Topic:Mature Horses
Mature horses refer to adult horses that have reached full physical development, typically around five years of age. These horses are often at the peak of their physical capabilities and are commonly used in various equestrian disciplines, including racing, dressage, and show jumping. Understanding the physiology, behavior, and health management of mature horses is essential for optimizing their performance and well-being. This topic encompasses research on the nutritional requirements, musculoskeletal health, and reproductive management of mature horses. Additionally, it includes studies on the effects of exercise, disease prevalence, and preventative healthcare practices. This page compiles peer-reviewed research studies and scholarly articles that explore the various aspects of mature horse management and health.
Evidence for dopamine production and distribution of dopamine D2 receptors in the equine gastrointestinal mucosa and pancreas. Insulin dysregulation in horses is characterised by hyperinsulinaemia and/or tissue insulin resistance and is associated with increased risk of laminitis. There is growing evidence in other species that dopamine attenuates insulin release from the pancreas; however, this has yet to be examined in horses. The present study aimed to identify whether there are cells capable of producing or responding to dopamine within the equine gastrointestinal mucosa and pancreas. Tissue samples were collected from the stomach, small and large intestines, and pancreas of six mature horses following euthanasia....
Improved quality of life and pain relief in mature horses with osteoarthritis after oral transmucosal cannabidiol oil administration as part of an analgesic regimen. The aim of this study was to evaluate the effect of oral cannabidiol (CBD) administration in addition to a conventional analgesic protocol on the clinical signs of 20 horses with mild joint osteoarthritis. The horses were randomly assigned to either the control group (C group) or the cannabidiol group (CBD group). Both groups were treated with phenylbutazone for 5 days. The CBD group received 0.03 mg/kg cannabidiol in hemp oil orally once daily for 14 days in addition to phenylbutazone treatment. All subjects were monitored for clinical parameters, oxidative status and blood counts. Pain...
Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment. Topical wound treatments rely on carrier formulations with little to no biological impact. The potential for a common vehicle, a propylene glycol (PG) gel, to affect wound healing measures including microbiota is not known. Microbiome characterization, based on next generation sequencing methods is typically performed on tissue or directly obtained wound fluid samples. The utility for primary wound dressings to characterize equine wound microbiota in the context of topical treatments is currently unknown. This investigation reports the topical effect of an 80% PG based gel on wound healing and...
Investigating the gastrointestinal physiology of mature horses with and without a history of cribbing behavior in response to feeding a digestive support supplement. Cribbing, a stereotypic oral behavior observed in horses, involves placing incisors on a fixed object, arching the neck, pulling against the object, and emitting an audible grunt. This behavior has been associated with gastrointestinal (GI) dysfunction and gastric ulceration. In this randomized crossover study, we investigated the impact of a GI support supplement (SPL) on the GI environment and physiology of four cribbing (CB) and four non-cribbing horses (NCB). Mature Quarter Horses, acclimated to individual stalls for 16 hours daily with paddock turnout in pairs for 8 hours per day, were ra...
A polymer network architecture provides superior cushioning and lubrication of soft tissue compared to a linear architecture. We report the relationships between linear network polymer architecture and biomechanical outcomes including lubrication and cushioning when the polymers are applied to the surface of articulating knee cartilage. Aqueous formulations of the bioinspired polymer poly(2-methacryloyloxylethyl phosphorylcholine) (pMPC) exhibit tuneable rheological properties, with network pMPC exhibiting increased elasticity and viscosity compared to linear pMPC. Application of a polymer network, compared to a linear one, to articulating tissue surfaces reduces friction, lessens tissue strain, minimizes wear, and ...
Evaluation of an Oral Supplemental Cannabidiol Product for Acceptability and Performance in Mature Horses. Thirty stock type geldings (15 ± 3 years; 556 ± 63 kg BW) were used in a randomized complete design over 28 days to determine the influence of cannabidiol (CBD) oil supplementation levels on body weight, body condition, and blood chemistry. Horses were randomly assigned to one of three dietary treatments (n = 10 per treatment) formulated with canola oil to provide 1.50 mg CBD/kg BW (TRTA), 0.75 mg CBD/kg BW (TRTB), or 0.00 mg CBD/kg BW (canola oil; CTRL). Treatments were top-dressed onto concentrate and individually administered twice daily. Horses were maintained in adjacent dry lots and re...
Impact of Gait and Diameter during Circular Exercise on Front Hoof Area, Vertical Force, and Pressure in Mature Horses. Circular exercise can be used at varying gaits and diameters to exercise horses, with repeated use anecdotally relating to increased lameness. This work sought to characterize mean area, mean vertical force, and mean pressure of the front hooves while exercising in a straight line at the walk and trot, and small (10-m diameter) and large circles (15-m diameter) at the walk, trot, and canter. Nine mature horses wore TekscanTM Hoof Sensors on their forelimbs adhered with a glue-on shoe. Statistical analysis was performed in SAS 9.4 with fixed effects of leg, gait, and exercise type (PROC GLIMMIX...
Furosemide administration results in a transient alteration in calcium balance in mature horses. Previous research documented that furosemide negatively impacted calcium balance for 3 days but did not determine when calcium balance returned to baseline. This study hypothesized that furosemide's impact on calcium would return to control values before 7 days post-administration. Ten mature geldings were assigned to either control (CON, n = 5) or treatment (FUR, n = 5) for the first of two 8-day total collections in crossover design. Treatment horses received one administration of furosemide (1 mg/kg, IV). A 10% sample of pooled faeces and urine from each day was kept. Calcium concent...
Reference values of hematological and blood biochemical parameters for the Noma horse. The Noma horse is a Japanese breed from the Noma region of Imabari City, Ehime Prefecture. To obtain reference hematological and biochemical values, we performed examinations in 39 clinically healthy, mature Noma horses managed at the Imabari public ranch. Hematological and biochemical results of Noma horses were close to the normal ranges of horses in the U.S.A. The erythrocyte parameters and hepatobiliary enzyme levels in Noma and Kiso horses were lower than those in Japanese racehorses. Noma horses showed higher erythrocyte parameters and triglyceride concentrations and a lower creatinine c...
Clinical findings associated with development of postoperative reflux and short-term survival after small intestinal surgery in geriatric and mature nongeriatric horses. To determine risk factors, especially age, associated with postoperative reflux (POR; >2 L of reflux present upon intubation), high-volume POR (≥20 L in 24 hours), and short-term outcome after small intestinal (SI) surgery. Methods: Retrospective case-control study. Methods: Horses aged ≥16 years (geriatric; range, 16-30; n = 44) and <16 years (mature; range, 2-15; n = 39) with an SI surgical lesion that survived general anesthesia and did not have a second exploratory celiotomy during the same visit. Methods: Medical records (2009-2015) were reviewed; perioperative var...
Comparison of limb kinematics between collected and lengthened (medium/extended) trot in two groups of dressage horses on two different surfaces. Dressage horses are often asked to work in lengthened paces during training and competition, but to date there is limited information about the biomechanics of dressage-specific paces. Preliminary work has shown increased fetlock extension in extended compared with collected paces, but further investigation of the kinematic differences between collected, medium and extended trot in dressage horses is warranted. Objective: Investigation of the effect of collected vs. medium/extended trot on limb kinematics of dressage horses. Methods: Prospective kinematic evaluation. Methods: Twenty clinically...
Cardiovascular effects of pimobendan in healthy mature horses. Pimobendan is an inodilator used in dogs for the management of heart failure due to myxomatous valve disease or dilated cardiomyopathy. The lack of data regarding the effects of pimobendan in horses prevents the rational use of this drug. Objective: To determine the cardiovascular effects of pimobendan in healthy mature horses. Methods: Randomised experimental study. Methods: Five horses were fasted overnight prior to receiving i.v. pimobendan (0.25 mg/kg bwt), intragastric (i.g.) pimobendan (0.25 mg/kg bwt) or i.g. placebo with a washout period of one week between each administration. Horses ...
Short-term complications after colic surgery in geriatric versus mature non-geriatric horses. To compare in geriatric and mature horses the occurrence of short-term complications and short-term outcome associated with complications after colic surgery. Methods: Retrospective case-control study. Methods: Horses aged ≥20 years (geriatric, n = 78) and 4-15 years (mature non-geriatric, n = 156) that had exploratory celiotomy for colic and survived recovery from general anesthesia. Methods: Medical records (2000-2010) of horses that recovered from general anesthesia after colic surgery were reviewed. Postoperative complications evaluated included postoperative reflux (POR), diarrh...
Echocardiographic evaluation of changes in left ventricular size and valvular regurgitation associated with physical training during and after maturity in Standardbred trotters. To assess whether physical training induces cardiac hypertrophy and valvular regurgitation in maturing Standardbred trotters and to establish a prediction model for the size of the left ventricle. Methods: Longitudinal observational study. Methods: 53 Standardbred trotters. Methods: Each horse underwent 2-D, M-mode, and color flow Doppler echocardiography at 5.5 years of age; previously, each horse had been examined at 2, 2.5, 3, and 3.5 (time of maturity) years of age. Horses were or were not in training or racing for variable periods during the entire assessment period; data for a given hors...
Influence of different mixing ratios on in-vessel co-composting of sewage sludge with horse stable straw bedding waste: maturity and process evaluation. Composting sewage sludge alone would reduce the decomposition efficiency due to free limited porosity in sludge. To alleviate this, the use of horse stable straw bedding waste (HSB) was evaluated as a co-composting material with sewage sludge in a 10 tonnes day(-1) in-vessel composter for a period of 7 days before curing in a static aeration pile. Sludge was mixed with HSB at 1 : 1.5 (HSL) and 1 : 2.9 (LSL) on a fresh weight basis. After a composting period of 56 days, both mixing ratios demonstrated to be feasible with LSL having a better organic decomposition and a shorter time to reach matu...
Pharmacokinetics of amikacin in plasma and selected body fluids of healthy horses after a single intravenous dose. No studies have determined the pharmacokinetics of low-dose amikacin in the mature horse. Objective: To determine if a single i.v. dose of amikacin (10 mg/kg bwt) will reach therapeutic concentrations in plasma, synovial, peritoneal and interstitial fluid of mature horses (n=6). Methods: Drug concentrations of amikacin were measured across time in mature horses (n=6); plasma, synovial, peritoneal and interstitial fluid were collected after a single i.v. dose of amikacin (10 mg/kg bwt). Results: The mean±s.d. of selected parameters were: extrapolated plasma concentration of amikacin at time ze...
Digestibility and nutrient retention of perennial peanut and bermudagrass hays for mature horses. Mature horses were used to determine apparent DM, OM, NDF, and CP digestibility values of 2 bermudagrass (BG; Cynodon dactylon) hays, Coastal (CB) and Tifton 85 (T85), and Florigraze perennial peanut (PP; Arachis glabrata) hay. In addition, N, Ca, and P balances were determined in horses fed those hays. Five mature Thoroughbred geldings and 1 Quarter Horse gelding (mean initial BW = 542 +/- 37 kg) were used (5 horses for the last period) in a 3 x 3 repeated Latin square design, with 2 horses per hay and 3 adjustment and collection periods. Horses were randomly assigned to pairs and the initial...
Anaesthetic and cardiorespiratory effects of propofol at 10% for induction and 1% for maintenance of anaesthesia in horses. Studies have demonstrated the clinical usefulness of propofol for anaesthesia in horses but the use of a concentrated solution requires further investigation. Objective: To determine the anaesthetic and cardiorespiratory responses to a bolus injection of 10% propofol solution in mature horses. Methods: Three randomised crossover experimental trials were completed. Trial 1: 6 horses were selected randomly to receive 10% propofol (2, 4 or 8 mg/kg bwt i.v.). Trial 2: 6 horses received 1.1 mg/kg bwt i.v. xylazine before being assigned at random to receive one of 5 different doses (1-5 mg/kg bwt) o...
Solute transport in the deep and calcified zones of articular cartilage. (1) To establish whether the tidemark and calcified cartilage are permeable to low molecular weight solutes, thereby providing a potential pathway for nutrition of cells in the deep cartilage. (2) To investigate transport from the subchondral microcirculation into calcified cartilage in an intact perfused joint and the effects on transport of static loading. Methods: The permeability of the tidemark and calcified cartilage was investigated in plugs of cartilage and subchondral bone which formed the membrane of a diffusion cell. Transport from the subchondral microcirculation and the effects of...
Scintigraphic evaluation of the stifle in normal horses and horses with forelimb lameness. We tested the hypotheses that mature horses without lameness have a repeatable radiopharmaceutical uptake pattern in the stifle, which is bilaterally symmetric; immature horses have a different radiopharmaceutical uptake pattern; and forelimb lameness alters the radiopharmaceutical uptake pattern in the stifle. The objectives of the study were to describe the normal radiopharmaceutical uptake patterns using region of interest (ROI) analysis; to compare uptake patterns between left and right stifles of the same horse and between mature and immature horses; to compare radiopharmaceutical uptake ...
Effect of GastroGard and three compounded oral omeprazole preparations on 24 h intragastric pH in gastrically cannulated mature horses. Ulceration of the squamous gastric mucosa is commonly associated with intensive training programmes in horses, but only one compound ('Gastrogard') has been subjected to controlled scrutiny as to therapeutic efficacy. Objective: To compare the gastric acid inhibitory efficacy of one manufactured ('GastroGard') and 3 generic pharmacy-compounded preparations of the proton pump inhibitor omeprazole (OME) in the mature horse. Objective: All OME preparations tested would induce a clinically acceptable effect. Methods: Six healthy mature gastrically cannulated horses of various breeds, 3 mares and 3...
Clostridium difficile: prevalence in horses and environment, and antimicrobial susceptibility. Clostridium difficile has been associated with acute colitis in mature horses. Objective: To survey C. difficile colonisation of the alimentary tract with age, occurrence of diarrhoea and history of antibiotic therapy; and to study the occurrence and survival of C. difficile in the environment and antimicrobial susceptibility of isolated strains. Methods: A total of 777 horses of different breeds, age and sex were studied. Further, 598 soil samples and 434 indoor surface samples were examined. Antimicrobial susceptibility of 52 strains was investigated by Etest for 10 antibiotics. Results: In ...
Photoperiodic versus metabolic signals as determinants of seasonal anestrus in the mare. The objectives of this study were to compare the timing and mechanisms controlling the onset of anestrus in young and mature mares treated either continuously with melatonin and in those that remained untreated. Changes in body weight, subcutaneous body fat measured to provide an estimate of total body fat, and circulating concentrations of leptin were compared throughout the 1-yr experimental period. The results demonstrate that in young mares the timing of anestrus occurs significantly earlier in the year than in mature mares and that mature mares are more likely to exhibit continuous reprod...
Repair of complete dorsal fracture of the proximal phalanx in two horses. Simple complete dorsal fractures of the proximal phalanx were repaired in 2 mature pleasure horses with cortical bone screws placed in lag fashion. Healing occurred within 12 weeks and both horses returned to their previous performance level of light pleasure riding within 6 months of injury.
Clostridium difficile associated with acute colitis in mature horses treated with antibiotics. Clostridium (C.) difficile, or its cytoxin, was demonstrated in faecal samples from 10 of 25 (40%) mature horses investigated with acute colitis treated primarily with antibiotics for disorders other than diarrhoea. C. difficile was not found in faecal samples from 140 horses without signs of enteric disorders, from 21 nondiarrhoeic horses treated with antibiotics, nor from 22 horses with colitis untreated with antibiotics. Except for C. difficile neither Salmonella nor any other investigated intestinal pathogen was isolated in any of the diarrhoeic horses. The findings strongly support some e...
Rifampin disposition in the horse: effects of age and method of oral administration. The effects of time and method of administration of rifampin with respect to feeding were evaluated in five mature horses. There was a significant (P less than or equal to 0.05) delay in time of maximum serum concentration and an apparent but not significant decrease in oral absorption when rifampin was given as a top dressing on grain as compared with administration in corn syrup 2 h before or 2 h after feeding. Although there were no differences between administration before or after feeding, administration 2 h prior to feeding was selected as the method of choice for future experiments. The...
Intra-osseous pressure and pressure pulse gradients along the equine third metatarsal bone. Intra-osseous pressure measurements in the third metatarsal bone of anesthetised young and mature ponies demonstrated that a pressure gradient exists along the bone, the pressure being highest at the level of the nutrient foramen and decreasing distally and proximally from this point. The height of the intra-osseous pressure pulse also decreased toward the bone ends. It is concluded that the sites of measurement of the intra-osseous pressure in clinical and experimental studies should be standardized.