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Repeatability of the ACTH stimulation test as reflected by salivary cortisol response in healthy horses.
Abstract: The aim of this study was to further characterize the ACTH stimulation test as reflected by salivary cortisol response and to measure the short- and long-term repeatability of it in healthy horses as a tool to assess the capacity of the adrenal cortex to secrete cortisol. Nineteen healthy horses were subjected to 3 ACTH stimulation tests. Intervals were 2 wk and 5 mo between the first and second and the second and third tests, respectively. A dose of 1-μg/kg BW synthetic ACTH was injected intravenously. Saliva samples were collected at baseline and at 30, 60, 90, 120, 150, and 180 min after administration for cortisol measurements using a competitive enzyme immunoassay. A repeated measures ANOVA was used to compare values within and among horses. Mean ± SD total increase in cortisol concentrations integrated over the entire sampling period was 34.5 ± 11.0 ng/mL. The highest measured concentration at a single time point was 9.7 ± 2.7 ng/mL and was reached after 122 ± 22 min. For the short- and long-term repeatability, intraclass correlation coefficient was 0.90 and 0.33, respectively. The 3 ACTH stimulation tests results differed significantly among (P < 0.00001) but not within (P = 0.538) individual horses. The Freiberger stallions had a higher salivary cortisol baseline concentration and a lower response to ACTH stimulation as compared with Warmblood mares and geldings. The present study confirmed that the administration of ACTH in healthy horses reliably stimulates the salivary secretion of cortisol and shows that the test is repeatable in the short- and long-term.
Copyright © 2016 Elsevier Inc. All rights reserved.
Publication Date: 2016-05-12 PubMed ID: 27565229DOI: 10.1016/j.domaniend.2016.04.002Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Clinical Trial
- Journal Article
- Research Support
- Non-U.S. Gov't
- Adrenal
- Adrenocorticotropic Hormone (ACTH)
- Analysis of Variance (ANOVA)
- Animal Studies
- Biochemistry
- Clinical Pathology
- Comparative Study
- Correlation Analysis
- Cortisol
- Diagnostic Technique
- Endocrine System
- Enzyme-Linked Immunosorbent Assay (ELISA)
- Equine Health
- Hormones
- Horses
- Physiology
- Salivary Cortisol
- Stress
- Veterinary Medicine
- Warmblood Horses
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.
This research aimed to further understand the ACTH stimulation test, interpreted via salivary cortisol response, in healthy horses. The study also aimed to determine the short- and long-term repeatability of this test as a measure of the adrenal cortex’s ability to secrete cortisol.
Study Design and Methods
- The study involved 19 healthy horses subjected to the ACTH stimulation test three times.
- The intervals between the first and second tests were two weeks, and the gap between the second and third tests was 5 months.
- A dose of 1-μg/kg bodyweight of synthetic ACTH was injected into the horses.
- Saliva samples were collected at different times (baseline and at 30, 60, 90, 120, 150, and 180 minutes post-injection) for cortisol measurement. The samples were tested using a competitive enzyme immunoassay.
Results
- The mean increase in cortisol concentrations throughout the entire sampling period was 34.5 ± 11.0 ng/mL.
- The peak cortisol concentration at a single time point was 9.7 ± 2.7 ng/mL, typically reached about 122 ± 22 minutes after injection.
- The intraclass correlation coefficient reflecting the short-term repeatability of the test was high (0.90), but it was lower in the long-term repeatability (0.33).
- There were significant differences in the results of the 3 ACTH stimulation tests among different horses but not within the same horse.
- Freiberger stallions showed higher salivary cortisol baseline concentration and a slower response to ACTH stimulation compared with Warmblood mares and geldings.
Conclusions
- The study confirmed that administering ACTH to healthy horses reliably stimulates the salivary secretion of cortisol.
- The ACTH stimulation test is repeatable in both the short-term and long-term, although repeatability is higher in the short term.
- The significant differences in ACTH test results among different horses suggest potential individual or breed-related variations in cortisol response.
Cite This Article
APA
Scheidegger MD, Gerber V, Ramseyer A, Schüpbach-Regula G, Bruckmaier RM, van der Kolk JH.
(2016).
Repeatability of the ACTH stimulation test as reflected by salivary cortisol response in healthy horses.
Domest Anim Endocrinol, 57, 43-47.
https://doi.org/10.1016/j.domaniend.2016.04.002 Publication
Researcher Affiliations
- Swiss Institute of Equine Medicine ISME, Agroscope and University of Berne, Switzerland. Electronic address: milena.scheidegger@vetsuisse.unibe.ch.
- Swiss Institute of Equine Medicine ISME, Agroscope and University of Berne, Switzerland.
- Swiss Institute of Equine Medicine ISME, Agroscope and University of Berne, Switzerland.
- Veterinary Public Health Institute, Vetsuisse Faculty, University of Berne, Switzerland.
- Veterinary Physiology, Vetsuisse Faculty, University of Berne, Switzerland.
- Swiss Institute of Equine Medicine ISME, Agroscope and University of Berne, Switzerland.
MeSH Terms
- Adrenocorticotropic Hormone / pharmacology
- Animals
- Female
- Horses / metabolism
- Hydrocortisone / chemistry
- Hydrocortisone / metabolism
- Male
- Saliva / chemistry
- Saliva / metabolism
Citations
This article has been cited 9 times.- Holtby AR, McGivney BA, Browne JA, Katz LM, Murphy KJ, Hill EW. Variation in salivary cortisol responses in yearling Thoroughbred racehorses during their first year of training. PLoS One 2023;18(4):e0284102.
- de Souza Farias S, Montechese ACD, Bernardino T, Rodrigues PHM, de Araujo Oliveira CA, Zanella AJ. Two Hours of Separation Prior to Milking: Is This Strategy Stressful for Jennies and Their Foals?. Animals (Basel) 2021 Jan 14;11(1).
- Mott RO, Hawthorne SJ, McBride SD. Blink rate as a measure of stress and attention in the domestic horse (Equus caballus). Sci Rep 2020 Dec 8;10(1):21409.
- Schoster A, Weese JS, Gerber V, Nicole Graubner C. Dysbiosis is not present in horses with fecal water syndrome when compared to controls in spring and autumn. J Vet Intern Med 2020 Jul;34(4):1614-1621.
- Sauer FJ, Hermann M, Ramseyer A, Burger D, Riemer S, Gerber V. Effects of breed, management and personality on cortisol reactivity in sport horses. PLoS One 2019;14(12):e0221794.
- Contreras-Aguilar MD, Henry S, Coste C, Tecles F, Escribano D, Cerón JJ, Hausberger M. Changes in Saliva Analytes Correlate with Horses' Behavioural Reactions to An Acute Stressor: A Pilot Study. Animals (Basel) 2019 Nov 18;9(11).
- Sauer FJ, Bruckmaier RM, Ramseyer A, Vidondo B, Scheidegger MD, Gerber V. Diagnostic accuracy of post-ACTH challenge salivary cortisol concentrations for identifying horses with equine glandular gastric disease. J Anim Sci 2018 Jun 4;96(6):2154-2161.
- Schwinn AC, Sauer FJ, Gerber V, Bruckmaier RM, Gross JJ. Free and bound cortisol in plasma and saliva during ACTH challenge in dairy cows and horses. J Anim Sci 2018 Feb 15;96(1):76-84.
- Boger B, Naraian M, Hernandez E, Eaton A, Rockburn R, Tillman I, Payne S, Yob C, Panek C, Manfredi JM. Effects of a rehabilitative whole-body resistance band wrap on equine gait, posture, cortisol, and muscular function. Front Vet Sci 2025;12:1738766.
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