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Animals : an open access journal from MDPI2025; 15(23); 3454; doi: 10.3390/ani15233454

Introducing an Innovative Pain Scale for Assessing Postpartum Pain in Mares: Preliminary Clinical Evaluation.

Abstract: Pain after giving birth is commonly observed in horses, yet there has not been a specific tool developed for assessing this pain in postpartum mares. The goal was to adapt existing equine pain scales and to preliminarily validate a practical pain scale for use by veterinarians and caregivers after foaling. Methods: The pain scale was developed by adapting items from other pain scales, including established orthopedic and colic equine pain scales, and incorporating caregiver feedback. The final scale includes eight areas for assessing pain: behavior, facial expressions, vital signs, udder examination, gastrointestinal function, hoof temperature, response to food, and movement. Observations were conducted on ten heavy draft mares that experienced dystocia, with pain scores recorded twice daily for 1 to 4 days postpartum. Simultaneous saliva samples were collected to measure cortisol levels. Results: The pain scale proved feasible for use at the stall and allowed for partial scoring when certain assessments were deemed risky. Pain scores were highest on the first day after foaling and decreased as the mares recovered. In a case of clinical deterioration, a substantial increase in pain score was noted. Increased pain scores were associated with elevated cortisol levels, supporting the biological relevance of the scale. In clinical practice, if a pain score exceeded 40% of the maximum score, the mare was identified as a patient requiring analgesic treatment. Conclusions: This postpartum-specific pain scale provides a standardized method for assessing pain in mares after foaling and may assist in guiding appropriate pain management. Although the proposed pain scale shows promise as a clinical tool, the present results are preliminary and require confirmation in larger studies.
Publication Date: 2025-11-30 PubMed ID: 41375512PubMed Central: PMC12691225DOI: 10.3390/ani15233454Google Scholar: Lookup
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  • Journal Article

Summary

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Overview

  • This research introduces a new pain scale specifically designed to assess postpartum pain in mares (female horses) after giving birth, adapting existing equine pain scales and validating its preliminary clinical use.

Introduction and Objective

  • Postpartum pain in mares is a common but under-assessed condition in equine medicine.
  • Prior to this study, no specialized tool existed to objectively measure pain specifically linked to foaling in mares.
  • The objective was to create and preliminarily validate a practical and reliable postpartum pain scale that veterinarians and caregivers could use in clinical settings.

Development of the Pain Scale

  • The scale was created by adapting items from existing equine pain scales, notably orthopedic and colic scales, which assess pain related to bone/joint issues and abdominal pain, respectively.
  • Additional input was collected from caregivers who regularly handle postpartum mares to ensure practicality and relevance.
  • The finalized scale consists of eight key assessment areas:
    • Behavioral changes (e.g., restlessness, posturing)
    • Facial expressions (specific grimacing or tension signs)
    • Vital signs (heart rate, respiratory rate, temperature)
    • Udder examination (signs of pain, heat, swelling)
    • Gastrointestinal function (motility and digestive activity)
    • Hoof temperature (as an indirect sign of systemic distress)
    • Response to food (appetite and eating behavior)
    • Movement (willingness to move, gait abnormalities)

Methodology

  • The study involved observing 10 heavy draft mares that had experienced dystocia, a difficult or abnormal labor, making pain assessment especially important.
  • Pain scoring was conducted twice daily covering 1 to 4 days following foaling.
  • Saliva samples were collected simultaneously to measure cortisol—a hormone commonly linked to stress and pain—to biologically validate the pain scores.
  • The scale allowed for partial scoring if some assessments could not be safely performed in the stall environment.

Results

  • The pain scale was feasible and practical for use at the stall, facilitating regular pain assessment without requiring special facilities.
  • Pain scores peaked on the first day postpartum, which aligns with the expected highest pain period after foaling, and progressively decreased as mares recovered.
  • In one mare whose health worsened clinically, a sharp increase in pain score was recorded, demonstrating the scale’s sensitivity to changes in condition.
  • There was a positive correlation between higher pain scores and elevated cortisol levels, supporting the biological relevance and validity of the scale.
  • A threshold was proposed: pain scores exceeding 40% of the maximum score indicated that analgesic intervention might be necessary.

Conclusions and Implications

  • The study presents the first specifically designed, standardized pain scale for postpartum mares, addressing a previously unmet clinical need.
  • This scale can help veterinarians and caregivers objectively monitor pain and inform decisions about pain management following foaling.
  • The preliminary results are promising, showing the scale’s practical applicability and biological correlation through cortisol measurements.
  • Further research with a larger sample size and diverse horse populations is necessary to fully validate and refine the scale.

Significance

  • Provides a tool to improve welfare and clinical care of postpartum mares by ensuring timely and appropriate analgesic treatment.
  • Enhances understanding of postpartum pain patterns in mares, potentially improving recovery outcomes and reducing complications.
  • Sets a foundation for future advancements in equine pain assessment and management tailored to different clinical scenarios.

Cite This Article

APA
Bolesławska-Szubartowska J, Kucharczuk M, Skrabska A, Zbysław A, Adamowicz J, Alszko A, Domagalska-Stomska K, Durska M, Dziekcierów A, Janiszewska Z, Korzeniowska R, Kraujutowicz K, Kulesza K, Marciniak P, Pacyna Z, Przeborowska J, Siwek Z, Leonard M, Rapacz-Leonard A. (2025). Introducing an Innovative Pain Scale for Assessing Postpartum Pain in Mares: Preliminary Clinical Evaluation. Animals (Basel), 15(23), 3454. https://doi.org/10.3390/ani15233454

Publication

ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 15
Issue: 23
PII: 3454

Researcher Affiliations

Bolesławska-Szubartowska, Julia
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Kucharczuk, Magdalena
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Skrabska, Aleksandra
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Zbysław, Aneta
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Adamowicz, Julia
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Alszko, Agnieszka
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Domagalska-Stomska, Klementyna
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Durska, Marta
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Dziekcierów, Agata
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Janiszewska, Zuzanna
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Korzeniowska, Roksana
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Kraujutowicz, Karolina
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Kulesza, Karolina
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Marciniak, Patrycja
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Pacyna, Zofia
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Przeborowska, Julia
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Siwek, Zuzanna
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.
Leonard, Mark
  • Leonard Data Lab, 10-719 Olsztyn, Poland.
Rapacz-Leonard, Anna
  • Students' Scientific Club 'Equine Reproduction', Department of Animal Reproduction with Clinic, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 14, 10-719 Olsztyn, Poland.

Conflict of Interest Statement

Author Mark Leonard is the owner of Leonard Data Lab. All authors declare that the research was conducted in the absence of any other commercial or financial relationships that could be construed as a potential conflict of interest.

References

This article includes 70 references
  1. Drewnowska O, Stefanik E, Samsel A, Turek B. Skale oceny bólu u koni. Mag. Weter. 2021;30:2.
  2. Dobrogowski J, Zajączkowska R, Dutka J, Wordliczek J. Patofizjologia i klasyfikacja bólu. Pol. Przegląd Neurol. 2011;7:20–30.
  3. Rapacz A, Raś A, Raś-Noryńska M. Wybrane schorzenia okresu okołoporodowego u klaczy. Med. Wet. 2010;66:93–96.
  4. Prunier A, Mounier L, Le Neindre P, Leterrier C, Mormède P, Paulmier V, Prunet P, Terlouw C, Guatteo R. Identifying and monitoring pain in farm animals: A review. Animal 2013;7:998–1010.
    doi: 10.1017/S1751731112002406pubmed: 23254122google scholar: lookup
  5. Menéndez S, Cabezas M.A, Gómez de Segura I.A. Attitudes to acute pain and the use of pain assessment scales among Spanish small animal veterinarians. Front. Vet. Sci. 2024;10:10.
    doi: 10.3389/fvets.2023.1302528pmc: PMC10758136pubmed: 38164392google scholar: lookup
  6. Gleerup K.B. Assessing pain in horses. Vet. Rec. 2019;184:124.
    doi: 10.1136/vr.l385pubmed: 30683786google scholar: lookup
  7. Sikorska U, Maśko M, Ciesielska A, Zdrojkowski Ł, Domino M. Role of cortisol in horse’s welfare and health. Agriculture 2023;13:2219.
  8. Herman J.P, McKlveen J.M, Ghosal S, Kopp B, Wulsin A, Makinson R, Scheimann J, Myers B. Regulation of the hypothalamic-pituitary-adrenocortical stress response. Compreh. Physiol. 2016;6:603–621.
  9. Choi M.H. Clinical and technical aspects in free cortisol measurement. Endocrinol. Metab. 2022;37:599–607.
    doi: 10.3803/EnM.2022.1549pmc: PMC9449105pubmed: 35982612google scholar: lookup
  10. Pritchett L.C, Ulibarri C, Roberts M.C, Schneider R.K, Sellon D.C. Identification of potential physiological and behavioral indicators of postoperative pain in horses after exploratory celiotomy for colic. Appl. Anim. Behav. Sci. 2003;80:31–43.
  11. Bussières G, Jacques C, Lainay O, Beauchamp G, Leblond A, Cadoré J.L, Desmazières L.M, Cuvelliez S.G, Troncy E. Development of a composite orthopaedic pain scale in horses. Res. Vet. Sci. 2008;85:294–301.
    doi: 10.1016/j.rvsc.2007.10.011pubmed: 18061637google scholar: lookup
  12. Menzies-Gow N.J, Stevens K.B, Sepulveda M.F, Jarvis N, Marr C.M. Repeatability and reproducibility of the Obel grading system for equine laminitis. Vet. Rec. 2010;167:52–55.
    doi: 10.1136/vr.c3668pubmed: 20622203google scholar: lookup
  13. van Loon J.P.A.M, van Dierendonck M.C. Monitoring acute equine visceral pain with the Equine Utrecht University Scale for Composite Pain Assessment (EQUUS-COMPASS) and the Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP): A scale-construction study. Vet. J. 2015;206:356–364.
    doi: 10.1016/j.tvjl.2015.08.023pubmed: 26526526google scholar: lookup
  14. van Loon J.P.A.M, Macri L. Objective assessment of chronic pain in horses using the Horse Chronic Pain Scale (HCPS): A scale-construction study. Animals 2021;11:1826.
    doi: 10.3390/ani11061826pmc: PMC8234780pubmed: 34207290google scholar: lookup
  15. Meier A, de Laat M, Pollitt C, Walsh D, McGree J, Reiche D.B, von Salis-Soglio M, Wells-Smith L, Mengeler U, Mesa Salas D. A “modified Obel” method for the severity scoring of (endocrinopathic) equine laminitis. PeerJ 2019;7:e7084.
    doi: 10.7717/peerj.7084pmc: PMC6557244pubmed: 31211020google scholar: lookup
  16. Maskato Y., Dugdale A.H.A., Singer E.R., Kelmer G., Sutton G.A. Prospective feasibility and revalidation of the Equine Acute Abdominal Pain Scale (EAAPS) in clinical cases of colic in horses. Animals. 2020;10:2242. doi: 10.3390/ani10122242.
    doi: 10.3390/ani10122242pmc: PMC7760242pubmed: 33260428google scholar: lookup
  17. van Loon J.P.A.M., de Grauw J.C., Burden F., Vos J.W., Bardelmeijer L.H., Rickards K. Objective assessment of chronic pain in donkeys using the Donkey Chronic Pain Scale (DCPS): A scale-construction study. Vet. J. 2021;267:105565. doi: 10.1016/j.tvjl.2020.105580.
    doi: 10.1016/j.tvjl.2020.105580pubmed: 33375958google scholar: lookup
  18. van Dierendonck M.C., Burden F.A., Rickards K., van Loon J.P.A.M. Monitoring acute pain in donkeys with the Equine Utrecht University Scale for Donkeys Composite Pain Assessment (EQUUS-DONKEY-COMPASS) and the Equine Utrecht University Scale for Donkey Facial Assessment of Pain (EQUUS-DONKEY-FAP) Animals. 2020;10:354. doi: 10.3390/ani10020354.
    doi: 10.3390/ani10020354pmc: PMC7070438pubmed: 32098391google scholar: lookup
  19. de Oliveira M.G.C., de Paula V.V., Mouta A.N., Lima I.O., de Macêdo L.B., Nunes T.L., Trindade P.H.E., Luna S.P.L. Validation of the Donkey Pain Scale (DOPS) for assessing postoperative pain in donkeys. Front. Vet. Sci. 2021;8:671330. doi: 10.3389/fvets.2021.671330.
    doi: 10.3389/fvets.2021.671330pmc: PMC8225999pubmed: 34179164google scholar: lookup
  20. Costa E.D., Minero M., Lebelt D., Stucke D., Canali E., Leach M.C. Development of the Horse Grimace Scale (HGS) as a pain assessment tool in horses undergoing routine castration. PLoS ONE. 2014;9:e92281.
    pmc: PMC3960217pubmed: 24647606
  21. Gleerup K.B., Forkman B., Lindegaard C., Andersen P.H. An equine pain face. Vet. Anaesth. Analg. 2015;42:103–115. doi: 10.1111/vaa.12212.
    doi: 10.1111/vaa.12212pmc: PMC4312484pubmed: 25082060google scholar: lookup
  22. Costa E.D., Stucke D., Dai F., Minero M., Leach M.C., Lebelt D. Using the horse grimace scale (HGS) to assess pain associated with acute laminitis in horses (Equus caballus) Animals. 2016;6:47. doi: 10.3390/ani6080047.
    doi: 10.3390/ani6080047pmc: PMC4997272pubmed: 27527224google scholar: lookup
  23. van Loon J.P.A.M., Trindade P.H.E., da Silva G.V., Keus J., Huberts C., de Grauw J.C., Lanci A. Objective assessment of acute pain in foals using a facial expression-based pain scale. Equine Vet. J. 2025;57:1520–1530. doi: 10.1111/evj.14481.
    doi: 10.1111/evj.14481pmc: PMC12508273pubmed: 39888021google scholar: lookup
  24. van Loon J.P.A.M., Verhaar N., van den Berg E., Ross S., de Grauw J. Objective assessment of acute pain in foals using a facial expression-based pain scale. Animals. 2020;10:1610. doi: 10.3390/ani10091610.
    doi: 10.3390/ani10091610pmc: PMC7552134pubmed: 32927590google scholar: lookup
  25. Lanci A., Benedetti B., Freccero F., Castagnetti C., Mariella J., van Loon J.P.A.M., Padalino B. Development of a composite pain scale in foals: A pilot study. Animals. 2022;12:439. doi: 10.3390/ani12040439.
    doi: 10.3390/ani12040439pmc: PMC8868425pubmed: 35203146google scholar: lookup
  26. Wong D.L., Baker C.M. Pain in children: Comparison of assessment scales. Pediatr. Nurs. 1988;14:9–17.
    pubmed: 3344163
  27. Ambuel B., Hamlett K.W., Marx C.M., Blumer J.L. Assessing distress in pediatric intensive care environments: The COMFORT scale. J. Pediatr. Psychol. 1992;17:95–109. doi: 10.1093/jpepsy/17.1.95.
    doi: 10.1093/jpepsy/17.1.95pubmed: 1545324google scholar: lookup
  28. Hodgkinson K., Bear M., Thorn J., Van Blaricum S. Measuring pain in neonates: Evaluating an instrument and developing a common language. Aust. J. Adv. Nurs. 1994;12:17–22.
    pubmed: 7786451
  29. Merkel S.I., Voepel-Lewis T., Shayevitz J.R., Malviya S. The FLACC: A behavioral scale for scoring postoperative pain in young children. Pediatr. Nurs. 1997;23:293–297.
    pubmed: 9220806
  30. Firth A.M., Haldane S.L. Development of a scale to evaluate postoperative pain in dogs. J. Am. Vet. Med. Assoc. 1999;214:651–659. doi: 10.2460/javma.1999.214.05.651.
    doi: 10.2460/javma.1999.214.05.651pubmed: 10088012google scholar: lookup
  31. Warden V., Hurley A.C., Volicer L. Development and psychometric evaluation of the Pain Assessment in Advanced Dementia (PAINAD) scale. J. Am. Med. Dir. Assoc. 2003;4:9–15. doi: 10.1097/01.JAM.0000043422.31640.F7.
  32. Haefeli M., Elfering A. Pain assessment. Eur. Spine J. 2006;15((Suppl. 1)):S17–S24. doi: 10.1007/s00586-005-1044-x.
    doi: 10.1007/s00586-005-1044-xpmc: PMC3454549pubmed: 16320034google scholar: lookup
  33. Brown D.C., Boston R.C., Coyne J.C., Farrar J.T. Development and psychometric testing of an instrument designed to measure chronic pain in dogs with osteoarthritis. Am. J. Vet. Res. 2007;68:631–637. doi: 10.2460/ajvr.68.6.631.
    doi: 10.2460/ajvr.68.6.631pmc: PMC2907349pubmed: 17542696google scholar: lookup
  34. Reid J., Nolan A., Hughes J., Lascelles D., Pawson P., Scott E. Development of the short-form Glasgow Composite Measure Pain Scale (CMPS-SF) and derivation of an analgesic intervention score. Anim. Welf. 2007;16:97–104. doi: 10.1017/S096272860003178X.
    doi: 10.1017/S096272860003178Xgoogle scholar: lookup
  35. Brown D.C., Boston R.C., Coyne J.C., Farrar J.T. Ability of the Canine Brief Pain Inventory to detect response to treatment in dogs with osteoarthritis. J. Am. Vet. Med. Assoc. 2008;233:1278–1283. doi: 10.2460/javma.233.8.1278.
    doi: 10.2460/javma.233.8.1278pmc: PMC2896492pubmed: 19180716google scholar: lookup
  36. Hudson C., Whay H., Huxley J. Recognition and management of pain in cattle. Practice. 2008;30:126–134. doi: 10.1136/inpract.30.3.126.
    doi: 10.1136/inpract.30.3.126google scholar: lookup
  37. Hielm-Björkman A.K., Rita H., Tulamo R.M. Psychometric testing of the Helsinki Chronic Pain Index by completion of a questionnaire in Finnish by owners of dogs with chronic signs of pain caused by osteoarthritis. Am. J. Vet. Res. 2009;70:727–734. doi: 10.2460/ajvr.70.6.727.
    doi: 10.2460/ajvr.70.6.727pubmed: 19496661google scholar: lookup
  38. Brondani J.T., Mama K.R., Luna S.P., Wright B.D., Niyom S., Ambrosio J., Vogel P.R., Padovani C.R. Validation of the English version of the UNESP-Botucatu multidimensional composite pain scale for assessing postoperative pain in cats. BMC Vet. Res. 2013;9:143. doi: 10.1186/1746-6148-9-143.
    doi: 10.1186/1746-6148-9-143pmc: PMC3722032pubmed: 23867090google scholar: lookup
  39. de Oliveira F.A., Luna S.P., do Amaral J.B., Rodrigues K.A., Sant’Anna A.C., Daolio M., Brondani J.T. Validation of the UNESP-Botucatu unidimensional composite pain scale for assessing postoperative pain in cattle. BMC Vet. Res. 2014;10:200. doi: 10.1186/s12917-014-0200-0.
    doi: 10.1186/s12917-014-0200-0pmc: PMC4172785pubmed: 25192598google scholar: lookup
  40. Gleerup K.B., Andersen P.H., Munksgaard L., Forkman B. Pain evaluation in dairy cattle. Appl. Anim. Behav. Sci. 2015;171:25–32. doi: 10.1016/j.applanim.2015.08.023.
  41. Reid J., Nolan A., Scott E.M. Measuring pain in dogs and cats using structured behavioural observation. Vet. J. 2018;236:72–79. doi: 10.1016/j.tvjl.2018.04.013.
    doi: 10.1016/j.tvjl.2018.04.013pubmed: 29871754google scholar: lookup
  42. Evangelista M.C., Watanabe R., Leung V.S., Monteiro B.P., O’Toole E., Pang D.S., Steagall P.V. Facial expressions of pain in cats: The development and validation of a Feline Grimace Scale. Sci. Rep. 2019;9:19128. doi: 10.1038/s41598-019-55693-8.
    doi: 10.1038/s41598-019-55693-8pmc: PMC6911058pubmed: 31836868google scholar: lookup
  43. Hernández-Avalos I., Mota-Rojas D., Mora-Medina P., Martínez-Burnes J., Casas Alvarado A., Verduzco-Mendoza A., Lezama-García K., Olmos-Hernández A. A review of different methods used for clinical recognition and assessment of pain in dogs and cats. Int. J. Vet. Sci. Med. 2019;7:43–54. doi: 10.1080/23144599.2019.1680044.
  44. Belli M., de Oliveira A.R., de Lima M.T., Trindade P.H.E., Steagall P.V., Luna S.P.L. Clinical validation of the short and long UNESP-Botucatu scales for feline pain assessment. PeerJ. 2021;9:e11225. doi: 10.7717/peerj.11225.
    doi: 10.7717/peerj.11225pmc: PMC8048399pubmed: 33954046google scholar: lookup
  45. Tschoner T. Methods for pain assessment in calves and their use for the evaluation of pain during different procedures—A review. Animals. 2021;11:1235. doi: 10.3390/ani11051235.
    doi: 10.3390/ani11051235pmc: PMC8146443pubmed: 33922942google scholar: lookup
  46. Wilcox R.R. A Guide to Robust Statistical Methods. Springer; New York, NY, USA: 2023.
  47. R Core Team . R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing; Vienna, Austria: 2024. [(accessed on 20 November 2025)]. Available online: https://www.R-project.org/
  48. Barr D.J., Levy R., Scheepers C., Tily H.J. Random effects structure for confirmatory hypothesis testing: Keep it maximal. J. Mem. Lang. 2013;68:255–278. doi: 10.1016/j.jml.2012.11.001.
    doi: 10.1016/j.jml.2012.11.001pmc: PMC3881361pubmed: 24403724google scholar: lookup
  49. Lemoine N.P. Moving beyond noninformative priors: Why and how to choose weakly informative priors in Bayesian analyses. Oikos. 2019;128:912–928. doi: 10.1111/oik.05985.
    doi: 10.1111/oik.05985google scholar: lookup
  50. Gelman A., Hill J., Vehtari A. Regression and Other Stories. Cambridge University Press; Cambridge, UK: 2021.
  51. Cavallone E., Di Giancamillo M., Secchiero B., Belloli A., Pravettoni D., Rimoldi E.M. Variations of serum cortisol in Argentine horses subjected to ship transport and adaptation stress. J. Equine Vet. Sci. 2002;22:541–545. doi: 10.1016/S0737-0806(02)70195-0.
  52. Cayado P., Muñoz-Escassi B., Dominguez C., Manley W., Olabarri B., De La Muela M.S., Castejon F., Marañon G., Vara E. Hormone response to training and competition in athletic horses. Equine Vet. J. 2006;38:274–278. doi: 10.1111/j.2042-3306.2006.tb05552.x.
  53. Irvine C.H., Alexander S.L. Factors affecting the circadian rhythm in plasma cortisol concentrations in the horse. Domest. Anim. Endocrinol. 1994;11:227–238. doi: 10.1016/0739-7240(94)90030-2.
    doi: 10.1016/0739-7240(94)90030-2pubmed: 8045104google scholar: lookup
  54. Schmidt A., Möstl E., Wehnert C., Aurich J., Müller J., Aurich C. Cortisol release and heart rate variability in horses during road transport. Horm. Behav. 2010;57:209–215. doi: 10.1016/j.yhbeh.2009.11.003.
    doi: 10.1016/j.yhbeh.2009.11.003pubmed: 19944105google scholar: lookup
  55. Bohák Z.S., Szabó F., Beckers J.F., de Sousa N.M., Kutasi O., Nagy K., Szenci O. Monitoring the circadian rhythm of serum and salivary cortisol concentrations in the horse. Domest. Anim. Endocrinol. 2013;45:38–42. doi: 10.1016/j.domaniend.2013.04.001.
  56. Goodrich B., Gabry J., Ali I., Brilleman S. rstanarm: Bayesian Applied Regression Modeling via Stan. R Foundation for Statistical Computing; Vienna, Austria: 2024. [(accessed on 20 November 2025)]. R package version 2.32.1. Available online: https://mc-stan.org/rstanarm.
  57. Vehtari A., Gelman A., Simpson D., Carpenter B., Bürkner P.C. Rank-normalization, folding, and localization: An improved ^R for assessing convergence of MCMC (with discussion) Bayesian Anal. 2021;16:667–718. doi: 10.1214/20-BA1221.
    doi: 10.1214/20-BA1221google scholar: lookup
  58. Bürkner P., Gabry J., Kay M., Vehtari A. posterior: Tools for Working with Posterior Distributions. R Foundation for Statistical Computing; Vienna, Austria: 2025. [(accessed on 20 November 2025)]. R package version 1.6.1. Available online: https://mc-stan.org/posterior.
  59. Gabry J., Mahr T. bayesplot: Plotting for Bayesian Models. R Foundation for Statistical Computing; Vienna, Austria: 2024. [(accessed on 20 November 2025)]. R package version 1.11.1. Available online: https://mc-stan.org/bayesplot.
  60. Limpert E., Stahel W.A. Problems with Using the Normal Distribution–and Ways to Improve Quality and Efficiency of Data Analysis. PLoS ONE. 2011;6:e21403. doi: 10.1371/journal.pone.0021403.
  61. LeBlanc M.M. Common peripartum problems in the mare. J. Equine Vet. Sci. 2008;28:709–715. doi: 10.1016/j.jevs.2008.10.007.
  62. Canisso I.F., Rodriguez J.S., Sanz M.G., da Silva M.A.C. A clinical approach to the diagnosis and treatment of retained fetal membranes with an emphasis on the critically ill mare. J. Equine Vet. Sci. 2013;33:570–579. doi: 10.1016/j.jevs.2012.08.006.
  63. Rapacz-Leonard A., Paździor K., Raś A., Rotkiewicz T., Janowski T.E. Retained fetal membranes in heavy draft mares associated with histological abnormalities. J. Equine Vet. Sci. 2012;32:38–44. doi: 10.1016/j.jevs.2011.06.015.
  64. Torcivia C., McDonnell S. In-Person Caretaker Visits Disrupt Ongoing Discomfort Behavior in Hospitalized Equine Orthopedic Surgical Patients. Animals. 2020;10:210. doi: 10.3390/ani10020210.
    doi: 10.3390/ani10020210pmc: PMC7070845pubmed: 32012670google scholar: lookup
  65. Hellhammer D.H., Wüst S., Kudielka B.M. Salivary cortisol as a biomarker in stress research. Psychoneuroendocrinology. 2009;34:163–171. doi: 10.1016/j.psyneuen.2008.10.026.
  66. Peeters M., Sulon J., Beckers J.F., Ledoux D., Vandenheede M. Comparison between blood serum and salivary cortisol concentrations in horses using an ACTH challenge. Equine Vet. J. 2011;43:487–493. doi: 10.1111/j.2042-3306.2010.00294.x.
  67. Schmidt A., Hödl S., Möstl E., Aurich J., Müller J., Aurich C. Cortisol release, heart rate, and HRV in transport-naïve horses during repeated road transport. Domest. Anim. Endocrinol. 2010;39:205–213. doi: 10.1016/j.domaniend.2010.06.002.
  68. Schmidt A., Möstl E., Wehnert C., Aurich J., Müller J., Aurich C. Changes in cortisol release and heart rate and HRV during initial training of 3-year-old sport horses. Horm. Behav. 2010;58:628–636. doi: 10.1016/j.yhbeh.2010.06.011.
    doi: 10.1016/j.yhbeh.2010.06.011pubmed: 20600048google scholar: lookup
  69. Kędzierski W., Strzelec K., Cywińska A., Kowalik S. Salivary cortisol concentration in exercised Thoroughbred horses. J. Equine Vet. Sci. 2013;33:1106–1109. doi: 10.1016/j.jevs.2013.04.011.
  70. Contreras-Aguilar M.D., Escribano D., Martín-Cuervo M., Tecles F., Cerón J.J. Salivary alpha-amylase activity and cortisol in horses with acute abdominal disease: A pilot study. BMC Vet. Res. 2018;14:156. doi: 10.1186/s12917-018-1482-4.
    doi: 10.1186/s12917-018-1482-4pmc: PMC5946548pubmed: 29747642google scholar: lookup

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