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.
Škerlová J, Ismail A, Lindström H, Sjödin B, Mannervik B, Stenmark P.Organotin compounds are highly toxic environmental pollutants with neurotoxic and endocrine-disrupting effects. They are potent inhibitors of glutathione transferases (GSTs), thus impeding their detoxication and antioxidant functions. Several GSTs, including equine GST A3-3 (EcaGST A3-3), exhibit steroid double-bond isomerase activity and are involved in the biosynthesis of testosterone and progesterone. We have performed enzyme kinetics analyses of the inhibition of EcaGST A3-3 by organotin compounds. We have also solved crystal structures of EcaGST A3-3 in complexes with glutathione, and wit...
Gomez A, Sharma AK, Grev A, Sheaffer C, Martinson K.Although contributions of the equine gut microbiome to forage utilization are well recognized, the impact of alfalfa (Medicago sativa L.) lignification on the equine gut microbiome remains unknown; thus, we characterized microbial communities in the equine gut when feeding reduced lignin (RL) and conventional (CON) alfalfa hays to adult stock-type horses. Dietary treatments were fed to six horses in a crossover study. Experimental periods consisted of a 9-day dietary adaptation phase followed by a 5-day total fecal collection phase, during which horses were housed in individual box stalls and ...
Daniels SP, Leng J, Swann JR, Proudman CJ.Anthelmintic treatment is a risk factor for intestinal disease in the horse, known as colic. However the mechanisms involved in the onset of disease post anthelmintic treatment are unknown. The interaction between anthelmintic drugs and the gut microbiota may be associated with this observed increase in risk of colic. Little is known about the interaction between gut microbiota and anthelmintics and how treatment may alter microbiome function. The objectives of this study were: To characterise (1) faecal microbiota, (2) feed fermentation kinetics in vitro and (3) metabolic profiles following m...
Loos CMM, McLeod KR, Stratton SC, van Doorn DA, Kalmar ID, Vanzant ES, Urschel KL.Activation of the mechanistic target of rapamycin (mTOR)-controlled anabolic signaling pathways in skeletal muscle of rodents and humans is responsive to the level of dietary protein supply, with maximal activation and rates of protein synthesis achieved with 0.2 to 0.4 g protein/kg body weight (BW). In horses, few data are available on the required level of dietary protein to maximize protein synthesis for maintenance and growth of skeletal muscle. To evaluate the effect of dietary protein level on muscle mTOR pathway activation, five mares received different amounts of a protein supplement t...
Garber A, Hastie P, McGuinness D, Malarange P, Murray JA.Abrupt dietary changes, as can be common when managing horses, may lead to compositional changes in gut microbiota, which may result in digestive or metabolic disturbances. The aim of this study was to describe and compare the faecal microbiota of ponies abruptly changed from pasture grazing ad libitum to a restricted hay-only diet and vice versa. The experiment consisted of two, 14-day periods. Faecal samples were collected on day 0 and days 1-3,7,14 after abrupt dietary change from grass to hay and from hay to grass. Microbial populations were characterised by sequencing the V3-V4 region of ...
Ekici S, Ozmen O.The active roles of microribonucleic acids (miRNAs) in gene regulation have made miRNAs a key point for the scientific world in the study of physiological processes. Although saliva includes the largest number of miRNAs, there is no miRNA study in saliva on horses has been found. Our study is the first study on miRNAs isolation from saliva in horses. In the present study, saliva was studied in Arabian racehorses to better understand the molecular mechanisms of expression levels that are effective in lipid metabolism of miRNAs and their target genes during the race. Identification of lipid meta...
Rahnama S, Spence R, Vathsangam N, Baskerville CL, Bailey SR, de Laat MA, Anderson ST, Pollitt CC, Sillence MN.Although it is understood that equine endocrinopathic laminitis can be triggered by high concentrations of insulin, it is unclear whether this represents a direct action on lamellar tissue via insulin receptors (InsR), an interaction with IGF-1 receptors (IGF-1R), or some other, indirect action. This uncertainty is because of the reported scarcity of InsR in lamellar tissue and the low affinity of insulin for equine IGF-1R. In the present study, the effects of insulin and IGF-1 (as a positive control) were examined using lamellar explants isolated from the hooves of healthy horses and incubate...
Bazzano M, Laghi L, Zhu C, Lotito E, Sgariglia S, Tesei B, Laus F.In the present study, data related to the metabolomics of saliva and serum in trained standardbred horses are provided for the first time. Metabolomic analysis allows to analyze all the metabolites within selected biofluids, providing a better understanding of biochemistry modifications related to exercise. On the basis of the current advances observed in metabolomic research on human athletes, we aimed to investigate the metabolites' profile of serum and saliva samples collected from healthy standardbred horses and the relationship with physical exercise. Twelve trained standardbred horses we...
Patterson Rosa L, Mallicote MF, Long MT, Brooks SA.An analogous condition to human metabolic syndrome, Equine Metabolic Syndrome (EMS) is defined by several clinical signs including obesity, hyperinsulinemia, and peripheral insulin dysregulation (ID). Affected horses may also exhibit hypertension, hyperlipemia and systemic inflammation. Measures of ID typically comprise the gold-standard for diagnosis in veterinary care. Yet, the dynamic nature of insulin homeostasis and complex procedures of typical assays make accurate quantification of ID and EMS challenging. This work aimed to investigate new strategies for identification of biochemical ma...
Cappai MG, Dimauro C, Biggio GP, Cherchi R, Accioni F, Pudda F, Boatto G, Pinna W.This study pointed to explore if variations in circulating levels of metabolites in the blood stream of no. 25 feral donkeys occur in view of the different coat color between specimens of Asinara (albino, no. 8) vs. Sardo (dun-grey, no. 17) breed. All individuals involved in this investigation are living in the nature, at Mediterranean latitudes and roam in the same areas all over the National Park of Capo Caccia, where they feed on spontaneous vegetation sources. The study was conducted during the positive photoperiod of the boreal hemisphere (peak in the month of June, 2019) to maximize the ...
Salinas C, Espinosa G, Morales N, Henríquez C, Morán G, Gajardo G, Uberti B.Obesity is a highly prevalent condition in horses. Dysfunctional neutrophil activity has been reported in metabolically healthy obese humans, but minimal data exist regarding horses. The present study evaluated the effect of obesity on apoptosis, phagocytosis and oxidative burst activity of peripheral blood neutrophils from lean and obese non-insulin dysregulated horses. Seven lean (BCS, body condition score 4-6/9) and five obese (BCS 8-9) horses were enrolled in the study. All animals underwent two metabolic tests (OGT, oral glucose test; IRT, insulin response test) before their selection to ...
Campolo A, Frantz MW, de Laat MA, Hartson SD, Furr MO, Lacombe VA.Endocrinopathic laminitis is pathologically similar to the multi-organ dysfunction and peripheral neuropathy found in human patients with metabolic syndrome. Similarly, endocrinopathic laminitis has been shown to partially result from vascular dysfunction. However, despite extensive research, the pathogenesis of this disease is not well elucidated and laminitis remains without an effective treatment. Here, we sought to identify novel proteins and pathways underlying the development of equine endocrinopathic laminitis. Healthy Standardbred horses ( = 4/group) were either given an electrolyte in...
Norton E, McCue ME.A role for a genetic contribution to equine metabolic syndrome (EMS) and pars pituitary intermedia dysfunction (PPID) has been hypothesized. Heritability estimates of EMS biochemical measurements were consistent with moderately to highly heritable traits. Further, genome-wide association analyses have identified hundreds of regions of the genome contributing to EMS and candidate variants have been identified. The genetics of PPID has not yet been proven. Continued research for the specific genetic risk factors for both EMS and PPID is crucial for gaining a better understanding of the pathophys...
Klein DJ, Anthony TG, McKeever KH.metabolomics is the high-throughput, multiparametric identification and classification of hundreds of low molecular weight metabolites in a biological sample. Ultimately, metabolites are the downstream readouts of cellular signalling, transcriptomic and proteomic changes that can provide a comprehensive view of tissue and organismal phenotype. The popularity of metabolomics in human sport and exercise has been gaining over the past decade and has provided important insights into the energetic demands and mechanistic underpinnings of exercise and training. To the contrary, metabolomics in the f...
Voga M, Adamic N, Vengust M, Majdic G.Regenerative medicine is a branch of medicine that develops methods to grow, repair, or replace damaged or diseased cells, organs or tissues. It has gained significant momentum in recent years. Stem cells are undifferentiated cells with the capability to self-renew and differentiate into tissue cells with specialized functions. Stem cell therapies are therefore used to overcome the body's inability to regenerate damaged tissues and metabolic processes after acute or chronic insult. The concept of stem cell therapy was first introduced in 1991 by Caplan, who proposed that massive differentiatio...
Shibany KA, Pratt SL, Aldurdunji M, Totemeyer S, Paine SW.Horses are exposed to various kinds of medication, however, there are limited determinations of plasma clearance (CL) for the drugs used due to the high cost of equine studies.Many of the CL values generated come from the equine sports industry for determining drug plasma screening limits in the control of medications at the time of competition.The kinetics of omeprazole metabolism were investigated in freshly isolated and cryopreserved equine hepatocytes and hepatic microsomes ( = 3 horses).The V, K and intrinsic clearance (CL) of omeprazole were determined via the substrate depletion me...
Lewis N, Hinrichs K, Leese HJ, McGregor Argo C, Brison DR, Sturmey RG.The use of in vitro embryo production in the horse is increasing in clinical and research settings; however, protocols are yet to be optimised. Notably, the two most commonly used base media for in vitro maturation (IVM) supply glucose at markedly different concentrations: physiological (5.6 mM, M199) or supraphysiological (17 mM, DMEM/F-12). Exposure to high glucose has detrimental effects on oocytes and early embryos in many mammalian species, but the impact has not yet been examined in the horse. To address this, we compared the energy metabolism of equine COCs matured in M199-based maturat...
Roy MM, Norton EM, Rendahl AK, Schultz NE, McFarlane D, Geor RJ, Mickelson JR, McCue ME.An 11G nucleotide repeat in the 3' UTR of FAM174A was recently postulated as a risk allele with a dominant mode of inheritance for equine metabolic syndrome (EMS) and laminitis status in Arabian horses. The objective of this project was to evaluate this hypothesis in a large and diverse across-breed population. A total of 301 ponies, 292 Morgans, 64 Arabians, 49 Tennessee Walking Horses and 59 Quarter Horses were genotyped for six observed G repeat alleles in the FAM174A 3' UTR. Phenotype data included laminitis status, baseline insulin, glucose, non-esterified fatty acids, triglycerides, adip...
Schedlbauer C, Blaue D, Raila J, Vervuert I.Vitamin A, vitamin E and retinol-binding protein 4 (RBP4) are a focus of current obesity research in humans. The impact of body weight (BW) gain on fat-soluble vitamins and its associated parameters in equines has not been previously reported. Ten Shetland ponies and 9 Warmblood horses, all adult geldings, non-obese and healthy, were fed an excessive energy diet for 20 months to induce BW gain. Serum α-tocopherol (vitamin E), retinol (vitamin A), retinol-binding protein 4 (RBP4) and retinol/RBP4 ratio were analysed before BW gain induction and at six timepoints during the BW gaining period. ...
Kuchler M, Zeyner A, Susenbeth A, Kienzle E.Renal energy losses of horses are high in comparison with other species. In the present study, more data were obtained on this parameter to improve predictive equations for renal energy losses. Four adult ponies (247-344 kg body weight [BW]) were fed with eight different diets based on first cut hay, second cut hay, early first cut fresh grass, late cut herbs-grass mix, early cut clover-grass mix, sugar beet pulp, rice bran and straw. Feed intake was measured, and urine and faeces were quantitatively collected for 3 × 12 hr at daytime and afterwards 3 × 12 hr at nighttime. Feed was an...
Blaue D, Schedlbauer C, Starzonek J, Gittel C, Brehm W, Blüher M, Pfeffer M, Vervuert I.Human obesity is linked with systemic inflammation. However, it is still controversial if equines produce more inflammatory cytokines with increasing body weight and if the production of those show breed type specific patterns. The main objective of this study was to determine if diet induced obesity is associated with increased inflammatory signatures in adipose tissue of equines and if a breed predisposition exists between ponies and horses. Additionally, we aimed to identify adipose tissue depot differences in inflammatory cytokine expression. Nineteen healthy, non-overweight and metabolica...
Journal of proteomicsApril 2, 2020
Volume 221 103765 doi: 10.1016/j.jprot.2020.103765
Martín-Cano FE, Gaitskell-Phillips G, Ortiz-Rodríguez JM, Silva-Rodríguez A, Román Á, Rojo-Domínguez P, Alonso-Rodríguez E, Tapia JA, Gil MC....Proteomic technologies allow the detection of thousands of proteins at the same time, being a powerful technique to reveal molecular regulatory mechanisms in spermatozoa and also sperm damage linked to low fertility or specific biotechnologies. Modifications induced by the cryopreservation in the stallion sperm proteome were studied using UHPLC/MS/MS. Ejaculates from fertile stallions were collected and split in two subsamples, one was investigated as fresh (control) samples, and the other aliquot frozen and thawed using standard procedures and investigated as frozen thawed subsamples. UHPLC/M...
Fitzgerald DM, Spence RJ, Stewart ZK, Prentis PJ, Sillence MN, de Laat MA.The equine microbiome can change in response to dietary alteration and may play a role in insulin dysregulation. The aim of this study was to determine the effect of adding pasture to a hay diet on the faecal bacterial microbiome of both healthy and insulin-dysregulated ponies. Faecal samples were collected from 16 ponies before and after dietary change to enable bacterial 16S rRNA sequencing of the V3-V4 region. The dominant phyla in all samples were the Firmicutes and Bacteroidetes. The evenness of the bacterial populations decreased after grazing pasture, and when a pony was moderately insu...
Spears JW, Lloyd KE, Siciliano P, Pratt-Phillips S, Goertzen EW, McLeod SJ, Moore J, Krafka K, Hyda J, Rounds W.Forty-eight Quarter Horse geldings (3 to 8 yr of age) were used to determine the effects of dietary chromium (Cr), in the form of Cr propionate (Cr Prop) on insulin sensitivity. Horses were blocked by age, body condition score, and glucose response to concentrate feeding on day 0 and randomly assigned to treatments. Treatments consisted of 0, 2, 4, or 8 mg Cr/d from Cr Prop. Horses were fed daily a concentrate mix at a rate of 0.2 kg/100 kg body weight (BW) and grass hay at 1.75 to 2.0 kg/100 kg BW. All horses were fed the control diet for 7 d prior to the initiation of the study. After an ove...
Ebert M, Moore-Colyer MJS.The aim of this study was to estimate the energy requirements of performance horses in active, variable training in the field. Sixty horses in England and Switzerland were measured over 2-wk periods and, for 15 of these, the measurement period was extended, ranging from 21 to 42 wk. Energy intake was estimated by measuring daily feed consumption. Energy output was measured using heart rate (HR) monitors during 608 training sessions, relating HR to volume of oxygen (VO₂) and converting VO₂ to energy. Field maintenance requirements were calculated by deducting the marginal energy cost of tra...
Zak A, Siwinska N, Elzinga S, Barker VD, Stefaniak T, Schanbacher BJ, Place NJ, Niedzwiedz A, Adams AA.Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concent...
Morrison PK, Newbold CJ, Jones E, Worgan HJ, Grove-White DH, Dugdale AH, Barfoot C, Harris PA, Argo CM.Obesity is an important equine welfare issue. Whilst dietary restriction is the most effective weight-loss tool, individual animals range in their weight-loss propensity. Gastrointestinal-derived bacteria play a fundamental role in host-health and have been associated with obesity and weight-loss in other species. This study evaluated the faecal microbiome (next-generation sequencing of 16S rRNA genes) of 15 obese Welsh Mountain pony mares, in the same 11-week period across 2 years (n = 8 Year 1; n = 7 Year 2). Following a 4-week acclimation period (pre-diet phase) during which t...
Kritchevsky JE, Muir GS, Leschke DHZ, Hodgson JK, Hess EK, Bertin FR.In metabolically stable horses, alpha-2-agonists suppress insulin secretion with transient hyperglycemia and rebound hyperinsulinemia. In horses with insulin dysregulation (ID), the effect of alpha-2-agonists has not been investigated; however, both the alpha-2-agonist-induced suppression of insulin secretion and rebound hyperinsulinemia could have clinical relevance. Objective: In horses with ID, alpha-2-agonists will alter insulin and glucose dynamics. Methods: Seven horses with ID and 7 control horses. Methods: In this randomized crossover study, xylazine hydrochloride (1.1 mg/kg) or detomi...
Lewis N, Hinrichs K, Leese HJ, McG Argo C, Brison DR, Sturmey R.Horses are one of the few species, beside humans, in which assisted reproductive technology has important clinical applications. Furthermore, the horse can serve as a valuable model for the study of comparative reproductive biology. Here we present the first comprehensive characterisation of energy metabolism and mitochondrial efficiency in equine cumulus-oocyte complexes (COCs) during in vitro maturation (IVM), as determined using a combination of non-invasive consumption and release assays and mitochondrial function analysis. These data reveal notable species-specific differences in the rate...
Jeffcott LB, Henson FM.The importance of osteochondrosis (dyschondroplasia) to the horse industry has been well documented since it was first recorded 50 years ago. The condition is known to be multifactorial in origin, arising from focal failure of endochondral ossification at predilection sites in articular/epiphyseal growth cartilage, but specific information on its aetiopathogenesis is sparse. This paper reviews the current knowledge of growth cartilage metabolism and the process of normal endochondral ossification in the horse. It highlights the localization of various protein products of chondrocytes and the d...
Valberg SJ, Perumbakkam S, McKenzie EC, Finno CJ.Equine myofibrillar myopathy (MFM) causes exertional muscle pain and is characterized by myofibrillar disarray and ectopic desmin aggregates of unknown origin. To investigate the pathophysiology of MFM, we compared resting and 3 h postexercise transcriptomes of gluteal muscle and the resting skeletal muscle proteome of MFM and control Arabian horses with RNA sequencing and isobaric tags for relative and absolute quantitation analyses. Three hours after exercise, 191 genes were identified as differentially expressed (DE) in MFM vs. control muscle with >1 log fold change (FC) in genes involve...
Bertin FR, Sojka-Kritchevsky JE.Equine insulin resistance is important because of its association with laminitis. The insulin-response test is described to diagnose insulin resistance in clinical settings. Practitioners may be reluctant to perform this test because of the time needed for the test and the fear of inducing hypoglycemia. The objective of the study was to compare a 2-step insulin-response test with a complete insulin-response test. A complete insulin-response test was performed on 6 insulin-resistant horses and 6 controls. A 2-step insulin-response test consisting of an intravenous injection of 0.1 IU/kg human i...
Wickler SJ, Hoyt DF, Cogger EA, Myers G.Two studies have focused on potential triggers for the trot-gallop transition in the horse. One study concluded that the transition was triggered by metabolic economy. The second study found that it was not metabolic factors but, rather, peak musculoskeletal forces that determine gait transition speeds. In theory, peak musculoskeletal forces should be the same when trotting up an incline as when trotting at the same speed on the level. Assuming this is the case, we hypothesized that if peak forces determine gait transition speeds then horses should switch from a trot to a gallop at the same sp...
Clarke LL, Roberts MC, Argenzio RA.The association of feeding practices with the development of digestive disorders in horses has long been recognized, although the underlying mechanisms had been barely considered. The physiologic consequences of meal frequency may help to explain the relationship and prove to be of major significance in the induction of many conditions. Many Equidae kept for performance and leisure activities are fed high-energy, low-forage rations twice daily, with limited access to hay or grazing. Rapid ingestion of such meals stimulates a copious outpouring of upper alimentary secretions and results in tran...
Venugopal CS, Eades S, Holmes EP, Beadle RE.One of the causes of equine laminitis is hyperinsulinaemia, which may be associated with endothelial dysfunction and insulin resistance of vessels. Objective: Insulin resistance can be induced in palmar digital vessels by continued exposure to insulin in vitro. The objective was to evaluate this in vitro model for future studies. Methods: Palmar digital vessel segments were collected immediately after euthanasia from horses with normal insulin/glucose blood values. Four arterial and 4 venous rings (3 mm wide) were prepared and each ring mounted in a tissue bath, containing Tyrode's solution at...
Harris RC, Marlin DJ, Snow DH, Harkness RA.The effect of 2 min treadmill exercise, at speeds of 6-12 m.s-1 on an incline of 5 degrees, upon muscle adenine nucleotide loss and lactate accumulation was studied in six Thoroughbred horses. Minimal change occurred in the adenosine triphosphate (ATP) content of the middle gluteal muscle at speeds of 10 m.s-1 or less, but significant loss (up to 47%) had occurred in all horses by 12 m.s-1. The decline in ATP significantly correlated with the accumulation of muscle lactate, beginning shortly after the accumulation of 40 mmol.kg-1 dry muscle lactate. Decline in muscle ATP was mirrored closely b...
Borer KE, Bailey SR, Menzies-Gow NJ, Harris PA, Elliott J.Identification of ponies (Equus caballus) at increased risk of pasture-associated laminitis would aid in the prevention of the disease. Insulin resistance has been associated with laminitis and could be used to identify susceptible individuals. Insulin resistance may be diagnosed by feeding supplementary water-soluble carbohydrate (WSC) and measuring blood glucose and insulin concentrations. The aim of this study was to assess the glycemic and insulinemic responses of 7 normal (NP) and 5 previously laminitic (PLP), mixed breed, native UK ponies fed glucose, fructose, and inulin [1 g/(kg·d) fo...
McKenzie HC.Hyperlipidemia is the presence of elevated lipid concentrations in the blood and is associated with periods of negative energy balance and physiologic stress. In increased concentrations, circulating lipids typically occur in the triglyceride form, which may interfere with numerous normal physiologic functions, particularly by reducing insulin sensitivity. Although the hyperlipidemia risk is greatest in ponies, miniature horses, and donkeys, all equids are at risk if they are in a situation involving negative energy balance. The sedentary lifestyle of many modern horses and the frequent feedin...
Marlin DJ, Harris PA, Schroter RC, Harris RC, Roberts CA, Scott CM, Orme CE, Dunnett M, Dyson SJ, Barrelet F.The present study was undertaken to investigate physiological, metabolic, haematological and biochemical changes in horses competing in the Speed and Endurance test of a Concours Complet International (CCI)*****3-day-event held under FEI rules. A total of 28 horses competing in the Burghley Horse Trials Speed and Endurance test were selected to be monitored: 11 horses in 1993 and 17 horses in 1994. Of the 28 horses selected, 17 completed the Speed and Endurance test and went on to complete the showjumping test. Mean +/- s.d. shade temperature and relative humidity, black globe temperature and ...
Daniels SP, Leng J, Swann JR, Proudman CJ.Anthelmintic treatment is a risk factor for intestinal disease in the horse, known as colic. However the mechanisms involved in the onset of disease post anthelmintic treatment are unknown. The interaction between anthelmintic drugs and the gut microbiota may be associated with this observed increase in risk of colic. Little is known about the interaction between gut microbiota and anthelmintics and how treatment may alter microbiome function. The objectives of this study were: To characterise (1) faecal microbiota, (2) feed fermentation kinetics in vitro and (3) metabolic profiles following m...
Menzies-Gow NJ, Wray H, Bailey SR, Harris PA, Elliott J.The mechanisms underlying predisposition to pasture-associated laminitis remain unclear; chronic inflammation is implicated, and this may be exacerbated by physical inactivity. Objective: To determine whether exercise affects the inflammatory profile of normal and previously laminitic ponies. Methods: Prospective case-control study. Methods: The short (1 day) and longer term (14 days) effects of low intensity (10 min walking and 5 min trotting) exercise on plasma inflammatory marker concentrations in normal (NL) and previously laminitic (PL) nonobese ponies (n = 6/group) was determined. Plasma...
Tóth F, Frank N, Elliott SB, Geor RJ, Boston RC.To evaluate the effects of endotoxin administered IV on glucose and insulin dynamics in horses. Methods: 16 healthy adult mares. Methods: Each week of a 2-week randomized crossover study, each horse received an IV injection (duration, 30 minutes) of Escherichia coli O55:B5 lipopolysaccharide (LPS) in 60 mL of sterile saline (0.9% NaCl) solution (20 ng/kg) or sterile saline solution alone (control treatment). Frequently sampled IV glucose tolerance test procedures were performed at 24 hours before (baseline) and 24 and 48 hours after injection; glucose and insulin dynamics were assessed via min...
Bennet ED, Parkin TDH.An epidemiological study of elite endurance riding was conducted using data from every Fédération Equestre Internationale (FEI) endurance event from 2010 to 2015, comprising 82,917 starts. The aim of the study was to identify risk factors associated with failure to qualify outcomes for horses during FEI endurance rides. The FEI endurance rules state that, during a ride, horses must be assessed by veterinarians several times, giving veterinarians the opportunity to prevent those horses exhibiting signs of lameness or metabolic problems from continuing further. Multivariable logistic regressio...
Bruynsteen L, Erkens T, Peelman LJ, Ducatelle R, Janssens GP, Harris PA, Hesta M.In humans, adipose tissue (AT) originating from different depots shows varying gene expression profiles. In horses, the risk of certain metabolic disorders may also be influenced by the impact of specific AT depots. Macrophage infiltration in human and rat AT is considered to be a source of inflammatory changes. In horses, this relationship has not been extensively studied yet. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), a useful method to evaluate differences in mRNA expression across different tissues, can be used to evaluate differences between equine A...
Durham AE, Hughes KJ, Cottle HJ, Rendle DI, Boston RC.Type 2 diabetes mellitus (T2DM) is diagnosed rarely in equine practice although it may be under-recognised. A greater awareness of the condition and therapeutic considerations would be to the benefit of such cases presenting in practice. More investigation into the pharmacological management of these cases is needed. Objective: Three cases of diabetes mellitus were investigated using a specific test for insulin sensitivity and pancreatic beta cell function in order to define accurately and characterise the existence of T2DM in all 3 subjects. Methods: The insulin-modified frequently sampled i....
Catandi GD, LiPuma L, Obeidat YM, Maclellan LJ, Broeckling CD, Chen T, Chicco AJ, Carnevale EM.Dietary supplementation is the most feasible method to improve oocyte function and developmental potential . During three experiments, oocytes were collected from maturing, dominant follicles of older mares to determine whether short-term dietary supplements can alter oocyte metabolic function, lipid composition, and developmental potential. Over approximately 8 weeks, control mares were fed hay (CON) or hay and grain products (COB). Treated mares received supplements designed for equine wellness and gastrointestinal health, flaxseed oil, and a proprietary blend of fatty acid and antioxidant s...
Lindåse S, Nostell K, Bröjer J.An oral sugar test (OST) using Karo® Light Corn Syrup has been developed in the USA as a field test for the assessment of insulin dysregulation in horses but the syrup is not available in Scandinavian grocery stores. The aim of the study was to compare the results of a modified OST between horses with equine metabolic syndrome (EMS) and healthy horses using a Scandinavian commercially available glucose syrup (Dansukker glykossirap). In addition, the effect of breed and the repeatability of the test were evaluated. In the present study, clinically healthy horses (7 Shetland ponies, 8 Icelandic...
Borer-Weir KE, Menzies-Gow NJ, Bailey SR, Harris PA, Elliott J.A simple, accurate test for identifying individual animals at increased risk of laminitis would aid prevention. Laminitis-prone ponies have a greater serum insulin response to dexamethasone administration than normal ponies in the summer, but the response during different seasons is unknown. Objective: To test the hypothesis that previously laminitic ponies have a greater insulin response to dexamethasone than normal ponies, which is present during all seasons. Methods: Prospective longitudinal study. Methods: Overnight dexamethasone suppression tests were performed on 7 normal ponies and 5 pr...
Banse HE, McCann J, Yang F, Wagg C, McFarlane D.Diagnosis of equine hyperinsulinemia requires an accurate method for quantification of equine insulin concentrations. The objectives of the current study were to compare 2 commercially available techniques for measurement of equine insulin, the radioimmunoassay (RIA) and chemiluminescent immunoassay (CIA). Recovery was poor for both assays, but worse for the CIA. Serial dilution of a high endogenous insulin sample yielded better linearity for the RIA ( r = 0.99, P < 0.001) than the CIA ( r = 0.92, P = 0.009). Bland-Altman analysis indicated that the CIA was, on average, 91 pmol/l higher tha...
McFarlane D.Despite there being only 2 common endocrine diseases in horses, pituitary pars intermedia dysfunction (PPID) and equine metabolic syndrome (EMS), diagnosis is still confusing. Failing to consider horse factors and treating based on laboratory results only have caused many animals to receive lifelong drug treatment unnecessarily. Increased plasma ACTH, baseline or TRH stimulated, supports a diagnosis of PPID; however, breed, age, thriftiness, illness, coat color, geography, diet, and season also affect ACTH concentration. Insulin dysregulation, the hallmark of EMS, can result from insulin resis...
Ralston SL.Abnormally high or low blood glucose and insulin concentrations after standardized glucose tolerance tests can reflect disorders such as pituitary dysfunction, polysaccharide storage myopathies, and other clinical disorders. Glucose and insulin responses, however, are modified by the diet to which the animal has adapted, time since it was last fed, and what it was fed. Body fat (obesity), fitness level, physiologic status, and stress also alter glucose and insulin metabolism. Therefore, it is important to consider these factors when evaluating glucose and insulin tests, especially if only one ...
Asplin KE, Curlewis JD, McGowan CM, Pollitt CC, Sillence MN.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. Objective: 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 investi...
Bowser JE, Elder SH, Rashmir-Raven AM, Swiderski CE.To describe the use of a cryogenic clamp of novel design for tensile strength testing of tendinous and ligamentous tissues with inherently high tensile strength. Methods: Inexpensive, easily machined steel clamps were manufactured to facilitate rapid insertion into a standard wedge-screw grip apparatus installed on a testing system with a control system attached. The deep digital flexor tendon (DDFT) of six horses was trimmed to a uniform dumbbell shape and secured in clamps using partial submersion in liquid nitrogen for approximately 45 seconds and immediately tested. Approximate time betwee...
Ott EC, Cavinder CA, Wang S, Smith T, Lemley CO, Dinh TTN.Oxidative stress caused by routine physical stressors may negatively impact the performance of equine athletes; thus, the present study identifies oxidative biomarkers in the blood plasma of exercising horses. Stock-type horses were subject to a standardized moderate-intensity exercise protocol 3 times per week for 8 wk. Exercise protocol followed NRC guidelines consisting of 30% walk, 55% trot, and 15% canter, with a target heart rate (HR) of 90 BPM. Blood plasma was collected in wk 1, 2, 7, and 8 immediately before and 0, 30, 60, and 90 min after exercise and analyzed for total antioxidant...
Delguste C, Amory H, Doucet M, Piccot-Crézollet C, Thibaud D, Garnero P, Detilleux J, Lepage OM.Tiludronate, a bisphosphonate, has recently been introduced in veterinary medicine to treat orthopedic conditions in the horse. This study was designed to evaluate its effects on biochemical biomarkers of bone metabolism and on bone density and structure in an experimental model of disuse osteoporosis induced by cast application in horses. Methods: Two groups of eight horses were immobilized during 8 weeks. The first group (P-group) received a placebo, and the second group (T-group) received tiludronate 1 mg/kg by slow IV infusion. Both treatments were administered twice, 28 days apart. Immobi...
Kinnunen S, Oksala N, Hyyppä S, Sen CK, Radak Z, Laaksonen DE, Szabó B, Jakus J, Atalay M.Several micronutrient supplementation strategies are used to cope with oxidative stress, although their benefits have recently been questioned. The aim of the present study was to examine the effects of DL-alpha-lipoic acid (LA) in response to acute exercise and during recovery in horses. Six standardbred trotters were tested on the treadmill before and after 5-week LA supplementation (25 mg/kg body weight/day). According to electron paramagnetic resonance measurements, strenuous aerobic exercise increased significantly free radical formation in the gluteus medius muscle, which was prevented b...
Brinkmann L, Gerken M, Hambly C, Speakman JR, Riek A.During winter, free-living herbivores are often exposed to reduced energy supply at the same time that energy needs for thermoregulation increase. Several wild herbivores as well as robust horse breeds reduce their metabolism during times of low ambient temperature and food shortage. Thyroid hormones (THs) affect metabolic intensity and a positive effect of THs on basal metabolic rate (BMR) has been demonstrated in mammals and birds. As BMR and field metabolic rate (FMR) are often assumed to be intrinsically linked, THs may represent a reliable indicator for FMR. To test this hypothesis, 10 Sh...
Domino M, Borowska M, Kozłowska N, Zdrojkowski Ł, Jasiński T, Smyth G, Maśko M.Infrared thermography (IRT) was applied as a potentially useful tool in the detection of pregnancy in equids, especially native or wildlife. IRT measures heat emission from the body surface, which increases with the progression of pregnancy as blood flow and metabolic activity in the uterine and fetal tissues increase. Conventional IRT imaging is promising; however, with specific limitations considered, this study aimed to develop novel digital processing methods for thermal images of pregnant mares to detect pregnancy earlier with higher accuracy. In the current study, 40 mares were divided i...
