Transcervical Insemination (TCI) for Dogs: How It Works and When to Use It

Transcervical insemination (TCI) — also called endoscopic insemination or non-surgical uterine insemination — is a method of depositing semen directly into the uterus through the cervix, without anaesthesia or surgery. For frozen semen especially, TCI dramatically improves conception rates over traditional vaginal AI. Understanding TCI helps breeders choose the right insemination method and know what to expect at their reproductive vet appointment.

How TCI Works

A rigid endoscope (a thin, illuminated fibre-optic scope) is passed vaginally to visualise the cervix. Once the cervical opening (os cervix) is located, a flexible catheter is threaded through the cervical canal into the uterine body. Semen is then deposited directly into the uterus.

The procedure is non-invasive — no incisions, no anaesthesia required in most cases. The dam stands or lies on her side, and the procedure typically takes 5–20 minutes depending on the dog's anatomy and the veterinarian's experience. Some dogs require mild sedation to remain still.

Why TCI Improves Conception Rates

In natural breeding and vaginal AI, semen is deposited at the anterior vagina or cervix, and sperm must travel through the cervix into the uterus on their own. Fresh sperm are excellent swimmers and navigate this journey well. Chilled or frozen sperm — with reduced motility — have a significantly harder time.

By depositing semen directly into the uterus, TCI bypasses the cervical barrier entirely. This is why TCI is the preferred method for:

• Frozen semen: TCI increases frozen semen conception rates by 20–30% over vaginal AI
• Chilled semen: When timing is not ideal, TCI provides an advantage over vaginal AI
• Dams with cervical strictures: Some bitches have anatomically narrow or tortuous cervixes that prevent sperm from passing efficiently

TCI vs Surgical AI

Surgical AI (surgically depositing semen directly into each uterine horn) was historically the gold standard for frozen semen. TCI has largely replaced it because:

• No anaesthesia required (lower risk)
• No surgical recovery
• Comparable conception rates with frozen semen when properly performed
• Lower cost than surgery

Surgical AI is still used in some situations — particularly when TCI is not possible due to anatomy, or when available equipment requires it.

Finding a TCI-Capable Vet

Not all veterinary clinics offer TCI. Reproductive vets (theriogenologists) at veterinary universities and specialty practices typically offer TCI. Ask specifically whether the vet has TCI equipment (endoscope) before booking an appointment. Many general practice vets can perform vaginal AI but not TCI.