginal examination technique used to time breeding?

Vaginoscopy

What external physical changes can be monitored to help time breeding?

Onset of vulvar softening or change in discharge

What are some reasons for pregnancy failure even when mating occurs at the apparently correct time?

Infertile male, aggressive/dominant male, stress, poor nutrition

What anatomical abnormality of the cervix can obstruct sperm entry?

Cervical stenosis

What ovarian dysfunctions can lead to pregnancy failure despite mating?

Failure of ovulation, follicular cyst

What uterine abnormalities can interfere with pregnancy establishment or maintenance?

Uterine tumours, cystic endometrial hyperplasia

What congenital defects of the reproductive tract can cause infertility?

Missing parts of the uterus or tuba uterina, congenital defects of the tuba uterina

Which viral infectious agent is a known cause of abortion in bitches?

Herpesvirus

What hormonal insufficiency during pregnancy can lead to pregnancy failure?

Hypoluteodism (insufficient progesterone production)