1
|
Hallowell KL, Dembek K, Horne CR, Knych HK, Messenger KM, Schnabel LV. Systemic absorption of triamcinolone acetonide is increased from intrasynovial versus extrasynovial sites and induces hyperglycemia, hyperinsulinemia, and suppression of the hypothalamic-pituitary-adrenal axis. Front Vet Sci 2024; 11:1388470. [PMID: 38828366 PMCID: PMC11141165 DOI: 10.3389/fvets.2024.1388470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/01/2024] [Indexed: 06/05/2024] Open
Abstract
Steroid-associated laminitis remains a major concern with use of corticosteroids in horses. Individual case factors such as joint pathology, pre-existing endocrinopathies, or corticosteroid type, dose, and timing influencing steroid-induced laminitis risk have not been investigated. This study aimed to determine if systemic absorption of triamcinolone acetonide (TA) varies between intrasynovial (antebrachiocarpal) and extrasynovial (sacroiliac) injection sites, and to determine the effects of TA absorption on glucose, insulin, cortisol, and adrenocorticotropic hormone (ACTH). Twenty adult horses were randomized into antebrachiocarpal or sacroiliac joint injection groups, and each horse received bilateral injections with a total dose of 18 mg triamcinolone. Blood was collected prior to injection and at 1, 2, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48, 60, and 72 h post-injection. Peak TA absorption occurred at 8 h in both groups, and was significantly higher in the intrasynovial group compared to the extrasynovial group (1.397 ng/mL, 0.672 ng/mL, p < 0.05). Plasma TA levels were significantly higher in the intrasynovial group from 8 to 36 h post-injection (p < 0.05). There was no difference in glucose, insulin, cortisol, or ACTH between groups at any time point. Insulin and glucose were significantly increased from baseline at all timepoints from 10-72 h and 1-72 h post-injection, respectively. Horses with elevated baseline insulin values (>20 μU/mL) from both groups experienced a more marked hyperinsulinemia, reaching a mean peak insulin of 197.5 μU/mL as compared to 90.06 μU/mL in those with normal baseline insulin. Cortisol and ACTH were significantly decreased from baseline at timepoints from 4-72 h post-injection in both groups. This study is the first to evaluate drug absorption from the sacroiliac site and demonstrates that drug absorption varies between intrasynovial and extrasynovial injection sites. TA absorption causes metabolic derangements, most notably a marked hyperinsulinemia that is more severe in horses with elevated baseline insulin values. The influence of baseline endocrinopathies on response to corticosteroid administration as well as the effect of corticosteroid-induced metabolic derangements warrant further investigation as risk factors for corticosteroid-associated laminitis.
Collapse
Affiliation(s)
- Kimberly L. Hallowell
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Katarzyna Dembek
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Caitlyn R. Horne
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Heather K. Knych
- K. L. Maddy Equine Analytical Pharmacology Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, United States
| | - Kristen M. Messenger
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - Lauren V. Schnabel
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
2
|
Shahinfar S, Maibach H. Enigma of Intramuscular Triamcinolone Acetonide (Kenalog ®) Efficacy. Clin Pharmacokinet 2023; 62:1189-1199. [PMID: 37598107 DOI: 10.1007/s40262-023-01297-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2023] [Indexed: 08/21/2023]
Abstract
Triamcinolone acetonide is a glucocorticosteroid used in standard clinical practice for its anti-inflammatory properties. Although it can be given via different routes of administration, the intramuscular route is unique compared with other corticosteroids-its effects remain potent over a longer period of time. We summarize the existing literature on the pharmacokinetic and pharmacodynamic mechanisms of intramuscular triamcinolone acetonide (Kenalog®). The fascinating nature of the purported efficacy of triamcinolone acetonide may be attributed to differing binding mechanisms, low solubility in blood, a low renal clearance rate, and various metabolites and other yet defined effects on skin. The enigma of the purported efficacy of triamcinolone acetonide may lie in the fact that it has a unique nature of having a long-term effect on dermatologic disease using a seemingly low dose compared with other routes of administration and other corticosteroids. Possible reasons for this may be binding differences at the intramuscular site, low solubility due to acetonide esters, a slow rate of absorption from the injected site, and a low renal clearance rate. There is still much to be learned about its mechanism of action, which may be of clinical and therapeutic significance.
Collapse
Affiliation(s)
- Sheeva Shahinfar
- Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA.
| | | |
Collapse
|
3
|
Marsella R, White S, Fadok VA, Wilson D, Mueller R, Outerbridge C, Rosenkrantz W. Equine allergic skin diseases: Clinical consensus guidelines of the World Association for Veterinary Dermatology. Vet Dermatol 2023; 34:175-208. [PMID: 37154488 DOI: 10.1111/vde.13168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/03/2023] [Accepted: 02/26/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND Allergic skin diseases are common in horses worldwide. The most common causes are insect bites and environmental allergens. OBJECTIVES To review the current literature and provide consensus on pathogenesis, diagnosis, treatment and prevention. MATERIALS AND METHODS The authors reviewed the literature up to November 2022. Results were presented at North America Veterinary Dermatology Forum (2021) and European Veterinary Dermatology Congress (2021). The report was available to member organisations of the World Association for Veterinary Dermatology for feedback. CONCLUSIONS AND CLINICAL RELEVANCE Insect bite hypersensitivity (IBH) is the best characterised allergic skin disease. An immunoglobulin (Ig)E response against Culicoides salivary antigens is widely documented. Genetics and environmental factors play important roles. Tests with high sensitivity and specificity are lacking, and diagnosis of IBH is based on clinical signs, seasonality and response to insect control. Eosinophils, interleukin (IL)-5 and IL-31 are explored as therapeutic targets. Presently, the most effective treatment is insect avoidance. Existing evidence does not support allergen-specific immunotherapy (ASIT) using commercially available extracts of Culicoides. Hypersensitivity to environmental allergens (atopic dermatitis) is the next most common allergy. A role for IgE is supported by serological investigation, skin test studies and positive response to ASIT. Prospective, controlled, randomised studies are limited, and treatment relies largely on glucocorticoids, antihistamines and ASIT based on retrospective studies. Foods are known triggers for urticaria, yet their role in pruritic dermatitis is unknown. Recurrent urticaria is common in horses, yet our understanding is limited and focussed on IgE and T-helper 2 cell response. Prospective, controlled studies on treatments for urticaria are lacking. Glucocorticoids and antihistamines are primary reported treatments.
Collapse
Affiliation(s)
- R Marsella
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - S White
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - V A Fadok
- Zoetis, US PET CARE, Bellaire, Texas, USA
| | - D Wilson
- School of Clinical Veterinary Sciences, University of Bristol, Bristol, UK
| | - R Mueller
- Medizinische Keleintierklinik, Zentrum für klinische Tiermedizin, LMU, Munich, Germany
| | - C Outerbridge
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | | |
Collapse
|
4
|
Manfredi JM, Jacob S, Norton E. A one-health lens offers new perspectives on the importance of endocrine disorders in the equine athlete. J Am Vet Med Assoc 2023; 261:153-164. [PMID: 36595370 DOI: 10.2460/javma.22.11.0485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Endocrine disorders are associated with joint pain and tendon injury in humans, but the effects in the horse are only starting to be understood. Similar patterns of clinical signs and injury appear to affect horses and humans for both orthopedic and endocrine disorders, supporting the use of a one-health approach to tackle these issues. In this Currents in One Health, we will discuss common equine endocrinopathies, current testing recommendations, dietary management, genetic predispositions, and endocrine disorders' effects on performance. Our aim is to use a one-health lens to describe current comparative research so that veterinarians can employ cutting-edge preventative, diagnostic, and therapeutic recommendations. Identified key gaps in knowledge include whether equine metabolic osteoarthritis exists, if steroid joint injections are safe in horses with endocrine disorders, and if the return to performance percentage improves with concurrent treatment of endocrine and musculoskeletal disorders. Key takeaways include that the relationship between endocrine disorders and musculoskeletal disease in the horse goes beyond laminitis to include lameness, muscle atrophy, suspensory ligament degeneration, osteochondritis dissecans, and potentially metabolic osteoarthritis. Approaches learned from human and equine comparative studies can offer insight into injury recognition and management, thus mitigating the impact of endocrine disorders on performance in both species. Readers interested in an in-depth description of current and future research involving pathophysiology, novel interventions, and multiomic approaches to identify individuals with athletic limitations induced by endocrine disorders are invited to read the companion Currents in One Health by Manfredi et al, AJVR, February 2023.
Collapse
Affiliation(s)
- Jane M Manfredi
- 1Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI
| | - Sarah Jacob
- 1Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI
| | - Elaine Norton
- 2Department of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ
| |
Collapse
|
5
|
Circulating hypothalamic-pituitary-adrenal axis hormones and insulin concentrations in horses and ponies. J Equine Vet Sci 2021; 111:103810. [DOI: 10.1016/j.jevs.2021.103810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 11/07/2021] [Accepted: 11/08/2021] [Indexed: 11/20/2022]
|
6
|
Mainguy-Seers S, Lavoie JP. Glucocorticoid treatment in horses with asthma: A narrative review. J Vet Intern Med 2021; 35:2045-2057. [PMID: 34085342 PMCID: PMC8295667 DOI: 10.1111/jvim.16189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 12/15/2022] Open
Abstract
Despite substantial research efforts to improve the treatment and outcome of horses with asthma, glucocorticoids (GC) remain the cornerstone of drug treatment of this prevalent disease. The high efficacy of GC to relieve airway obstruction explains their extensive use despite potential deleterious effects. However, much is yet to be uncovered concerning GC use in horses with asthma, including the comparative efficacy of the different drugs, the determination of minimal effective doses and the mechanisms underlying their variable modulation of airway inflammation. The objectives of this structured review were to report and compare the plethora of effects of the various GC used in asthmatic horses with a focus on impact on lung function, airway inflammation, and bronchial remodeling. Adverse effects are also briefly described, with an emphasis on those that have been specifically reported in horses with asthma. Ultimately, we aimed to highlight gaps in the literature and to identify future research areas.
Collapse
Affiliation(s)
- Sophie Mainguy-Seers
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Jean-Pierre Lavoie
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Université de Montréal, St-Hyacinthe, Quebec, Canada
| |
Collapse
|
7
|
Potter K, Stevens K, Menzies-Gow N. Prevalence of and risk factors for acute laminitis in horses treated with corticosteroids. Vet Rec 2019; 185:82. [DOI: 10.1136/vr.105378] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/15/2019] [Accepted: 05/15/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Katya Potter
- Department of Clinical Sciences and Services; Royal Veterinary College; North Mymms Hertfordshire UK
| | - Kim Stevens
- Department of Pathobiology and Population Sciences; Royal Veterinary College; North Mymms Hertfordshire UK
| | - Nicola Menzies-Gow
- Department of Clinical Sciences and Services; Royal Veterinary College; North Mymms Hertfordshire UK
| |
Collapse
|
8
|
Coleman MC, Belknap JK, Eades SC, Galantino-Homer HL, Hunt RJ, Geor RJ, McCue ME, McIlwraith CW, Moore RM, Peroni JF, Townsend HG, White NA, Cummings KJ, Ivanek-Miojevic R, Cohen ND. Case-control study of risk factors for pasture-and endocrinopathy-associated laminitis in North American horses. J Am Vet Med Assoc 2019; 253:470-478. [PMID: 30058970 DOI: 10.2460/javma.253.4.470] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate risk factors for the development of pasture- and endocrinopathy-associated laminitis (PEAL) in horses and ponies in North America. DESIGN Case-control study. ANIMALS 199 horses with incident cases of PEAL and 351 horses from 2 control populations (healthy horses [n = 198] and horses with lameness not caused by laminitis [153]) that were evaluated in North America between January 2012 and December 2015 by veterinarian members of the American Association of Equine Practitioners. PROCEDURES North American members of the American Association of Equine Practitioners were contacted to participate in the study, and participating veterinarians provided historical data on incident cases of PEAL, each matched with a healthy control and a lameness control. Conditional logistic regression analysis was used to compare data on PEAL-affected horses with data on horses from each set of controls. RESULTS Horses with an obese body condition (ie, body condition score ≥ 7), generalized or regional adiposity (alone or in combination), preexisting endocrinopathy, or recent (within 30 days) glucocorticoid administration had increased odds of developing PEAL, compared with horses that did not have these findings. CONCLUSIONS AND CLINICAL RELEVANCE The present study identified several risk factors for PEAL that may assist not only in managing and preventing this form of laminitis, but also in guiding future research into its pathogenesis.
Collapse
|
9
|
Mazan MR. Lower Airway Disease in the Athletic Horse. Vet Clin North Am Equine Pract 2018; 34:443-460. [PMID: 30007452 DOI: 10.1016/j.cveq.2018.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The airways are the first part of the pathway in the oxygen transport chain that is critical to excellent athletic performance, and the lower airways are considered the final gatekeeper before oxygen enters the blood and carbon dioxide exits. Horses are blessed with large airways and lungs that allow them to be superb athletes, but the down side of this largesse on the part of evolution is that unless they are truly elite athletes they may withstand noninfectious disease of the lower respiratory tract for months to years before the owner or trainer notices. The two conditions of the lower respiratory tract that affect the athletic horse during exercise are exercise-induced pulmonary hemorrhage and inflammatory airway disease. The former may be considered, at least at the onset, as a problem of physiology rather than a disease, and the latter is a disease primarily of domestication: both are widespread among the athletic horse population and account for an impressive number of horses that fail to perform to their potential. Because of the high demands for oxygen in the athletic horse, even minor insults to the oxygen-carrying capacity of the body can affect performance, so it is of critical importance to keep the lungs as healthy as possible.
Collapse
Affiliation(s)
- Melissa R Mazan
- Department of Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA.
| |
Collapse
|
10
|
|
11
|
Welsh CE, Duz M, Parkin TDH, Marshall JF. Disease and pharmacologic risk factors for first and subsequent episodes of equine laminitis: A cohort study of free-text electronic medical records. Prev Vet Med 2016; 136:11-18. [PMID: 28010903 DOI: 10.1016/j.prevetmed.2016.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 11/16/2016] [Accepted: 11/21/2016] [Indexed: 01/03/2023]
Abstract
Electronic medical records from first opinion equine veterinary practice may represent a unique resource for epidemiologic research. The appropriateness of this resource for risk factor analyses was explored as part of an investigation into clinical and pharmacologic risk factors for laminitis. Amalgamated medical records from seven UK practices were subjected to text mining to identify laminitis episodes, systemic or intra-synovial corticosteroid prescription, diseases known to affect laminitis risk and clinical signs or syndromes likely to lead to corticosteroid use. Cox proportional hazard models and Prentice, Williams, Peterson models for repeated events were used to estimate associations with time to first, or subsequent laminitis episodes, respectively. Over seventy percent of horses that were diagnosed with laminitis suffered at least one recurrence. Risk factors for first and subsequent laminitis episodes were found to vary. Corticosteroid use (prednisolone only) was only significantly associated with subsequent, and not initial laminitis episodes. Electronic medical record use for such analyses is plausible and offers important advantages over more traditional data sources. It does, however, pose challenges and limitations that must be taken into account, and requires a conceptual change to disease diagnosis which should be considered carefully.
Collapse
Affiliation(s)
- Claire E Welsh
- Equine Clinical Sciences Division, Weipers Centre Equine Hospital, School of Veterinary Medicine, University of Glasgow, UK.
| | - Marco Duz
- School of Veterinary Medicine and Science, University of Nottingham, UK
| | - Timothy D H Parkin
- Equine Clinical Sciences Division, Weipers Centre Equine Hospital, School of Veterinary Medicine, University of Glasgow, UK
| | - John F Marshall
- Equine Clinical Sciences Division, Weipers Centre Equine Hospital, School of Veterinary Medicine, University of Glasgow, UK
| |
Collapse
|
12
|
Jordan VJ, Ireland JL, Rendle DI. Does oral prednisolone treatment increase the incidence of acute laminitis? Equine Vet J 2016; 49:19-25. [PMID: 26713748 DOI: 10.1111/evj.12565] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/17/2015] [Indexed: 01/11/2023]
Abstract
REASONS FOR PERFORMING STUDY It is accepted among equine practitioners that glucocorticoid treatment is a risk factor for the development of laminitis. However, there is little published evidence of a link between glucocorticoids and laminitis. OBJECTIVES To determine whether horses receiving oral prednisolone are at increased risk of laminitis. STUDY DESIGN Retrospective case-control study. METHODS Clinical records of horses registered with the ambulatory service at Liphook Equine Hospital between January 2001 and November 2014 were reviewed retrospectively to identify horses that had received treatment with oral prednisolone. For each treated horse, 2 time-matched controls that received veterinary attention but were not treated with prednisolone were selected. Incidence of laminitis was compared between the 2 groups and factors associated with laminitis were assessed using Cox regression analysis. RESULTS Of the 416 horses treated with prednisolone, 16 (3.8%) were diagnosed with laminitis subsequent to the initiation of prednisolone treatment with an overall incidence of 2.60 (95% CI 1.49-4.22) cases per 100 horse-years at risk. A total of 7 horses (1.7%) developed laminitis during the course of their treatment and 3 (0.7%) of the horses treated with prednisolone were ultimately subjected to euthanasia as a result of laminitis. A total of 46 (5.7%), of the 814 time-matched control horses were diagnosed with laminitis during the study period with an overall incidence of 3.46 (95% CI 2.54-4.62) cases per 100 horse-years at risk. Of these, 12 (1.5%) were subjected to euthanasia as a result of laminitis. There were no significant differences in the overall laminitis incidence rate (P = 0.8), incidence rate during prednisolone treatment (P = 0.09), or probability of laminitis (P = 0.3) between the 2 groups. Mean survival time was greater in the prednisolone than the control group. Equine metabolic syndrome and increasing age were associated with increased risk of laminitis. CONCLUSIONS Administration of oral prednisolone did not increase the risk of laminitis.
Collapse
Affiliation(s)
- V J Jordan
- Liphook Equine Hospital, Liphook, Hampshire, UK
| | - J L Ireland
- The Animal Health Trust, Newmarket, Suffolk, UK
| | - D I Rendle
- Rainbow Equine Hospital, Rainbow Farm, Old Malton, North Yorkshire, UK
| |
Collapse
|
13
|
Valenzuela OA, Jellyman JK, Allen VL, Holdstock NB, Fowden AL. Effects of maternal dexamethasone treatment on pancreatic β cell function in the pregnant mare and post natal foal. Equine Vet J 2016; 49:99-106. [DOI: 10.1111/evj.12560] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 12/11/2015] [Indexed: 01/06/2023]
Affiliation(s)
- O. A. Valenzuela
- Department of Physiology, Development and Neuroscience; University of Cambridge; CB2 3EG UK
| | - J. K. Jellyman
- Department of Physiology, Development and Neuroscience; University of Cambridge; CB2 3EG UK
| | - V. L. Allen
- Department of Physiology, Development and Neuroscience; University of Cambridge; CB2 3EG UK
| | - N. B. Holdstock
- Department of Clinical Veterinary Medicine; University of Cambridge; CB2 3EG UK
| | - A. L. Fowden
- Department of Physiology, Development and Neuroscience; University of Cambridge; CB2 3EG UK
| |
Collapse
|
14
|
Hart KA, Wochele DM, Norton NA, McFarlane D, Wooldridge AA, Frank N. Effect of Age, Season, Body Condition, and Endocrine Status on Serum Free Cortisol Fraction and Insulin Concentration in Horses. J Vet Intern Med 2016; 30:653-63. [PMID: 26860336 PMCID: PMC4913614 DOI: 10.1111/jvim.13839] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/04/2015] [Accepted: 01/18/2016] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Increased free cortisol fraction is associated with insulin dysregulation (ID) in people with Metabolic Syndrome and Cushing's Disease. Free cortisol has not been investigated in equine endocrine disorders. HYPOTHESES (1) In healthy horses, sex, age, body condition score (BCS), and season impact free cortisol; (2) free cortisol is increased in horses with Pituitary Pars Intermedia Dysfunction (PPID) or Equine Metabolic Syndrome (EMS). ANIMALS Fifty-seven healthy horses; 40 horses and ponies with PPID (n = 20) or EMS (n = 20). METHODS Prospective study. Serum collected seasonally from healthy animals and archived serum from PPID and EMS animals was analyzed for insulin, total and free cortisol concentrations, and free cortisol fraction (FCF). Linear mixed models were used to determine effects of age, sex, season, and BCS on hormones in controls. Hormone measurements were compared between disease groups and age- and season-matched controls with t-tests. EMS and hyperinsulinemic PPID animals were combined in an ID (hyperinsulinemia) group. RESULTS Free cortisol concentrations were increased in overweight/obese controls (0.3 ± 0.1 μg/dL) compared to lean controls (0.2 ± 0.1 μg/dL; P = .017). Mean FCF was significantly higher in animals with PPID (8.8 ± 5.8 μg/dL, P = .005) or ID (8.8 ± 10.2 μg/dL, P = .039) than controls (5.0 ± 0.9 μg/dL), but total cortisol concentrations were similar (P ≥ .350) (PPID: 4.2 ± 4.3 μg/dL; ID: 5.0 ± 4.5 μg/dL; controls: 4.6 ± 1.7 and 5.1 ± 2.1 μg/dL). CONCLUSIONS AND CLINICAL IMPORTANCE Increased FCF is associated with obesity in healthy horses and with ID (hyperinsulinemia) in horses and ponies with endocrine disease. Decreased plasma cortisol-binding capacity could be a component of these endocrine disorders in horses.
Collapse
Affiliation(s)
- K A Hart
- University of Georgia College of Veterinary Medicine, Athens, GA
| | - D M Wochele
- University of Georgia College of Veterinary Medicine, Athens, GA
| | - N A Norton
- University of Georgia College of Veterinary Medicine, Athens, GA
| | - D McFarlane
- Oklahoma State College of Veterinary Medicine, Stillwater, OK
| | - A A Wooldridge
- Auburn University College of Veterinary Medicine, Auburn, AL
| | - N Frank
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA
| |
Collapse
|
15
|
Knych HK, Harrison LM, White A, McKemie DS. Disposition of isoflupredone acetate in plasma, urine and synovial fluid following intra-articular administration to exercised Thoroughbred horses. Drug Test Anal 2015; 8:141-7. [DOI: 10.1002/dta.1834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 03/18/2015] [Accepted: 06/08/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Heather K. Knych
- K.L. Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis 95616 CA USA
- Department of Veterinary Molecular Biosciences, School of Veterinary Medicine; University of California; Davis 95616 CA USA
| | | | - Alexandria White
- K.L. Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis 95616 CA USA
| | - Daniel S. McKemie
- K.L. Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis 95616 CA USA
| |
Collapse
|
16
|
Mazan MR. Update on noninfectious inflammatory diseases of the lower airway. Vet Clin North Am Equine Pract 2015; 31:159-85. [PMID: 25770068 DOI: 10.1016/j.cveq.2014.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Inflammatory airway disease and recurrent airway obstruction are 2 nonseptic diseases of the equine respiratory system with a shared cause of exposure to particulate matter. They appear to occupy 2 ends of a spectrum of disease, but are differentiated by history, clinical signs, and response to treatment. Diagnosis can be made by sampling of respiratory fluids and lung function testing. Treatment consists of environmental modification and pharmacologic treatment with systemic or inhaled corticosteroids and bronchodilators.
Collapse
Affiliation(s)
- Melissa R Mazan
- Large Animal Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, 200 Westborough Road, North Grafton, MA 01536, USA.
| |
Collapse
|
17
|
Knych HK, Vidal MA, Casbeer HC, McKemie DS. Pharmacokinetics of triamcinolone acetonide following intramuscular and intra-articular administration to exercised Thoroughbred horses. Equine Vet J 2013; 45:715-20. [DOI: 10.1111/evj.12059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 01/27/2013] [Indexed: 11/30/2022]
Affiliation(s)
- H. K. Knych
- K.L. Maddy Equine Analytical Chemistry Laboratory; School of Veterinary Medicine; University of California; USA
- Department of Veterinary Molecular Biosciences; School of Veterinary Medicine; University of California; USA
| | - M. A. Vidal
- Department of Surgery and Radiology; School of Veterinary Medicine; University of California; USA
| | - H. C. Casbeer
- K.L. Maddy Equine Analytical Chemistry Laboratory; School of Veterinary Medicine; University of California; USA
| | - D. S. McKemie
- K.L. Maddy Equine Analytical Chemistry Laboratory; School of Veterinary Medicine; University of California; USA
| |
Collapse
|
18
|
Katz LM, Bailey SR. A review of recent advances and current hypotheses on the pathogenesis of acute laminitis. Equine Vet J 2013; 44:752-61. [PMID: 23106629 DOI: 10.1111/j.2042-3306.2012.00664.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
With the increasing number of studies being published on the different experimental models used to induce and study acute laminitis, the pathophysiological events associated with these various models (i.e. starch overload, oligofructose overload, black walnut extract and hyperinsulinaemia) can be compared more realistically. Within this review, the mechanisms for metabolic vs. inflammatory laminitis are discussed, and the question of how pasture laminitis may fit into any of the proposed mechanisms is addressed.
Collapse
Affiliation(s)
- L M Katz
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland.
| | | |
Collapse
|
19
|
Keen JA, McGorum BC, Hillier C, Nally JE. Short-term incubation of equine laminar veins with cortisol and insulin alters contractility in vitro: possible implications for the pathogenesis of equine laminitis. J Vet Pharmacol Ther 2012; 36:382-8. [PMID: 22943152 DOI: 10.1111/j.1365-2885.2012.01429.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 07/07/2012] [Indexed: 11/25/2022]
Abstract
This study investigated the effects of cortisol and insulin, hormones that affect both glycaemic status and vascular function, on the in vitro contractility of isolated healthy equine small laminar veins. Small veins (150-500 μm) draining the digital laminae from healthy horses or ponies were investigated by wire myography. Concentration response curves were constructed for noradrenaline (NA), phenylephrine (PE), endothelin-1 (ET-1) and 5-hydroxytryptamine (5-HT) in the presence of either cortisol (10(-6 ) m) or insulin (1000 μIU/mL). Cortisol significantly increased the maximum contractility of laminar veins to the vasoconstrictors NA and 5-HT but decreased the maximal contraction to ET-1. Insulin decreased the contractility of vessels to PE and ET-1. It is possible that short-term cortisol excess could enhance venoconstrictor responses to 5-HT and NA in laminar veins in vivo, thereby predisposing to laminitis. Additionally, a reduction in the ability of insulin to counteract alpha-adrenoreceptor and ET-1-mediated contraction, likely to occur in subjects with insulin resistance, may further exacerbate venoconstriction in animals prone to laminitis. These mechanisms may also predispose horses with disorders such as equine Cushing's disease and equine metabolic syndrome to laminitis.
Collapse
Affiliation(s)
- J A Keen
- Department of Biological and Biochemical Science, Glasgow Caledonian University, Glasgow, UK.
| | | | | | | |
Collapse
|
20
|
|
21
|
|
22
|
Soma LR, Uboh CE, You Y, Guan F, Boston RC. Pharmacokinetics of intra-articular, intravenous, and intramuscular administration of triamcinolone acetonide and its effect on endogenous plasma hydrocortisone and cortisone concentrations in horses. Am J Vet Res 2011; 72:1234-42. [DOI: 10.2460/ajvr.72.9.1234] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
23
|
Asplin KE, Curlewis JD, McGowan CM, Pollitt CC, Sillence MN. Glucose transport in the equine hoof. Equine Vet J 2011; 43:196-201. [PMID: 21592215 DOI: 10.1111/j.2042-3306.2010.00127.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
REASONS FOR PERFORMING STUDY Several conditions associated with laminitis in horses are also associated with insulin resistance, which represents the failure of glucose uptake via the insulin-responsive glucose transport proteins in certain tissues. Glucose starvation is a possible mechanism of laminitis, but glucose uptake mechanisms in the hoof are not well understood. OBJECTIVES To determine whether glucose uptake in equine lamellae is dependent on insulin, to characterise the glucose transport mechanism in lamellae from healthy horses and ponies, and to compare this with ponies with laminitis. METHODS Study 1 investigated the effects of insulin (300 µU/ml; acute and 24 h) and various concentrations of glucose up to 24 mmol/l, on 2-deoxy-D-[2,6-(3)H] glucose uptake in hoof lamellar explants in vitro. Study 2 measured the mRNA expression of GLUT1 and GLUT4 transport proteins by PCR analysis in coronary band and lamellar tissue from healthy horses and ponies, ponies with insulin-induced laminitis, and ponies suffering from chronic laminitis as a result of equine Cushing's syndrome. RESULTS Glucose uptake was not affected by insulin. Furthermore, the relationship between glucose concentration and glucose uptake was consistent with an insulin-independent glucose transport system. GLUT1 mRNA expression was strong in brain, coronary band and lamellar tissue, but was weak in skeletal muscle. Expression of GLUT4 mRNA was strong in skeletal muscle, but was either absent or barely detectable in coronary band and lamellar tissue. CONCLUSIONS The results do not support a glucose deprivation model for laminitis, in which glucose uptake in the hoof is impaired by reduced insulin sensitivity. Hoof lamellae rely on a GLUT1-mediated glucose transport system, and it is unlikely that GLUT4 proteins play a substantial role in this tissue. POTENTIAL RELEVANCE Laminitis associated with insulin resistance is unlikely to be due to impaired glucose uptake and subsequent glucose deprivation in lamellae.
Collapse
Affiliation(s)
- K E Asplin
- School of Veterinary Science, The University of Queensland, Australia.
| | | | | | | | | |
Collapse
|
24
|
Serum thyroid hormone, insulin, glucose, triglycerides and protein concentrations in normal horses: Association with topical dexamethasone usage. Vet J 2011; 188:307-12. [DOI: 10.1016/j.tvjl.2010.05.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/24/2010] [Accepted: 05/30/2010] [Indexed: 11/19/2022]
|
25
|
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. [DOI: 10.1080/01652176.2011.570127] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
26
|
Divers TJ. Clinical Application of Current Research Findings Toward the Prevention and Treatment of Acute Laminitis in Horses With Systemic Inflammatory Diseases: An Internist’s Perspective. J Equine Vet Sci 2010. [DOI: 10.1016/j.jevs.2010.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
27
|
Abstract
In laminitis occurring in the field, as opposed to laminitis occurring during hospitalization or severe illness, endocrinopathic laminitis is the predominant form of laminitis. Prevalent causes of endocrinopathic laminitis are ECS and EMS. Exclusion of inflammatory or weight bearing causes of laminitis and focussing on the identification and treatment of underlying endocrine conditions will improve laminitis management strategies.
Collapse
Affiliation(s)
- Catherine M McGowan
- School of Veterinary Science, Faculty of Health and Life Sciences, University of Liverpool, Leahurst, UK.
| |
Collapse
|
28
|
Abstract
A direct causal association between corticosteroid use and laminitis has yet to be proven scientifically, and there have been few studies specifically addressing this aspect. New evidence, however, is improving the understanding of the causes of laminitis, particularly related to endocrine factors. The focus of this article is discussing the circumstances under which steroids might cause this condition.
Collapse
|
29
|
McCluskey MJ, Kavenagh PB. Clinical use of triamcinolone acetonide in the horse (205 cases) and the incidence of glucocorticoid-induced laminitis associated with its use. EQUINE VET EDUC 2010. [DOI: 10.1111/j.2042-3292.2004.tb00272.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
30
|
|
31
|
ABRAHAM G, ALLERSMEIER M, GOTTSCHALK J, SCHUSSER GF, HOPPEN HO, UNGEMACH FR. Effects of dermal dexamethasone application on ACTH and both basal and ACTH-stimulated cortisol concentration in normal horses. J Vet Pharmacol Ther 2009; 32:379-87. [DOI: 10.1111/j.1365-2885.2008.01054.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
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
|
33
|
Brown PA, Bodles-Brakhop A, Draghia-Akli R. Plasmid growth hormone releasing hormone therapy in healthy and laminitis-afflicted horses-evaluation and pilot study. J Gene Med 2008; 10:564-74. [PMID: 18302303 DOI: 10.1002/jgm.1170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND In vivo electroporation dramatically improves the potency of plasmid-mediated therapies, including in large animal models. Laminitis and arthritis are common and debilitating diseases in the horse, as well as humans. METHODS The effects of growth hormone releasing hormone (GHRH) on healthy horses and on horses with laminitis that were followed for 6 months after a single intramuscular injection and electroporation of 2.5 mg of an optimized myogenic GHRH-expressing plasmid were examined. RESULTS In the first study on six healthy horses, we observed a significant increase in body mass by day 180 compared to baseline (P < 0.003), and an increase in erythrocyte production (hematocrit, red blood cells, hemoglobin, P = 0.03). IGF-I levels were increased by 7% by day 120 (P = 0.02). A pilot study was performed on two horses with chronic laminitis, a vascular condition often associated with arthritis, with two horses with similar clinical disease serving as non-treated controls. Treated horses experienced an increase in weight compared to control horses that received standard care (P = 0.007). By 6 months post-treatment, treated subjects were rated pasture sound. Physical and radiographic evaluation demonstrated significant improvement with reduced inflammation and decreased lameness. CONCLUSIONS These results demonstrate that a plasmid therapy delivered by electroporation can potentially be used to treat chronic conditions in horses, and possibly other very large mammals. While further studies are needed, overall this proof-of-concept work presents encouraging data for studying gene therapeutic treatments for Raynaud's syndrome and arthritis in humans.
Collapse
|
34
|
Abstract
Insulin resistance is thought to be involved in the pathogenesis of many equine conditions such as pars intermedia dysfunction, equine metabolic syndrome, diabetes mellitus, hyperlipaemia, laminitis, endotoxaemia and osteochondrosis dissecans (OCD); whereas polysaccharide storage myopathy in Quarter Horses and equine motor neuron disease (EMD) have been associated with increased insulin sensitivity. However, it is clear that there is not one ideal test, in terms of both practicality and accuracy, for evaluating insulin sensitivity in horses and improved diagnostic techniques are required. This review sets out the background to the subject and identifies current knowledge regarding the measurement of insulin sensitivity by tolerance testing and clamping techniques. Factors affecting insulin sensitivity, such as breed, pregnancy, lactation, obesity and nutritional factors are discussed. In addition, the relationship with training, nutritional supplementation and drug administration are considered.
Collapse
Affiliation(s)
- A M Firshman
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
| | | |
Collapse
|
35
|
Affiliation(s)
- Jonathan H Magid
- Dr. T's Equine Clinic, 586 Lonesome Dove Lane, Salado, TX 76571, USA.
| |
Collapse
|
36
|
Tiley HA, Geor RJ, McCutcheon LJ. Effects of dexamethasone on glucose dynamics and insulin sensitivity in healthy horses. Am J Vet Res 2007; 68:753-9. [PMID: 17605611 DOI: 10.2460/ajvr.68.7.753] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine effects of dexamethasone on glucose dynamics and insulin sensitivity in healthy horses. ANIMALS 6 adult Standardbreds. PROCEDURES In a balanced crossover study, horses received dexamethasone (0.08 mg/ kg, IV, q 48 h) or an equivalent volume of saline (0.9% NaCl) solution (control treatment) during a 21-day period. Horses underwent a 3-hour frequently sampled IV glucose tolerance test (FSIGT) 2 days after treatment. Minimal model analysis of glucose and insulin data from FSIGTs were used to estimate insulin sensitivity (Si), glucose effectiveness (Sg), acute insulin response to glucose (AIRg), and disposition index. Proxies for Si (reciprocal of the inverse square of basal insulin concentration [RISQI]) and beta-cell responsiveness (modified insulin-to-glucose ratio [MIRG]) were calculated from basal plasma glucose and serum insulin concentrations. RESULTS Mean serum insulin concentration was significantly higher in dexamethasone-treated horses than control horses on days 7, 14, and 21. Similarly, mean plasma glucose concentration was higher in dexamethasone-treated horses on days 7, 14, and 21; this value differed significantly on day 14 but not on days 7 or 21. Minimal model analysis of FSIGT data revealed a significant decrease in Si and a significant increase in AIRg after dexamethasone treatment, with no change in Sg or disposition index. Mean RISQI was significantly lower, whereas MIRG was higher, in dexamethasone-treated horses than control horses on days 7, 14, and 21. CONCLUSIONS AND CLINICAL RELEVANCE The study revealed marked insulin resistance in healthy horses after 21 days of dexamethasone administration. Because insulin resistance has been associated with a predisposition to laminitis, a glucocorticoid-induced decrease in insulin sensitivity may increase risk for development of laminitis in some horses and ponies.
Collapse
Affiliation(s)
- Heather A Tiley
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | | | | |
Collapse
|
37
|
Bailey SR, Elliott J. The corticosteroid laminitis story: 2. Science of if, when and how. Equine Vet J 2007; 39:7-11. [PMID: 17228587 DOI: 10.2746/042516407x166035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- S R Bailey
- Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK
| | | |
Collapse
|
38
|
Cornelisse CJ, Robinson NE, Berney CA, Eberhart S, Hauptman JE, Derksen FJ. Thermographic study of in vivo modulation of vascular responses to phenylephrine and endothelin-1 by dexamethasone in the horse. Equine Vet J 2006; 38:119-26. [PMID: 16536380 DOI: 10.2746/042516406776563251] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY In vitro, glucocorticoids potentiate vasoconstriction of equine digital vessels to catecholamines and this has been implicated as a mechanism of glucocorticoid-induced laminitis. This observation has never been confirmed in vivo. OBJECTIVES To study the effects of glucocorticoid therapy on vasoconstrictor responsiveness in the horse in vivo. METHODS In a blinded, randomised cross-over experiment, 9 horses were treated with either dexamethasone (0.1 mg/kg bwt i.v. q. 24 h) or saline i.v. for 6 days. The changes in local average skin temperature before (baseline) and after intradermal injections of the alpha1-adrenoceptor agonist phenylephrine (PHE; 10(-4), 10(-5), 10(-6), 10(-7) and 10(-8) mol/l), endothelin-1 (ET-1; 10(-5), 10(-6), 10(-7), 10(-8) and 10(-9) mol/l) or ET-1 plus a blocker (BQ-123 10(-6) mol/l; RES-701 10(-6) mol/l; and L-NAME 10(-4) mol/l) were investigated with a thermograph. RESULTS Dexamethasone (DEX) decreased baseline skin temperatures, suggesting reduced blood flow as a consequence of an increase in vasomotor tone. This was accompanied by potentiation of the response to PHE as demonstrated by a left shift in the dose-response curve and a decrease in the EC50. Dexamethasone did not potentiate ET-1, but the interplay with the lower baseline temperature resulted in a significantly lower skin temperature for this vasoconstrictor after DEX. The different ET-1 blockers had no effect on ET-1 modulated skin temperatures. CONCLUSIONS Dexamethasone decreases skin perfusion. This is accompanied by a potentiated alpha1-adrenoceptor agonist response and a greater response to ET-1. POTENTIAL RELEVANCE Glucocorticoid therapy probably decreases perfusion of the equine hoof. During disease states that already are characterised by hypoperfusion and/or increased levels of circulating catecholamines, glucocorticoid therapy could, according to the vascular model of laminitis, tilt the balance in favour of laminitis.
Collapse
Affiliation(s)
- C J Cornelisse
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48823-1314, USA
| | | | | | | | | | | |
Collapse
|
39
|
de Graaf-Roelfsema E, Tharasanit T, van Dam KG, Keizer HA, van Breda E, Wijnberg ID, Stout TAE, van der Kolk JH. Effects of short- and long-term recombinant equine growth hormone and short-term hydrocortisone administration on tissue sensitivity to insulin in horses. Am J Vet Res 2005; 66:1907-13. [PMID: 16334949 DOI: 10.2460/ajvr.2005.66.1907] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the effects of short-term IV administration of hydrocortisone or equine growth hormone (eGH) or long-term IM administration of eGH to horses on tissue sensitivity to exogenous insulin. ANIMALS 5 Standardbreds and 4 Dutch Warmblood horses. PROCEDURE The euglycemic-hyperinsulinemic clamp technique was used to examine sensitivity of peripheral tissues to exogenous insulin 24 hours after administration of a single dose of hydrocortisone (0.06 mg/kg), eGH (20 microg/kg), or saline (0.9% NaCl) solution and after long-term administration (11 to 15 days) of eGH to horses. The amounts of metabolized glucose (M) and plasma insulin concentration (I) were determined. RESULTS Values for M and the M-to-I ratio were significantly higher 24 hours after administration of a single dose of hydrocortisone than after single-dose administration of eGH or saline solution. After long-term administration of eGH, basal I concentration was increased and the mean M-to-I ratio was 22% lower, compared with values for horses treated with saline solution. CONCLUSIONS AND CLINICAL RELEVANCE Increases in M and the M-to-I ratio after a single dose of hydrocortisone imply that short-term hydrocortisone treatment increases glucose use by, and insulin sensitivity of, peripheral tissues. Assuming a single dose of hydrocortisone improves sensitivity of peripheral tissues to insulin, it may be an interesting candidate for use in reducing insulin resistance in peripheral tissues of horses with several disease states. In contrast, long-term administration of eGH decreased tissue sensitivity to exogenous insulin associated with hyperinsulinemia. Therefore, increased concentrations of growth hormone may contribute to insulin resistance in horses with various disease states.
Collapse
Affiliation(s)
- Ellen de Graaf-Roelfsema
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Donaldson MT, McDonnell SM, Schanbacher BJ, Lamb SV, McFarlane D, Beech J. Variation in Plasma Adrenocorticotropic Hormone Concentration and Dexamethasone Suppression Test Results with Season, Age, and Sex in Healthy Ponies and Horses. J Vet Intern Med 2005. [DOI: 10.1111/j.1939-1676.2005.tb02685.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
41
|
Rio Tinto J, Alves G, Faleiros R, Santos R, Marques Júnior A, Melo E. Utilização de hidrocortisona em eqüinos submetidos a isquemia e reperfusão no jejuno e suas conseqüências sobre o cório laminar. ARQ BRAS MED VET ZOO 2004. [DOI: 10.1590/s0102-09352004000300002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Estudou-se o efeito da administração de succinato sódico de hidrocortisona (SSH) no desenvolvimento de lesões no cório laminar de eqüinos. Doze animais foram submetidos à laparotomia sob anestesia geral e à isquemia total em dois segmentos do jejuno, enquanto três foram usados como controle. Após uma hora de isquemia, seis animais receberam 4,0mg/kg de SSH por via intravenosa (grupo T) e seis receberam placebo (grupo NT). Após duas horas de isquemia foi restabelecido o fluxo de sangue local e, decorridas duas horas de reperfusão, foi realizada a laparorrafia e permitiu-se a recuperação anestésica. Após 12 horas do início da reperfusão, os animais foram sacrificados e deles colhidas amostras de tecido laminar para avaliação histomorfológica. As alterações avaliadas ao microscópio óptico foram quantificadas por escores que variaram de 0 a 3. Os escores para lesão no tecido laminar foram semelhantes nos animais dos grupos T (0,41) e NT (0,54), permitindo concluir que a hidrocortisona não acentuou as lesões produzidas no tecido laminar após a isquemia e reperfusão no jejuno.
Collapse
|
42
|
Donaldson MT, Jorgensen AJR, Beech J. Evaluation of suspected pituitary pars intermedia dysfunction in horses with laminitis. J Am Vet Med Assoc 2004; 224:1123-7. [PMID: 15074858 DOI: 10.2460/javma.2004.224.1123] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine prevalence and clinical features of pituitary pars intermedia dysfunction (PPID) in horses with laminitis. DESIGN Case series. ANIMALS 40 horses with laminitis. PROCEDURES Horses with laminitis that survived an initial episode of pain and were not receiving medications known to alter the hypothalamic-pituitary-adrenal axis were tested for PPID by evaluation of endogenous plasma ACTH concentration. Signalment, suspected cause, month of onset and duration of laminitis, Obel grade of lameness, pedal bone rotation, physical examination findings, results of endocrine function tests, treatment, outcome, and postmortem examination findings were recorded. RESULTS Prevalence of PPID as defined by a single high plasma ACTH concentration was 70%. Median age of horses suspected of having PPID (n = 28) was 15.5 years, and median age of horses without PPID (12) was 14.5 years. Laminitis occurred most frequently in horses with and without suspected PPID during September and May, respectively. Chronic laminitis was significantly more common in horses suspected of having PPID. In horses suspected of having PPID, the most common physical examination findings included abnormal body fat distribution, bulging supraorbital fossae, and hirsutism. Five horses suspected of having PPID had no clinical abnormalities other than laminitis. Seventeen horses suspected of having PPID that were treated with pergolide survived, and 3 horses that were not treated survived. CONCLUSIONS AND CLINICAL RELEVANCE Evidence of PPID is common among horses with laminitis in a primary-care ambulatory setting. Horses with laminitis may have PPID without other clinical signs commonly associated with the disease.
Collapse
Affiliation(s)
- Mark T Donaldson
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, USA
| | | | | |
Collapse
|
43
|
Johnson PJ, Messer NT, Slight SH, Wiedmeyer C, Buff P, Ganjam VK. Endocrinopathic laminitis in the horse. ACTA ACUST UNITED AC 2004. [DOI: 10.1053/j.ctep.2004.07.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
44
|
|
45
|
Abstract
Heaves, or recurrent airway obstruction (RAO), is a chronic respiratory disease featuring lower airway inflammation, bronchoconstriction, and mucus accumulation. Inhaled organic dusts and T helper 2 type immunologic reactions are involved in the complex pathophysiology of RAO. Clinical signs vary and alternate with remission periods. The diagnosis is often based on history and clinical examination in severe cases, but bronchoalveolar lavage may be useful for the detection of early cases. The most important aspect of treatment is to avoid exposure to allergens. Corticosteroids may be administered systemically or by inhalation in combination with bronchodilators and environmental control.
Collapse
Affiliation(s)
- Renaud Léguillette
- Meakins-Christie Laboratories, McGill University, 3626 St. Urbain Street, Montreal, Quebec H2X 2P2, Canada.
| |
Collapse
|
46
|
Abstract
PPID in older equids has become a major health concern of horse owners. In response, equine practitioners have made greater efforts at understanding, diagnosing, and treating this disorder. Although PPID is recognized to be a different form of pituitary-dependent hyperadrenocorticism than is seen in canine or human patients, relatively little is known about the pathophysiology and natural progression of the disease. At present, the diagnosis is best supported by manifestation of characteristic clinical signs and endocrinologic test results, preferably a supportive DST result. Treatment must focus on improving overall health care, including body clipping, dentistry, and nutrition. As the condition progresses, administration of pergolide or a combination of pergolide and cyproheptadine is currently considered the best medical treatment. The time point at which medication should be added to improved health care and management changes is not currently known, but loss of body condition and development of hyperglycemia suggest more advanced PPID that would likely benefit from drug therapy. Whether medical treatment needs to be continuous or could be intermittent is also unknown. As the demand for treatment of affected equids continues to increase, clinical response and endocrinologic testing data as well as pharmacologic data for currently used drugs and other agents should be expected. Similarly, novel medical, and perhaps surgical, treatment strategies for this condition should also be anticipated in the future.
Collapse
Affiliation(s)
- Harold C Schott
- Department of Large Animal Clinical Sciences, D-202 Veterinary Medical Center, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824-1314, USA.
| |
Collapse
|
47
|
Johnson PJ, Slight SH, Ganjam VK, Kreeger JM. Glucocorticoids and laminitis in the horse. Vet Clin North Am Equine Pract 2002; 18:219-36. [PMID: 15635906 DOI: 10.1016/s0749-0739(02)00015-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The administration of exogenously administered GCs and syndromes associated with GC excess are both attended by increased risk for the development of laminitis in adult horses. However, there exists substantial controversy as to whether excess GCs cause laminitis de novo. If true, the pathogenesis of laminitis arising from the effects of GC excess is probably different from that associated with diseases of the gastrointestinal tract and endotoxemia. Although a satisfactory explanation for the development of laminitis as a consequence of GC action is currently lacking, numerous possible and plausible theoretical mechanisms do exist. Veterinarians must exert caution with respect to the use of GCs in adult horses. The extent to which individual horses are predisposed to laminitis as a result of GC effect cannot be predicted based on current information. However, the administration of systemic GCs to horses that have been previously affected by laminitis should be used only with extreme caution, and should be accompanied by careful monitoring for further signs of laminitis. The risk of laminitis appears to be greater during treatment using some GCs (especially dexamethasone and triamcinalone) compared with others (prednisone and prednisolone). Whenever possible, to reduce the risk of laminitis, GCs should be administered locally. For example, the risk of GC-associated laminitis is evidently considerably reduced in horses affected with chronic obstructive pulmonary disease (COPD) if GC treatment is administered via inhalation. We have hypothesized that structural changes in the equine hoof that resemble laminitis may arise as a consequence of excess GC effect. Although these changes are not painful per se, and are not associated with inflammation, they could likely predispose affected horses to the development of bona fide laminitis for other reasons. Moreover, the gross morphological appearance of the chronically GC-affected hoof resembles that of a chronically foundered hoof in some respects. Further investigation into the effect of GC on the hoof lamellar interface is clearly needed.
Collapse
Affiliation(s)
- Philip J Johnson
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Clydesdale Hall, Columbia, MO 65211, USA.
| | | | | | | |
Collapse
|
48
|
|