Exercise in horses encompasses the physical activities that horses engage in, either through natural behaviors or structured training programs. These activities impact a horse's musculoskeletal, cardiovascular, and respiratory systems, influencing overall health and performance. Exercise can vary in intensity, duration, and frequency, and its effects are studied to understand conditioning, endurance, and recovery processes in equines. Research in this field often focuses on the physiological adaptations to different types of exercise, the prevention of exercise-related injuries, and the optimization of training regimens for various equestrian disciplines. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological, biomechanical, and health-related aspects of exercise in horses.
Sosa León LA, Hodgson DR, Rose RJ.We examined the gastric emptying (GE) of oral rehydration solutions (ORS) at rest and after exercise in four Standardbred horses. In one study isotonic, cold isotonic (5 degrees C), isotonic containing glucose and hypertonic fluid were tested at rest. In another study, isotonic fluid was given following a bout of treadmill exercise at 70 per cent VO2 max until exhaustion or at rest. In both studies, a single dose of 8 litres was given via nasogastric tube. GE and electrolyte concentrations (Na+, K+ and Cl-) of the stomach content were measured at 15 minutes intervals for one hour. In both stud...
Muñoz A, Santisteban R, Rubio MD, Vivo R, Agüera EI, Escribano BM, Castejón FM.The physiological and metabolic adaptations to exercise of the Andalusian horse seem to differ slightly from those found in other breeds. The authors studied the locomotor adaptation of 18 Andalusian horses to a training programme in relation to anaerobic energy metabolism, efficacy of the training programme, and changes associated with the onset of fatigue. They also tried to find out if these changes had become diminished by training. Several locomotor variables during trotting and galloping were determined and plasma lactate concentrations were measured before training and after two trainin...
Ainsworth DM, Smith CA, Eicker SW, Ducharme NG, Henderson KS, Snedden K, Dempsey JA.In exercising quadrupeds, limb movement is often coupled with breathing frequency. This finding has lead some investigators to conclude that locomotory forces, associated with foot plant, abdominal visceral displacements or lumbo-sacral flexion, are the primary determinants of airflow generation. Analysis of respiratory muscle electrical activation (EMG) and contraction profiles in chronically instrumented dogs and horses, along with measurements of esophageal pressure (Pes) changes and limb movements, provide evidence that each breath during the exercise hyperpnea is determined by respiratory...
McKeever KH, Malinowski K.To test the hypothesis that, compared with unfit young horses, unfit older horses have lower aerobic capacity and reduction in other indices of exercise capacity. Methods: 6 young (mean +/- SEM, 5.3 +/- 0.8 years and 445 +/- 13 kg) and 6 aged (22.0 +/- 0.4 years and 473 +/- 18 kg) healthy Standardbred and Thoroughbred mares. Methods: The mares, accustomed to running on a treadmill, were tested by use of an incremental exercise test. None of the mares had received exercise training for at least 4 months prior to the study. During testing, mares ran up a fixed 6% grade, starting at a speed of 4 ...
Keg PR, van Weeren PR, Back W, Barneveld A.The influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb was investigated in a group of eight sound horses. The degree of lameness after the flexion test was scored by a standard clinical classification, and by measuring the angle of maximum fetlock extension by means of the infrared light-based MacReflex gait analysis system. There was a good correlation between the clinical score and this electronically recorded kinematic parameter (r = 0.96). Both the force applied and the period of application affected the outcome of the tes...
de la Rúa-Domènech R, Mohammed HO, Cummings JF, Divers TJ, de Lahunta A, Summers BA.To identify intrinsic, management, nutritional, and environmental risk factors associated with equine motor neuron disease (EMND) and to determine whether epidemiologic evidence supports oxidative stress as a risk factor for developing EMND. Methods: Case-control study. Methods: 87 horses with EMND and 259 control horses. Methods: Information concerning each horse's history of exposure to multiple environmental factors prior to developing EMND was obtained by means of a questionnaire or personal interview. Exposure histories of horses with EMND and control horses were compared, and the associa...
Kawcak CE, Frisbie DD, Trotter GW, McIlwraith CW, Gillette SM, Powers BE, Walton RM.To evaluate the effects of arthroscopic surgery, osteochondral fragmentation, and treatment with IV administered hyaluronate on histologic, histochemical, and biochemical measurements within the carpal joints of horses. Methods: 12 clinically normal horses, 2 to 7 years of age. Methods: Horses had an osteochondral fragment created at the distal aspect of the radiocarpal bone of 1 randomly chosen middle carpal joint to simulate osteochondral fragmentation. Horses were treated with 40 mg of hyaluronate or saline solution (placebo) intravenously once a week for 3 consecutive weeks (days 13, 20, a...
Couroucé A, Chatard JC, Auvinet B.The purpose of this study was to examine the relationship between V4 (velocity which results in a blood lactate concentration of 4 mmol/l), age and racing performance of Standardbred trotters and to establish V4 normal values to select good and poor performers. The specific influence of racing (RT) and training (T1 and T2) tracks was also examined. A total of 159 horses were divided into 5 age-groups from 2 to 6 and over and performed 330 standardised exercise tests of 3 steps performed at increasing speeds. The velocity of the horses was measured with a tachometer on the sulky. Blood lactate ...
Frisbie DD, Kawcak CE, Trotter GW, Powers BE, Walton RM, McIlwraith CW.The objective of this study was to determine the effects of intra-articularly administered triamcinolone acetonide (TA) in exercised equine athletes with carpal osteochondral fragmentation. Eighteen horses were randomly assigned to each of 3 groups. An osteochondral chip fragment was created in one randomly chosen intercarpal joint of each horse. Both intercarpal joints in the placebo control group (CNT) horses were injected with intra-articular administration (IA) of polyionic fluid. Both joints in the TA control group (TA CNT) horses were treated with 12 mg of TA in the intercarpal joint wit...
Muñoz A, Santisteban R, Rubio MD, Vivo R, Agüera EI, Escribano BM, Castejón FM.The fitness of 8 Andalusian horses between 3 and 4 years of age was analysed. The animals were subjected to an exercise test on a sandy track consisting of 2 stages of different intensities. The first stage was of submaximal intensity at 4 speeds which increased progressively (4.17, 5.56, 6.94 and 8.33 m/sec.) covering a distance of 1,000 m in each level. Between each of these speeds, the horses rested for 2 min. The second stage was a maximal speed test over the same distance carried out 2 min after the ending of the maximal phase. Data of heart rate, plasma lactate concentration, velocity, P...
Kunugiyama I, Ito N, Narizuka M, Kataoka S, Furukawa Y, Hiraga A, Kai M, Kubo K.Erythrocyte volumes of thoroughbred horses were measured. The volumes of splenectomized horses and sham-operated horses 2 hr after injection of 50Cr-tagged erythrocytes (at rest) and during maximal exercise were measured using the non-radioactive isotope 50Cr. Because splenic erythrocytes are released into circulation during exercise, it was estimated that the erythrocyte volumes of the sham-operated horses during maximal exercise are larger than those of the horses at rest. However, the erythrocyte volumes of the sham-operated horses at rest were about equal to those during maximal exercise. ...
Kingston JK, Geor RJ, McCutcheon LJ.Rate and ionic composition of sweat fluid losses and partitioning of evaporative heat loss into respiratory and cutaneous components were determined in six horses during three 15-km phases of exercise at approximately 40% of maximal O2 uptake. Pattern of change in sweat rate (SR) and composition was similar during each phase. SR increased rapidly for the first 20 min of exercise but remained at approximately 24-28 ml . m-2 . min-1 during the remainder of each phase. Similarly, the concentrations of Na and Cl in sweat increased until 30 min of exercise but were unchanged thereafter. Sweat osmol...
Todhunter PG, Schumacher J, Finn-Bodner ST.Chronic lameness was determined to be caused by desmitis of the accessory ligament of the deep digital flexor tendon and adhesions associated with these 2 structures. Desmotomy of the accessory ligament, resection of adhesions, and controlled exercise during convalescence resulted in return to normal use without apparent lameness.
Holcombe SJ, Derksen FJ, Stick JA, Robinson NE.To determine the effect of bilateral hypoglossal and and glossopharyngeal nerve block on epiglottic and soft palate position and tracheal and pharyngeal pressures in exercising horses. Methods: 5 Standardbreds. Methods: Tracheal and pharyngeal pressures were measured in 5 Standardbreds exercising at the speed at which the horses achieved 50, 75, and 100% of maximal heart rate after bilateral hypoglossal and glossopharyngeal nerve block and without nerve block. Nerve block was achieved by injection of 1 to 2 ml of 2% mepivicaine hydrochloride between the glossopharyngeal and hypoglossal nerves,...
Patterson-Kane JC, Parry DA, Goodship AE, Firth EC.One of the current concepts with regard to equine superficial digital flexor tendonitis is that cumulative subclinical microscopic damage weakens the structure, predisposing the tendon to partial or complete rupture. This microtrauma is likely to affect the waveform or crimp of the collagen fibrils, which are the units of tensile strength. Collagen fibril crimp morphology characteristics were determined in superficial digital flexor tendons of 18 horses presented for necropsy. Horses were separated into exercised (n = 9) and non-exercised groups (n = 9), based on recent function. Five of the e...
Jackson JA, Ducharme NG, Hackett RP, Rehder RS, Ainsworth DM, Shannon KJ, Erickson BK, Erb HN, Jansson N, Soderholm LV, Thorson LM.To determine whether laryngeal hemiplegia would increase transmural pulmonary artery pressure (TPAP). Methods: 6 horses. Methods: Horses were studied under 5 conditions: control conditions, after induction of left laryngeal hemiplegia, during obstruction of the left nostril, after placement of an instrumented tracheostomy, and after placement of an open tracheostomy. Horses were evaluated after being given saline solution and after being given furosemide. Methods: Horses were exercised on a high speed treadmill, using a maximum speed of 13 m/s. During each exercise, airway pressures, airflow, ...
Manohar M, Goetz TE, Sullivan E, Griffin R.The frusemide dose-response for attenuation of exercise-induced pulmonary capillary hypertension was studied in 7 healthy, exercise-conditioned Thoroughbred horses using previously described haemodynamic procedures. Four different doses of frusemide were tested: 250 mg regardless of bodyweight (amounting to 0.56 +/- 0.03 mg/kg bwt), 1.0 mg/kg bwt, 1.5 mg/kg bwt and 2.0 mg/kg bwt. Frusemide was administered i.v., 4 h before exercise. Haemodynamic data were obtained at rest and during treadmill exercise performed at 14.2 m/s on a 3.5% uphill grade; this workload elicited maximal heart rate of ho...
Essén-Gustavsson B, Ronéus N, Pösö AR.Histochemical and biochemical analyses were performed on muscle biopsies obtained after racing from the gluteus muscle of 18 standardbred trotters. Fibre type composition and enzyme activities varied among the horses. The percentage of type IIB fibres showed a positive correlation to the lactate dehydrogenase activity and a negative correlation to the citrate synthase activity. ATP concentrations in whole muscle after racing showed a negative correlation to both lactate and IMP concentrations. Within individual fibres, ATP concentrations varied markedly, with some type II fibres having values ...
Christley RM, Hodgson DR, Evans DL, Rose RJ.To compare the development of exercise-induced arterial hypoxemia in horses before and after training, and to determine whether increases in maximum oxygen uptake (VO2max) following training results in a greater degree of exercise-induced arterial hypoxemia. Methods: 13 three- to five-year-old. Standardbred geldings without clinical signs of respiratory or cardiovascular disorders. Methods: Horses were rested for 4 months prior to commencing a 16-week training program. Arterial blood was collected from the transverse facial artery during standardized exercise tests performed before and after 8...
Siciliano PD, Parker AL, Lawrence LM.The effect of vitamin E intake on indicators of muscle integrity was studied in exercised horses. Nineteen horses were blocked by sex and then assigned to one of three diets: no supplemental vitamin E (BASAL), BASAL plus 80 IU of supplemental vitamin E/kg DM (80), or BASAL plus 300 IU of supplemental vitamin E/kg DM (300). The BASAL diet contained less than 44 IU of vitamin E/kg DM, but it was adequate in all other nutrients. During the 90-d treatment period, horses were exercised 5 d/wk; in addition, serum and middle gluteal muscle alpha-tocopherol concentrations were measured at 0, 30, and 9...
Birch HL, Wilson AM, Goodship AE.Tendons that store energy during locomotion, such as the equine superficial digital flexor tendon (SDFT) and human Achilles tendon, suffer a high incidence of central core degeneration which is thought to precede tendon rupture. Although energy storage contributes to the efficiency of locomotion, tendons are not perfectly elastic and some energy is lost in the form of heat. Recent studies have shown that the central core of equine SDFT reaches temperatures as high as 45 degrees C during high-speed locomotion. In this study, we test the hypothesis that hyperthermia causes tendon cell death and ...
Gottlieb-Vedi M, Lindholm A.The responses in heart rate, plasma lactate and rectal temperature of standardbred trotters to draught loaded interval exercise on a treadmill and a race track were studied. The horses were exercised with incrementally increasing trotting speeds for two-minute intervals with draught loads of 10, 20 and 30 kilopond (kp) in three different tests. Each trotting interval was followed by two-minute periods at a walk without a draught load. Measurements of heart rate and plasma lactate were made at the end of each interval and the rectal temperature was taken at the end of the exercise. The heart ra...
Burn JF, Wilson A, Nason GP.Impact is implicated in the development of several types of musculoskeletal injury in the horse. Characterisation of impact experienced during strenuous exercise is an important first step towards understanding the mechanism for injury. Measurement and analysis of large, short duration impacts is difficult. The measurement system must be able to record transient peaks and high frequencies accurately. The analysis technique must be able to characterise the impact signal in time and frequency. This paper presents a measurement system and analysis technique for the characterisation of large impac...
Persson SG.The purposes of this study were to elucidate the influences of age and sex on the heart rate (HR, bpm) and blood lactate (LA, mmol/l) related exercise tolerance parameters V2000 (tread ill velocity at HR 200), VLA4 (velocity at LA 4), W200 (power output at V2000), and WLA4 (power output at VLA4), and to establish reference values for these in normally performing Standardbred trotting race horses. A further aim was to improve the predictability of individual normal values by correlating them with the total red blood cell volume (CV) alone or in combination with the blood lactate response at V20...
Uhlir C, Licka T, Kübber P, Peham C, Scheidl M, Girtler D.In order to study the mechanism of lameness transfer from fore- and hindlimb lamenesses 2 hypotheses were investigated. Hypothesis 1: Horses with a true supporting limb lameness in one hindlimb show a false supporting limb lameness in the ipsilateral forelimb. Hypothesis 2: Horses with a true supporting limb lameness in one forelimb show a false supporting limb lameness in the contralateral hindlimb. Fourteen horses with fore- or hindlimb lameness were used for this study. Each horse was measured at the trot on a treadmill with standardised speed, before and after diagnostic blocks (9 horses),...
Sloet van Oldruitenborgh-Ooste , Barneveld A, Schamhardt HC.To evaluate the effects of uphill trotting on stride characteristics, 6 well trained Dutch Warmblood horses trotted at 4 m/s on a horizontal and on an inclined (6%) treadmill. This was done under 3 different conditions, unloaded, mounted by an experienced 90 kg rider and loaded with 90 kg of lead, to study whether extra weight provoked more or different alterations than the incline per se. In all 3 test situations (unloaded, mounted and lead-loaded), heart rates were significantly higher on the inclined treadmill than on the horizontal treadmill. Stride duration tended to increase on the incli...
Little CB, Ghosh P, Rose R.Articular cartilage degeneration in the middle carpal joint is a common problem in racing horses. This study evaluated the effect of exercise on the in-vitro synthesis of the large aggregating proteoglycans (aggrecan) and two small proteoglycans, biglycan and decorin, in articular cartilage taken from three weight bearing regions of the third carpal bone of horses which were subjected to moderate or strenuous exercise. Twelve Standardbred horses free from clinical and radiographic disease of the middle carpal joint were subjected to an 8 week moderate exercise program. The horses were then ran...
Kai M, Hiraga A, Kubo K, Tokurik M.The purpose of this study was to determine whether there was any difference in the stride characteristics between cantering on a flat or inclined treadmill. Five 2-year-old Thoroughbred horses were cantered on a treadmill at 3 different velocities and at 3 different slopes. The sequence of speeds at each slope was chosen at random and 16 mm cinefilms at 300 frames/s were taken from a lateral view at a distance of 15 m from the treadmill to record the linear and temporal data. On the slope, stride length, stride duration, stance duration and swing duration did not change. However, midstep lengt...
Clayton HM.Six event horses jumped a 1.10 m high table fence 4 times under each of 2 conditions; the rider weight condition involved carrying the weight of the rider and saddle (61 kg), whereas the added weight condition included an additional 18 kg weight cloth. Sagittal view, 60 Hz video recordings were analysed using standard methods. Comparisons between the rider weight and added weight conditions using paired t tests (P<0.05) showed a number of significant differences. In the added weight condition the leading forelimb landed closer to the fence, and there were increases in the maximal extension ...
Logan AA, Snyder AJ, Nielsen BD.The effects of gait and diameter have been studied independently, but rarely together in equine circular exercise studies. This study aimed to determine the impact of diameter (10-m or 15-m) at various gaits (walk, trot, and canter) on stride frequency or forelimb stance duration. Nine mature horses were outfitted with Tekscan™ Hoof Sensors on their forelimbs during circular and straight-line exercise at various gaits on a clay and sand arena surface. Statistical analysis was performed in SAS 9.4 with fixed effects of exercise type, recording, leg, and breed (PROC GLIMMIX, p < 0.05 significa...
Dąbek J, Koczy B, Piotrkowicz J.Horse riding becoming increasingly common and popular form of recreation and leisure activities. However, enforced, proper posture while riding a horse, may contribute to decrease mobility of spine and lead to occurrence back pain. Objective: The aim of this study was to assess the impact of the systematic training of horse riding on the global mobility of the spine and back pain prevalence in-training horse riders professionally and recreational. Methods: The study included 70 horse riders. The subjects were divided into two groups: 1) professional horse riders (n=50; 71.43%) or 2) a group of...
Marlin DJ, Scott CM, Mills PC, Louwes H, Vaarten J.The administration of 41 of an isotonic, plasma-like oral rehydration solution (ORS) with an osmotic skeleton and 41 of water (water; no osmotic skeleton), were evaluated in five thoroughbred horses. Solutions were administered by nasogastric tube 4 h after feeding. Uptake of deuterium, concentrations of plasma sodium, potassium, chloride, glucose, total protein and packed cell volume, pH, PCO2, HCO3-, total CO2, actual base excess, standard base excess, plasma volume and weight loss were assessed both at rest, and during and after exercise on a treadmill. Each horse underwent four experimenta...
Marqués FJ, Waldner C, Reed S, Autet F, Corbeil L, Campbell J.The primary objective of this study was to investigate whether rider experience influences the assessment and grading of lameness in horses based on under-saddle gait analysis. Thirteen adult sports horses in active training were included in the study. After a baseline lameness and neurologic examination by the principal investigators, horses were videotaped while being ridden by an experienced and a less experienced rider. A 3-minute video was made for each horse and rider and 26 videos were randomly ordered and compiled on a DVD. Veterinarians with different levels of experience in evaluatin...
Keenan DM.Changes in concentration of a number of blood metabolites in 30 thoroughbred horses were recorded after an 1110 metre race. No significant changes occurred in blood urea or aspartate aminotransferase during the three hours after racing. Plasma sodium, potassium and calcium levels were increased immediately after racing but had returned to normal one hour after racing. Plasma phosphate showed a significant fall in concentration one hour after racing. Creatinine and lactic acid concentrations were elevated ten minutes after racing and although they subsequently decreased, the level of lactic aci...
Rugh KS, Garner HE, Miramonti JR, Hatfield DG.Myocardial and haemodynamic responses to strenuous treadmill exercise were monitored with chronically implanted instrumentation in seven physically untrained ponies. In two other ponies, haemodynamics were monitored using a conventional catheter technique. During exercise (mean +/- sem heart rate = 203 +/- 3 beats/min), left ventricular peak systolic ahd end-diastolic blood pressure significantly increased from 125 +/- 2 to 208 +/- 6 mmHg and from 29 +/- 1 to 58 +/- 3 mmHg, respectively (P less than 0.05). Peak positive first derivative of left ventricular pressure (dP/dt) was also increased s...
Barr AR, Wotton SF, Dow SM, Waterman AE, Goodship AE, Duance VC.The effects of osteochondral defect location and post-operative walking exercise on structural repair and recovery of joint function were examined in the midcarpal joints of ponies. Functional recovery was monitored by measuring ground reaction forces using a force plate. Structural repair was evaluated histologically and by measuring the total collagen and uronic acid content and relative proportions of Type I and II collagen in the repair tissue. Central defects tended to cause a more marked functional disturbance but were repaired with fibrocartilage rather than fibrous tissue in 3 out of 6...
Back W, Smit LD, Schamhardt HC, Barneveld A.To study the influence of different exercise regimens on the development of locomotion, 40 Warmblood foals aged 1 week were subdivided into 3 groups: box-rest, training and pasture exercise. The box-rest group remained for 24 h a day in a box stall while the training group was housed similarly, but additionally received a 30 min workout with gallop sprints 6 times a week. The pasture group served as a control group and was kept at pasture for 24 h a day. After 5 months, the locomotion pattern at the trot of every foal was recorded overground with a 2-D MacReflex gait analysis system. A randoml...
Amato C, Martin L, Dumon H, Jaillardon L, Nguyen P, Siliart B.Leptin is an adipocytokine mainly expressed by adipose tissue. Secretion of leptin in healthy animals is closely related to fat mass and metabolic activity. The aim of this study was to investigate plasma leptin variations, in relation to nutritional and exercise parameters in adult show horses during a work season. EDTA-blood samples were taken at rest from 37 Iberian horses. Body weight, body condition score and fat percentage determined by ultrasonic measurement of rump fat thickness were measured. Plasma leptin was determined with a multi-species RIA kit. Linear mixed effects model was use...
Fey K.Horses are obligate nasal breathers and depend on patency of their nasal passages. Several dynamic obstructive diseases in the pharyngeal and laryngeal area can be differentiated by high speed treadmill endoscopy and may be responsible for impaired exercise tolerance in the equine athlete. The anatomical specialty of guttural pouches predisposes the horse to species-specific diseases.
Manohar M, Goetz TE, Saupe B, Hutchens E, Coney E.Using radionuclide-labeled 15-microm-diameter microspheres injected into the left ventricle, we examined blood flow to the thyroid gland, adrenal glands, kidneys, and various gastrointestinal tract tissues in 9 healthy horses while they were standing quietly (rest) and during exercise at 2 work intensities (8 and 1 m/s). Hemodynamic measurements were made during steady-state conditions, as judged by the stability of heart rate as well as aortic, pulmonary, and right atrial pressures. The similarity of blood flow values for the left and the right kidneys during each of the 3 conditions indicate...
Fitzharris LE, Lane JG, Allen KJ.To determine the proportion of horses treated by laryngoplasty prosthesis removal (LPR) for complications associated with prosthetic laryngoplasty (LP), the reason for LPR, and the outcome of horses undergoing LPR to manage iatrogenic coughing/dysphagia. Methods: Retrospective study. Methods: Client-owned horses treated with LP (n = 1202) and LPR (n = 58). Methods: Clinical case records were reviewed to determine the number of horses treated with LP and LPR by the same surgeon. Historical, clinical, endoscopic, and surgical data were extracted for those horses undergoing LPR. Long-term...
Franck T, Votion DM, Ceusters J, De La Rebière de Pouyade G, Mouithys-Mickalad A, Niesten A, Fraipont A, VAN Erck E, Goachet AG, Robert C, Serteyn D.Intense exercise in horses induces an increase of creatine kinase (CK) and stimulation of neutrophils which release the strong oxidant enzyme, myeloperoxidase (MPO) into the blood. It is not known whether active MPO is found in equine muscles and whether oxidant activity of neutrophils could affect muscular tissues and mitochondrial activity. Objective: Specific immuno-extraction followed by enzymatic detection (SIEFED) methods will be employed for the first time to assess both the normal range of MPO and mitochondrial complex I (MCI) activities in equine muscular microbiopsies and to study th...
Burn JF, Portus B, Brockington C.The equine carpus has a well-defined limit to joint extension at approximately 180 degrees . During locomotion however, the carpus hyperextends during stance phase. Hyperextension is resisted by the carpal bones and ligaments, and it has been proposed that large increased hyperextension might relate to potentially damaging stress levels in the carpus. The aim of this study was to investigate the relationship between peak hyperextension of the carpus (PCE) and speed during locomotion on the level and on an incline. Five Thoroughbred horses were exercised on a treadmill at speeds between 1.8 and...
Kamerling SG, Owens JG.The actions of most drugs are dependent upon achieving adequate plasma concentrations. Plasma concentrations are influenced by the degree to which a drug is absorbed, distributed, metabolized and excreted. Pharmacokinetic assessment reflects changes in these variables as a function of time. Pharmacodynamics refers to specific drug effects or mechanisms of drug action. Individual drug pharmacokinetics provides information on which to base a therapeutic dose, route of administration and dosing interval. However, not all drug actions temporally correlate with plasma kinetics. To resolve this disc...
Canada NC, Beard WL, Guyan ME, White BJ.To determine the influence of 3 types of bandages on sub-bandage pressures over the distal limb, carpus, and tarsus. Methods: Observational study. Methods: Eight healthy horses. Methods: Each of the 6 following bandages was applied on each horse in randomized order: (1) distal limb compression bandage (DLC), (2) double layer bandage (DL), (3) inner sanctum bandage (IS), (4) carpal compression bandage (CC), (5) tarsal compression bandage (TC), and (6) adhesive elastic carpal bandage (C-ELA). Sub-bandage pressures were measured with the Picopress compression measuring system (Microlab Electonica...
Soma LR, Laster L, Oppenlander F, Barr-Alderfer V.In 3 groups of horses with exercise-induced pulmonary hemorrhage (EIPH), comparisons of racing times and finishing positions were made between the 5 races before the horses were given furosemide and 5 races after furosemide administration. The horses were grouped according to 3 methods used to diagnose EIPH: group 1, observation of hemorrhage at the nostrils within 1 hour after a workout or race; group 2, observation of pulmonary hemorrhage only by endoscopic examination after a race or workout; and group 3, observation of hemorrhage at the nostrils during a race or immediately after a race. G...
van de Pol C, Sloet van Oldruitenborgh-Oosterbaan MM.Measuring the height at the withers of a pony is one of the requirements of the Fédération Equestre Internationale (FEI), before competitors can participate in an official pony event. A pony has to be measured each year until it is eight years old. With and without shoes the height at the withers must be below 149.0cm and 148.0cm, respectively. When a pony exceeds the regulated height, it is excluded from participating in FEI pony competitions. Besides being excluded from competing, the selling price of the pony decreases dramatically, because the animal is then classified as a horse. For th...
Dzięgielewska A, Dunislawska A.Mitochondria are an essential part of most eukaryotic cells. The crucial role of these organelles is the production of metabolic energy, which is converted into ATP in oxidative phosphorylation. They are also involved in and constitute apoptosis, the site of many metabolic processes. Some of the factors that negatively affect mitochondria are stress, excessive exercise, disease, and the aging process. Exercise can cause the release of large amounts of free radicals, inflammation, injury, and stress. All of these factors can contribute to mitochondrial dysfunction, which can consistently lead t...
Ross WA, Kaneene JB, Gardiner JC.To evaluate the associations of operation and individual animal-level risk factors with occurrence of lameness in the Michigan horse population. Methods: 3,925 horses monitored from 138 randomly selected Michigan operations for a total of 814,753 horse-days. Methods: All horses monitored < 60 days were eliminated from the source population. From the remaining horses, a prospective unmatched case-control study population was generated that included all cases and a random sample of noncases. Analysis of risk factors associated with occurrence of lameness was conducted, using Cox's propor...
Semanchik PL, Wesolowski LT, Ryan PJ, White-Springer SH, Fluckey JD.Skeletal muscle is a highly dynamic organ that is essential for locomotion as well as endocrine regulation in all populations of horses. However, despite the importance of adequate muscle development and maintenance, the mechanisms underlying protein anabolism in horses on different diets, exercise programs, and at different life stages remain obscure. Mechanistic target of rapamycin (mTOR) is a key component of the protein synthesis pathway and is regulated by biological factors such as insulin and amino acid availability. Providing a diet ample in vital amino acids, such as leucine and gluta...
Deldar A, Fregin FG, Bloom JC, Davanipour Z.The effects of strenuous exercise on serum electrolytes, blood metabolites, and serum enzymes were studied in a group of 13 horses participating in a 50-mile endurance ride. Blood samples were collected before, during, and at the end of the ride, as well as 1 hour and 16 hours after the completion of the ride. There were significant changes in these values when preride values were compared with those of samples taken at different sample-collection periods. Significant (P less than 0.001) decreases were observed in serum concentrations of chloride, potassium, and calcium. A significant increase...
Cheng X, Kong X, Fan Y, Wang X, Li Z, Wu H.Generally, adequate motor coordination (MC) ability is one among the critical factors for the overall development of children. In this paper, we have thoroughly analyzed the effects of equine-assistant activity (EAA) training on MC in children. For this purpose, MC test, specifically for children, was used to the Körperkoordinationstest für Kinder (KTK), and a total of 100 children, particularly those in 8 to 10 age, were equally separated into equine-assistant activity group (EAAG) and control group (CG), respectively. The EAAG group has attended a 14-week EAA training program, while the CG...
McKane SA, Rose RJ, Evans DL.Twenty-four Thoroughbred and twelve Standardbred racehorses aged between 2 and 6 years, presented for reported poor racing performance, underwent clinical exercise testing. During the last 10 s of exercise at each speed throughout an incremental speed exercise test on a treadmill inclined at a 10% slope, samples of arterial blood and expired gases were collected. Maximum oxygen uptake and the partial pressures of oxygen and carbon dioxide in arterial blood were determined. These values were compared between the two breeds of horses and also with reference to cytological findings of bronchoalve...
Kim W, McArdle BH, Kawcak CE, McIlwraith CW, Firth EC, Broom ND.To investigate histomorphometric changes in the cartilage and subchondral bone of the third carpal bone associated with conditioning exercise in young Thoroughbreds. Methods: Nine 18-month-old Thoroughbreds. Procedures-Both third carpal bones of 9 horses (4 exercised spontaneously at pasture only and 5 given additional conditioning exercise beginning at a mean age of 3 weeks) were evaluated. Histomorphometric variables (hyaline and calcified cartilage thickness and collagen orientation; vascular channel area, number, and orientation; and osteochondral junction rugosity) of the third carpal bon...
Brown DG.Physiologic responses of irradiated and nonirradiated Shetland Ponies to controlled exercise were measured over a period of 5 years. The 5-year test began when the ponies were 3 years old and 5 months after they were exposed to 650 R of 60-Co gamma radiation. Significant differences in heart rates, respiratory rates, and rectal temperatures were demonstrated between irradiated and nonirradiated ponies when subjected to exercise and high ambient temperatures. Inthe irradiated group, heart rates were usually slower, especially during recovery immediately after exercise, and respiratory rates and...
Buckingham SH, McCarthy RN, Anderson GA, McCartney RN, Jeffcott LB.Transmission ultrasound speed was determined in the third metacarpal bone of 347 Thoroughbred racehorses in training. In addition to direct measurement of apparent ultrasound speed and lateral bone diameter, several derived parameters were estimated (cortical ultrasound speed, corticomedullary ratio and cortical cross-sectional area). Multiple regression equations were developed for each ultrasound measurement using the explanatory variables: sex, age, duration and intensity of training, preparation number and previous shin soreness. The horses (114 females, 82 entire males and 151 geldings ra...
Powers SK, Beadle RE, Lawler J, Thompson D.The O2 deficit-O2 debt relationship in ponies was examined at two levels of treadmill exercise. Five healthy ponies exercised for 8 min at two work rates (WR):(1) 50 m/min at 6% grade and (2) 70 m/min at 12% grade. The O2 deficit and O2 debt were calculated using open-circuit measurement of pulmonary gas exchange during the transition from rest to steady-state exercise and during recovery from exercise. The O2 deficit was significantly lower (P less than 0.05) than the O2 debt at each of the two work rates. The means (+/- SEM) for the deficit and the O2 debt, respectively, in liters were: (1) ...
Hördegen KM.115 horseback riders have undergone clinical and radiologic examinations of the spine. A minimum of 10 years' riding was required. Depending on intensity of training and number of riding hours, the subjects were divided into three groups: roughriders, sport riders and hobby riders. It was striking that of the bare half of cases (51) suffering from lower back, only 8 (about 15%) had had medical treatment and actually been disabled. Moreover, 47% of the riders with lower back pain were painfree in the saddle, i.e. when riding. No causal connection was found between riding and a higher incidence ...
Snow DH, Munro CD, Nimmo MA.The effect of 11 weekly injections of nandrolone phenylpropionate (400 mg) was investigated by a crossover trial (2 training periods) in 6 Thoroughbred geldings undergoing training. A decrease in body weight and flank measurement occurred only during the first training period and was not modified by the anabolic steroid. Urinary nitrogen excretion was lower in the anabolic treated animals only in the first training period. Neither training nor training plus nandrolone phenylpropionate administration caused any marked alteration in blood biochemistry or haematology. A significant decrease in pl...
