Volume: 57 Issue: 3
Year: 2026, Page: 423-429, Doi: https://doi.org/10.51966/jvas.2026.57.3.423-429
Received: April 19, 2026 Accepted: June 30, 2026 Published: Sept. 30, 2026
The study compared haematological and serum biochemical parameters in bitches with complete primary uterine inertia (PUI) and obstructive dystocia (OD), and evaluated a non-invasive method for monitoring uterine contractions using M-mode ultrasonography. Twelve full term pregnant bitches with dystocia were equally divided into PUI (n=6) and OD (n=6) groups. Radiography was used to determine foetal number and confirm obstruction in OD cases. Ultrasonographic examination was performed in all animals, with M-mode used to assess myometrial activity. Blood samples were analysed for complete blood count, glucose, calcium, and progesterone levels. Data were analysed using an independent t-test following Shapiro–Wilk normality testing. M-mode ultrasonography revealed active myometrial contractions in OD (wavy pattern), whereas PUI cases showed absence of contractions (straight line pattern). No significant differences (p > 0.05) were observed in haematological or biochemical parameters between groups. The findings indicate that variations in calcium, glucose, or progesterone may not underlie PUI in otherwise healthy bitches. M-mode ultrasonography is a useful tool for early diagnosis of uterine inertia.
Keywords: Primary uterine inertia, Obstructive dystocia, haematology, serological analysis, M-mode
Bachmann S. (2018). Dystocia in the bitch: A retrospective study of 182 cases. Tierärztliche Praxis Kleintiere, 46(1), 33–40. 170492 https://doi.org/10.15654/TPK170492
Beccaglia M., Luvoni G. C., & Anastasi P. (2016). Prediction of parturition in the bitch using fetal heart rate and maternal progesterone concentration. Theriogenology, 85(7), 1430–1435. https://doi. org/10.1016/j.theriogenology.2016.01.012
Bergstrom, A., Nodtvedt, A., Lagerstedt, A. S., & Egenvall, A. (2006). Incidence and breed predilection for dystocia and risk factors for cesarean section in a Swedish population of insured dogs. Veterinary Surgery, 35, 786–791. https://doi.org/10.1111/ j.1532-950X.2006.00223.x
Campbell, M. L. H., & England, G. C. W. (2002). M-mode ultrasound imaging of the contractions of the equine uterus. The Veterinary Record, 150(18), 574-577. https://doi.org/10.1136/vr.150.18.575
Concannon, P.W., McCann, J. P., & Temple, M. (1989) Biology and endocrinology of ovulation, pregnancy and parturition in the dog. Journal of Reproduction and Fertility, Supplement, 39, 3–25.
Cynthia, K. M., & Scott, L. (2010). The Merck veterinary manual (10th ed.). Merck & Co.
Davidson, A. P. (2010). Problems during and after parturition. In G. C. W. England & A. von Heimendahl (Eds.), BSAVA manual of canine and feline reproduction and neonatology (2nd ed., pp. 121–134). British Small Animal Veterinary Association. https://doi. org/10.22233/9781905319541.14
De Cramer, K. G., Joubert, K. E., & Nothling, J. O. (2016). Hematocrit changes in healthy periparturient bitches that underwent elective cesarean section. Theriogenology, 86, 1333–1340. https://doi. org/10.1016/j.theriogenology.2016.04.075
Dimco, E., Prela A., Lika E., & Kamberi A. (2013). Dystocia in the dog: A retrospective study of 182 cases. Bulgarian Journal of Veterinary Medicine, 16(2), 95–103.
Doxey, D. L. (1966). Some conditions associated with variations in circulating oestrogens–blood picture alterations. Journal of Small Animal Practice, 7, 375–385. https://doi.org/10.1111/j.1748 5827.1966.tb04455.x
Frehner, B., Reichler, I., Keller, S., Goericke-Pesch, S., & Balogh, O. (2018). Blood calcium, glucose and haematology profiles of parturient bitches diagnosed with uterine inertia or obstructive dystocia. Reproduction in Domestic Animals. 53, 680–687. https://doi.org/10.1111/rda.13157
Gram A., Boos A., & Kowalewski M. P. (2014). Uterine and placental expression of canine oxytocin receptor during pregnancy and normal and induced parturition. Reproduction in Domestic Animals, 49(Suppl. 2), 41–49. https://doi.org/10.1111/ rda.12295
Hollinshead F. K., Hanlon D. W., & Gilbert R. O. (2010). Dystocia in the bitch: A retrospective study of 182 cases. New Zealand Veterinary Journal, 58(2), 74 79. https://doi.org/10.1080/00480169.2010.66293
Jayakumar, C., Raheema, S., Sophia, X., Vidhya, S., & Kurien, M. O. (2019). Uterine contraction monitoring in dogs using tocodynamometer. Indian Journal of Canine Practice, 11(2), 135–139. https://doi. org/10.29005/IJCP.2019.11.2.135-139
Kowalewski M. P., Beceriklisoy H. B., Aslan S., Agaoglu A. R., & Hoffmann B. (2009). Time-related changes in luteal prostaglandin synthesis and steroidogenic capacity during pregnancy, normal and antiprogestin-induced luteolysis in the bitch. Animal Reproduction Science, 116(1–2), 129–138. https://doi.org/10.1016/j.anireprosci.2008.12.011
Li, H., Gudmundsson, S., & Olofsson, P. (2003). Uterine artery blood flow velocity waveforms during uterine contractions. Ultrasound in Obstetrics & Gynecology, 22(6), 578–585. https://doi.org/10.1002/uog.921
Linde-Forsberg, C. and Eneroth, A. (2000). Abnormalities in pregnancy, parturition and the periparturient period. In : S. J. Ettinger and E. C. Feldman (Eds.), Textbook of Veterinary Internal Medicine. (Fifth ed., pp. 1527-1538). https://res.slu.se/id/publ/7487
Lucio, C. F., Silva, L. C., Rodrigues, J. A., Veiga, G. A., & Vannucchi, C. I. (2009). Peripartum haemodynamic status of bitches with normal birth or dystocia. Reproduction in Domestic Animals, 44, 133–136.https://doi.org/10.1111/j.1439-0531.2009.01427.x
Magnus, P.K. (2022). Assessment of myometrial contractility, gene expression of hormone receptors in uterus and foeto-maternal velocity indices in canine uterine inertia. [Doctoral dissertation, Kerala Veterinary and Animal Sciences University]
Magnus, P. K., Jayakumar, C., Thomas, N., Abhilash, R. S., & Ajithkumar, S. (2022). Tocodynamometry in canine uterine inertia. Journal of Veterinary and Animal Sciences, 53(4), 535–540. https://doi. org/10.51966/jvas.2022.53.4.535-540
aMagnus, P. K., Jayakumar, C., Thomas, N., Abhilash, R. S., Hiron, M. H., & Ajithkumar, S. (2023). Haematology profile of dogs with primary uterine inertia. Journal of Veterinary and Animal Sciences, 54(1), 7–12. https://doi.org/10.51966/jvas.2023.54.1.7-12
bMagnus, P. K., Jayakumar, C., Thomas, N., Lali F A., Abhilash, R. S., Hiron, M. H., & Ajithkumar, S. (2023). Etiology behind canine uterine inertia: Role of uterine expression of MLCK4, MYH2, and PKC genes. Animal reproduction science, 256, 107298. https://doi.org/10.1016/j.anireprosci.2023.107298
Maul, H., Maner, W. L., Saade, G. R., & Garfield, R. E. (2003). The physiology of uterine contractions. Clinics in Perinatology, 30(4), 665–676. https://doi. org/10.1016/S0095-5108(03)00105-2
Merck & Co., Inc. (2023). Reference intervals for laboratory tests in dogs. In Merck Veterinary Manual. https:// www.merckvetmanual.com
Papa P. C., & Kowalewski M. P. (2020). Factors affecting the fate of the canine corpus luteum: Potential contributors to pregnancy and non-pregnancy. Theriogenology, 150, 339–346. https://doi. org/10.1016/j.theriogenology.2020.01.081
Polster, K. J. (2006). Untersuchungen zur Häufigkeit, zu den Ursachen und der Therapie von Geburtsstörungen bei den Hündinnen: Eine statistische Auswertung von Patientengut (Doctoral dissertation, Freie Universität Berlin).
Scully, C. M. (2023). Dystocia in small animals. In MSD Veterinary Manual. Retrieved from https:// www.msdvetmanual.com/reproductive-system/ reproductive-diseases-of-the-female-small-animal/ dystocia-in-small-animals
Stengel, B. (1997). Untersuchungen über Auftreten und Verlauf von Geburtsstörungen bei der Hündin: Eine retrospektive Studie über 648 Fälle (Doctoral dissertation, Ludwig-Maximilians-Universität München).
Trautmann, T. (2003). Hochbegabt–was n (t) un?. LIT Verlag Münster.
Verstegen-Onclin, K., & Verstegen, J. (2008). Endocrinology of pregnancy in the dog: A review. Theriogenology, 70, 291–299. https://doi. org/10.1016/j.theriogenology.2008.04.038
Zatta A., Piazza V., Barbato O., & Parravicini E. (2017). Dystocia in the bitch: A retrospective study of 182 cases. Theriogenology, 97, 104–109. https://doi. org/10.1016/j.theriogenology.2017.04.026
© 2026 Gayatri et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Gayatri, S., Magnus, P. K., Jayakumar, C., Simon, S., George. A., Rojan P. M. & Stephy, J.J. (2026). Ultrasonographic M-mode for diagnosing uterine inertia and comparative analysis of blood parameters in canines. Journal of Veterinary and Animal Sciences, 57(3), 423-429