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Home / Equine Research Bank / Vet Med Sci / Changes in the Mare Oviduct Across Different Seasons Through...
Veterinary medicine and science2026; 12(2); e70753; doi: 10.1002/vms3.70753

Changes in the Mare Oviduct Across Different Seasons Throughout the Year.

Abstract: At present, oviductal pathologies and their influence on mare fertility have not been clearly determined. Checking changes throughout the year in the oviductal structure may be relevant to understand the influence on the appearance of problems in oviductal functionality and, thus, the impact on fertility, which is the objective of this work. The oviducts of 56 mares were examined. Their anatomy, permeability, oviductal cellularity and the presence of pathologies were assessed to establish the correlations between the time of the year and each of these parameters. We cannot conclude whether there is a correlation between oviductal permeability or the presence of pathologies and season. Also, we did not find a relationship between oviductal permeability and the presence of pathologies; in fact, most of the oviducts analysed were permeable throughout the year (88.13%), and only 5.93% showed partial permeability, while 5.93% were not permeable. Regarding pathologies, 7.62% of the oviducts presented adhesions, with an increased incidence during anoestrus and the spring transitional period, while 23.72% of the oviducts presented paraoviductal cysts and 41.52% presented paraovarian cysts. The incidence of oviductal thickening was observed only during the reproductive season (14.7%). Regarding oviductal cellularity, it´s correlated (0.236) with the ovarian activity observed throughout the year.
© 2026 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.
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Publication Date: 2026-03-14 PubMed ID: 41830181DOI: 10.1002/vms3.70753Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study investigates how the structure and condition of the mare’s oviduct change throughout different seasons of the year.
  • The goal is to understand if these changes affect fertility by examining anatomy, permeability, cellularity, and pathologies of the oviducts across seasons.

Study Objective and Importance

  • Oviductal pathologies (diseases or abnormalities in the oviduct) may influence mare fertility, but their role is not well understood.
  • The study aims to determine if there are seasonal changes in the mare’s oviduct that could relate to fertility problems.
  • Understanding these changes could help explain why some mares experience fertility issues linked to oviduct function.

Methods and Sample

  • Researchers examined the oviducts from 56 mares.
  • They analyzed the oviducts for various parameters, including:
    • Anatomy — the physical structure of the oviduct
    • Permeability — whether the oviducts are open or blocked
    • Cellularity — the number and arrangement of cells in the oviduct
    • Presence of pathologies — such as adhesions or cysts
  • These features were correlated with specific times or seasons throughout the year.

Key Findings – Permeability and Pathologies

  • Most oviducts (88.13%) were permeable year-round, meaning they remained open and theoretically functional.
  • A small portion showed partial permeability (5.93%) or were not permeable (5.93%).
  • No clear correlation was found between the season of the year and whether the oviducts were permeable or blocked.
  • No direct relationship was established between the presence of pathologies and oviductal permeability.
  • Types and incidence of pathologies observed included:
    • Adhesions (7.62%) — fibrous bands that can cause obstruction; these were more common during the anoestrus and spring transitional period.
    • Paraoviductal cysts (23.72%) — cysts near the oviduct.
    • Paraovarian cysts (41.52%) — cysts near the ovary.
    • Oviductal thickening (14.7%) — observed only during the reproductive season, which might affect oviduct function.

Key Findings – Oviductal Cellularity

  • Oviductal cellularity, which reflects the number and arrangement of cells in the oviduct lining, showed a low but positive correlation (0.236) with ovarian activity throughout the year.
  • This suggests cellularity varies somewhat with the mare’s reproductive state or hormonal changes connected with ovarian function.

Conclusions and Implications

  • The study could not confirm that season directly affects oviduct permeability or the prevalence of pathologies in mares.
  • Despite some pathologies being present, most oviducts remained open and potentially functional year-round.
  • The increased incidence of specific pathologies during certain reproductive phases (e.g., adhesions during anoestrus) may suggest seasonal susceptibility but is not definitive.
  • Changes in oviductal cellularity in line with ovarian activity highlight a biological link between reproductive status and oviduct structure.
  • Overall, findings enhance understanding of seasonal oviduct changes but indicate that further research is needed to clarify impacts on fertility.

Cite This Article

APA
González N, Varela A, de Blas N, Gil L. (2026). Changes in the Mare Oviduct Across Different Seasons Throughout the Year. Vet Med Sci, 12(2), e70753. https://doi.org/10.1002/vms3.70753

Publication

Veterinary medicine and science
ISSN: 2053-1095
NlmUniqueID: 101678837
Country: England
Language: English
Volume: 12
Issue: 2
Pages: e70753

Researcher Affiliations

González, Noelia
  • Department of Animal Pathology, Faculty of Veterinary Sciences, Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), Universidad de Zaragoza, Zaragoza, Spain.
Varela, Agatha
  • Hospital Veterinario La Chopera. P.° de la Chopera, Madrid, Spain.
de Blas, Nacho
  • Department of Animal Pathology, Faculty of Veterinary Sciences, Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), Universidad de Zaragoza, Zaragoza, Spain.
Gil, Lydia
  • Department of Animal Pathology, Faculty of Veterinary Sciences, Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), Universidad de Zaragoza, Zaragoza, Spain.

MeSH Terms

  • Animals
  • Female
  • Horses / physiology
  • Horses / anatomy & histology
  • Seasons
  • Oviducts / anatomy & histology
  • Oviducts / physiology
  • Horse Diseases / pathology
  • Fallopian Tubes / anatomy & histology
  • Fallopian Tubes / physiology

Grant Funding

  • A17_17R-RAySA / Government of Aragon
  • FEDER 2014-2020 / Building Europe from Aragon

References

This article includes 50 references
  1. Aguilar J, Reyley M. The Uterine Tubal Fluid: Secretion, Composition and Biological Effects. Animal Reproduction 2, no. 2: 91–105.
  2. Aguilar J J, Cuervo‐Arango J, Mouguelar H, Losinno L. Histological Characteristics of the Equine Oviductal Mucosa at Different Reproductive Stages. Journal of Equine Veterinary Science 32, no. 2: 99–105.
    doi: 10.1016/j.jevs.2011.08.001google scholar: lookup
  3. Aguilar J J, Woods G L, Miragaya M H, Olsen L M. Living Fibroblast Cells in the Oviductal Masses of Mares. Equine Veterinary Journal 25: 103–108.
    doi: 10.1111/j.2042‐3306.1997.tb05112.xgoogle scholar: lookup
  4. Allen W R, Wilsher S, Morris L, Crowhurst J S, Hillyer M H, Neal H N. Laparoscopic Application of PGE2 to Re‐Establish Oviducal Patency and Fertility in Infertile Mares: A Preliminary Study. Equine Veterinary Journal 38, no. 5: 454–459.
    doi: 10.2746/042516406778400628google scholar: lookup
  5. Arnold C E, Love C C. Laparoscopic Evaluation of Oviductal Patency in the Standing Mare. Theriogenology 79: 90.
    doi: 10.2746/042516406778400628google scholar: lookup
  6. Bennett S, Richard L, Griffin R, Rhoads W. Surgical Evaluation of Oviduct Disease and Patency in the Mare. Proceedings of the Annual Convention of the AAEP 48: 347–349.
  7. Blue M G. A Tubo‐Ovarian Cyst, Paraovarian Cysts and Lesions of the Oviduct in the Mare. New Zealand Veterinary Journal 33, no. 1–2: 8–10.
    doi: 10.1080/00480169.1985.35134google scholar: lookup
  8. Campbell D L, Douglas L W, Ramge J C. Cannulation of the Equine Oviduct and Chemical Analysis of Oviduct Fluid. Theriogenology 12, no. 2: 47–59.
    doi: 10.1016/0093‐691x(79)90009‐8google scholar: lookup
  9. Costello M F, Shrestha S M, Sjoblom P. Power Doppler Ultrasound Assessment of Ovarian Perifollicular Blood Flow in Women With Polycystic Ovaries and Normal Ovaries During in Vitro Fertilization Treatment. Fertility and Sterility 83, no. 4: 945–954.
    doi: 10.1016/j.fertnstert.2004.09.025google scholar: lookup
  10. Desantis S, Zizza S, Accogli G, Acone F, Rossi R, Resta L. Morphometric and Ultrastructural Features of the Mare Oviduct Epithelium During Oestrus. Theriogenology 75, no. 4: 671–678.
    doi: 10.1016/j.theriogenology.2010.10.007google scholar: lookup
  11. Dixon R E, Hwang S J, Hennig G W. Chlamydia Infection Causes Loss of Pacemaker Cells and Inhibits Oocyte Transport in the Mouse Oviduct. Biology of Reproduction 80, no. 4: 665–673.
    doi: 10.1095/biolreprod.108.073833google scholar: lookup
  12. Fiala S M, Amaral M G, Cruz L A, Rodrigues R F, Pimentel A M, Mattos R C. Inflammatory Lesions in the Oviducts and Its Relationship With Endometrial Inflammation and Ovarian Activity in Criollo Mares. Journal of Equine Veterinary Science 35, no. 9: 731–734.
    doi: 10.1016/j.jevs.2015.07.006google scholar: lookup
  13. Fiala S M, Pimentel C A, Mattos A L G, Gregory R M, Mattos R C. Effect of Sperm Numbers and Concentration on Sperm Transport and Uterine Inflammatory Response in the Mare. Theriogenology 67, no. 3: 556–562.
    doi: 10.1016/j.theriogenology.2006.09.005google scholar: lookup
  14. Freeman D A, Weber J A, Geary R T, Woods G L. Time of Embryo Transport Through the Mare Oviduct. Theriogenology 36: 823–830.
    doi: 10.1016/0093691x(91)90348‐hgoogle scholar: lookup
  15. Getty R. Sistema Urogenital de los Equinos. In Anatomía de los Animales Domésticos, 585–614.
  16. Gonçalves, S., V. Julliand, and A. Leblond. 2002. “Risk Factors Associated With Colic in Horses.” Veterinary Research 33, no. 6: 641–652. https://doi.org/10.1051/vetres:2002044.
  17. Goudet, G. 2011. “Fertilization in the Horse and Paracrine Signalling in the Oviduct.” Reproduction, Fertility, and Development 23, no. 8: 941–951. https://doi.org/10.1071/RD10285.
  18. Hugentobler, S. A., J. M. Sreenan, P. G. Humpherson, H. J. Leese, M. G. Diskin, and D. G. Morris. 2010. “Effects of Changes in the Concentration of Systemic Progesterone on Ions, Amino Acids and Energy Substrates in Cattle Oviduct and Uterine Fluid and Blood.” Reproduction, Fertility, and Development 22, no. 4: 684–694. https://doi.org/10.1071/RD09129.
  19. Hughes, J. P., G. H. Stabenfeldt, and P. C. Kennedy. 1980. “Estrous Cycle and Selected Funcional and Pathologic Ovarian Abnormalities in the Mare.” The Veterinary Clinics of North America Large Animal Practice 2, no. 2: 225–239. https://doi.org/10.1016/s0196‐9846(17)30158‐1.
  20. Inoue, Y., and M. Sekiguchi. 2018. “Clinical Application of Hysteroscopic Hydrotubation for Unexplained Infertility in the Mare.” Equine Veterinary Journal 50, no. 4: 470–473. https://doi.org/10.1111/evj.12781.
  21. Kainer, R. A. 1993. “Reproductive Organs of the mare.” In Equine Reproduction, edited by A. O. Mc‐Kinnon, and J. L. Voss, 5–19. Philadelphia: Lea and Febiger.
  22. Katila, T. 2012. “Post‐mating Inflammatory Responses of the Uterus.” Reproduction in Domestic Animals = Zuchthygiene 47, no. 5: 31–41. https://doi.org/10.1111/j.1439‐0531.2012.02120.x.
  23. Kenney, R. M. 2010. “A Review of the Pathology of the Equine Oviduct.” Equine Veterinary Journal 25, no. S15: 42–46. https://doi.org/10.1111/j.2042‐3306.1993.tb04823.x.
  24. Killian, G. 2011. “Physiology and Endocrinology Symposium: Evidence That Oviduct Secretions Influence Sperm Function: a Retrospective View for Livestock.” Journal of Animal Science 89, no. 5: 1315–1322. https://doi.org/10.2527/jas.2010‐3349.
  25. Kölle, S., S. Dubielzig, S. Reese, A. Wehrend, P. König, and W. Kummer. 2009. “Ciliary Transport, Gamete Interaction, and Effects of the Early Embryo in the Oviduct: Ex Vivo Analyses Using a New Digital Videomicroscopic System in the Cow.” Biology of Reproduction 81, no. 2: 267–274. https://doi.org/10.1095/biolreprod.108.073874.
  26. Konig, H. E., and H. G Liebich. 2011. “Anatomía de los Animales domésticos.” In Órganos, Sistema Circulatorio y Sistema Nervioso. Editorial Médica Panamericana.
  27. Kotilainen, T., M. Huhtinen, and T. Katila. 1964. “Sperm‐induced Leukocytosis in the Equine Uterus.” Theriogenology 41, no. 3: 629–636. https://doi.org/10.1016/0093‐691x(94)90173‐g.
  28. Lantz, K. C., A. C. Enders, and I. K. Liu. 1998. “Possible Significance of Cells Within Intraluminal Collagen Masses in Equine Oviducts.” Anatomical Record 252, no. 4: 568–579. https://doi.org/10.1002/(SICI)1097‐0185(199812)252:4<568:AID‐AR7>3.0.CO;2‐T.
  29. Liu, I. K., K. C. Lantz, S. Schlafke, J. M. Bavers, and A. C. Enders. 1990. “Clinical Observations of Oviductal Masses in the Mare.” In Proceedings of the Annual Convention of the American Association of Equine Practitioners (USA), 41–45. AAEP.
  30. Losinno, L., G. L. Woods, and M. H. Miragaya. 1997. “Uterine and Oviductal Inflammation in Anovulatory Mares With Ultrasonographically Etected Intrauterine Fluid.” Theriogenology 48, no. 8: 1361–1368. https://doi.org/10.1016/S0093‐691X(97)00377‐4.
  31. McEntee, K. 1990. “The Uterine Tube.” In Reproductive Pathology of Domestic Mammals, 94–109. Elsevier. https://doi.org/10.1016/B978‐0‐12‐483375‐3.50012‐3.
  32. Medenbachl, K., H. Aupperlel, D. Schoonl, M. M. Wittenbrinkz, and H. A. Schoonl. 1999. “Pathology of the Equine Salpinx.” Pferdeheilkunde Equine Medicine 15, no. 6: 560–567.
  33. Miragaya, M. H., G. L. Woods, and L. Losinno. 1997. “Endometritis, Salpingitis and Fertilisation Rates After Mating Mares With a History of Intrauterine Lumenal Fluid Accumulation.” Equine Veterinary Journal 25: 19–112. https://doi.org/10.1111/j.2042‐3306.1997.tb05113.x.
  34. Mouguelar, H., T. Díaz, D. Borghi, et al. 2015. “Morphometric Study of the Mare Oviductal Mucosa at Different Reproductive Stages.” Anatomical Record 298, no. 11: 1950–1959. https://doi.org/10.1002/ar.23193.
  35. Muglia, U., and P. M. Motta. 2001. “A New Morpho‐functional Classification of the Fallopian Tube Based on Its Three‐Dimensional Myoarchitecture.” Histology and Histopathology 16, no. 1: 227–237. https://doi.org/10.14670/HH‐16.227.
  36. Onuma, H., and Y. Ohnami. 1975. “Retention of Tubal Eggs in Mares.” Reproduction 23: 507–511.
  37. Pinto, P., M. R. Rebordão, A. Amaral, et al. 2018. “Is Mare Endometrosis Linked to Oviduct Fibrosis?” Pferdeheilkunde–Equine Medicine 34: 43–46. https://doi.org/10.21836/PEM20180107.
  38. Pycock, J. F., and W. E. Allen. 1990. “Inflammatory Components in Uterine Fluid From Mares With Experimentally Induced Bacterial Endometritis.” Equine Veterinary Journal 22, no. 6: 422–425. https://doi.org/10.1111/j.2042‐3306.1990.tb04309.x.
  39. Pye, J., J. Clulow, and A. Adkins. 2018. “Laparoscopic Transection of Restrictive Bands of the Mesosalpinx as Adjunct to the Use of Prostaglandin E2 for Mares With Suspected Uterine Tubal Blockage.” Australian Veterinary Journal 96, no. 7: 252–256. https://doi.org/10.1111/avj.12713.
  40. Saltie, A., R. Páramo, C. Murcia, and J. Tolosa. 1986. “Pathologic Findings in the Oviducts of Mares.” American Journal of Veterinary Research 47, no. 3: 594–597.
  41. Samper, J. C. 2009. “Uterine Edema in the Mare. Equine Breeding Management and Artificial Insemination.” Elsevier 12: 133–138. https://doi.org/10.1016/B978‐1‐4160‐5234‐0.00012‐X.
  42. Senger, P. L. 2011. Pathway to Pregnancy and Parturition. 3rd ed. Current Conception, Inc.
  43. Stangroom, J. E., and R. D. G. Weevers. 1962. “Anticoagulant Activity of Equine Follicular Fluid.” Reproduction 3, no. 2: 269–282. https://doi.org/10.1530/jrf.0.0030269.
  44. Teilmann, S. C., C. A. Clement, J. Thorup, A. G. Byskov, and S. T. Christensen. 2006. “Expression and Localization of the Progesterone Receptor in Mouse and Human Reproductive Organs.” Journal of Endocrinology 191, no. 3: 525–535. https://doi.org/10.1677/joe.1.06565.
  45. Troedsson, M. H., M. A. Scott, and I. K. Liu. 1995. “Comparative Treatment of Mares Susceptible to Chronic Uterine Infection.” American Journal of Veterinary Research 56, no. 4: 468–472.
  46. Troedsson, M. H. T., K. Loset, A. M. Alghamdi, B. Dahms, and B. G. Crabo. 2001. “Interaction Between Equine Semen and the Endometrium: The Inflammatory Response to Semen.” Animal Reproduction Science 68, no. 3–4: 273–278. https://doi.org/10.1016/S0378‐4320(01)00164‐6.
  47. Tsutsumi, Y., H. Suzuki, T. Takeda, and Y. Terami. 1979. “Evidence of the Origin of the Gelatinous Masses in the Oviducts of Mares.” Reproduction 57, no. 2: 287–290. https://doi.org/10.1530/jrf.0.0570287.
  48. Vandeplassche, M., and M. Henry. 1977. “Salpingitis in the Mare.” Proceedings of the Annual Convention of the American Association of Equine Practitioners 23: 123–131.
  49. Wilson, R. F., A. V. Nalbandov, and J. L. Krider. 1949. “A Study of Impaired Fertility in Female Swine.” Journal of Animal Science 8, no. 4: 558–568. https://doi.org/10.2527/jas1949.84558x.
  50. Wrobel, K. H., R. Kujat, and G. Fehle. 1993. “The Bovine Tubouterine Junction: General Organization and Surface Morphology.” Cell and Tissue Research 271, no. 2: 227–239. https://doi.org/10.1007/BF00318609.

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