First clinical use of the kisspeptin analog TAK-683 in the treatment of a follicular cyst in a goat: case report.

This case report presents the therapeutic response to TAK‑683, a long-acting kisspeptin analog, in the treatment of a follicular cyst that developed following a conventional estrus synchronization protocol in a goat during the non-breeding season. A two-year-old lactating Aleppo goat showing persistent nymphomaniac behaviour after estrus synchronization was diagnosed with an ovarian follicular cyst by transrectal ultrasonography. The left ovary contained a 17.7 mm thin-walled anechoic cyst, while serum estradiol (14.5 pg/mL) was elevated and progesterone (1.6 ng/mL) was low. The goat was treated with a single subcutaneous dose of the kisspeptin analog TAK-683 (5 µg, Day 0). Therapeutic efficacy was assessed by monitoring ovarian ultrasonography and serum hormones on Days 3, 10, 13, and 17. Following treatment, the cyst underwent luteinization accompanied by a rise in progesterone (peak 6.4 ng/mL) and a decline in estradiol to basal levels, alongside normalization of behaviour. Color Doppler assessment confirmed progressive luteal development and vascularization, followed by natural luteolysis on Day 17 and resumption of follicular activity. In conclusion, this is the first clinical report demonstrating the successful use of TAK‑683 in resolving a follicular cyst in goats. These findings suggest that TAK‑683, beyond its ovulation-inducing role, may offer a promising therapeutic alternative to GnRH agonists for managing reproductive pathologies in veterinary gynaecology.