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Abstract
Advances in the understanding of equine protozoal myeloencephalitis (EPM) are reviewed. It is now apparent that EPM can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S neurona is the most common etiologic pathogen. Horses are commonly infected, but clinical disease occurs only infrequently; the factors influencing disease occurrence are not well understood. Epidemiologic studies have identified risk factors for the development of EPM, including the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses, but have not consistently produced neurologic disease. Diagnosis of EPM has improved by detecting intrathecal antibody production against the parasite. Sulfadiazine/pyrimethamine (ReBalance) and the triazine compounds diclazuril (Protazil) and ponazuril (Marquis) are effective anticoccidial drugs that are now available as FDA-approved treatments for EPM.
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Affiliation(s)
- Robert J MacKay
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 2015 Southwest 16th Avenue, PO Box 100136, Gainesville, FL 32610-0125, USA
| | - Daniel K Howe
- Department of Veterinary Science, M.H. Gluck Equine Research Center, University of Kentucky, 108 Gluck Equine Research Center, Lexington, KY 40546-0099, USA.
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Siard-Altman MH, Harris PA, Moffett-Krotky AD, Ireland JL, Betancourt A, Barker VD, McMurry KE, Reedy SE, Adams AA. Relationships of inflamm-aging with circulating nutrient levels, body composition, age, and pituitary pars intermedia dysfunction in a senior horse population. Vet Immunol Immunopathol 2020; 221:110013. [PMID: 32058159 DOI: 10.1016/j.vetimm.2020.110013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/07/2020] [Accepted: 01/16/2020] [Indexed: 12/27/2022]
Abstract
Similarly to aged humans, senior horses (≥20 years) exhibit chronic low-grade inflammation systemically, known as inflamm-aging. Inflamm-aging in the senior horse has been characterized by increased circulating inflammatory cytokines as well as increased inflammatory cytokine production by lymphocytes and monocytes in response to a mitogen. Little is currently known regarding underlying causes of inflamm-aging. However, senior horses are also known to present with muscle wasting and often the endocrinopathy pituitary pars intermedia dysfunction (PPID). Despite the concurrence of these phenomena, the relationships inflamm-aging may have with measures of body composition and pituitary function in the horse remain unknown. Furthermore, nutrition has been a focus of research in an attempt to promote health span as well as life span in senior horses, with some nutrients, such as omega-3 fatty acids, having known anti-inflammatory effects. Thus, an exploratory study of a population of n = 42 similarly-managed senior horses was conducted to determine relationships between inflamm-aging and measures of circulating nutrients, body composition, age, and PPID. Serum was collected to determine vitamin, mineral, and fatty acid content. Peripheral blood mononuclear cells were also isolated to determine inflammatory cytokine production of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) following stimulation with a mitogen, as well as to determine gene expression of interleukin(IL)-1β, IL-6, IL-10, IFN-γ, and TNF-α. Serum IL-6 and C-reactive protein were determined by enzyme-linked immunosorbent assay. Whole blood was collected for hematological and biochemical analysis. Body composition was evaluated via ultrasound and muscle scoring for all 42 horses as well as by deuterium oxide dilution for a subset of n = 10 horses. Pituitary function was evaluated by measuring basal adrenocorticotropin hormone concentrations as well as by thyrotropin releasing hormone stimulation testing (to determine PPID status). Results showed various relationships between inflammatory markers and the other variables measured. Most notably, docosadienoic acid (C22:2n6c), docosapentaenoic acid (C22:5n3c), and folate were positively associated with numerous inflammatory parameters (P ≤ 0.05). Although no relationships were found between inflamm-aging and PPID, being positive for PPID was negatively associated with vitamin B12 (P ≤ 0.01). No relationships between inflammation and body composition were found. Even within this senior horse population, age was associated with multiple parameters, particularly with numerous inflammatory cytokines and fatty acids. In summary, inflamm-aging exhibited relationships with various other parameters examined, particularly with certain fatty acids. This exploratory study provides insights into physiological changes associated with inflamm-aging in the senior horse.
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Affiliation(s)
| | - Patricia A Harris
- Equine Studies Group, WALTHAM Petcare Science Institute, Waltham-on-the-Wolds, Melton Mowbray, LE14 4RT, UK
| | | | - Joanne L Ireland
- Equine Clinical Sciences, Department of Health and Life Sciences, University of Liverpool, Neston, Wirral, CH64 7TE, UK
| | - Alejandra Betancourt
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA
| | - Virginia D Barker
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA
| | - Kellie E McMurry
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA
| | - Stephanie E Reedy
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA
| | - Amanda A Adams
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA
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MacKay R, McLellan J, Mallicote M. Pyrimethamine toxicosis in horses given a compounded medication. EQUINE VET EDUC 2017. [DOI: 10.1111/eve.12812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. MacKay
- Large Animal Clinical Sciences; University of Florida College of Veterinary Medicine; Gainesville Florida USA
| | - J. McLellan
- Florida Equine Veterinary Associates; Ocala Florida USA
| | - M. Mallicote
- Large Animal Clinical Sciences; University of Florida College of Veterinary Medicine; Gainesville Florida USA
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Cudmore L, Jalim S, Williamson MM, McKinnon AO. Pancytopenia in two horses following administration of potentiated sulfonamide antimicrobials. EQUINE VET EDUC 2012. [DOI: 10.1111/eve.12000] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. Cudmore
- Goulburn Valley Equine Hospital; Victoria Australia
| | - S. Jalim
- Goulburn Valley Equine Hospital; Victoria Australia
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Ordakowski-Burk AL, Kronfeld DS, Williams CA, Gay LS, Sklan DJ. Temporal folate status during lactation in mares and growth in foals. Am J Vet Res 2005; 66:1214-21. [PMID: 16111161 DOI: 10.2460/ajvr.2005.66.1214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To identify changes in folate status of mares and foals during lactation and growth, respectively. ANIMALS 20 Thoroughbred mares and foals. PROCEDURES Pregnant mares, and following foaling the same mares with their foals, were maintained on mixed grass-legume pasture and fed either a traditional dietary supplement rich in sugar and starch (SS) or a dietary supplement high in fat and fiber (FF). Blood samples were collected monthly from mares and foals up to 6 months after foaling. Total folate concentration in feed and forage was determined. Analyses of plasma folate, RBC folate, plasma homocysteine (HCY), and milk folate concentrations were performed. RESULTS Mare plasma folate concentrations declined moderately during 6 months of lactation. Mare RBC folate concentrations initially increased after foaling up to 3 months but declined toward the end of the study. Plasma HCY concentration was higher for mares fed the SS supplement, compared with mares fed the FF supplement from foaling to 6 months of lactation. Milk folate concentrations decreased during the first 3 months and then increased. Foal plasma folate initially declined but then increased. Stable concentrations of RBC folate were observed in foals. Plasma HCY concentrations in foals were unaffected by growth during the last 5 months. References range values for plasma folate, RBC folate, milk folate, and plasma HCY concentrations in healthy lactational mares and young growing foals were determined. CONCLUSIONS AND CLINICAL RELEVANCE Folate status was not impaired in lactating mares and growing foals under the conditions in our study. It appears that folate supplementation is not necessary.
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Affiliation(s)
- Amy L Ordakowski-Burk
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA
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