Metabolic health in horses refers to the physiological processes that manage energy production, utilization, and storage in equine bodies. These processes are critical for maintaining overall health, performance, and well-being. Metabolic health encompasses various aspects, including glucose metabolism, insulin sensitivity, and lipid regulation. Conditions such as Equine Metabolic Syndrome (EMS) and insulin dysregulation are common metabolic disorders that affect horses, impacting their ability to process and store energy efficiently. This topic compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, diagnostic approaches, and management strategies related to metabolic health in horses.
Teles Filho ACA, Sanchez DJD, Viana AGA, Sheheryar S, Guerreiro DD, Bustamante-Filho IC, Martins AMA, Sousa MV, Ricart CAO, Fontes W, Moura AA.The present study was conducted to investigate the global proteome of 8-day-old equine blastocysts. Follicular dynamics of eight adult mares were monitored by ultrasonography and inseminated 24 h after the detection of a preovulatory follicle. Four expanded blastocysts were recovered, pooled, and subjected to protein extraction and mass spectrometry. Protein identification was conducted based on four database searches (PEAKS, Proteome Discoverer software, SearchGUI software, and PepExplorer). Enrichment analysis was performed using g:Profiler, Panther, and String platforms. After the elimina...
Fresa K, Catandi GD, Whitcomb L, Gonzalez-Castro RA, Chicco AJ, Carnevale EM.Obesity is a complex disease associated with augmented risk of metabolic disorder development and cellular dysfunction in various species. The goal of the present study was to investigate the impacts of obesity on the metabolic health of old mares as well as test the ability of diet supplementation with either a complex blend of nutrients designed to improve equine metabolism and gastrointestinal health or L-carnitine alone to mitigate negative effects of obesity. Mares (n = 19, 17.9 ± 3.7 years) were placed into one of three group: normal-weight (NW, n = 6), obese (OB, n = 7...
Pardié M, Kalpokas I, Freccero F, Castagnetti C, Meikle A.The aim of this study was to determine the effect of body condition score (BCS) on metabolic and endocrine parameters in pregnant Criollo mares (n=41), which were categorized according to their BCS as obese (7 to 9 BCS, n=26) or normal (5 to 7, n=15). Blood samples were taken during gestation in 3 periods: between 3.5 and 5 months (I), 8 and 9 months (II) and in the last month of gestation (III). The data was analyzed in the statistical model by mixed procedures, including BCS, gestational period and their interaction as fixed effects. BCS was only different in period I, as normal mares increa...
Hallowell KL, Dembek K, Horne CR, Knych HK, Messenger KM, Schnabel LV.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 hors...
Ward AB, Harris PA, Argo CM, Watson CA, Burns NM, Neacsu M, Russell WR, Grove-White D, Morrison PK.Native ponies are at increased risk of obesity and metabolic perturbations, such as insulin dysregulation (ID), a key risk factor for endocrinopathic laminitis. Management and feeding practices can be adapted to maintain healthy body condition and support metabolic health, but owners may inadvertently provide their ponies with inappropriate management leading to obesity and exacerbating risk of metabolic disease. Adoption of preventative weight management approaches (WMAs), including regular monitoring of body condition, providing appropriate preserved forage, promoting seasonal weight loss, a...
Knowles EJ, Harris PA, Elliott J, Chang YM, Menzies-Gow NJ.Serum insulin concentration at 60 min (InsulinT60) during an oral sugar test (OST) indicates future laminitis risk and insulin dysregulation (ID). Associations between InsulinT60 and physical and owner-reported variables may help clinicians select individuals for ID testing. Associations between InsulinT60 and other metabolic markers may help elucidate ID pathophysiology. Objective: To describe associations between (A) season, physically-apparent and owner-reported factors and binary InsulinT60 interpretation (initial models) and (B) variables included in the initial models, other metabolic ...
Vidal Moreno de Vega C, Lemmens D, de Meeûs d'Argenteuil C, Boshuizen B, de Maré L, Leybaert L, Goethals K, de Oliveira JE, Hosotani G, Deforce D....Important changes in glucose transporter (GLUT) expression should be expected if the glucose influx plays a pivotal role in fuelling or connecting metabolic pathways that are upregulated in response to exercise. The aim was to assess GLUT4, 8, and 12 dynamics in response to training and acute exercise. Sixteen untrained Standardbred mares (3-4 year) performed an incremental SET at the start and end of 8 weeks harness training. M. pectoralis (PM) and M. vastus lateralis (VL) muscle biopsies were taken before and after each SET, allowing for comparing rest and acute samples in untrained (UT) ...
Luo J, Wang Z, Tang C, Yin Z, Huang J, Ruan D, Fei Y, Wang C, Mo X, Li J, Zhang J, Fang C, Li J, Chen X, Shen W.Tendinopathy is a common motor system disease that leads to pain and reduced function. Despite its prevalence, our mechanistic understanding is incomplete, leading to limited efficacy of treatment options. Animal models contribute significantly to our understanding of tendinopathy and some therapeutic options. However, the inadequacies of animal models are also evident, largely due to differences in anatomical structure and the complexity of human tendinopathy. Different animal models reproduce different aspects of human tendinopathy and are therefore suitable for different scenarios. This rev...
Myćka G, Ropka-Molik K, Cywińska A, Szmatoła T, Stefaniuk-Szmukier M.Recent studies have shown that in Arabian horse muscle, long-term exercise-induced expression of genes related to fatty acid degradation and the downregulation of genes belonging to the glycolysis/gluconeogenesis and insulin signalling pathways. Long-lasting physical exertion may trigger the metabolism to switch the main energy source from carbohydrates to lipids due to higher caloric content. Objective: To describe the metabolism adaptation at the whole transcriptome of blood to endurance effort in Arabian horses. Methods: In vivo experiment. Methods: Venous blood samples from 10 Arabian hors...
Colmer SF, Adams AA, Adam E, Miller R, Stefanovski D, Kulp JC, van Eps A.A single dose of metformin administered 1 h prior to oral glucose challenge was previously shown to reduce insulinaemic responses in horses with experimentally-induced insulin dysregulation (ID). Targeted administration could be useful for controlling post-prandial hyperinsulinaemia in horses with naturally-occurring ID.
Bertin FR, Frank N, Breuhaus BA, Schott HC, Kritchevsky JE.Equine thyroid disorders pose a diagnostic challenge in clinical practice because of the effects of nonthyroidal factors on the hypothalamic-pituitary-thyroid axis, and the horse's ability to tolerate wide fluctuations in thyroid hormone concentrations and survive without a thyroid gland. While benign thyroid tumours are common in older horses, other disorders like primary hypothyroidism or hyperthyroidism in adult horses and congenital hypothyroidism in foals are rare. There is a common misunderstanding regarding hypothyroidism in adult horses, especially when associated with the clinical pro...
Clark BL, Stewart AJ, Kemp KL, Bamford NJ, Bertin FR.Field tests and their association with laminitis have not been evaluated in large cohorts. The objectives of this study were to evaluate the performance of basal insulin (BI), the oral sugar test (OST) and the insulin tolerance test (ITT) to diagnose ID and investigate their association with laminitis. Insulin dysregulation status was determined in 146 ponies using BI (insulin concentration >20 µIU/mL), an OST (insulin concentration >65 µIU/mL at 60 or 90min after oral administration of 0.45mL/kg corn syrup) and an ITT (< 50% reduction in glucose concentration 30min after intravenous adminis...
Stefaniuk-Szmukier M, Piórkowska K, Ropka-Molik K.Equine metabolic syndrome (EMS) has become an important issue in modern veterinary medicine and is linked to the common, extremely painful, most-of-the-time performance-terminating hoof laminitis. The growing knowledge in the field of genetic background, inducing environmental factors, diagnosis, treatment and maintenance of affected equines led us to summarise the available information to be used not only for scientific purposes but for fieldwork. In horses, the clinical presentation of EMS includes: obesity or local fat deposition, bilateral lameness or hoof rings attributed to ongoing or pr...
Oliver A, Wulster K, Stefanovski D, Spriet M, Ciamillo S, Ford M, Kulp J, van Eps A.Measure 18F-FDG uptake in digital tissues of healthy horses subjected to different ambulatory conditions between the time of injection and positron emission tomography (PET) scan acquisition. Methods: 8 healthy adult horses. Methods: Horses were walked (AMB) or tied in stalls (NONAMB) immediately after injection with ∼1.5 MBq/kg 18F-FDG until scan acquisition using a randomized crossover design. Steps were quantified using accelerometers. Standardized uptake values (SUV; mean and maximum) in digital tissues including the dorsal lamellae (proximal, middle, and distal), quarter lamellae (media...
Bourebaba L, Zyzak M, Sikora M, Serwotka-Suszczak A, Mularczyk M, Al Naem M, Marycz K.Sex hormone binding globulin (SHBG) deteriorated expression has been recently strongly correlated to increased level of circulating pro-inflammatory cytokines and insulin resistance, which are typical manifestations of equine metabolic syndrome (EMS). Despite previous reports demonstrated the potential therapeutic application of SHBG for liver-related dysfunctions, whether SHBG might modulate equine adipose-derived stem/stromal cells (EqASCs) metabolic machinery remains unknown. Therefore, we evaluated for the first time the impact of SHBG protein on metabolic changes in ASCs isolated from hea...
Jacquay ET, Harris PA, Adams AA.Transportation of horses on short journeys can lead to an increase in stress. There are known age-associated changes in immune and metabolic responses in horses; however, no research exists evaluating how age may influence these responses to transportation stress. Eleven mares within two age groups, aged (n = 5, 22 ± 1 year) or young (n = 6, 2 ± 1 year), were transported 1 hour and 20 minutes. Peripheral blood and saliva were collected before and after transportation at baseline (2 to 3 weeks prior to transportation), 24 hours pre-transport, 1 hour before loading, 15 minutes, 30 minutes,...
McGowan CM, Ireland JL.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 researc...
Bollinger L, Bartel A, Weber C, Gehlen H.High elimination rates and concerns for horse welfare are important issues in endurance riding. Improved understanding of the causes of elimination could increase completion rates in this sport. We have identified pre-ride laboratory risk factors that enable an assessment of potential elimination before the ride. A longitudinal cohort study was performed among 49 healthy horses competing in the 160 km endurance ride at the 2016 World Championship of Endurance Riding in Samorin/Slovakia. Blood samples were taken before the event. For statistical evaluation, horses were categorized into three gr...
Clark BL, Bamford NJ, Stewart AJ, McCue ME, Rendahl A, Bailey SR, Bertin FR, Norton EM.The HMGA2:c.83G>A variant was identified in Welsh ponies having pleiotropic effects on height and insulin concentration. Objective: Determine whether the HMGA2:c.83G>A variant is associated with decreased height and higher basal insulin concentrations across pony breeds. Methods: Two hundred thirty-six ponies across 6 breeds. Methods: Cross-sectional study. Ponies were genotyped for the HMGA2:c.83G>A variant and phenotyped for height and basal insulin concentrations. Stepwise regression was performed for model analysis using a linear regression model for height and mixed linear model ...
Fielding CL, Deane EL, Major DS, Mayer JR, Love JC, Peralez MS, Magdesian KG.The addition of calcium to resuscitation fluids is a common practice in horses, but studies evaluating the effects of calcium supplementation are limited. In healthy horses, decreases in heart rate and changes in serum electrolyte concentrations have been reported. Objective: Calcium gluconate administration at a rate of 0.4 mg/kg/min to eliminated endurance horses with metabolic problems will affect heart rate, gastrointestinal sounds, and serum electrolyte concentrations. Methods: Endurance horses eliminated from the Tevis Cup 100-mile (160 km) endurance ride for metabolic problems and req...
Pakula PD, Halama A, Al-Dous EK, Johnson SJ, Filho SA, Suhre K, Vinardell T.Exercise-induced hemolysis occurs as the result of intense physical exercise and is caused by metabolic and mechanical factors including repeated muscle contractions leading to capillary vessels compression, vasoconstriction of internal organs and foot strike among others. We hypothesized that exercise-induced hemolysis occurred in endurance racehorses and its severity was associated with the intensity of exercise. To provide further insight into the hemolysis of endurance horses, the aim of the study was to deployed a strategy for small molecules (metabolites) profiling, beyond standard molec...
van Bömmel-Wegmann S, Gehlen H, Barton AK, Büttner K, Zentek J, Paßlack N.Little is known about the animal- and diet-related factors that could interfere with the plasma zinc (Zn) concentrations of equines. Additionally, the adequacy of plasma to reflect changes in the Zn intake is unclear. In the first part of this study, the plasma Zn concentrations of hospitalized horses and ponies ( = 538) were measured and evaluated for the impact of the age, sex, horse type, and internal diseases of the animals. In the second part, the effects of increasing dietary Zn chloride hydroxide and Zn methionine supplementations were assessed on the plasma and mane hair Zn concentrati...
Wright AL, Earley ET, Austin C, Arora M.Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) is a common, painful and poorly understood disease. Enamel, dentin and cementum accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into the role that toxic elements play and inform biological processes affecting these hard dental tissues for future research. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to map the distribution of multiple trace elements and heavy metals across equin...
Kellon EM, Gustafson KM.Sodium-Glucose CoTransporter-2 (SGLT2) inhibitors, the -flozin group of drugs, which block glucose reuptake in the renal proximal tubule, are being increasingly used off-label to treat horses with refractory hyperinsulinemia. After 2 years of use by animals in our group, a horse on canagliflozin was incidentally noted to be hyperlipemic. We have been following a cohort of equines (n = 20) treated with SGLT2 inhibitors due to refractory hyperinsulinemia. The animals are owned by members of the Equine Cushing's and Insulin Resistance Group and treated by their attending veterinarians. The index ...
Bourebaba L, Serwotka-Suszczak A, Pielok A, Sikora M, Mularczyk M, Marycz K.Equine metabolic syndrome (EMS) is a multifactorial pathology gathering insulin resistance, low-grade inflammation and past or chronic laminitis. Among the several molecular mechanisms underlying EMS pathogenesis, increased negative insulin signalling regulation mediated by protein tyrosine phosphatase 1 B (PTP1B) has emerged as a critical axis in the development of liver insulin resistance and general metabolic distress associated to increased ER stress, inflammation and disrupted autophagy. Thus, the use of PTP1B selective inhibitors such as MSI-1436 might be considered as a golden therapeut...
de Laat MA, Fitzgerald DM.Equine insulin dysregulation (ID) comprises amplified insulin responses to oral carbohydrates or insulin resistance, or both, which leads to sustained or periodic hyperinsulinaemia. Hyperinsulinaemia is important in horses because of its clear association with laminitis risk, and the gravity of this common sequela justifies the need for a better understanding of insulin and glucose homoeostasis in this species. Post-prandial hyperinsulinaemia is the more commonly identified component of ID and is diagnosed using tests that include an assessment of the gastrointestinal tract (GIT). There are se...
Carver C, Bruemmer J, Coleman S, Landolt G, Hess T.Laminitis associated with equine metabolic syndrome causes significant economic losses in the equine industry. Diets high in non-structural carbohydrates (NSC) have been linked to insulin resistance and laminitis in horses. Nutrigenomic studies analyzing the interaction of diets high in NSCs and gene expression regulating endogenous microRNAs (miRNA) are rare. This study's objectives were to determine whether miRNAs from dietary corn can be detected in equine serum and muscle and its impacts on endogenous miRNA. Twelve mares were blocked by age, body condition score, and weight and assigned to...
Pratt-Phillips S, Munjizun A.There is ample research describing the increased risk of health concerns associated with equine obesity, including insulin dysregulation and laminitis. For athletes, the negative effect of weight carriage is well documented in racing thoroughbreds (i.e., handicapping with weight) and rider weight has been shown to impact the workload of ridden horses and to some degree their gait and movement. In many groups of competitive and athletic horses and ponies, obesity is still relatively common. Therefore, these animals not only are at risk of metabolic disease, but also must perform at a higher wor...
MacNicol JL, Renwick S, Ganobis CM, Allen-Vercoe E, Weese JS, Pearson W.The microbes that reside within the equine hindgut create a complex and dynamic ecosystem. The equine hindgut microbiota is intimately associated with health and, as such, represents an area which can be beneficially modified. Synbiotics, supplements that combine probiotic micro-organisms with prebiotic ingredients, are a potential means of influencing the hindgut microbiota to promote health and prevent disease. The objective of the current study was to evaluate the influence of an equine probiotic/prebiotic supplement on characteristics of the microbiota and metabolite production in vitro. E...
Alicka M, Marycz K.Metabolic syndrome (MetS) is highly associated with a modern lifestyle. The prevalence of MetS has reached epidemic proportion and is still rising. The main cause of MetS and finally type 2 diabetes occurrence is excessive nutrient intake, lack of physical activity, and inflammatory cytokines secretion. These factors lead to redistribution of body fat and oxidative and endoplasmic reticulum (ER) stress occurrence, resulting in insulin resistance, increase adipocyte differentiation, and much elevated levels of proinflammatory cytokines. Cellular therapies, especially mesenchymal stem cell (MSC)...
Hart KA, Wochele DM, Norton NA, McFarlane D, Wooldridge AA, Frank N.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. Objective: (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). Methods: Fifty-seven healthy horses; 40 horses and ponies with PPID (n = 20) or EMS (n = 20). Methods: Prospective study. Serum collected seasonally from healthy...
Meier AD, de Laat MA, Reiche DB, Pollitt CC, Walsh DM, McGree JM, Sillence MN.The aim of this study was to investigate the relationship between laminitis development in ponies and insulin/glucose concentrations in response to the oral glucose test (OGT) and a dietary challenge high in nonstructural carbohydrates (NSCs). After undergoing an OGT (1 g dextrose/kg BW in feed), 37 ponies with 2-h serum insulin concentrations ranging from 22 to 1,133 μIU/mL were subjected to a diet challenge period (DCP), consuming 12 g NSC/kg BW/d for up to 18 d. Insulin and glucose responses were measured on day 2 of the DCP. Clinical laminitis was diagnosed by blinded experts and confi...
Brama PA, Tekoppele JM, Bank RA, Barneveld A, van Weeren PR.Biochemical heterogeneity of cartilage within a joint is well known in mature individuals. It has recently been reported that heterogeneity for proteoglycan content and chondrocyte metabolism in sheep develops postnatally under the influence of loading. No data exist on the collagen network in general or on the specific situation in the horse. The objective of this study was to investigate the alterations in equine articular cartilage biochemistry that occur from birth up to age one year, testing the hypothesis that the molecular composition of equine cartilage matrix is uniform at birth and b...
Donaldson MT, McDonnell SM, Schanbacher BJ, Lamb SV, McFarlane D, Beech J.The purpose of this study was to evaluate the variation in plasma adrenocorticotropic hormone (ACTH) concentration and dexamethasone suppression test (DST) results with season, age, and sex in healthy, pony mares (n=15) and pony stallions (n=14) living under semiferal conditions and horse mares (n=10) living at pasture. Plasma ACTH concentrations were measured in September 2002, and in January, May, and September 2003. DSTs were performed in January and September 2003. Plasma ACTH concentrations in September 2002 and September 2003 were similar and were significantly greater than in January an...
Glinsky MJ, Smith RM, Spires HR, Davis CL.Three experiments, each utilizing three ponies, were conducted using a mixed VFA solution of [1−14C] acetate, [1−14C] propionate and [2–33H] butyrate to determine VFA production rates in the cecum of the pony. Diet A used in experiment 1, contained a forage to grain ratio of 1:2, while diet B, used in experiments 2 and 3, contained a forage to grain ratio of 3:1. Experiment 1, in which a constant infusion technique was used, resulted in net VFA production rates (mmoles/min) of 3.667 to 3.977 (x̄=3.836) for acetate, .410 to 1.664 (x̄=1.213) for propionate and .342 to 1.124 (x̄=.629) fo...
Burns TA, Geor RJ, Mudge MC, McCutcheon LJ, Hinchcliff KW, Belknap JK.Insulin resistance has been associated with risk of laminitis in horses. Genes coding for proinflammatory cytokines and chemokines are expressed more in visceral adipose tissue than in subcutaneous adipose tissue of insulin-resistant (IR) humans and rodents. Objective: To investigate adipose depot-specific cytokine and chemokine gene expression in horses and its relationship to insulin sensitivity (SI). Methods: Eleven light breed mares. Methods: Animals were classified as IR (SI=0.58+/-0.31x10(-4) L/min/mU; n=5) or insulin sensitive (IS; SI=2.59+/-1.21x10(-4) L/min/mU; n=6) based on results o...
Warnken T, Huber K, Feige K.Exact analysis of equine insulin in blood samples is the key element for assessing insulin resistance or insulin dysregulation in horses. However, previous studies indicated marked differences in insulin concentrations obtained from sample analyses with different immunoassays. Most assays used in veterinary medicine are originally designed for use in human diagnostics and are based on antibodies directed against human insulin, although amino acid sequences between equine and human insulin differ. Species-specific assays are being used more frequently and seem to provide advantages compared to ...
Bertin FR, de Laat MA.Insulin dysregulation is the hallmark of equine metabolic syndrome and has received attention because of its direct association with laminitis. In the absence of an adequate treatment for laminitis, a focus on prophylaxis is needed, making early detection of individuals at risk of developing laminitis one of the main challenges in equine endocrinology. Recent studies have shown that insulin dysregulation goes beyond tissue insulin resistance and it is now demonstrated that the equine enteroinsular axis plays a major role in insulin secretion and equine hyperinsulinaemia. In this review, we dis...
Hdud IM, Mobasheri A, Loughna PT.The metabolic activity of articular chondrocytes is influenced by osmotic alterations that occur in articular cartilage secondary to mechanical load. The mechanisms that sense and transduce mechanical signals from cell swelling and initiate volume regulation are poorly understood. The purpose of this study was to investigate how the expression of two putative osmolyte channels [transient receptor potential vanilloid 4 (TRPV4) and large-conductance Ca(2+)-activated K(+) (BKCa)] in chondrocytes is modulated in different osmotic conditions and to examine a potential role for MAPKs in this process...
Nawrocka D, Kornicka K, Śmieszek A, Marycz K.Equine Metabolic Syndrome (EMS) is a steadily growing life-threatening endocrine disorder linked to insulin resistance, oxidative stress, and systemic inflammation. Inflammatory microenvironment of adipose tissue constitutes the direct tissue milieu for various cell populations, including adipose-derived mesenchymal stromal cells (ASCs), widely considered as a potential therapeutic cell source in the course of the treatment of metabolic disorders. Moreover, elevated oxidative stress induces inflammation in intestinal epithelial cells (IECs)-the first-line cells exposed to dietary compounds. In...
Westermann CM, Dorland L, Votion DM, de Sain-van der Velden MG, Wijnberg ID, Wanders RJ, Spliet WG, Testerink N, Berger R, Ruiter JP, van der Kolk JH.The aim of the current study was to assess lipid metabolism in horses with atypical myopathy. Urine samples from 10 cases were subjected to analysis of organic acids, glycine conjugates, and acylcarnitines revealing increased mean excretion of lactic acid, ethylmalonic acid, 2-methylsuccinic acid, butyrylglycine, (iso)valerylglycine, hexanoylglycine, free carnitine, C2-, C3-, C4-, C5-, C6-, C8-, C8:1-, C10:1-, and C10:2-carnitine as compared with 15 control horses (12 healthy and three with acute myopathy due to other causes). Analysis of plasma revealed similar results for these predominantly...
Hodgson DR, McCutcheon LJ, Byrd SK, Brown WS, Bayly WM, Brengelmann GL, Gollnick PD.Horses were exercised at 40, 65, and 90% of their maximum O2 uptake (VO2max) until moderately fatigued (approximately 38, 15, and 9 min, respectively) to assess heat loss through different routes. Approximately 4,232, 3,195, and 2,333 kcal of heat were generated in response to exercise at these intensities. Of this, approximately 7, 16, and 20% remained as stored heat 30 min postexercise. Respiratory heat loss, estimated from the temperature difference between blood in the pulmonary and carotid arteries and the cardiac output, was estimated to be 30, 19, and 23% of the heat produced during exe...
Jensen RB, Danielsen SH, Tauson AH.Obesity is related to the development of several diseases like insulin resistance and laminitis in horses. The prevalence of obesity among mature Icelandic horses in Denmark has not been investigated previously. This study aimed to find the prevalence of obesity, to compare body condition score (BCS) based on owner perception with that of an experienced person and to correlate the BCS to body weight (BW) and morphometric measures in a group of mature Icelandic horses in Denmark. A total of 254 Icelandic horses (≥4 years; 140 geldings, 105 mares, 9 stallions) from 46 different farms were inc...
Dugdale AH, Curtis GC, Harris PA, Argo CM.Evaluation of equine body fat content is important for nutritional and clinical purposes. However, our understanding of total body fat and its regional distribution in the body is sparse. Currently, body fat evaluation relies on the subjective assessment of body condition score (BCS), which has never been validated against 'gold standard' chemical analysis or dissection measurements in ponies. Objective: To define the relationships between subjective (BCS), objective (morphometric) indices of body fat and 'gold standard' measurements of actual body composition. Objective: BCS and morphometry o...
Bamford NJ, Potter SJ, Baskerville CL, Harris PA, Bailey SR.The relationships between diet, obesity and insulin dysregulation in equids require further investigation due to their association with laminitis. This study examined the effect of dietary glycaemic load and increased adiposity on insulin sensitivity and adipokine concentrations in different equine breeds. Equal numbers of Standardbred horses, mixed-breed ponies and Andalusian horses were provided with ad libitum hay plus either cereal-rich (CHO; n = 12), fat-rich (FAT; n = 12) or control (CON; n = 9) meals over 20 weeks. The isocaloric CHO and FAT diets were fed to induce obesity ...
Eiler H, Frank N, Andrews FM, Oliver JW, Fecteau KA.To characterize the physiologic response to i.v. bolus injection of glucose and insulin for development of a combined glucose-insulin test (CGIT) in horses. Methods: 6 healthy mares and 1 mare each with pituitary adenoma and urolithiasis. Methods: Horses were given a CGIT (glucose, 150 mg/kg; insulin, 0.1 U/kg); results were compared with a singular i.v. glucose tolerance test (GTT; 150 mg/kg) and a singular i.v. insulin sensitivity test (IST; 0.1 U/kg). Healthy horses were also given a CGIT after receiving xylazine and undergoing stress. Results: Physiologically, the CGIT resulted in a 2-phas...
Mach N, Ramayo-Caldas Y, Clark A, Moroldo M, Robert C, Barrey E, López JM, Le Moyec L.Endurance exercise in horses requires adaptive processes involving physiological, biochemical, and cognitive-behavioral responses in an attempt to regain homeostasis. We hypothesized that the identification of the relationships between blood metabolome, transcriptome, and miRNome during endurance exercise in horses could provide significant insights into the molecular response to endurance exercise. For this reason, the serum metabolome and whole-blood transcriptome and miRNome data were obtained from ten horses before and after a 160 km endurance competition. We obtained a global regulatory ...
Finno CJ, Valberg SJ.Vitamin E is a primary chain-breaking antioxidant that prevents cyclic propagation of lipid peroxidation. Across species, vitamin E is essential for normal neuromuscular function by acting as a potent antioxidant, as well as by modulating the expression of certain genes, inhibiting platelet aggregation and stabilizing plasma membranes. This review focuses on vitamin E structure, absorption, metabolism, current equine dietary recommendations, the interplay between antioxidants and exercise, a discussion of the necessity of vitamin E supplementation in the horse above the Nutritional Research Co...
Kawai M, Minami Y, Sayama Y, Kuwano A, Hiraga A, Miyata H.We examine the muscle fiber population and metabolic properties of skeletal muscles from the whole body in Thoroughbred horses. Postmortem samples were taken from 46 sites in six Thoroughbred horses aged between 3 and 6 years. Fiber type population was determined on muscle fibers stained with monoclonal antibody to each myosin heavy chain isoform and metabolic enzyme activities were determined spectrophotometrically. Histochemical analysis demonstrated that most of the muscles had a high percentage of Type IIa fibers. In terms of the muscle characteristic in several parts of the horse body, th...
Park T, Cheong H, Yoon J, Kim A, Yun Y, Unno T.(1) Background: The intestinal microbiota plays an essential role in maintaining the host's health. Dysbiosis of the equine hindgut microbiota can alter the fermentation patterns and cause metabolic disorders. (2) Methods: This study compared the fecal microbiota composition of horses with intestinal disease and their healthy counterparts living in Korea using 16S rRNA sequencing from fecal samples. A total of 52 fecal samples were collected and divided into three groups: horses with large intestinal disease (n = 20), horses with small intestinal disease (n = 8), and healthy horses (n = 24). (...
Couëtil L, Paradis MR, Knoll J.Pituitary adenomas are commonly reported in older horses. The typical clinical signs associated with this condition, also known as equine Cushing's disease (ECD), are related to increased adrenocorticotropin (ACTH) production resulting in hyperadrenocorticism. The primary purpose of this study was to determine whether plasma ACTH concentrations differed between cushingoid and healthy horses. The second objective was to determine the effects of blood sample handling techniques on ACTH concentrations. A commercial human ACTH radioimmunoassay (RIA) was used to quantify equine plasma ACTH. Intra-a...
Dolan E, O'Connor H, McGoldrick A, O'Loughlin G, Lyons D, Warrington G.In this study, we describe diet and lifestyle practices of professional jockeys. Participants completed a 59-item nutrition, lifestyle, and health questionnaire (n = 21) and a 7-day estimated food diary (n = 18). Acute weight loss strategies included the use of saunas (86%), exercising to induce sweating (81%), and restricted energy intake (71%). Of the smokers (38%), 56% used smoking to control weight. Most (86%) jockeys reported attaining a 2-kg weight loss for racing (if required) 24-48 h before or on the designated race-day. Mean daily energy intake (1803 ± 564 kcal) was low and appeared ...
Carter RA, McCutcheon LJ, Valle E, Meilahn EN, Geor RJ.To determine effects of exercise training without dietary restriction on adiposity, basal hormone and lipid concentrations and glucose and insulin dynamics in overweight or obese, insulin-resistant horses. Methods: 12 overweight or obese (body condition score > or = 7), insulin-resistant (insulin sensitivity < or = 1.2 x 10(-4) L/min/mU) geldings. Methods: 4 horses remained sedentary, and 8 horses were exercised for 4 weeks at low intensity and 4 weeks at higher intensity, followed by 2 weeks of detraining. Prior to and after each training period, frequently sampled IV glucose tolerance ...
Tadros EM, Fowlie JG, Refsal KR, Marteniuk J, Schott HC.Hyperinsulinaemia is the suspected component of insulin dysregulation having the strongest association with laminitis and occurs variably in equids with pituitary pars intermedia dysfunction (PPID). Objective: We hypothesised that magnitude of hyperinsulinaemia correlates with laminitis severity in PPID-affected equids. Furthermore, we hypothesised that owners can be unaware of chronic endocrinopathic laminitis. Methods: Cross-sectional study. Methods: Serum insulin concentrations, owner-reported laminitis history and radiographic evidence of laminitis were determined in 38 client-owned horses...
O'Callaghan DJ, Hyde JM, Gentry GA, Randall CC.Infection of exponential-phase suspension cultures of mouse fibroblast cells (L-M) with equine abortion virus (EAV) resulted in inhibition of cell growth and marked alterations in host metabolic processes. The synthesis of deoxyribonucleic acid (DNA) and ribonucleic acid was inhibited within 4 hr after infection and was suppressed by more than 90% by the time of maximal virus replication (14 to 18 hr). The overall rate of protein synthesis, however, was similar in uninfected and virus-producing cells as determined by measurements of net protein and isotope incorporation. The time course of vir...
Skedros JG, Mason MW, Nelson MC, Bloebaum RD.Functionally induced strains provide epigenetic signaling for bone modeling and remodeling activities. Strain gauge documentation of the equine third metacarpal reveals a neutral axis passing through the craniolateral cortex, resulting in a narrow band of cortex loaded predominantly in tension, with the remainder of the cortex experiencing a wide range of compression strain magnitudes that are maximal in the caudomedial cortex. This predictable strain pattern provides a model for examining the hypothesis that strain mode, magnitude, and strain energy density are potential correlates of compact...
Morgan RA, McGowan TW, McGowan CM.To determine the prevalence of hyperinsulinaemia in a population of ponies in Queensland, Australia, and identify associated factors. Methods: Breeders or traders of ponies within a 100 km radius of Gatton, Queensland, were recruited for study using an internet database. Clinical and management details were obtained, including body condition score, fat deposition and history or evidence of laminitis. Blood samples were analysed for serum insulin and triglyceride concentrations and plasma adrenocorticotrophic hormone (ACTH) and leptin concentrations following short-term removal from pasture and...
Marycz K, Kornicka K, Irwin-Houston JM, Weiss C.Endocrine disorders have become more and more frequently diagnosed in humans and animals. In horses, equine metabolic syndrome (EMS) is characterized by insulin resistance, hyperleptinemia, hyperinsulinemia, inflammation and usually by pathological obesity. Due to an increased inflammatory response in the adipose tissue, cytophysiological properties of adipose derived stem cells (ASC) have been impaired, which strongly limits their therapeutic potential. Excessive accumulation of reactive oxygen species, mitochondria deterioration and accelerated ageing of those cells affect their multipotency...
