Comprehensive assessment of the effects of genotypic and paratypic factors on the reproductive potential of dogs
DOI:
https://doi.org/10.31210/spi2026.29.01.15Keywords:
dogs, prolificacy, fertility, inbreeding, spermatogenesis, age dynamics, artificial insemination, synthetic extendersAbstract
The article presents the results of comprehensive studies aimed at investigating the influence of genotypic and paratypic factors on the reproductive function of dogs in modern breeding conditions. The relevance of the work is determined by the need to improve the efficiency of selection and the introduction of biotechnological methods of controlling dog reproduction. The study was conducted on 65 breeding dogs from different kennels, including 40 bitches and 25 dogs of different breeds aged 1.5 to 8 years. It was found that the reproductive performance of dogs significantly depends on age, season, and homozygosity level. The analysis showed that the average fertility of outbred bitches is 6.8–7.4 puppies per litter, while in closely inbred animals this indicator reliably decreases to 4.3–5.6 puppies (P<0.001), which is 25–28 % less than the average population values. The optimal reproductive age for females is determined to be 4–5 years, during which the maximum fertility of 7.4 puppies is recorded. Seasonal determination of fertility was revealed: the highest fertility of bitches (84.7–86.4 %) was observed in the spring-summer period, while the minimum values were recorded in winter – 69.5 % (P<0.01), which correlates with the change in the length of daylight hours. The quality of male dogs' sperm is also largely determined by genetic and age factors. In outbred dogs, sperm concentration reached 312 million/ml, motility was 82.4 %, and the proportion of morphologically normal forms was 87.5 %. In contrast, closely inbred individuals showed pronounced inbreeding depression: these indicators decreased to 241 million/ml, 68.3 %, and 73.6 % (P<0.001), respectively. It has been established that after 6 years of age, dogs experience a significant decrease in motility and concentration of sperm cells, which indicates the limit of intensive breeding use. It was found that when using chilled semen, sperm motility remains at 74.1 % after 48 hours and 62.5 % after 72 hours of exposure, which ensures the high biological integrity of the biomaterial for remote breeding. The effectiveness of artificial insemination of bitches with chilled semen was 81.0 %, which was statistically not inferior to the use of native semen (87.5 %, P>0.05). The data obtained confirm the high efficiency of the cooling method and the feasibility of its implementation in breeding work as an alternative to natural mating, which allows the rational use of the genetic potential of valuable studs without losing the level of fertility. An integrated assessment of reproductive function confirmed that closely inbred animals of older age groups have the lowest reproductive potential (index 0.68).
References
1. Aiello, S. E., Moses, M. A., & Allen, D. G. (2016). The Merck veterinary manual (11th ed.). Merck & Company, Inc.
2. Christensen, B. W., & Meyers, S. (2023). Canine semen evaluation and processing. Veterinary Clinics of North America: Small Animal Practice, 53 (5), 921–930. https://doi.org/10.1016/j.cvsm.2023.05.006
3. Concannon, P. W. (2011). Reproductive cycles of the domestic bitch. Animal Reproduction Science, 124 (3-4), 200–210. https://doi.org/10.1016/j.anireprosci.2010.08.028
4. David, O. S., Imaben, K. G., Otaka, A. F., & Chuka, E. (2024). Studies on breeding failures in dogs: A review. Saudi Journal of Medicine, 9 (02), 48–54. https://doi.org/10.36348/sjm.2024.v09i02.006
5. De los Reyes, M., & Songsasen, N. (2021). New insights in canine reproduction. Animals, 11 (7), 2021. https://doi.org/10.3390/ani11072021
6. Del Prete, C., Iannuzzi, A., Longobardi, V., Pasolini, M. P., Pistucci, R., Calabria, A., Gasparrini, B., & Cocchia, N. (2026). Telomere lengths in blood and sperm as biomarkers of reproductive aging and semen quality in dogs. Theriogenology, 254, 117827. https://doi.org/10.1016/j.theriogenology.2026.117827
7. Domain, G., Buczkowska, J., Kalak, P., Wydooghe, E., Banchi, P., Pascottini, O. B., Niżański, W., & Van Soom, A. (2022). Serum anti-müllerian hormone: A potential semen quality biomarker in stud dogs? Animals, 12 (3), 323. https://doi.org/10.3390/ani12030323
8. Forkun, V. I., Bobrytska, O. M., Ugai, K. D., Vodopianova, L. A., Zhukova, I. O., Denisova, O. M., & Levchenko, A. G. (2023). The content of some sexual hormones in the blood of female dogs with different temperament traits. Theoretical and Applied Veterinary Medicine, 11 (4), 11–15. https://doi.org/10.32819/2023.11017
9. Hallberg, I., Olsson, H., Lau, A., Wallander, S., Snell, A., Bergman, D., & Holst, B. S. (2024). Endocrine and dog factors associated with semen quality. Scientific Reports, 14 (1), 718. https://doi.org/10.1038/s41598-024-51242-0
10. Hanim, M. S., & Chotimanukul, S. (2025). Age-related canine reproductive health. Journal of Veterinary Science, 26 (S1), S139. https://doi.org/10.4142/jvs.25218
11. Hori, T., Yoshikuni, R., Kobayashi, M., & Kawakami, E. (2014). Effects of storage temperature and semen extender on stored canine semen. Journal of Veterinary Medical Science, 76 (2), 259–263. https://doi.org/10.1292/jvms.13-0303
12. Johnson, C. A. (2008). Pregnancy management in the bitch. Theriogenology, 70 (9), 1412–1417. https://doi.org/10.1016/j.theriogenology.2008.09.009
13. Kolster, K. A. (2018). Evaluation of canine sperm and management of semen disorders. Veterinary Clinics of North America: Small Animal Practice, 48 (4), 533–545. https://doi.org/10.1016/j.cvsm.2018.02.003
14. Koziol, J., Gibbons, P., & Dascanio, J. (2023). A survey of the use of theriogenology related models across veterinary curricula. Clinical Theriogenology, 15, 38–45. https://doi.org/10.58292/ct.v15.9594
15. Maenhoudt, C., Santos, N. R., & Fontbonne, A. (2018). Manipulation of the oestrous cycle of the bitch-what work for now. Reproduction in Domestic Animals, 53 (S3), 44–52. https://doi.org/10.1111/rda.13364
16. Mason, S. J. (2023). An update on male canine infertility. Veterinary Clinics of North America: Small Animal Practice, 53 (5), 1063–1081. https://doi.org/10.1016/j.cvsm.2023.04.006
17. Menor-Campos, D. J. (2024). Ethical concerns about fashionable dog breeding. Animals, 14 (5), 756. https://doi.org/10.3390/ani14050756
18. Nagashima, J. B., & Songsasen, N. (2021). Canid reproductive biology: Norm and unique aspects in strategies and mechanisms. Animals, 11 (3), 653. https://doi.org/10.3390/ani11030653
19. O’Neill, D. G., McMillan, K. M., Church, D. B., & Brodbelt, D. C. (2023). Dog breeds and conformations in the UK in 2019: VetCompass canine demography and some consequent welfare implications. Plos One, 18 (7), e0288081. https://doi.org/10.1371/journal.pone.0288081
20. Reynaud, K., Saint-Dizier, M., Thoumire, S., & Chastant-Maillard, S. (2020). Follicle growth, oocyte maturation, embryo development, and reproductive biotechnologies in dog and cat. Clinical Theriogenology, 12 (3), 189–203.
21. Robert, M. A., Jayaprakash, G., Pawshe, M., Tamilmani, T., & Sathiyabarathi, M. (2016). Collection and evaluation of canine semen – A review. International Journal of Science, Environment and Technology, 5 (3), 1586–1595.
22. Rota, A., Linde‐Forsberg, C., Vannozzi, J., Romagnoli, S., & Rodriguez‐Martinez, H. (1998). Cryosurvival of dog spermatozoa at different glycerol concentrations and freezing/thawing rates. Reproduction in Domestic Animals, 33 (5), 355–361. https://doi.org/10.1111/j.1439-0531.1998.tb01370.x
23. Roos-Pichenot, J., & Zakošek Pipan, M. (2025). “My Bitch Is Empty!” an overview of the preconceptional causes of infertility in dogs. Veterinary Sciences, 12 (7), 663. https://doi.org/10.3390/vetsci12070663
24. Schwartz, D. W., Kvernum, J., Macias, N., Waqas, M. S., & Ciccarelli, M. (2025). Incorporating Morphological evaluations into breeding soundness examinations for female dogs. Animals, 15 (14), 2045. https://doi.org/10.3390/ani15142045
25. Sones, J., & Balogh, O. (2023). Body condition and fertility in dogs. Veterinary Clinics of North America: Small Animal Practice, 53 (5), 1031–1045. https://doi.org/10.1016/j.cvsm.2023.04.005
26. Sorkytė, Š., Šiugždinienė, R., Virgailis, M., Vaičiulienė, G., Wysokińska, A., Wójcik, E., Matusevičius, P., Rekešiūtė, A., & Sutkevičienė, N. (2024). The interaction between canine semen bacteria and semen quality parameters. Animals, 14 (15), 2151. https://doi.org/10.3390/ani14152151
27. Tesi, M., Sabatini, C., Vannozzi, I., Di Petta, G., Panzani, D., Camillo, F., & Rota, A. (2018). Variables affecting semen quality and its relation to fertility in the dog: A retrospective study. Theriogenology, 118, 34–39. https://doi.org/10.1016/j.theriogenology.2018.05.018
28. Venianaki, A. P., Barbagianni, M. S., Fthenakis, G. C., Galatos, A. D., & Gouletsou, P. G. (2024). Ultrasonography of testicular maturation and correlation with body growth and semen evaluation in beagle dog model. Veterinary Sciences, 11 (6), 270. https://doi.org/10.3390/vetsci11060270
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Copyright (c) 2026 М. В. Себа, М. О. Хоменко, Р. В. Кононенко, Н. П. Свириденко, Т. В. Литвиненко, Л. М. Хмельничий, В. М. Бочков, О. Г. Маховий
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