FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Equine veterinary journal2023; 56(2); 220-242; doi: 10.1111/evj.14009

BEVA primary care clinical guidelines: Diagnosis and management of equine pituitary pars intermedia dysfunction.

Abstract: Pituitary pars intermedia dysfunction (PPID) is a prevalent, age-related chronic disorder in equids. Diagnosis of PPID can be challenging because of its broad spectrum of clinical presentations and disparate published diagnostic criteria, and there are limited available treatment options. Objective: To develop evidence-based primary care guidelines for the diagnosis and treatment of equine PPID based on the available literature. Methods: Evidence-based clinical guideline using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. Methods: Research questions were proposed by a panel of veterinarians and developed into PICO or another structured format. VetSRev and Veterinary Evidence were searched for evidence summaries, and systematic searches of the NCBI PubMed and CAB Direct databases were conducted using keyword searches in July 2022 and updated in January 2023. The evidence was evaluated using the GRADE framework. Conclusions: The research questions were categorised into four areas: (A) Case selection for diagnostic testing, pre-test probability and diagnostic test accuracy, (B) interpretation of test results, (C) pharmacological treatments and other treatment/management options and (D) monitoring treated cases. Relevant veterinary publications were identified and assessed using the GRADE criteria. The results were developed into recommendations: (A) Case selection for diagnostic testing and diagnostic test accuracy: (i) The prevalence of PPID in equids aged ≥15 years is between 21% and 27%; (ii) hypertrichosis or delayed/incomplete hair coat shedding provides a high index of clinical suspicion for PPID; (iii) the combination of clinical signs and age informs the index of clinical suspicion prior to diagnostic testing; (iv) estimated pre-test probability of PPID should be considered in interpretation of diagnostic test results; (v) pre-test probability of PPID is low in equids aged <10 years; (vi) both pre-test probability of disease and season of testing have strong influence on the ability to diagnose PPID using basal adrenocorticotropic hormone (ACTH) or ACTH after thyrotropin-releasing hormone (TRH) stimulation. The overall diagnostic accuracy of basal ACTH concentrations for diagnosing PPID ranged between 88% and 92% in the autumn and 70% and 86% in the non-autumn, depending on the pre-test probability. Based on a single study, the overall diagnostic accuracy of ACTH concentrations in response to TRH after 30 minutes for diagnosing PPID ranged between 92% and 98% in the autumn and 90% and 94% in the non-autumn, depending on the pre-test probability. Thus, it should be remembered that the risk of a false positive result increases in situations where there is a low pre-test probability, which could mean that treatment is initiated for PPID without checking for a more likely alternative diagnosis. This could compromise horse welfare due to the commencement of lifelong therapy and/or failing to identify and treat an alternative potentially life-threatening condition. (B) Interpretation of diagnostic tests: (i) There is a significant effect of breed on plasma ACTH concentration, particularly in the autumn with markedly higher ACTH concentrations in some but not all 'thrifty' breeds; (ii) basal and/or post-TRH ACTH concentrations may also be affected by latitude/location, diet/feeding, coat colour, critical illness and trailer transport; (iii) mild pain is unlikely to have a large effect on basal ACTH, but caution may be required for more severe pain; (iv) determining diagnostic thresholds that allow for all possible contributory factors is not practical; therefore, the use of equivocal ranges is supported; (v) dynamic insulin testing and TRH stimulation testing may be combined, but TRH stimulation testing should not immediately follow an oral sugar test; (vi) equids with PPID and hyperinsulinaemia appear to be at higher risk of laminitis, but ACTH is not an independent predictor of laminitis risk. (C) Pharmacologic treatments and other treatment/management options: (i) Pergolide improves most clinical signs associated with PPID in the majority of affected animals; (ii) Pergolide treatment lowers basal ACTH concentrations and improves the ACTH response to TRH in many animals, but measures of insulin dysregulation (ID) are not altered in most cases; (iii) chasteberry has no effect on ACTH concentrations and there is no benefit to adding chasteberry to pergolide therapy; (iv) combination of cyproheptadine with pergolide is not superior to pergolide alone; (v) there is no evidence that pergolide has adverse cardiac effects in horses; (vi) Pergolide does not affect insulin sensitivity. (D) Monitoring pergolide-treated cases: (i) Hormone assays provide a crude indication of pituitary control in response to pergolide therapy, however it is unknown whether monitoring of ACTH concentrations and titrating of pergolide doses accordingly is associated with improved endocrinological or clinical outcome; (ii) it is unknown whether monitoring the ACTH response to TRH or clinical signs is associated with an improved outcome; (iii) there is very weak evidence to suggest that increasing pergolide dose in autumn months may be beneficial; (iv) there is little advantage in waiting for more than a month to perform follow-up endocrine testing following initiation of pergolide therapy; there may be merit in performing repeat tests sooner; (v) timing of sampling in relation to pergolide dosing does not confound measurement of ACTH concentration; (vi) there is no evidence that making changes after interpretation of ACTH concentrations measured at certain times of the year is associated with improved outcomes; (vii) evidence is very limited, however, compliance with PPID treatment appears to be poor and it is unclear whether this influences clinical outcome; (viii) evidence is very limited, but horses with clinical signs of PPID are likely to shed more nematode eggs than horses without clinical signs of PPID; it is unclear whether this results in an increased risk of parasitic disease or whether there is a need for more frequent assessment of faecal worm egg counts. Conclusions: Limited relevant publications in the veterinary scientific literature. Conclusions: These findings should be used to inform decision-making in equine primary care practice.
© 2023 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Get Full Text
Publication Date: 2023-10-05 PubMed ID: 37795557DOI: 10.1111/evj.14009Google 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.
LinkedInCopy
  • Journal Article
  • Review

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 study provides a detailed guide for diagnosing and managing Pituitary Pars Intermedia Dysfunction (PPID), a common age-related equine disease. Applying the GRADE framework, the researchers systematically reviewed available literature, categorized their results into areas like case selection, diagnostic testing, interpretation of test results, treatment options, and monitoring. This comprehensive approach is expected to help inform decision-making in equine primary care.

Research Parameters and Methods

  • The researchers employed an evidence-based clinical guideline using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology.
  • A panel of veterinarians posed research questions, which were later turned into a structured format such as PICO (problem, intervention, comparison, outcome).
  • Databases like VetSRev, Veterinary Evidence, NCBI PubMed, and CAB Direct were searched for relevant literature using targeted keywords. The literature search was first conducted in July 2022 and later updated in January 2023.
  • The evidence collected was evaluated utilizing the GRADE framework.

Evidence Evaluation and Recommendations

  • Using the collected literature, the research questions were grouped into four areas: case selection for diagnostic testing, interpretation of test results, pharmacological treatments, and monitoring treated cases. The findings were developed into recommendations under each area.
  • The prevalence of PPID in equids aged over 15 was found to be between 21% and 27%. Particular clinical signs and age combined increased the suspicion of PPID.
  • The researchers advised that the pre-test probability of PPID should be considered in interpreting diagnostic test results, noting that the pre-test probability is low in equids under 10 years.
  • The study recommended monitoring of ACTH concentrations and adjusting pergolide doses accordingly, though it’s unclear if this is associated with improved outcomes.

Interpretation of Diagnostic Tests

  • Factors such as breed, latitude/location, diet/feeding, coat color, illness severity, and trailer transport significantly affect plasma ACTH concentration.
  • The study reported that mild pain is unlikely to have a substantial impact on basal ACTH, but greater caution may be required for more severe pain.
  • Researchers found equids with PPID and hyperinsulinaemia to be at a higher risk of laminitis, although ACTH is not an independent predictor of laminitis risk.

Pharmacological Treatments and Management Options

  • Pergolide was found to improve most clinical signs associated with PPID in the majority of affected animals.
  • Researchers reported that chasteberry has no effect on ACTH concentrations, and adding it to pergolide therapy does not provide any benefits.
  • The study also found no evidence that pergolide has adverse cardiac effects or affects insulin sensitivity in horses.

Monitoring Treated Cases

  • The researchers gave weak evidence to suggest that increasing pergolide dose in autumn months was beneficial.
  • They also found no evidence suggesting that changes in ACTH concentrations measured at specific times of the year led to improved outcomes.
  • The study identified poor compliance with PPID treatment, but the impact on clinical outcomes is unclear.
  • Lastly, the research found that horses with clinical signs of PPID are likely to shed more nematode eggs than horses without clinical signs of PPID.

Conclusions

  • The research concluded upon the need for more relevant scientific literature in veterinary science for better understanding and management of PPID.
  • The findings of this study can serve as a valuable resource to inform decision-making in equine primary care practices.

Cite This Article

APA
Menzies-Gow NJ, Banse HE, Duff A, Hart N, Ireland JL, Knowles EJ, McFarlane D, Rendle D. (2023). BEVA primary care clinical guidelines: Diagnosis and management of equine pituitary pars intermedia dysfunction. Equine Vet J, 56(2), 220-242. https://doi.org/10.1111/evj.14009

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 56
Issue: 2
Pages: 220-242

Researcher Affiliations

Menzies-Gow, Nicola J
  • Royal Veterinary College, Hertfordshire, UK.
Banse, Heidi E
  • School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
Duff, Aimi
  • Rainbow Equine Hospital, North Yorkshire, UK.
Hart, Nicholas
  • Royal Veterinary College, Hertfordshire, UK.
Ireland, Joanne L
  • Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Wirral, UK.
Knowles, Edward J
  • Bell Equine Veterinary Clinic, Kent, UK.
McFarlane, Dianne
  • College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA.
Rendle, David
  • EMT Consulting, Devon, UK.

MeSH Terms

  • Horses
  • Animals
  • Pergolide / therapeutic use
  • Horse Diseases / diagnosis
  • Horse Diseases / therapy
  • Pituitary Gland, Intermediate
  • Pituitary Diseases / diagnosis
  • Pituitary Diseases / therapy
  • Pituitary Diseases / veterinary
  • Adrenocorticotropic Hormone
  • Insulin
  • Pain / drug therapy
  • Pain / veterinary
  • Primary Health Care

References

This article includes 113 references
  1. McGowan TW, Pinchbeck GP, McGowan CM. Prevalence, risk factors and clinical signs predictive for equine pituitary pars intermedia dysfunction in aged horses.. Equine Vet J 2013;45:74-79.
  2. Tatum RC, McGowan CM, Ireland JL. Evaluation of the sensitivity and specificity of basal plasma adrenocorticotrophic hormone concentration for diagnosing pituitary pars intermedia dysfunction in horses: a systematic review.. Vet J 2021;275:105695.
  3. Meyer JC, Hunyadi LM, Ordonez-Mena JM. The accuracy of ACTH as a biomarker for pituitary pars intermedia dysfunction in horses: a systematic review and meta-analysis.. Equine Vet J 2022;54:457-466.
  4. Tatum RC, McGowan CM, Ireland JL. Efficacy of pergolide for the management of equine pituitary pars intermedia dysfunction: a systematic review.. Vet J 2020;266:105562.
  5. Patel GW, Roderman N, Gehring H, Saad J, Bartek W. Assessing the effect of the surviving sepsis campaign treatment guidelines on clinical outcomes in a community hospital.. Ann Pharmacother 2010;44:1733-1738.
  6. Woolf S, Schunemann HJ, Eccles MP, Grimshaw JM, Shekelle P. Developing clinical practice guidelines: types of evidence and outcomes; values and economics, synthesis, grading, and presentation and deriving recommendations.. Implement Sci 2012;7:61.
  7. Bowen IM, Redpath A, Dugdale A, Burford JH, Lloyd D, Watson T. BEVA primary care clinical guidelines: analgesia.. Equine Vet J 2020;52:13-27.
  8. Freeman SL, Ashton NM, Elce YA, Hammond A, Hollis AR, Quinn G. BEVA primary care clinical guidelines: wound management in the horse.. Equine Vet J 2021;53:18-29.
  9. Guyatt GH, Oxman AD, Kunz R, Atkins D, Brozek J, Vist G. GRADE guidelines: 2. Framing the question and deciding on important outcomes.. J Clin Epidemiol 2011;64:395-400.
  10. Schunemann H, Brozek J, Guyatt G, Oxman A. Handbook for grading the quality of evidence and strength of recommendations using the GRADE approach (updated October 2013).. 2013.
  11. Grindlay DJ, Brennan ML, Dean RS. Searching the veterinary literature: a comparison of the coverage of veterinary journals by nine bibliographic databases.. J Vet Med Educ 2012;39:404-412.
  12. Guyatt G, Oxman AD, Akl EA, Kunz R, Vist G, Brozek J. GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables.. J Clin Epidemiol 2011;64:383-394.
  13. What is GRADE. BMJ best practice. BMJ; 2023. www.bestpractice.bmj.com/toolkit/learn-ebm/what-is-grade/
  14. Erdody M, Galinelli N, Bamford NJ, Mackensie S, Warnken T, Harris PA. Plasma immunoreactive β-endorphin concentrations and spontaneous blink rate as an index of stresss, measured in a population of aged horses and ponies with and without PPID.. 5th Global Equine Endocrine Symposium Bern, Switzerland: National Horse Center; 2023.
  15. Hsu J, Brozek JL, Terracciano L, Kreis J, Compalati E, Stein AT. Application of GRADE: making evidence-based recommendations about diagnostic tests in clinical practice guidelines.. Implement Sci 2011;6:62.
  16. Hotchkiss JW, Reid SW, Christley R. Construction and validation of a risk-screening questionnaire for the investigation of recurrent airway obstruction in epidemiological studies of horse populations in Great Britain.. Prev Vet Med 2006;75:8-21.
  17. Ireland JL, McGowan CM. Epidemiology of pituitary pars intermedia dysfunction: a systematic literature review of clinical presentation, disease prevalence and risk factors.. Vet J 2018;235:22-33.
  18. Love S. Equine Cushing's disease.. Br Vet J 1993;149:139-153.
  19. Rohrbach BW, Stafford JR, Clermont RS, Reed SM, Schott HC 2nd, Andrews FM. Diagnostic frequency, response to therapy, and long-term prognosis among horses and ponies with pituitary par intermedia dysfunction, 1993-2004.. J Vet Intern Med 2012;26:1027-1034.
  20. Bradaric Z, May A, Gehlen H. Use of the chasteberry preparation Corticosal® for the treatment of pituitary pars intermedia dysfunction in horses.. Pferdeheilkunde 2013;29:721-728.
  21. Dunkel B, Wilford SA, Parkinson NJ, Ward C, Smith P, Grahame L. Severe hypertriglyceridaemia in horses and ponies with endocrine disorders.. Equine Vet J 2014;46:118-122.
  22. Schramm E, Schwarz A, Alber H, Alber G. Effects of the multi-compound complex in Corticosal® in 177 horses with PPID in a retrospective veterinary questionnaire analysis in Germany.. Pferdeheilkunde 2018;34:538-549.
  23. Horn R, Bamford NJ, Afonso T, Sutherland M, Buckerfield J, Tan RHH. Factors associated with survival, laminitis and insulin dysregulation in horses diagnosed with equine pituitary pars intermedia dysfunction.. Equine Vet J 2019;51:440-445.
  24. Christiansen A. Prevalence of equine Cushing's syndrome among older horses in southern Vestsjaelland. Denmark. Dansk Veterinaertidsskrift 2009;92:24-29.
  25. Nanao Y, Ueno T. Two cases of equine Cushing's disease in thoroughbred mares.. J Jpn Vet Med Assoc 2012;65:771-775.
  26. Tadros EM, Fowlie JG, Refsal KR, Marteniuk J, Schott HC 2nd. Association between hyperinsulinaemia and laminitis severity at the time of pituitary pars intermedia dysfunction diagnosis.. Equine Vet J 2019;51:52-56.
  27. Kirkwood NC, Hughes KJ, Stewart AJ. Prospective case series of clinical signs and adrenocorticotrophin (ACTH) concentrations in seven horses transitioning to pituitary pars intermedia dysfunction (PPID).. Vet Sci 2022;9(10):572.
  28. Tsuchiya T, Noda R, Ikeda H, Maeda M, Sato F. Relationship between endogenous plasma adrenocorticotropic hormone concentration and reproductive performance in thoroughbred broodmares.. J Vet Intern Med 2021;35:2002-2008.
  29. Nitzsche AM, Fey K, Buttner K, Grof M, Staszyk C. The gingiva of horses with pituitary pars intermedia dysfunction: a macroscopic anatomical evaluation.. Front Vet Sci 2021;8:786971.
  30. Grubbs ST, Neal DL, Keefe DJ. Development and evaluation of a clinical sign scoring system for pituitary pars intermedia dysfunction in horses.. 4th Global Equine Endocrine Symposium Gut Ising, Germany: Boehringer Ingelheim; 2020.
  31. Durham AE, Clarke BR, Potier JFN, Hammarstrand R, Malone GL. Clinically and temporally specific diagnostic thresholds for plasma ACTH in the horse.. Equine Vet J 2021;53:250-260.
  32. Erdody M, Mackenzie S, Galinelli N, Bamford NJ, Warnken T, Sillence MN. Muscle atrophy scores in a population of aged horses and ponies with and without PPID.. 5th Global Equine Endocrine Symposium Bern, Switzerland: National Horse Center; 2023. p. 27.
  33. Miller MA, Moore GE, Bertin FR, Kritchevsky JE. What's new in old horses? Postmortem diagnoses in mature and aged equids.. Vet Pathol 2016;53:390-398.
  34. Welsh CE, Duz M, Parkin TDH, Marshall JF. Prevalence, survival analysis and multimorbidity of chronic diseases in the general veterinarian-attended horse population of the UK.. Prev Vet Med 2016;131:137-145.
  35. Steel NL, Ireland JL, McGowan CM. Management of pituitary pars intermedia dysfunction in practice: A clinical audit.. Vet J 2022;289:105899.
  36. Donaldson MT, Jorgensen AJ, Beech J. Evaluation of suspected pituitary pars intermedia dysfunction in horses with laminitis.. J Am Vet Med Assoc 2004;224:1123-1127.
  37. Karikoski NP, Horn I, McGowan TW, McGowan CM. The prevalence of endocrinopathic laminitis among horses presented for laminitis at a first-opinion/referral equine hospital.. Domest Anim Endocrinol 2011;41:111-117.
  38. van Proosdij R, Frietman S. Retrospective analysis of cause-of-death at an equine retirement Center in The Netherlands over an eight-year period.. J Equine Vet 2022;110:103824.
  39. Christen G, Precht C, van der Kolk J, Fouche N, Gerber V. Age over 25 years, but not plasma adrenocorticotropic hormone concentration above the seasonally adjusted reference range is predictive for radio-graphically assessed changes of chronic laminitis in elderly horses.. Schweiz Arch Tierheilkd 2020;162:781-785.
  40. Miller MA, Pardo ID, Jackson LP, Moore GE, Sojka JE. Correlation of pituitary histomorphometry with adrenocorticotrophic hormone response to domperidone administration in the diagnosis of equine pituitary pars intermedia dysfunction.. Vet Pathol 2008;45:26-38.
  41. Horn R, Stewart AJ, Jackson KV, Dryburgh EL, Medina-Torres CE, Bertin FR. Clinical implications of using adrenocorticotropic hormone diagnostic cutoffs or reference intervals to diagnose pituitary pars intermedia dysfunction in mature horses.. J Vet Intern Med 2021;35:560-570.
  42. McFarlane D, Paradis MR, Zimmel D, Sykes B, Brorsen BW, Sanchez A. The effect of geographic location, breed, and pituitary dysfunction on seasonal adrenocorticotropin and alpha-melanocyte-stimulating hormone plasma concentrations in horses.. J Vet Intern Med 2011;25:872-881.
  43. Haffner JC, Hoffman RM, Grubbs ST, Shepard KN, Neal DL, Pearce GL. The thyrotropin releasing hormone procedure produces repeatable ACTH concentrations in PPID-negative and PPID-positive horses.. 66th Annual Convention of the American Association of Equine Practitioners Las Vegas, NV: American Association of Equine Practitioners; 2020. p. 303-307.
  44. Jacob S, Geor R, Weber P, Harris P, McCue M. Effect of dietary carbohydrates and time of year on ACTH and cortisol concentrations in adult and aged horses.. Domest Anim Endocrinol 2018;63:15-22.
  45. Restifo MM, Frank N, Hermida P, Sanchez-Londono A. Effects of withholding feed on thyrotropin-releasing hormone stimulation test results and effects of combined testing on oral sugar test and thyrotropin-releasing hormone stimulation test results in horses.. Am J Vet Res 2016;77:738-748.
  46. De Castro ED, Lopez I, Cortes B, Pineda C, Garfia B, Aguilera-Tejero E. Influence of feeding status, time of the day, and season on baseline adrenocorticotropic hormone and the response to thyrotropin releasing hormone-stimulation test in healthy horses.. Domest Anim Endocrinol 2014;48:77-83.
  47. Kam YN, McKenzie K, Coyle M, Bertin FR. Repeatability of a thyrotropin-releasing hormone stimulation test for diagnosis of pituitary pars intermedia dysfunction in mature horses.. J Vet Intern Med 2021;35:2885-2890.
  48. Goodale L, Frank N, Hermida P, D'Oench S. Evaluation of a thyrotropin-releasing hormone solution stored at room temperature for pituitary pars intermedia dysfunction testing in horses.. Am J Vet Res 2015;76:437-444.
  49. Vaughn SA, Norton NA, Hart KA. Circulating hypothalamic-pituitary-adrenal axis hormones and insulin concentrations in horses and ponies.. J Equine Vet 2022;111:103810.
  50. Bamford N, Harris P, Bailey S. Circannual variation in plasma adrenocorticotropic hormone concentrations and dexamethasone suppression test results in Standardbred horses, Andalusian horses and mixed-breed ponies.. Aust Vet J 2020;98:616-621.
  51. McFarlane D, Paradis M, Zimmel D, Sykes B, Brorsen B, Sanchez A. The effect of geographic location, breed, and pituitary dysfunction on seasonal adrenocorticotropin and α-melanocyte-stimulating hormone plasma concentrations in horses.. J Vet Intern Med 2011;25:872-881.
  52. Banse HE, Whitehead AE, McFarlane D, Chelikani PK. Markers of muscle atrophy and impact of treatment with pergolide in horses with pituitary pars intermedia dysfunction and muscle atrophy.. Domest Anim Endocrinol 2021;76:106620.
  53. Fouché N, van der Kolk J, Bruckmaier R, Luz I, Foerster G, Gerber V. Venipuncture does not affect adrenocorticotropic hormone concentration in horses.. Vet Rec 2015;177:223.
  54. Gehlen H, Jaburg N, Merle R, Winter J. Can endocrine dysfunction be reliably tested in aged horses that are experiencing pain?. Animals 2020;10:1426.
  55. Durham AE, Potier J, Huber L. The effect of month and breed on plasma adrenocorticotropic hormone concentrations in equids.. Vet J 2022;286:105857.
  56. Byrne D, Secombe C, Tan R, Perera D, Watts S, Wearn J. Circannual variability in adrenocorticotropic hormone responses to administration of thyrotropin-releasing hormone in clinically normal horses in Australia.. Vet J 2018;238:58-62.
  57. Secombe C, Tan R, Perara D, Byrne D, Watts S, Wearn J. The effect of geographic location on circannual adrenocorticotropic hormone plasma concentrations in horses in Australia.. J Vet Intern Med 2017;31:1533-1540.
  58. Fisher D, Schliewert E, Hooijberg E. Temporally specific adrenocorticotropic hormone reference intervals for horses in South Africa.. J S Afr Vet Assoc 2022;93:116-123.
  59. Horn R, Bertin FR. Evaluation of combined testing to simultaneously diagnose pituitary pars intermedia dysfunction and insulin dysregulation in horses.. J Vet Intern Med 2019;33:2249-2256.
  60. Ayala I, Martos NF, Silvan G, Gutierrez-Panizo C, Clavel JG, Illera JC. Cortisol, adrenocorticotropic hormone, serotonin, adrenaline and noradrenaline serum concentrations in relation to disease and stress in the horse.. Res Vet Sci 2012;93:103-107.
  61. Hada T, Onaka T, Takahashi T, Hiraga A, Yagi K. Effects of novelty stress on neuroendocrine activities and running performance in thoroughbred horses.. J Neuroendocrinol 2003;15:638-648.
  62. Fazio E, Medica P, Aronica V, Grasso L, Ferlazzo A. Circulating β-endorphin, adrenocorticotrophic hormone and cortisol levels of stallions before and after short road transport: stress effect of different distances.. Acta Vet Scand 2008;50:6.
  63. Hodson NP, Wright JA, Hunt J. The sympatho-adrenal system and plasma levels of adrenocorticotropic hormone, cortisol and catecholamines in equine grass sickness.. Vet Rec 1986;118:148-150.
  64. Fazio E, Medica P, Cravana C, Aveni F, Ferlazzo A. Comparative endocrinological responses to short transportation of Equidae (Equus asinus and Equus caballus).. Anim Sci J 2013;84:258-263.
  65. Fazio E, Medica P, Cravana C, Ferlazzo AA. Pituitary-adrenocortical adjustments to transport stress in horses with previous different handling and transport conditions.. Vet World 2016;9:856-861.
  66. Stewart AJ, Hackett E, Bertin FR, Towns TJ. Cortisol and adrenocorticotropic hormone concentrations in horses with systemic inflammatory response syndrome.. J Vet Intern Med 2019;33:2257-2266.
  67. Cayado P, Munoz-Escassi B, Dominguez C, Manley W, Olabarri B, Sanchez de la Muela M. Hormone response to training and competition in athletic horses.. Equine Vet J 2006;38(S36):274-278.
  68. Haffner JC, Grubbs SG. The effect of trailering on thyrotropin releasing hormone stimulation of adrenocorticotropic hormone concentration in horses.. 5th Global Equine Endocrine Symposium Bern, Switzerland: National Horse Center; 2023. p. 17-18.
  69. Haffner JC, Hoffman RM, Grubbs SG. A combined TRH-insulin procedure identifies pituitary pars intermedia dysfunction and insulin dysregulation in horses.. 5th Global Equine Endocrinology Symposium Bern, Switzerland: National Horse Center; 2023.
  70. Fredrick J, McFarlane D, Yang F. ACTH releasing following TRH stimulation in thrifty horses compared to metabolically normal horses.. ACVIM Forum Nashville, TN; 2014.
  71. Durham AE. Is equine pituitary pars intermedia activity subdued in the spring?. Dorothy Havemeyer Foundation Equine Endocrinology Summit Miami, FL; 2017.
  72. Haffner JC, Hoffman RM, Grubbs ST. The effect of trailering and dentistry on resting adrenocorticotrophic hormone concentrations in horses.. 4th Global Equine Endocrine Symposium Gut Ising, Germany: Boehringer Ingelheim; 2020.
  73. Potier J, Durham AE. The effect of latitude and breed on circannual ACTH concentrations in the UK.. 4th Global Equine Endocrine Symposium Gut Ising, Germany: Boehringer Ingelheim; 2020.
  74. Durham AE, Shreeve H. Horse-factors influencing the seasonal increase in plasma ACTH secretion.. Dorothy Havemeyer Equine Endocrine Summit Coral Gables, FL; 2017.
  75. Miller AB, Loynachan AT, Bush HM, Hart KA, Barker VD, Campana-Emard AG. Effects of pituitary pars intermedia dysfunction and Prascend (pergolide tablets) treatment on endocrine and immune function in horses.. Domest Anim Endocrinol 2021;74:106531.
  76. Rendle DI, Doran G, Ireland J, Edwards S. Pharmacokinetics and pharmacodynamics of pergolide mesylate after oral administration in horses with pituitary pars intermedia dysfunction.. Domest Anim Endocrinol 2019;68:135-141.
  77. Durham AE. The effect of pergolide mesylate on adrenocorticotrophic hormone responses to exogenous thyrotropin releasing hormone in horses.. Vet J 2022;285:105831.
  78. Beech J. Comparison of Vitex agnus castus extract and pergolide in treatment of equine Cushing's syndrome.. Proc Am Assoc Equine Pract 2002;48:175-177.
  79. Gehlen H, Fisch J, Merle R, Trachsel DS. Preliminary study on the effects of pergolide on left ventricular function in the horses with pituitary pars intermedia dysfunction.. J Vet Sci 2021;22:e64.
  80. Arana-Valencia N, Thompson DL, Oberhaus EL. Dopaminergic and Antidopaminergic effects on heart rate in healthy horses when challenged with brief 2-minute exercise bouts.. J Equine Vet 2018;71:120-128.
  81. Donaldson MT, LaMonte BH, Morresey P, Smith G, Beech J. Treatment with pergolide or cyproheptadine of pituitary pars intermedia dysfunction (equine Cushing's disease).. J Vet Intern Med 2002;16:742-746.
  82. Gehlen H, May A, Bradaric Z. Comparison of insulin and glucose metabolism in horses with pituitary pars intermedia dysfunction treated versus not treated with Pergolide.. J Equine Vet 2014;34:508-513.
  83. Rendle DI, Frost R, Byrne A. Efficacy of a novel palatable pergolide paste formulation for the treatment of pituitary pars intermedia dysfunction (PPID) in ponies.. Equine Vet J 2018;50:16.
  84. Perkins GA, Lamb S, Erb HN, Schanbacher B, Nydam DV, Divers TJ. Plasma adrenocorticotropin (ACTH) concentrations and clinical response in horses treated for equine Cushing's disease with cyproheptadine or pergolide.. Equine Vet J 2002;34:679-685.
  85. Pongratz MC, Graubner C, Eser MW. Equine Cushing's syndrome: long-term effect of Pergolide therapy.. Pferdeheilkunde 2010;26:598-603.
  86. Schott H, Rapson J, Marteniuk J, Wisner S. Long-term response of equids with pituitary pars intermedia dysfunction to treatment with pergolide.. Proc Am Assoc Equine Pract 2014;60:329.
  87. Rendle DI, Taylor E, Duz M, Parkin TD, Copas VEN, Durham AE. Effects of pergolide mesylate on plasma adrenocorticotropic hormone concentration in horses with pituitary pars intermedia dysfunction.. Equine Vet J 2013;45:19.
  88. Froin HR, Assmann G, Hoppen HO. Effective long-term treatment of equine pituitary pars intermedia adenomas with dopamine agonist.. Exp Clin Endocrinol Diabetes 1998;106:23.
  89. McFarlane D, Banse H, Knych HK, Maxwell LK. Pharmacokinetic and pharmacodynamic properties of pergolide mesylate following long-term administration to horses with pituitary pars intermedia dysfunction.. J Vet Pharmacol Ther 2017;40:158-164.
  90. Christen G, Gerber V, van der Kolk JH, Frey CF, Fouche N. Fecal strongyle egg counts in horses with suspected pre-clinical pituitary pars intermedia dysfunction before and after treatment with pergolide.. Vet J 2018;235:60-62.
  91. Williams PD. Equine Cushing's syndrome-retrospective study of twenty four cases and response to medication.. Proceedings of British Equine Veterinary Association Congress 1995.
  92. Spelta CW, Axon JE. Case series of equine pituitary pars intermedia dysfunction in a tropical climate.. Aust Vet J 2012;90:451-456.
  93. Rendle DI, Hughes KJ, Doran GS, Edwards SH. Pharmacokinetics of pergolide after intravenous administration to horses.. Am J Vet Res 2015;76:155-160.
  94. Gehring R, Beard L, Wright A, Coetzee J, Havel J, Apley M. Single-dose oral pharmacokinetics of pergolide mesylate in healthy adult mares.. Vet Ther 2010;11:E1-E8.
  95. Anon. Prascend Freedom of Information Summary.. 2011.
  96. Schott HC, Coursen CL, Eberhart SW, Nachreiner RJ, Refsal KR, Ewart SL. The Michigan Cushing's project.. American Association of Equine Practitioners 2001.
  97. Peters D, Erfle J, Slobojan GT. Low-dose pergolide mesylate treatment for equine hypophyseal adenomas (Cushing's syndrome).. Proceedings of the American Association of Equine Practitioners, Lexington, KY 1995.
  98. Munoz MC, Doreste F, Ferrer O, Gonzalez J, Montoya JA. Pergolide treatment for Cushing's syndrome in a horse.. Vet Rec 1996;139:41-43.
  99. Beech J, Boston RC, McFarlane D, Lindborg S. Evaluation of plasma ACTH, alpha-melanocyte-stimulating hormone, and insulin concentrations during various photoperiods in clinically normal horses and ponies and those with pituitary pars intermedia dysfunction.. J Am Vet Med Assoc 2009;235:715-722.
  100. Copas VE, Durham AE. Circannual variation in plasma adrenocorticotropic hormone concentrations in the UK in normal horses and ponies, and those with pituitary pars intermedia dysfunction.. Equine Vet J 2012;44:440-443.
  101. Orth DN, Holscher MA, Wilson MG, Nicholson WE, Plue RE, Mount CD. Equine Cushing's disease: plasma immunoreactive proopiolipomelanocortin peptide and cortisol levels basally and in response to diagnostic tests.. Endocrinology 1982;110:1430-1441.
  102. Walsh DM, McGowan CM, McGowan T, Lamb SV, Schanbacher BJ, Place NJ. Correlation of plasma insulin concentration with laminitis score in a field study of equine Cushing's disease and equine metabolic syndrome.. J Equine Vet 2009;29:87-94.
  103. Lee ZY, Zylstra R, Haritou SJ. The use of adrenocorticotrophic hormone as a potential biomarker of pituitary pars intermedia dysfunction in horses.. Vet J 2010;185:58-61.
  104. Hague N, Durham AE, Menzies-Gow NJ. The effect of pergolide dosing compliance on the laboratory control of pituitary pars intermedia dysfunction.. 4th Global Equine Endocrine Symposium Gut Ising, Germany: Boehringer Ingelheim; 2020.
  105. McFarlane D, Hale GM, Johnson EM, Maxwell LK. Fecal egg counts after anthelmintic administration to aged horses and horses with pituitary pars intermedia dysfunction.. J Am Vet Med Assoc 2010;236:330-334.
  106. de Laat MA, Reiche DB, Sillence MN, McGree JM. Incidence and risk factors for recurrence of endocrinopathic laminitis in horses.. J Vet Intern Med 2019;33:1473-1482.
  107. de Laat MA, Sillence MN, Reiche DB. Phenotypic, hormonal, and clinical characteristics of equine endocrinopathic laminitis.. J Vet Intern Med 2019;33:1456-1463.
  108. Meier A, de Laat M, Reiche D, Pollitt C, Walsh D, McGree J. The oral glucose test predicts laminitis risk in ponies fed a diet high in nonstructural carbohydrates.. Domest Anim Endocrinol 2018;63:1-9.
  109. Knowles EJ, Elliott J, Harris PA, Chang YM, Menzies-Gow NJ. Predictors of laminitis development in a cohort of nonlaminitic ponies.. Equine Vet J 2023;55:12-23.
  110. Karikoski N, Patterson-Kane J, Singer E, McFarlane D, McGowan C. Lamellar pathology in horses with pituitary pars intermedia dysfunction.. Equine Vet J 2016;48:472-478.
  111. Carter RA, Treiber K, Geor R, Douglass L, Harris PA. Prediction of incipient pasture-associated laminitis from hyperinsulinaemia, hyperleptinaemia and generalised and localised obesity in a cohort of ponies.. Equine Vet J 2009;41:171-178.
  112. Klinkhamer K, Menheere PP, van der Kolk JH. Basal glucose metabolism and peripheral insulin sensitivity in equine pituitary pars intermedia dysfunction.. Vet Q 2011;31:19-28.
  113. Potier J, Durham A. Association between ACTH, insulin, glucose, and triglycerides with laminitis in PPID.. 4th Global Equine Endocrine Symposium Gut Ising, Germany: Boehringer Ingelheim; 2020.

Citations

This article has been cited 6 times.
  1. Parmantier S, Kyriazopoulou P, McClendon M, Adams A, Murphy BA. Influence of Extended Photoperiod Using Blue Light Masks on Hypertrichosis, Coat Condition and General Health Parameters in Horses with Pituitary Pars Intermedia Dysfunction. Animals (Basel) 2025 Oct 5;15(19).
    doi: 10.3390/ani15192905pubmed: 41096500google scholar: lookup
  2. Menzies-Gow NJ. Equine Pituitary Pars Intermedia Dysfunction. Vet Sci 2025 Aug 20;12(8).
    doi: 10.3390/vetsci12080780pubmed: 40872730google scholar: lookup
  3. Schott HC 2nd, Strachota JR, Marteniuk JV, Refsal KR. Long-Term Response of Equids With Pituitary Pars Intermedia Dysfunction to Treatment With Pergolide. J Vet Intern Med 2025 May-Jun;39(3):e70109.
    doi: 10.1111/jvim.70109pubmed: 40317948google scholar: lookup
  4. Bouquet A, Nicol C, Knowles EJ, Schofield I, Menzies-Gow NJ. Development of a health-related quality-of-life assessment tool for equines with pituitary pars intermedia dysfunction. Equine Vet J 2026 Jan;58(1):190-202.
    doi: 10.1111/evj.14513pubmed: 40314080google scholar: lookup
  5. Fouché N, Doras C, Schüpbach-Regula G, Scherer A, Freudenschuss B, Gerber V. Association Between Adrenocorticotropic Hormone Concentration and Clinical Signs of Pituitary Pars Intermedia Dysfunction in Swiss and Austrian Equids. J Vet Intern Med 2025 Mar-Apr;39(2):e70008.
    doi: 10.1111/jvim.70008pubmed: 40095750google scholar: lookup
  6. Neufang L, Ramos J, Eda S, Flatland B, Giori L. Initial development of a rapid, portable, stall-side ELISA for the measurement of equine adrenocorticotropic hormone. J Vet Diagn Invest 2025 Jan;37(1):208-211.
    doi: 10.1177/10406387241285453pubmed: 39320416google scholar: lookup
Subscribe to our newsletter
Join 99,727 horse owners like you who receive our email updates on horse health and nutrition.