Mare Infertility Investigations

There can be various reasons why your mare might not be getting pregnant or carrying a pregnancy. Investigations involve a:

• General physical exam
• Assessment of vulva conformation
• Transrectal palpation and ultrasound examination of the reproductive tract
• Vaginal and cervix evaluation by palpation and speculum
• A clitoral swab for CEM
• Endometrial swab / low volume lavage for culture and cytology 
• Uterine biopsy

Further investigations may include:

Hysteroscopic examination

Direct visualisation of the uterus to identify any anatomical abnormalities, adhesions, presence of foreign bodies, or endometrial cysts.

Specific blood tests

Blood tests include measuring ACTH levels to check for Cushing's syndrome, a potential cause of infertility. Sometimes reproductive hormones are measured to assess ovarian pathology.

Treatment of blocked oviducts

The oviduct is the tube that connects the ovary to the uterus (in human medicine it’s called Fallopian tubes). It is in the oviduct where fertilization occurs.

Sometimes these oviducts may become blocked by debris from the ovulations or previous pregnancies with non-viable embryos. Even though this blockage usually allows the passage of the sperm, due to its very small size, an embryo might be unable to descend into the uterus.

This can be done by administration of misoprostol (a prostaglandin):

• Deep uterine topical application via transcervical (non-surgical)
• Laparoscopy (surgical): allows visualization of the oviducts and detect any anatomical abnormalities, if present.

Don’t forget:

Good pregnancy rates are dependent of the mare and stallion. There are stallions with poor semen quality which contributes to a mare’s infertility or, sometimes, simply the mare is just not compatible with the stallion.