Low-dose histrelin for ovulation induction in mares: a partially randomized crossover pilot study.
4 affiliations
- 1Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Prado Velho, Curitiba, Paraná, 80215-901, Brazil.
- 2Veterinary Program, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Prado Velho, Curitiba, Paraná, 80215-901, Brazil.
- 3Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Prado Velho, Curitiba, Paraná, 80215-901, Brazil. [email protected].
- 4Veterinary Program, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Prado Velho, Curitiba, Paraná, 80215-901, Brazil. [email protected].
Abstract
This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints. Eleven mares were enrolled, of which nine completed all eight protocols and were included in the analyses. The protocols comprised 250 µg histrelin IM (standard dose), 75 µg IM, 25 µg IM, no intervention, saline at Bai-hui, saline at Yan-chi, 25 µg histrelin at Bai-hui, and 25 µg histrelin at Yan-chi. Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome. Ovulations first detected at 24 h were excluded from the primary analysis. Ovulation within 48 h occurred in 88.9% (8/9) of observations with 250 µg IM, 87.5% (7/8) with 75 µg IM, 87.5% (7/8) with 25 µg IM, 37.5% (3/8) with no intervention, 50.0% (3/6) with saline at Bai-hui, 100% (9/9) with 25 µg histrelin at Bai-hui, 12.5% (1/8) with saline at Yan-chi, and 87.5% (7/8) with 25 µg histrelin at Yan-chi. Exact 95% confidence intervals were wide, reflecting the small sample size. Exploratory pairwise comparisons with the no-intervention protocol were performed without adjustment for multiple comparisons and should be interpreted cautiously. The findings provide preliminary evidence that reduced histrelin doses, including 25 µg, may induce ovulation within 48 h in mares. However, this study did not demonstrate an advantage of pharmacopuncture over IM administration of the same reduced dose. Larger, fully randomized studies are required to confirm the efficacy of reduced-dose histrelin and determine whether administration at specific acupoints provides any additional effect.
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BibTeX
@article{fogagnoli2026lowdose,
title = {{Low-dose histrelin for ovulation induction in mares: a partially randomized crossover pilot study.}},
author = {Lys de Barros Fogagnoli and Kallena Canali Abdala Jose and Rachel Weckl and Clara Mantovani Ozorio Mota and Mirelle Ochrimowicz Fernandes and Rafaela Caroline Machado and Carlos Eduardo Camargo and Pedro Vicente Michelotto},
journal = {Veterinary research communications},
year = {2026},
month = oct,
doi = {10.1007/s11259-026-11583-9},
url = {https://europepmc.org/article/MED/42897392},
note = {CC BY},
}
RIS
TY - JOUR
TI - Low-dose histrelin for ovulation induction in mares: a partially randomized crossover pilot study.
AU - Lys de Barros Fogagnoli
AU - Kallena Canali Abdala Jose
AU - Rachel Weckl
AU - Clara Mantovani Ozorio Mota
AU - Mirelle Ochrimowicz Fernandes
AU - Rafaela Caroline Machado
AU - Carlos Eduardo Camargo
AU - Pedro Vicente Michelotto
PY - 2026
DA - 2026/10/20
JO - Veterinary research communications
DO - 10.1007/s11259-026-11583-9
UR - https://europepmc.org/article/MED/42897392
AB - This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints. Eleven mares were enrolled, of which nine completed all eight protocols and were included in the analyses. The protocols comprised 250 µg histrelin IM (standard dose), 75 µg IM, 25 µg IM, no intervention, saline at Bai-hui, saline at Yan-chi, 25 µg histrelin at Bai-hui, and 25 µg histrelin at Yan-chi. Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome. Ovulations first detected at 24 h were excluded from the primary analysis. Ovulation within 48 h occurred in 88.9% (8/9) of observations with 250 µg IM, 87.5% (7/8) with 75 µg IM, 87.5% (7/8) with 25 µg IM, 37.5% (3/8) with no intervention, 50.0% (3/6) with saline at Bai-hui, 100% (9/9) with 25 µg histrelin at Bai-hui, 12.5% (1/8) with saline at Yan-chi, and 87.5% (7/8) with 25 µg histrelin at Yan-chi. Exact 95% confidence intervals were wide, reflecting the small sample size. Exploratory pairwise comparisons with the no-intervention protocol were performed without adjustment for multiple comparisons and should be interpreted cautiously. The findings provide preliminary evidence that reduced histrelin doses, including 25 µg, may induce ovulation within 48 h in mares. However, this study did not demonstrate an advantage of pharmacopuncture over IM administration of the same reduced dose. Larger, fully randomized studies are required to confirm the efficacy of reduced-dose histrelin and determine whether administration at specific acupoints provides any additional effect.
SN - 0165-7380
SN - 1573-7446
ER -