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Stewart AJ, Ireland JL, Durham AE, McGowan CM. Diagnosis of equine pituitary pars intermedia dysfunction. Vet J 2023; 300-302:106036. [PMID: 37805159 DOI: 10.1016/j.tvjl.2023.106036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Equine pituitary pars intermedia dysfunction (PPID) is common in aged horses. The majority of horses respond well to treatment, but treatment is lifelong, meaning accurate diagnosis of PPID is important. Similar to any condition, there is no perfect laboratory test to diagnose PPID and accuracy is affected by the characteristics of the population in which the test is being evaluated. This review details the importance of consideration of clinical factors and diagnostic test accuracy. Basal adrenocorticotrophic hormone (ACTH) concentration is used most frequently in practice and has very good diagnostic accuracy when used in combination with clinical judgement and the correct application of diagnostic thresholds. The thyrotropin-releasing hormone stimulation test can be used in horses with equivocal test results following basal ACTH testing, or to evaluate subtle cases due to its improved accuracy.
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Affiliation(s)
| | - Joanne L Ireland
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK
| | - Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK
| | - Catherine M McGowan
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK.
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2
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McGowan CM, Ireland JL. Equine Endocrine Disease: Challenges With Case Definition for Research. J Equine Vet Sci 2023; 124:104491. [PMID: 37236726 DOI: 10.1016/j.jevs.2023.104491] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 05/28/2023]
Abstract
Equine endocrine disease is an important area for equine research, requiring an appropriate case definition for inclusion and criteria for exclusion from disease. Defining a case for research may be different from criteria for clinical diagnosis. Further, clinical diagnosis recommendations have been changing regularly, making this area challenging for equine scientists. This review discusses the diagnosis of major equine endocrine diseases, pituitary pars intermedia dysfunction, equine metabolic syndrome and insulin dysregulation, focusing on the most appropriate diagnostic methods for research case definitions. Different diagnostic methods, including use of reference intervals and clinical decision limits, will be discussed with their relative merits for use in case definition for research.
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Affiliation(s)
- Catherine M McGowan
- School of Veterinary Science, Institute of Infection, Ecological and Veterinary Sciences, the University of Liverpool, Neston, UK.
| | - Joanne L Ireland
- School of Veterinary Science, Institute of Infection, Ecological and Veterinary Sciences, the University of Liverpool, Neston, UK
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Plasma Amino Acids in Horses Suffering from Pituitary Pars Intermedia Dysfunction. Animals (Basel) 2022; 12:ani12233315. [PMID: 36496836 PMCID: PMC9737035 DOI: 10.3390/ani12233315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022] Open
Abstract
Pituitary pars intermedia dysfunction is one of the most common diseases of aged horses and ponies. In Parkinson's disease, which is, similar to PPID, a disease that involves oxidative damage to dopaminergic pathways but with different clinical signs, alterations to the serum amino acid profile have been reported. To examine changes in the plasma amino acid profile in horses with PPID, EDTA plasma of horses that were presented for various reasons that required laboratory examinations of blood anticoagulated with EDTA was collected. With this plasma, the basal ACTH concentration as well as the amino acid profile was determined. Horses were considered PPID patients if the ACTH concentration was ≥ 100 pg/mL, i.e., they would be considered affected at any time. Horses were defined as non-PPID (nPPID) patients if the ACTH concentration was below 30 pg/mL. Horses receiving pergolide with ACTH ≤ 30 pg/mL were allocated to the group PPIDrr (PPID, ACTH in reference range) and horses receiving pergolide with ACTH ≥ 100 pg/mL to the group PPIDarr (PPID, ACTH above reference range). In total, 93 horses were examined, including 88 horses at the clinic and 5 horses at a private practice. Of these, 53 horses fulfilled the inclusion criteria (ACTH ≤ 30 pg/mL or ACTH ≥ 100 pg/mL). A total of 25 horses were diagnosed as nPPID, 20 as PPID, 5 as PPIDrr, and 3 as PPIDarr. Arginine was significantly higher in PPIDrr than in PPID and nPPID, asparagine was significantly higher in PPID, PPIDrr, and PPIDarr than in nPPID, citrulline was significantly higher in PPIDrr than in nPPID and PPID, cysteine was significantly lower in PPIDrr than in PPID, nPPID, and PPIDarr, and glutamine was significantly higher in PPID and PPIDarr than in nPPID. Especially, asparagine, citrulline, and glutamine may be potential diagnostic markers and may offer interesting approaches for research regarding amino supplementation in PPID.
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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:vetsci9100572. [PMID: 36288186 PMCID: PMC9607114 DOI: 10.3390/vetsci9100572] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 12/31/2022] Open
Abstract
Simple Summary Pituitary pars intermedia dysfunction (PPID) is a common disease of the geriatric horse population. The most common clinical sign of PPID is hypertrichosis, or a long hair-coat with delayed shedding. Hypertrichosis is the most easily recognized clinical sign of PPID. However, the presence of hypertrichosis is often associated with severe end-stage disease. There is little research investigating sub-clinical or early PPID and the clinical signs associated with these stages of disease. The benefit of being able to recognize early PPID, is that we are able to begin treatment earlier on in disease process, potentially reducing the deleterious consequences of PPID and improving survival. Laboratory tests are available to more accurately diagnose PPID, and these tests include the basal ACTH and TRH-stimulated ACTH tests. Basal ACTH is easy to perform and is recommended in cases where clinical disease is suspected. The TRH-stimulation test improves diagnostic accuracy in early PPID cases. This study documents both test results and clinical signs associated with the transition from subclinical to clinical PPID, so that we are better able to recognize potential early PPID, as well as interpret results in these horses. Abstract Poor recognition of subtle clinical abnormalities and equivocal ACTH concentrations make early diagnosis of PPID difficult. Progressive clinical findings and corresponding ACTH concentrations in horses transitioning to PPID over time have not been documented. Seven horses with ACTH concentrations equivocal for PPID (utilizing locally derived, seasonally adjusted diagnostic-cut off values (DCOV)) and no clinical signs of PPID were selected. Sequential measurement of basal and thyrotropin-releasing hormone (TRH)-stimulated ACTH concentrations and recording of clinical findings occurred from October 2017 to November 2021 in a prospective case series. In two horses, marked hypertrichosis developed. Although 1/11 basal ACTH concentrations were below DCOV in 2018, subsequently all basal ACTH concentrations in these two horses without treatment were greater than DCOV. One horse was treated with pergolide which normalized basal ACTH concentrations. Four horses developed intermittent, mild hypertrichosis, and one horse never developed hypertrichosis. Basal ACTH concentrations in these five horses were greater than DCOV in 63/133 (47.4%) of testing points. TRH-stimulated ACTH concentrations in these five horses were greater than DCOV in 77/133 (57.9%) of testing points, sometimes markedly increased and greater than the assay upper limit of detection (LoD) of 1250pg/mL. TRH-stimulated ACTH concentrations were most frequently positive in late summer and early autumn, with 24/37 (64.9%) of TRH-stimulated ACTH concentrations greater than the DCOV in February and March. Horses transitioning to PPID can have subtle clinical signs and equivocal ACTH concentrations. However, TRH-stimulated ACTH concentrations can be markedly greater than DCOV, especially in late summer and early autumn (February and March) allowing for identification of subclinical and transitional cases.
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Affiliation(s)
- Naomi C. Kirkwood
- School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Kristopher J. Hughes
- School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Allison J. Stewart
- School of Veterinary Science, Gatton Campus, The University of Queensland, Gatton, QLD 4343, Australia
- Correspondence: ; Tel.: +61-754-601-799
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Pituitary Pars Intermedia Dysfunction (PPID) in Horses. Vet Sci 2022; 9:vetsci9100556. [PMID: 36288169 PMCID: PMC9611634 DOI: 10.3390/vetsci9100556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/25/2022] [Accepted: 10/04/2022] [Indexed: 12/12/2022] Open
Abstract
Substantial morbidity results from pituitary pars intermedia dysfunction (PPID) which is often underestimated by owners and veterinarians. Clinical signs, pathophysiology, diagnostic tests, and treatment protocols of this condition are reviewed. The importance of improved recognition of early clinical signs and diagnosis are highlighted, as initiation of treatment will result in improved quality of life. Future research should be targeted at improving the accuracy of the diagnosis of PPID, as basal adrenocorticotropic hormone (ACTH) concentration can lack sensitivity and thyrotropin releasing hormone (TRH) used to assess ACTH response to TRH stimulation is not commercially available as a sterile registered product in many countries. The relationship between PPID and insulin dysregulation and its association with laminitis, as well as additional management practices and long-term responses to treatment with pergolide also require further investigation.
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Herbst AC, Reedy SE, Page AE, Horohov DW, Adams AA. Effect of aging on monocyte phagocytic and inflammatory functions, and on the ex vivo inflammatory responses to lipopolysaccharide, in horses. Vet Immunol Immunopathol 2022; 250:110459. [PMID: 35863208 DOI: 10.1016/j.vetimm.2022.110459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 07/08/2022] [Accepted: 07/10/2022] [Indexed: 11/16/2022]
Abstract
Studies investigating age-related changes in the function of monocytes are currently limited for horses. Thus, the main goal of this study was to determine the effect of aging on monocyte phagocytic capacity and pro-inflammatory cytokine responses to bacterial lipopolysaccharide (LPS). A second goal of this work was to examine the effect of aging on the inflammatory cytokine responses to LPS in a whole blood ex vivo model. Seven healthy young adult (4-6 years of age) and seven healthy senior horses (>20 years of age) were enrolled. Phagocytosis of E. coli, and pro-inflammatory cytokine (TNFα) responses to LPS, were measured in monocytes by flow cytometry. Gene expressions of pro-inflammatory cytokines (TNFα, IL-1β, IL-6, IL-8, IL-18, CCL-5, CCL-2) were measured in peripheral blood mononuclear cells (PBMCs) and whole blood by RT-qPCR post incubation for 2 h or 6 h with a low (0.01 µg/mL) or a high (1 µg/mL) dose of LPS. Two sets of statistical models were applied to compare the age groups, one adjusted, and one unadjusted for the horses' body condition scores (BCS). The percentage of monocytes that phagocytosed E. coli after 2 h of incubation was significantly lower in senior compared to young adult horses in the BCS-adjusted model. In the senior group, the expression of IL-1β in 2 h-0.01 µg/mL LPS-stimulated PBMCs was significantly higher than in the young adult group (BCS-adjusted and unadjusted models). In senior horses, expressions of IL-8 and IL-6 in whole blood samples stimulated for 6 h with 0.01 µg/mL LPS and for 2 h with 1 µg/mL LPS, respectively, were significantly lower than in young adult horses (BCS-adjusted models). The results of this study suggest that the phagocytic function of monocytes, as well as their IL-1β response to LPS may be altered in senior horses. In addition, the whole blood IL-8 and IL-6 gene expression responses to LPS may be insufficient in senior horses. While investigation of the effect of BCS on monocyte functions and whole blood pro-inflammatory LPS-responses was not a major goal of this work, it appears that adiposity may play a role in innate immune cell function, as significant differences between the age groups were often not apparent until the models were adjusted for BCS.
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Affiliation(s)
- A C Herbst
- M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
| | - S E Reedy
- M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - A E Page
- M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - D W Horohov
- M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - A A Adams
- MARS EQUESTRIAN™ Research Fellow, M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
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Satué K, Fazio E, Muñoz A, Medica P. Successful Pregnancy Outcome in Mares: The Potential Role of Body Conditional Score, Age and Biochemical Parameter's Adjustments. J Equine Vet Sci 2022; 115:104023. [PMID: 35643379 DOI: 10.1016/j.jevs.2022.104023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/19/2022] [Accepted: 05/21/2022] [Indexed: 10/18/2022]
Abstract
The objective of this research was to evaluate the changes in body condition score (BCS), age and the main biochemical parameters in pregnant Spanish Purebred mares. A total of 45 pregnant Spanish broodmares has been studied, classified in three different groups: group A (n = 15), aging 14-18 years old and BCS lower than 4 of 10, group B (n = 15), with ages of 4 to 8 years and a BCS of 5-6/10, and group C (n = 15), aging between 6 and 11 years and a BCS of 8 of 10. Three pregnancy periods were considered: the 1st period, from the 1st to the 3rd, the 2nd from the 4th to the 6th, and the last period, from the 7th month of pregnancy to delivery. Blood samples were taken every month along the pregnancy. The following plasma biochemical parameters were measured: triglycerides, total cholesterol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol, total, direct and indirect bilirubin, aspartate aminotransferase, lactate dehydrogenase, γ-glutamyl transferase, alkaline phosphatase, total plasma proteins, albumin, glucose, urea and creatinine. Pregnancy in the Spanish broodmare induced hyperlipidemia with hypertriglyceridemia and increased plasma concentrations of total, direct and indirect bilirubin (P < .05). Older pregnant mares showed biochemical changes probably consistent with decreased organ functionality (P < .05). Obesity did not influence lipidic metabolism during pregnancy (P > .05).
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Affiliation(s)
- Katiuska Satué
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, CEU-Cardenal Herrera University, Valencia, Spain.
| | - Esterina Fazio
- Department of Veterinary Sciences, Veterinary Physiology Unit, Messina University, Messina, Italy
| | - Ana Muñoz
- Department of Animal Medicine and Surgery, School of Veterinary Medicine, University of Córdoba, Córdoba, Spain
| | - Pietro Medica
- Department of Veterinary Sciences, Veterinary Physiology Unit, Messina University, Messina, Italy
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Nitzsche AM, Fey K, Büttner K, Gröf M, Staszyk C. The Gingiva of Horses With Pituitary Pars Intermedia Dysfunction: A Macroscopic Anatomical Evaluation. Front Vet Sci 2022; 8:786971. [PMID: 35146012 PMCID: PMC8821874 DOI: 10.3389/fvets.2021.786971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
Pituitary pars intermedia dysfunction (PPID) is a common neurodegenerative disease mainly in horses older than 15 years. The domestic equine population is following the same demographic change as that seen in humans; it is aging and veterinarians are asked to attend to geriatric horses more frequently. Common problems seen regularly in older equines are dental disorders and especially periodontal disease. As a systemic and endocrine disease, associated with delayed wound healing and impaired immune function, PPID should be considered before major dental treatment in aged equines is started. Possible negative effects of PPID on epithelial tissues could also affect the periodontium. Therefore, the aim of the present study was to identify gross changes in the gingiva associated with PPID. Fourteen horses with clinical signs of PPID and adenoma in the pituitary pars intermedia and 13 controls showing neither clinical signs nor PPID-associated histological changes in the pituitary gland were included. PPID-affected horses (26.9 ± 0.73 years) were significantly older than controls (20.0 ± 1.24 years). In the PPID-affected group, significantly more often an irregular and bulky appearance of the gingival texture was observed, as well as an irregular shape of the gingival margin. Furthermore, the sulcus gingivalis of cheek teeth frequently was deeper than 1 mm. These findings indicate a possible association between age, soft tissue alterations, and PPID and suggest a potential predisposition of PPID-affected horses for periodontal diseases.
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Affiliation(s)
- Anne Maria Nitzsche
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
- *Correspondence: Anne Maria Nitzsche
| | - Kerstin Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
| | - Kathrin Büttner
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus-Liebig-University, Giessen, Germany
| | - Manuela Gröf
- Faculty of Veterinary Medicine, Institute of Veterinary Pathology, Justus-Liebig-University, Giessen, Germany
| | - Carsten Staszyk
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University, Giessen, Germany
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Thane K, Uricchio C, Frank N. Effect of early or late blood sampling on thyrotropin releasing hormone stimulation test results in horses. J Vet Intern Med 2022; 36:770-777. [PMID: 35049089 PMCID: PMC8965261 DOI: 10.1111/jvim.16362] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 01/21/2023] Open
Abstract
Background Diagnosis of pituitary pars intermedia dysfunction (PPID) using the thyrotropin‐releasing hormone (TRH) stimulation test requires blood collection 10 minutes after TRH injection; it is unknown if small differences in timing affect test results. Objective To determine whether early or late sampling results in a significant (≥10%) difference in plasma adrenocorticotropic hormone (ACTH) concentration compared to standard 10‐minute sampling. Animals Twenty‐four healthy adult horses with unknown PPID status. Methods In this prospective study, subjects underwent a single TRH stimulation test, with blood collected exactly 9 minutes (early), 10 minutes (standard), and 11 minutes (late) after injection. ACTH was measured by chemiluminescent immunoassay. Two aliquots of the 10‐minute plasma sample were analyzed separately to assess intra‐assay variability. Data were reported descriptively and bias was calculated using Bland‐Altman plots. Significance was set at P = .05. Results Minor variability was observed between the paired 10‐minute sample aliquots (range, 0%‐6%; median 3%). Overall variability of early or late samples compared to the corresponding paired (average) 10‐minute standard concentration ranged from 0% to 92% (median 10%). Seventy‐five percent of horses (18/24) tested had at least 1 early or late reading that differed by ≥10% from its corresponding 10‐minute standard concentration, and 21% of horses (5/24) would have a different interpretation of testing result with either early or late sampling. Incidence of ≥10% variability was independent of PPID status (P = .59). Conclusions and Clinical Importance Precise timing of sample collection is critical to ensure accurate assessment of PPID status given the observation of significant variability associated with minor alterations in timing of sample collection.
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Affiliation(s)
- Kristen Thane
- Tufts Cummings School of Veterinary Medicine, Department of Comparative Pathobiology, North Grafton, Massachusetts, USA
| | - Cassandra Uricchio
- University of Massachusetts, Department of Veterinary and Animal Sciences, Amherst, Massachusetts, USA
| | - Nicholas Frank
- Tufts Cummings School of Veterinary Medicine, Department of Comparative Pathobiology, North Grafton, Massachusetts, USA
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Miller AB, Murphy BA, Adams AA. Impact of blue light therapy on plasma adrenocorticotropic hormone (ACTH) and hypertrichosis in horses with pituitary pars intermedia dysfunction. Domest Anim Endocrinol 2022; 78:106651. [PMID: 34656964 DOI: 10.1016/j.domaniend.2021.106651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 06/30/2021] [Accepted: 07/21/2021] [Indexed: 11/19/2022]
Abstract
Blue light therapy can be used in horses to alter the natural photoperiod and inhibit winter hair coat growth. Seasonal increases in ACTH occur in the fall season but are exaggerated in horses with pituitary pars intermedia dysfunction (PPID). Additionally, PPID horses frequently present with hypertrichosis. Thus, blue light therapy was proposed as a potential management tool for hypertrichosis and for investigating the impact of photoperiod manipulation on ACTH. Eighteen PPID horses, aged 18 to 31 yr, from a university-owned research herd were selected and assigned to either the control group (n = 10) or the treatment (blue light therapy) group (n = 8) based on age and clinical history, which included the results of multiple endocrine tests. Consistent daylength of approximately 14.5 h was maintained for the treated horses from July 15 through approximately late October via the extension of natural daylength using wearable masks that provided short wavelength blue light (465 nm) to 1 eye. The control group was exposed to only the natural photoperiod during this time. All horses were housed on the same farm and remained on pasture for the duration of the study. On Day 0, thyrotropin-releasing hormone (TRH) stimulation tests were performed to confirm PPID status; there were no differences between the 2 groups in resting plasma ACTH or plasma ACTH at 10 min after TRH administration. To determine an effect of treatment on ACTH, blood was collected via jugular venipuncture for measurement of ACTH at sequential timepoints over a 16-h period in mid-October. Hair weights were also assessed throughout the study. No differences in resting plasma ACTH were observed between the 2 groups across the seasonal analysis (July and October) or during the 16-h testing. The PPID horses receiving blue light therapy had lighter hair weights compared to the PPID control horses. These results suggest that blue light therapy does not alter ACTH concentrations but could potentially be used as an additional management tool for hypertrichosis in PPID horses. Manipulation of the photoperiod using blue light therapy did not affect seasonal changes in ACTH in this study.
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Affiliation(s)
- A B Miller
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
| | - B A Murphy
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - A A Adams
- M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
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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 Sci 2021; 110:103824. [PMID: 34843889 DOI: 10.1016/j.jevs.2021.103824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/13/2021] [Accepted: 11/18/2021] [Indexed: 10/19/2022]
Abstract
Geriatric horses (>15 years) represent a substantial proportion of the equine population. The objective of this study was to (1) report on the cause of death in geriatric horses on a single retirement centre, (2) to evaluate the relationship between PPID status, and mortality rate. Data of 194 horses was collected over an eight-year period. This providing data for 80 geriatric cases of mortality. The average age of horses that died was 26.2 years (±4.8 years). The majority (95%) of mortalities were euthanised, most frequently due to colic (20%), old age (19%), and lameness (15%). Overall mortality rate was 16.3 per 100 horse years at risk (95% C.I. 15.2-17.5) for the total geriatric (>15 years) population. PPID had a prevalence of 48.8% (61 out of 125 horses). The results of this study demonstrate increasing mortality rates with increasing age in geriatric horses. The most common reasons for euthanasia were lameness, old age, and colic. The treatment of PPID does not result in an older age of death. The effect of treatment on the welfare status was not studied. Management, of both veterinarians and care taker, has an important role in maintaining health and welfare in geriatric horses. Findings of this study could be relevant to veterinary surgeons and stable managers providing care for geriatric horses.
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12
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Development and Evaluation of a Muscle Atrophy Scoring System (MASS) for Horses. J Equine Vet Sci 2021; 110:103771. [PMID: 34973594 DOI: 10.1016/j.jevs.2021.103771] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/25/2021] [Accepted: 09/13/2021] [Indexed: 02/06/2023]
Abstract
Loss of skeletal muscle mass likely compromises performance and welfare in horses and thus routine monitoring would be valuable. Currently available methods to assess muscle mass require expert knowledge and are often expensive. To provide a simple method, a muscle atrophy scoring system (MASS) was created and tested by three evaluators (raters) in 38 horses of varying age, breed, and health status. Inter-rater agreement on atrophy scores was in the good-to-excellent range for ratings of the neck (ICC = 0.62), back (ICC = 0.62) and hind (ICC = 0.76) regions but was poor for the abdominal region (ICC = 0.29). Due to this low agreement, the abdominal region was excluded from further analysis. Associations between muscle atrophy scores and age, pituitary pars intermedia dysfunction (PPID) status, and body composition indicators, including weight and estimated fat-free mass (FFM), were examined. Weight was inversely associated with neck, back and hind muscle atrophy scores (β = -0.008, β = -0.008, β = -0.009, respectively; all P <0.001), but estimated FFM was not associated with muscle atrophy scores at any region (P >0.05). Age was positively related to neck (β = 0.030, P <0.01), back (β = 0.037, P <0.001) and hind (β = 0.040, P <0.001) muscle atrophy scores. PPID-positive horses (n = 4) had higher muscle atrophy scores than PPID-negative horses (n = 23), even after adjusting for age (P <0.05). This data suggests that neck, back and hind region evaluations by individual raters likely have acceptable reliability. In addition, these findings support further evaluation of the potential benefits of the MASS to identify and monitor muscle atrophy in horses.
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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. [PMID: 34028083 PMCID: PMC8295711 DOI: 10.1111/jvim.16145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 01/10/2023] Open
Abstract
Background Pituitary pars intermedia dysfunction (PPID) is an endocrine disorder the clinical signs of which include infertility, but few reports have examined the relationship between PPID and reproductive performance in broodmares. Hypothesis/Objective Broodmares with infertility of unknown etiology were screened for PPID using baseline endogenous plasma ACTH concentrations, and its relationship with subsequent reproductive performance was analyzed. Animals Sixty‐seven Thoroughbred broodmares. Methods Adrenocorticotropic hormone concentrations were measured in autumn. The broodmares were divided into 3 groups based on endogenous plasma ACTH concentration (low, <50 pg/mL; intermediate 50‐100 pg/mL; and high >100 pg/mL) as recommended by the Equine Endocrinology Group. We compared these results with those of other blood tests, clinical examinations, subsequent conception, and frequency of normal delivery. Results The numbers of horses per group (percentage) were 22 (32.8%), 20 (29.9%), and 25 (37.3%). The mean ± SD ages (years) were 11.1 ± 3.4, 12.1 ± 4.5, and 13.0 ± 4.3, with no significant difference among groups. Mean ± SD plasma cortisol concentrations (μg/dL) were 4.0 ± 1.6, 7.1 ± 1.4, and 7.6 ± 1.9, with the intermediate and high ACTH groups having significantly higher results than the low ACTH group (P < .001). Conception rates were 77.3%, 89.5%, and 56.5% and normal delivery rates were 77.2%, 84.2%, and 43.5% with the percentage of each significantly lower in the high ACTH group (P = .02, P = .008, respectively). Conclusions and Clinical Importance The study group of infertile broodmares may include horses with PPID. The reproductive performance of the high ACTH group was significantly lower than the other groups. Early diagnosis and treatment of infertile broodmares by screening plasma ACTH concentrations could help improve reproductive performance.
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Affiliation(s)
- Takeru Tsuchiya
- Northern Farm Tenei, Fukushima, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Ryusuke Noda
- Equine Medical Center, Hidaka Horse Breeders Association, Hokkaido, Japan
| | - Hiroki Ikeda
- Equine Medical Center, Hidaka Horse Breeders Association, Hokkaido, Japan
| | - Masaya Maeda
- Equine Medical Center, Hidaka Horse Breeders Association, Hokkaido, Japan
| | - Fumio Sato
- United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,Equine Research Institute, Japan Racing Association, Tochigi, Japan
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14
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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. [PMID: 34099343 DOI: 10.1016/j.tvjl.2021.105695] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/12/2021] [Accepted: 05/19/2021] [Indexed: 02/01/2023]
Abstract
Measurement of basal adrenocorticotrophic hormone (ACTH) is currently used to diagnose pituitary pars intermedia dysfunction (PPID) in horses, yet a systematic review of the evidence for its use has not been undertaken. This study aimed to systematically review evidence regarding the sensitivity and specificity of the basal ACTH diagnostic test. Electronic databases were systematically searched in January 2019, September 2020 and January 2021, for English language publications published prior to these dates. Screening, data extraction and quality assessment of publications was undertaken by the authors using predefined criteria. Study design, methodology and information reported in included studies were assessed using Standards for Reporting of Diagnostic Accuracy (STARD) checklists. Risk of bias and applicability were appraised using the Quality Assessment tool for Diagnostic Accuracy Studies (QUADAS-2) quality assessment tool. Due to identified biases and marked between-study variations, meta-analysis was not undertaken. After removal of duplicates, 415 publications were identified, of which 25 were evaluated in full, with 11 of these meeting inclusion criteria. In most studies, basal ACTH was reported to have good sensitivity (overall median 75.5%; interquartile range [IQR], 64.0-86.5%; range, 36.0-100%) and excellent specificity (overall median, 95.2%; IQR, 84.2-98.9%; range, 63.3-100%). However, QUADAS-2 and STARD assessment highlighted that studies did not utilise optimal study design and/or study populations for the evaluation of a diagnostic test and the majority were subject to bias, or provided insufficient information to fully assess possible biases. Based on this review, basal ACTH performed better at ruling out PPID than detecting it.
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15
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Equine pituitary pars intermedia dysfunction: Identifying research priorities for diagnosis, treatment and prognosis through a priority setting partnership. PLoS One 2021; 16:e0244784. [PMID: 33395695 PMCID: PMC7781667 DOI: 10.1371/journal.pone.0244784] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/15/2020] [Indexed: 01/04/2023] Open
Abstract
Pituitary pars intermedia dysfunction (PPID) is the most prevalent endocrine disorder of older equids. To date, key research areas likely to have the greatest impact on equine health have not been identified. In human medicine, public and patient involvement is widely used to inform research agendas. This study aimed to engage with veterinary surgeons and horse owners to identify evidence gaps ('uncertainties') and prioritise these into a list of the 10 most important PPID research questions. The James Lind Alliance (JLA) Priority Setting Partnership (PSP) Framework was adapted. Questions about the diagnosis, treatment and prognosis of PPID were gathered via an online survey targeting veterinary surgeons and horse owners with experience of PPID. Thematic analysis was used to form a longlist of collated indicative research questions (CIRQs), defined by the JLA as true 'evidence uncertainties' when not answered by a published, clinically relevant, up-to-date systematic review. In an interim prioritisation survey, questions were ranked by weighted scores creating a shortlist of 25 that were taken forward to the PSP workshop, where participants reached a consensus on the top 10. Useable responses containing ≥1 question were received from 524 respondents (92.6% owners, n = 485; 7.4% veterinary surgeons, n = 39). After screening for relevance, 1,260 individual questions were included in thematic analysis, resulting in 47 CIRQs. Interim prioritisation votes for the CIRQs were received from 360 respondents. The top 10 questions prioritised at the PSP workshop focused on long-term prognosis, diagnostic accuracy, efficacy of pergolide treatment, alternative treatment/management strategies and potential treatment options for poor responders to pergolide. The quantity of questions generated indicates an extensive number of uncertainties regarding the diagnosis, treatment and prognosis of PPID. The top 10 research questions will help to inform key areas for evidence synthesis and knowledge translation, and to direct future research into areas most important to end users involved in caring for and treating animals with PPID.
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16
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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 2020; 35:560-570. [PMID: 33368633 PMCID: PMC7848300 DOI: 10.1111/jvim.16017] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Diagnosis of pituitary pars intermedia dysfunction (PPID) is problematic because of large variations in ACTH concentrations. HYPOTHESIS/OBJECTIVES Compare the test characteristics of baseline and post-thyrotropin-releasing hormone (TRH) stimulation plasma ACTH concentrations in horses using diagnostic cutoff values (DCOVs) and reference intervals (RIs) and determine the clinical consequences of using each method. ANIMALS One hundred six mature horses: 72 control cases and 34 PPID cases. METHODS Prospective case-controlled study. Horses underwent monthly TRH stimulation tests. Diagnostic cutoff values were determined monthly by receiver operating characteristic curves using the Youden index. Reference intervals were determined monthly by a robust method. For each case age, sex and body condition score (BCS) were recorded. RESULTS Baseline ACTH concentrations varied by month (P < .001) with significant "month × age" (P = .003), "month × sex" (P = .003), and "month × BCS" (P = .007) effects. Baseline ACTH concentrations were accurate to diagnose PPID (0.91 ± 0.06) with DCOVs increasing the test sensitivity (0.61 ± 0.21 to 0.87 ± 0.05, P = .002) and RI increasing test specificity (0.85 ± 0.12 to 0.98 ± 0.01, P = .01). Thyrotropin-releasing hormone stimulation improved test accuracy (0.91 ± 0.06 to 0.97 ± 0.03, P = .004). CONCLUSIONS AND CLINICAL IMPORTANCE ACTH concentrations follow a circannual rhythm and vary with physiological factors. As using DCOVs increases the ability to detect mild cases and using RI decreases the risk of unnecessary treatments, ACTH concentrations should be interpreted within a specific clinical context. The TRH stimulation test improves the diagnosis of PPID.
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Affiliation(s)
- Remona Horn
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Allison J Stewart
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Karen V Jackson
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | | | - Carlos E Medina-Torres
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - François-René Bertin
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
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17
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Pituitary Pars Intermedia Dysfunction and Metabolic Syndrome in Donkeys. Animals (Basel) 2020; 10:ani10122335. [PMID: 33302557 PMCID: PMC7763272 DOI: 10.3390/ani10122335] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/11/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Donkeys are one of the six species of the equid family. Even though they may look similar to horses, there are optical, behavioral, and physiological differences between the two species. The most important endocrine diseases in horses (equine metabolic syndrome and pituitary pars intermedia dysfunction: PPID) also exist in donkeys. The key symptoms of asinine metabolic syndrome (AMS), similar to horses, are obesity, insulin dysregulation, and laminitis. It can be diagnosed with either basal glucose and insulin concentration or dynamic tests. The intravenous glucose tolerance test and the combined glucose insulin tolerance test were evaluated for donkeys. The therapy of AMS is aimed at weight and exercise management. Donkeys suffering from PPID are often laminitic. Other authors have reported on hypertrichosis as a cardinal sign. Donkey-specific differences in shedding compared to horses have to be considered. The PPID can be diagnosed with donkey-specific reference values or dynamic testing. The dexamethasone suppression test, the thyrotropin releasing hormone (TRH) test, and the combined dexamethasone suppression/TRH test were evaluated for donkeys. Abstract Appropriate medical care for donkeys is challenging despite being important working animals in non-industrialized countries and pets in first world countries. Although the same principles of diagnosis and therapy as in horses are commonly applied, there are differences in reference values and physiologic reaction to dynamic tests. However, donkeys seem to suffer from typical equine diseases, such as metabolic syndrome and pituitary pars intermedia dysfunction (PPID). Asinine metabolic syndrome (AMS) comprises obesity, insulin dysregulation, and laminitis. The principles of diagnosis are similar to horses. Donkey-specific reference ranges for insulin and glucose have been evaluated previously. Examinations regarding dynamic testing revealed differences in the intravenous glucose tolerance test and the combined insulin tolerance test compared to horses. The therapy of AMS is based mainly on weight loss and exercise. There are conflicting data regarding the incidence of PPID in donkeys. Laminitis and hypertrichosis were described as the main clinical signs. Species-specific and seasonal reference ranges were defined to diagnose PPID in donkeys. Furthermore, the dexamethasone suppression test, the thyrotropin releasing hormone (TRH) test and the combined dexamethasone suppression/TRH test were evaluated. Pergolide is commonly recommended for treatment.
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18
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Bamford NJ, Harris PA, Bailey SR. 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. [PMID: 33001453 DOI: 10.1111/avj.13022] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/18/2020] [Accepted: 09/04/2020] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To compare circannual plasma concentrations of adrenocorticotropic hormone (ACTH) and seasonal dexamethasone suppression test (DST) results between three different equine breed groups. METHODS Six Standardbred horses, six Andalusian horses and six mixed-breed ponies were followed over a 1-year period, during which time groups were managed identically. Blood samples were collected monthly (around the autumn equinox) or in every second month (other times of the year) for the determination of plasma ACTH concentrations using a chemiluminescent immunoassay. Overnight DSTs were performed quarterly, with suppression of plasma cortisol to below 27 nmol/L at 19 h considered a normal result. RESULTS Seasonal variation in plasma ACTH concentrations was present among all breed groups with, as expected, higher levels detected around the autumn equinox, from February to April (P < 0.001). Plasma ACTH concentrations were different between breed groups in March, with higher levels in Andalusians compared with Standardbreds (P = 0.048) and in ponies compared with Standardbreds (P = 0.010). Suppression of cortisol during the DST was normal for all animals in winter, spring and summer, but five Andalusians and three ponies returned abnormally high results in autumn, compared with zero Standardbreds. CONCLUSION Higher plasma ACTH concentrations and more false-positive DST results were obtained during autumn in ponies and Andalusian horses when compared with Standardbred horses. Potential differences between breeds should be considered when interpreting test results for horses and ponies that are evaluated for pituitary pars intermedia dysfunction. Further work is recommended to establish population-based reference intervals and clinical cut-off values for ACTH in different equine breeds.
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Affiliation(s)
- N J Bamford
- Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - P A Harris
- Equine Studies Group, WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, UK
| | - S R Bailey
- Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
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19
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Held F, Ekstrand C, Cvijovic M, Gabrielsson J, Jirstrand M. Modelling of oscillatory cortisol response in horses using a Bayesian population approach for evaluation of dexamethasone suppression test protocols. J Pharmacokinet Pharmacodyn 2019; 46:75-87. [PMID: 30673914 PMCID: PMC6394511 DOI: 10.1007/s10928-018-09617-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 12/31/2018] [Indexed: 11/12/2022]
Abstract
Cortisol is a steroid hormone relevant to immune function in horses and other species and shows a circadian rhythm. The glucocorticoid dexamethasone suppresses cortisol in horses. Pituitary pars intermedia dysfunction (PPID) is a disease in which the cortisol suppression mechanism through dexamethasone is challenged. Overnight dexamethasone suppression test (DST) protocols are used to test the functioning of this mechanism and to establish a diagnosis for PPID. However, existing DST protocols have been recognized to perform poorly in previous experimental studies, often indicating presence of PPID in healthy horses. This study uses a pharmacokinetic/pharmacodynamic (PK/PD) modelling approach to analyse the oscillatory cortisol response and its interaction with dexamethasone. Two existing DST protocols were then scrutinized using model simulations with particular focus on their ability to avoid false positive outcomes. Using a Bayesian population approach allowed for quantification of uncertainty and enabled predictions for a broader population of horses than the underlying sample. Dose selection and sampling time point were both determined to have large influence on the number of false positives. Advice on pitfalls in test protocols and directions for possible improvement of DST protocols were given. The presented methodology is also easily extended to other clinical test protocols.
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Affiliation(s)
- Felix Held
- Fraunhofer-Chalmers Centre, Chalmers Science Park, Gothenburg, Sweden.
- Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden.
| | - Carl Ekstrand
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marija Cvijovic
- Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden
| | - Johan Gabrielsson
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mats Jirstrand
- Fraunhofer-Chalmers Centre, Chalmers Science Park, Gothenburg, Sweden
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20
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Mejia‐Pereira S, Perez‐Ecija A, Buchanan BR, Toribio RE, Mendoza FJ. Evaluation of dynamic testing for pituitary pars intermedia dysfunction diagnosis in donkeys. Equine Vet J 2018; 51:481-488. [DOI: 10.1111/evj.13034] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/16/2018] [Indexed: 11/26/2022]
Affiliation(s)
| | - A. Perez‐Ecija
- Department of Animal Medicine and Surgery University of Cordoba, Campus Rabanales Cordoba Spain
| | | | - R. E. Toribio
- Department of Veterinary Clinical Sciences The Ohio State University Columbus Ohio USA
| | - F. J. Mendoza
- Department of Animal Medicine and Surgery University of Cordoba, Campus Rabanales Cordoba Spain
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21
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Secombe CJ, Bailey SR, de Laat MA, Hughes KJ, Stewart AJ, Sonis JM, Tan RHH. Equine pituitary pars intermedia dysfunction: current understanding and recommendations from the Australian and New Zealand Equine Endocrine Group. Aust Vet J 2018; 96:233-242. [DOI: 10.1111/avj.12716] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/29/2018] [Accepted: 05/02/2018] [Indexed: 12/25/2022]
Affiliation(s)
- CJ Secombe
- College of Veterinary Medicine, School of Veterinary and Life Sciences; Murdoch University; Murdoch Western Australia Australia
| | - SR Bailey
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Werribee VIC Australia
| | - MA de Laat
- Science and Engineering Faculty; Queensland University of Technology; Brisbane QLD Australia
| | - KJ Hughes
- School of Animal and Veterinary Sciences; Charles Sturt University; Wagga Wagga NSW Australia
| | - AJ Stewart
- Equine Specialist Hospital, School of Veterinary Science; The University of Queensland; Gatton QLD Australia
| | - JM Sonis
- Veterinary Associates Equine and Farm, Karaka; Auckland New Zealand
| | - RHH Tan
- Samford Valley Veterinary Hospital; Samford, QLD Australia
- Discipline of Veterinary Clinical Sciences, College of Public Health, Medical and Veterinary Sciences; James Cook University; Townsville QLD Australia
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22
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Madrigal RG, Andrews FM, Rademacher N, McConnico RS, Duplantis D, Eades SC. Large pituitary adenoma in an 8-year-old Arabian stallion. EQUINE VET EDUC 2018. [DOI: 10.1111/eve.12621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- R. G. Madrigal
- Equine Health Studies Program; Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; Baton Rouge USA
| | - F. M. Andrews
- Equine Health Studies Program; Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; Baton Rouge USA
| | - N. Rademacher
- Imaging Section; Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; Baton Rouge USA
| | - R. S. McConnico
- Equine Health Studies Program; Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; Baton Rouge USA
| | - D. Duplantis
- Equine Health Maintenance; Port Allen Louisiana USA
| | - S. C. Eades
- Equine Health Studies Program; Department of Veterinary Clinical Sciences; School of Veterinary Medicine; Louisiana State University; Baton Rouge USA
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23
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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. [PMID: 29704935 DOI: 10.1016/j.tvjl.2018.03.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 02/23/2018] [Accepted: 03/04/2018] [Indexed: 11/25/2022]
Abstract
Pituitary pars intermedia dysfunction (PPID) is caused by an age-related degenerative disease of dopaminergic neurones. Despite its importance in equine practice, available information regarding its epidemiology is limited. This systematic review aimed to assess published literature to evaluate available evidence regarding the clinical presentation, prevalence and risk factors for PPID in horses and ponies. Electronic database searches were undertaken using a range of terms, and English language publications published prior to August 2016 were included. Both authors independently reviewed screened papers for inclusion, extracted data, and assessed the quality of reporting using predefined criteria. Data were extracted using modified critically appraised topic data collection forms. Meta-analysis was not undertaken due to marked between-study variations. Following removal of duplicate records, of 358 published papers yielded by the search, 97 abstracts were screened for eligibility and 29 publications meeting inclusion criteria were included in the review. Most studies reviewed were case series or cross-sectional studies, with considerable variation in study populations and PPID case definition. Hypertrichosis and/or other hair coat abnormalities, laminitis and epaxial muscle wastage or muscle atrophy are the most frequently reported clinical signs, with prevalence of these signs increasing with increasing horse age. The most robust prevalence estimates for PPID were 21.2% in horses and ponies aged ≥15 years and 2.9% amongst the general equine population. Findings regarding breed and sex predispositions were equivocal and only increasing age has been identified as a significant risk factor for PPID.
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Affiliation(s)
- J L Ireland
- Department of Equine Clinical Science, Institute of Veterinary Science, Leahurst Campus, The University of Liverpool, Wirral, CH64 7TE, United Kingdom
| | - C M McGowan
- Department of Equine Clinical Science, Institute of Veterinary Science, Leahurst Campus, The University of Liverpool, Wirral, CH64 7TE, United Kingdom.
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24
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Thompson DL, Arana Valencia N. Thyrotropin-Releasing Hormone: A Powerful Tripeptide With Diverse Effects in Horses. J Equine Vet Sci 2017. [DOI: 10.1016/j.jevs.2017.08.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Ireland JL. Demographics, Management, Preventive Health Care and Disease in Aged Horses. Vet Clin North Am Equine Pract 2016; 32:195-214. [PMID: 27449388 DOI: 10.1016/j.cveq.2016.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Gerontology has become increasingly important in equine veterinary medicine, with aged animals representing a significant proportion of the equine population. Horses are defined as geriatric or aged from age 15 years onwards but can have a life span of more than 40 years. Despite a high level of owner concern for the well-being of their geriatric animal, provision of preventive health care may be suboptimal. Owners seem to under-recognize some of the most prevalent diseases identified in geriatric horses. This review focuses on the demographic characteristics of the equine geriatric population and management and preventive care practices of older horses.
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Affiliation(s)
- Joanne L Ireland
- Epidemiology and Disease Surveillance, Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
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26
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Burns TA. Effects of Common Equine Endocrine Diseases on Reproduction. Vet Clin North Am Equine Pract 2016; 32:435-449. [PMID: 27726988 DOI: 10.1016/j.cveq.2016.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Endocrine diseases, such as equine metabolic syndrome and pituitary pars intermedia dysfunction, are common in domesticated horse populations, and the frequency with which these diseases are encountered and managed by equine veterinary practitioners is expected to increase as the population ages. As clinicians learn more about the effects of these diseases on equine reproductive physiology and efficiency (including effects on reproductive seasonality, ovulation efficiency, implantation, early pregnancy loss, duration of pregnancy, and lactation), strategies and guidelines for improving fertility in affected animals continue to evolve. It is hoped that further research will establish these recommendations more firmly.
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Affiliation(s)
- Teresa A Burns
- Equine Internal Medicine, Department of Veterinary Clinical Sciences, The Ohio State University, College of Veterinary Medicine, 601 Vernon L. Tharp St, Columbus, OH 43210, USA.
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27
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Leitenbacher J, Herbach N. Age-related Qualitative Histological and Quantitative Stereological Changes in the Equine Pituitary. J Comp Pathol 2016; 154:215-24. [DOI: 10.1016/j.jcpa.2015.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/23/2015] [Accepted: 11/27/2015] [Indexed: 11/30/2022]
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28
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Karikoski NP, Patterson-Kane JC, Singer ER, McFarlane D, McGowan CM. Lamellar pathology in horses with pituitary pars intermedia dysfunction. Equine Vet J 2015; 48:472-8. [PMID: 25869529 DOI: 10.1111/evj.12450] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 04/07/2015] [Indexed: 01/11/2023]
Abstract
REASONS FOR PERFORMING STUDY Hoof lamellar pathology in horses with pituitary pars intermedia dysfunction (PPID) has not been described previously. OBJECTIVES To describe the histomorphometry and pathological lesions in hoof lamellar tissue of animals that had PPID with or without concurrent laminitis, with reference to age-matched controls. We hypothesised that lamellar lesions consistent with laminitis would be associated with PPID, even in animals without current or historical laminitis. STUDY DESIGN Prospective case-control study. METHODS Mid-dorsal hoof histological sections were obtained post mortem from the forelimbs of 16 PPID-affected animals either with (n = 6) or without laminitis (n = 10) and 10 age- and breed-matched controls. Sections were examined by a blinded veterinary pathologist. The length and width of 10 primary epidermal lamellae were measured using image analysis software. The morphology and pathology of primary and secondary epidermal lamellae were then typed or graded in axial, middle and abaxial regions. Fasting serum insulin, plasma adrenocorticotropin and blood glucose concentration were measured from blood samples taken prior to euthanasia. RESULTS All animals with PPID and laminitis had fasting hyperinsulinaemia (median 74.1 miu/l, interquartile range 49.9-349.5 miu/l) whereas PPID animals without laminitis had serum insulin concentrations below the upper limit of the reference range (<20 miu/l). Lamellar pathology in PPID animals with laminitis was variable in severity and unrelated to the reported duration of laminitis (range 2 months-5 years). Most lesions were located abaxially within the lamellar tissue and included increased length and width of the lamellae, chronic abnormal keratinisation, interlamellar epidermal bridging and cell death with more acute lamellar tearing in some cases. The lamellae of PPID animals without laminitis were normal referent to the relevant control group. CONCLUSIONS Whether PPID and hyperinsulinaemia have a causal inter-relationship or not, it may only be the hyperinsulinaemia that is associated with lamellar morphological alteration and pathology consistent with laminitis.
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Affiliation(s)
- N P Karikoski
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - J C Patterson-Kane
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - E R Singer
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
| | - D McFarlane
- Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma, USA
| | - C M McGowan
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
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Karikoski NP, McGowan CM, Singer ER, Asplin KE, Tulamo RM, Patterson-Kane JC. Pathology of Natural Cases of Equine Endocrinopathic Laminitis Associated With Hyperinsulinemia. Vet Pathol 2014; 52:945-56. [PMID: 25232034 DOI: 10.1177/0300985814549212] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Laminitis in equids is a clinical syndrome usually associated with systemic disease. Endocrinopathies recently have been recognized as the most common cause of laminitis, with hyperinsulinemia playing a key role. Descriptions of laminitis-associated lesions have been confusing due to the wide range of experimental models used, failure of adequate clinical documentation for naturally occurring cases, lack of separate analysis of inflammatory and endocrinopathic laminitis, and uncertainty regarding normal morphological variation of lamellae. In this study, lamellar morphology and pathology were described in 14 laminitic horses and ponies that had hyperinsulinemia (>20 mIU/l), with reference to 25 age- and breed-matched controls. The type and severity of lesions noted had no correlation with reported clinical duration and in at least some cases must have preceded it. Lesions were largely localized abaxially within the lamellar tissue and included apoptotic cell death, as well as lamellar fusion, hyperplasia, and partial replacement with aberrant keratin containing nucleated debris and proteinaceous lakes. The lesions resulted in irregular margins between the inner horn and the lamellar tissue. Acute separation originated from the abaxial region, with minimal associated inflammation. Axially, epidermal lamellar tapering was the most frequent morphological observation. The lesions in these chronic cases of laminitis were similar to those described in some inflammatory laminitis models and contained features seen in developmental phases of hyperinsulinemic models. These findings support the theory that repeated episodes of subclinical laminitis occur prior to clinical presentation. In addition, the pathology does not include extensive basement membrane failure seen in some inflammatory models.
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Affiliation(s)
- N P Karikoski
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki, Finland
| | - C M McGowan
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, United Kingdom
| | - E R Singer
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, United Kingdom
| | - K E Asplin
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - R-M Tulamo
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki, Finland
| | - J C Patterson-Kane
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
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Bamford NJ, Potter SJ, Harris PA, Bailey SR. Breed differences in insulin sensitivity and insulinemic responses to oral glucose in horses and ponies of moderate body condition score. Domest Anim Endocrinol 2014; 47:101-7. [PMID: 24308928 DOI: 10.1016/j.domaniend.2013.11.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/31/2013] [Accepted: 11/03/2013] [Indexed: 11/17/2022]
Abstract
Breed-related differences may occur in the innate insulin sensitivity (SI) of horses and ponies, an important factor believed to be associated with the risk of laminitis. The aim of this study was to measure the glucose and insulin responses of different breeds of horses and ponies in moderate body condition to a glucose-containing meal and to compare these responses with the indices of SI as determined by a frequently sampled intravenous glucose tolerance test (FSIGT). Eight Standardbred horses, 8 mixed-breed ponies, and 7 Andalusian-cross horses with a mean ± SEM BCS 5.0 ± 0.3 of 9 were used in this study. Each animal underwent an oral glucose tolerance test (OGTT) in which they were fed a fiber-based ration (2.0 g/kg BW) containing 1.5 g/kg BW added glucose, as well as a standard FSIGT with minimal model analysis. The glucose response variables from the OGTT were similar between groups; however, the peak insulin concentration was higher in ponies (94.1 ± 29.1 μIU/mL; P = 0.003) and Andalusians (85.3 ± 18.6; P = 0.004) than in Standardbreds (21.2 ± 3.5). The insulin area under the curve was also higher in ponies (13.5 ± 3.6 IU · min · L(-1); P = 0.009) and Andalusians (15.0 ± 2.7; P = 0.004) than in Standardbreds (3.1 ± 0.6). Insulin sensitivity, as determined by the FSIGT, was lower in Andalusians (0.99 ± 0.18 × 10(-4)/[mIU · min]) than in Standardbreds (5.43 ± 0.94; P < 0.001) and in ponies (2.12 ± 0.44; P = 0.003) than in Standardbreds. Peak insulin concentrations from the OGTT were negatively correlated with SI (P < 0.001; rs = -0.75). These results indicate that there are clear breed-related differences in the insulin responses of horses and ponies to oral and intravenous glucose. All animals were in moderate body condition, indicating that breed-related differences in insulin dynamics occurred independent of obesity.
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Affiliation(s)
- N J Bamford
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia
| | - S J Potter
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia
| | - P A Harris
- Equine Studies Group, WALTHAM Centre for Pet Nutrition, Melton Mowbray, LE14 4RT, UK
| | - S R Bailey
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia.
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31
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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 Sci 2014. [DOI: 10.1016/j.jevs.2013.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Durham AE, McGowan CM, Fey K, Tamzali Y, van der Kolk JH. Pituitarypars intermediadysfunction: Diagnosis and treatment. EQUINE VET EDUC 2014. [DOI: 10.1111/eve.12160] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - K. Fey
- Justus-Liebig-Universität; Gießen Germany
| | - Y. Tamzali
- INP-Ecole Vétérinaire de Toulouse; France
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33
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Miller C, Utter ML, Beech J. Evaluation of the effects of age and pituitary pars intermedia dysfunction on corneal sensitivity in horses. Am J Vet Res 2013; 74:1030-5. [DOI: 10.2460/ajvr.74.7.1030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Innerå M, Petersen AD, Desjardins DR, Steficek BA, Rosser EJ, Schott HC. Comparison of hair follicle histology between horses with pituitary pars intermedia dysfunction and excessive hair growth and normal aged horses. Vet Dermatol 2013; 24:212-7.e46-7. [DOI: 10.1111/j.1365-3164.2012.01080.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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35
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Spelta CW, Axon JE. Case series of equine pituitary pars intermedia dysfunction in a tropical climate. Aust Vet J 2012; 90:451-6. [DOI: 10.1111/j.1751-0813.2012.00997.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2012] [Indexed: 11/30/2022]
Affiliation(s)
- CW Spelta
- Townsville Vet Clinic; 32-34 Anne St; Aitkenvale; Queensland; 4814; Australia
| | - JE Axon
- Scone Equine Hospital; Scone; New South Wales; Australia
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36
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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 2012; 45:74-9. [DOI: 10.1111/j.2042-3306.2012.00578.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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37
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Mc Gowan TW, Pinchbeck GP, Mc Gowan CM. Evaluation of basal plasma α-melanocyte-stimulating hormone and adrenocorticotrophic hormone concentrations for the diagnosis of pituitary pars intermedia dysfunction from a population of aged horses. Equine Vet J 2012; 45:66-73. [PMID: 22563728 DOI: 10.1111/j.2042-3306.2012.00575.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
REASONS FOR PERFORMING STUDY The sensitivity and specificity of basal plasma α-melanocyte-stimulating hormone (α-MSH) and adrenocorticotrophic hormone (ACTH) for the diagnosis of pituitary pars intermedia dysfunction (PPID) has not been evaluated in a population-based study. OBJECTIVES To evaluate basal plasma α-MSH and ACTH concentrations for the diagnosis of PPID in a population of horses aged ≥ 15 years. METHODS Owner-reported data were obtained using a postal questionnaire distributed to an equestrian group. A subgroup of surveyed owners was visited and veterinary examination performed on horses aged ≥ 15 years. Blood samples were analysed for plasma α-MSH and ACTH concentrations. Seasonally adjusted cut-off values for α-MSH and ACTH concentrations for the diagnosis of PPID were obtained using Youden index values against a clinical gold standard diagnosis (hirsutism plus 3 or more clinical signs of PPID). RESULTS α-melanocyte-stimulating hormone and ACTH were highly correlated with each other and with clinical and historical indicators of PPID. The increase in both α-MSH and ACTH with increasing numbers of clinical signs in affected horses supports a spectrum of disease. Both variables were affected by season, with derived cut-off values being higher in autumn compared with other seasons. Sensitivity and specificity were moderate and good in nonautumn seasons (59 and 93%, respectively) for α-MSH using a cut-off of 52.0 pmol/l. Sensitivity and specificity were good in nonautumn seasons (80 and 83%, respectively) for ACTH using a cut-off of 29.7 pg/ml. For both α-MSH and ACTH, sensitivity and specificity were close to 100% for samples obtained during the autumn period. CONCLUSIONS AND POTENTIAL RELEVANCE Basal plasma α-MSH and ACTH had moderate-to-good sensitivity and specificity for the diagnosis of PPID, which improved substantially during the autumn period, suggesting this may be the ideal time to test. Further studies to develop seasonally adjusted reference intervals for different geographical locations are warranted.
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Affiliation(s)
- T W Mc Gowan
- Faculty of Natural Resources, Agriculture and Veterinary Science, University of Queensland, Gatton, Australia.
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38
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Rohrbach B, Stafford J, Clermont R, Reed S, Schott H, Andrews F. 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; 26:1027-34. [DOI: 10.1111/j.1939-1676.2012.00932.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 01/21/2012] [Accepted: 03/10/2012] [Indexed: 11/28/2022] Open
Affiliation(s)
| | | | | | - S.M. Reed
- Department of Veterinary Clinical Sciences; Ohio State University; Columbus; OH
| | - H.C. Schott
- Department of Large Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing; MI
| | - F.M. Andrews
- Large Animal Clinical Sciences; College of Veterinary Medicine; University of Tennessee; Knoxville; TN
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39
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The Effect of Season on the Histologic and Histomorphometric Appearance of the Equine Pituitary Gland. J Equine Vet Sci 2012. [DOI: 10.1016/j.jevs.2011.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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40
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Beech J, Boston R, Lindborg S. Comparison of Cortisol and ACTH Responses after Administration of Thyrotropin Releasing Hormone in Normal Horses and Those with Pituitary Pars Intermedia Dysfunction. J Vet Intern Med 2011; 25:1431-8. [DOI: 10.1111/j.1939-1676.2011.00810.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 08/09/2011] [Accepted: 08/22/2011] [Indexed: 11/26/2022] Open
Affiliation(s)
- J. Beech
- Department of Clinical Studies; School of Veterinary Medicine; University of Pennsylvania; New Bolton Center; Kennett Square; PA
| | - R. Boston
- Department of Clinical Studies; School of Veterinary Medicine; University of Pennsylvania; New Bolton Center; Kennett Square; PA
| | - S. Lindborg
- Department of Clinical Studies; School of Veterinary Medicine; University of Pennsylvania; New Bolton Center; Kennett Square; PA
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41
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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; 41:111-7. [PMID: 21696910 DOI: 10.1016/j.domaniend.2011.05.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 05/19/2011] [Accepted: 05/22/2011] [Indexed: 10/18/2022]
Abstract
Endocrinopathic causes of laminitis may be a common underlying causative pathogenesis in first-opinion or field cases presenting with laminitis, as opposed to laminitis produced in inflammatory research models. This study aimed to determine whether evidence of an underlying endocrinopathy was present in horses presented for laminitis to a first-opinion/referral veterinary teaching hospital. A second aim was to compare the signalment of horses and ponies with laminitis with the equine hospital population during the same period. All horses presenting for laminitis at Helsinki University Equine Teaching Hospital, Finland, over a 16-month period were examined for an underlying endocrinopathy. Horses presenting for laminitis were compared with the hospitalized population over the same period. There were 36 horses presented for laminitis, and evidence of endocrinopathy was present in 89%. Of the horses showing an underlying endocrinopathy, one-third had a diagnosis of pituitary pars intermedia dysfunction, and two-thirds showed basal hyperinsulinemia indicative of insulin resistance, without evidence of hirsutism. Phenotypic indicators of obesity were present in 95% of horses with basal hyperinsulinemia without hirsutism. Compared with the hospital population during the same period, horses with laminitis associated with an underlying endocrinopathy were significantly older and more likely to be pony breeds. Our data support that endocrine testing should be performed on all cases of laminitis that do not have a clear inflammatory or gastrointestinal origin.
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Affiliation(s)
- N P Karikoski
- Equine Teaching Hospital, Faculty of Veterinary Science, University of Helsinki, Helsinki, Finland.
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42
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McFarlane D, Paradis M, Zimmel D, Sykes B, Brorsen B, Sanchez A, Vainio K. 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; 25:872-81. [DOI: 10.1111/j.1939-1676.2011.0745.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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43
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Beech J, McFarlane D, Lindborg S, Sojka JE, Boston RC. α-Melanocyte—stimulating hormone and adrenocorticotropin concentrations in response to thyrotropin-releasing hormone and comparison with adrenocorticotropin concentration after domperidone administration in healthy horses and horses with pituitary pars intermedia dysfunction. J Am Vet Med Assoc 2011; 238:1305-15. [DOI: 10.2460/javma.238.10.1305] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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44
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Hurcombe SDA. Hypothalamic-pituitary gland axis function and dysfunction in horses. Vet Clin North Am Equine Pract 2011; 27:1-17. [PMID: 21392650 DOI: 10.1016/j.cveq.2010.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Hypothalamic-pituitary (HP) dysfunction has been documented in a limited capacity in horses and foals associated with critical illness, stress, and pain. This article reviews species-specific details of anatomy, function, hormones, receptors, and testing of the HP axis in the horse. A discussion of critical care medicine relevant to HP dysfunction in the horse with some reference to current understanding in human medicine is made, focusing primarily on current and relevant literature. A brief mention of other conditions described in human and veterinary medicine is also provided for reference only, such as syndrome of inappropriate antidiuretic hormone secretion and other conditions.
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Affiliation(s)
- Samuel D A Hurcombe
- Department of Veterinary Clinical Sciences, Galbreath Equine Center, The Ohio State University, 601 Vernon L Tharp Street, Columbus, OH 43210, USA.
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45
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Abstract
Equine pituitary pars intermedia dysfunction (PPID), also known as equine Cushing's syndrome, is a widely recognized disease of aged horses. Over the past two decades, the aged horse population has expanded significantly and in addition, client awareness of PPID has increased. As a result, there has been an increase in both diagnostic testing and treatment of the disease. This review focuses on the pathophysiology and clinical syndrome, as well as advances in diagnostic testing and treatment of PPID, with an emphasis on those findings that are new since the excellent comprehensive review by Schott in 2002.
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Affiliation(s)
- Dianne McFarlane
- Department of Physiological Sciences, 264 McElroy Hall, Oklahoma State University, Stillwater, OK 74078, USA.
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46
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Funk R, Stewart A, Wooldridge A, Kwessi E, Kemppainen R, Behrend E, Zhong Q, Johnson A. Seasonal Changes in Plasma Adrenocorticotropic Hormone and α-Melanocyte-Stimulating Hormone in Response to Thyrotropin-Releasing Hormone in Normal, Aged Horses. J Vet Intern Med 2011; 25:579-85. [DOI: 10.1111/j.1939-1676.2011.0712.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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47
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Grenager N. How Does Cushing’s Disease Relate to Laminitis? Advances in Diagnosis and Treatment. J Equine Vet Sci 2010. [DOI: 10.1016/j.jevs.2010.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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48
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Haffner JC, Fecteau KA, Eiler H, Tserendorj T, Hoffman RM, Oliver JW. Blood steroid concentrations in domestic Mongolian horses. J Vet Diagn Invest 2010; 22:537-43. [PMID: 20622223 DOI: 10.1177/104063871002200407] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Traditionally, analysis of blood cortisol alone has been used to evaluate adrenal function. Currently, multisteroid analyses are considered more informative than analysis of a single hormone to assess adrenal function. The objective of the present research was to create a database for steroid reference values for domestic Mongolian horses. Seven adrenal steroid levels were determined in the blood of 18 colts, 34 stallions, 25 geldings, 17 fillies, and 29 mares. Results were as follows (lowest and highest group median, in nanograms per milliliter): progesterone: <0.030 (fillies), 4.30 (mares), and 0.070 (all horses); 17-OH-progesterone: 0.070 (colts), 0.520 (mares), and 0.110 (all horses); androstenedione: 0.101 (colts), 0.256 (stallions), and 0.181 (all horses); testosterone: <0.040 (mares, stallions, and fillies), 0.040 (geldings and colts), and <0.40 (all horses); estradiol: 0.066 (stallions), 0.093 (fillies), and 0.085 (all horses); cortisol: 23.040 (colts), 70.210 (geldings), and 50.770 (all horses); and aldosterone: 0.018 (colts), 0.297 (geldings), and 0.191 (all horses). Overall medians indicate that cortisol (98.70%) is the predominant steroid, followed by aldosterone (0.37%), androstenedione (0.35%), 17-OH-progesterone (0.21%), estradiol (0.17%), progesterone (0.14%), and testosterone (0.06%). This information provides adrenal and gonadal steroid reference concentrations to assist in physiological characterization and diagnosis of endocrine disorders in domestic Mongolian horses.
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Affiliation(s)
- John C Haffner
- Department of Agribusiness and Agriscience, Horse Science Center, Middle Tennessee State University, Murfreesboro, TN, USA
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49
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The Pharmacologic Basis for the Treatment of Endocrinopathic Laminitis. Vet Clin North Am Equine Pract 2010; 26:303-14. [DOI: 10.1016/j.cveq.2010.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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50
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Haffner JC, Eiler H, Hoffman RM, Fecteau KA, Oliver JW. Effect of a single dose of dexamethasone on glucose homeostasis in healthy horses by using the combined intravenous glucose and insulin test1. J Anim Sci 2009; 87:131-5. [DOI: 10.2527/jas.2008-1179] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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