Topic:Adult Horses
Adult horses encompass a category of equines that have reached maturity, typically considered to be around five years of age and older. This stage of life is characterized by full physical development and the potential for peak performance in various activities such as riding, racing, and work. Adult horses require specific nutritional, health, and management practices to maintain optimal condition and performance. The study of adult horses covers a range of topics, including physiology, behavior, and the impact of environmental factors on their well-being. This page compiles peer-reviewed research studies and scholarly articles that explore the physiology, health management, and performance aspects of adult horses.
The effect of intramuscular atipamezole on head height and sedation scores in detomidine-sedated horses. To assess the effect of two different doses of intramuscular atipamezole on head height (HH) in horses after sedation with detomidine. Methods: Randomized, blinded, triple crossover study. Methods: Eight healthy adult horses. Methods: Baseline HH was measured before detomidine (40 μg kg) was injected intravenously. HH was measured at 10 and 20 minutes after injection. Then, saline, atipamezole 60 μg kg (AT60) or 120 μg kg (AT120) was injected intramuscularly. HH measurements were repeated at 10 minutes intervals for 100 minutes. HH data were analyzed with a linear mixed model. Significance ...
Nutraceutical Supplement Mitigates Insulin Resistance in Horses with a History of Insulin Dysregulation During a Challenge with a High-Starch Diet. Insulin dysregulation (ID) is associated with an increased risk of laminitis which often necessitates the need for clinical intervention. To test the contention that the prophylactic supplementation of nutraceuticals could mitigate ID in susceptible horses, 16 mature horses with a history of ID were supplemented with either the placebo (n = 8) or nutraceutical (n = 8) once daily. Horses were housed in dry lots with ad libitum access to grass hay and fed a concentrate twice daily to provide 0.5 g starch/kg BW/meal. A combined glucose-insulin tolerance test was performed on all horses before and...
Effect of phenylbutazone administration on the enteroinsular axis in horses with insulin dysregulation. Phenylbutazone is prescribed for laminitis-associated pain and decreases glucose and insulin responses to an oral glucose test (OGT) in horses with insulin dysregulation (ID). Objective: Investigate the effect of phenylbutazone administration on the enteroinsular axis in horses. Methods: Sixteen horses, including 7 with ID. Methods: Randomized cross-over study design, with horses assigned to treatment with phenylbutazone (4.4 mg/kg IV q24h) or placebo (5 mL 0.9% saline). On Day 9 of treatment, an OGT was conducted, followed by a 10-day washout period, administration of the alternative trea...
Anesthesia for non-obstetric surgery during late term pregnancy in mares. Submitting late-term pregnant mares to anesthesia for non-obstetric surgery raises concerns about the survival of the mother and fetus. This study aimed to evaluate and describe transient maternal and fetal hemodynamic changes during general inhalation anesthesia in mares during the last month of gestation. Nine adult mares in the last month of gestation were subjected to general inhalation anesthesia and dorsal recumbency for 90 minutes. Trans-anesthetic vital parameters, arterial hemogasometry, cardiac output, pulmonary arterial pressure, central venous pressure, and fetal heart rates were a...
Comparison of serum microRNA in healthy horses and horses with moderate to severe mitral valve regurgitation using a commercially available canine cardiac panel. MicroRNA (miRNA) has previously been used as a biomarker for cardiac disease in humans and dogs, however, studies in horses are not yet available. Objective: To determine if adult horses with moderate or severe mitral valve regurgitation have a different serum miRNA expression profile compared to healthy controls. Methods: Retrospective cross-sectional. Methods: Serum samples from 77 adult horses with moderate or severe mitral valve regurgitation and 77 healthy control horses were analysed using a commercial cardiac disease-specific miRNA panel previously used in dogs. Results: The commercial ...
Evaluation of Recovery Time and Quality After Two Different Post-Operative Doses of Medetomidine in Spanish Purebred Horses Anaesthetized with Medetomidine-Isoflurane Partial Intravenous Anaesthesia. Recovery from general anaesthesia is risky in horses. Alpha-agonist administration after anaesthesia enhances the quality of recovery but may prolong this phase. Recovery time and quality were investigated after medetomidine administration at the end of general anaesthesia in a prospective, randomised, masked and clinical study. Horses underwent medetomidine-isoflurane partial intravenous anaesthesia. Medetomidine (0.5 or 1 µg/kg) IV was administered just after isoflurane was discontinued. The duration of different recovery phases and the number of attempts were recorded. A composite scale (f...
Intrathecal enalapril reduces adhesion formation in experimentally induced digital flexor tendon sheath injuries in horses. The objectives of the study were to describe a standing percutaneous adhesion induction model in the digital flexor tendon sheath (DFTS) of horses and to evaluate the effect of intrathecal administration of the angiotensin-converting enzyme (ACE) inhibitor enalapril on tendon healing and adhesion formation. Methods: Randomized, blinded, controlled experimental study. Methods: Eight healthy horses. Methods: A collagenase-induced adhesion model was implemented in the deep digital flexor tendon (DDFT) of both forelimbs under standing ultrasonographic guidance. Daily intrathecal injections of 5 ...
Administration of sodium hyaluronate to adult horses prior to and immediately after exercise does not alter the range of motion in either the tarsus or metacarpophalangeal joints. Hyaluronic acid (HA), a glycosaminoglycan found in joint synovial fluid, is administered to horses as an anti-inflammatory with lubrication properties. This experiment examined the effects of HA administered before and shortly after an exercise test on metacarpophalangeal (MCP; fetlock) and tibiotarsal (hock) joint range of motion (ROM). Horses were injected intravenously (IV) with placebo (4Â mL, saline) or HA (4Â mL, 40Â mg) 24Â h before performing a standardized exercise test (SET) on a high-speed treadmill and again at 6-h post-SET. Passive fetlock flexion was measured at 4 and 24Â h post-...
Equine bone marrow-derived mesenchymal stromal cells reduce established S. aureus and E. coli biofilm matrix in vitro. Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate...
Decreased Circulating Red Cell Mass Induced by Intravenous Acepromazine Administration Alters Viscoelastic and Traditional Plasma Coagulation Testing Results in Healthy Horses. Coagulopathy is common in equine critical illness, with its early recognition being crucial for patient management and prognosis. In vitro viscoelastic (VE) hypercoagulability with decreased RCM/PCV has been demonstrated in dogs but not horses. Our objective was to evaluate the effects of acepromazine-induced (0.1 mg/kg IV) decreased RCM on VE and plasma coagulation parameters using a prospective interventional study of eight adult horses. Complete blood count (CBC), fibrinogen, prothrombin time (PT), partial thromboplastin time (PTT), packed cell volume (PCV), total solids (TS), and VCM Vetâ„...
Comparison of a customized glycemic pellets challenge with the oral sugar test to measure glycemic and insulinemic responses in horses. Testing for insulin dysregulation (ID) in horses is commonly performed to guide management and therapeutic strategies. Objective: To evaluate a newly developed glycemic pellets challenge (GPC) and compare results to those obtained using the low-dose oral sugar test (OST). Methods: Twenty-four adult horses with unknown insulin status. Methods: A randomized crossover trial was performed. Horses underwent GPC (0.5 g glycemic carbohydrates/kg body weight) and OST (0.15 mL corn syrup/kg body weight) 7 days apart. Feed was withheld before testing and blood samples were collected at T0, T60, T1...
The Memory Abilities of the Elderly Horse. Studies on short- and long-term memory and their decline with aging in horses are still limited. This research aimed to assess the learning and short- and long-term memory abilities of adult and senior horses. A total of 21 adult horses (5-15 years) and 23 senior horses (16 years and older) were subjected to a behavioral test (Target Touch Test), which was repeated three times each for the initial test (T1) and again after 10 days (T10). Statistical analysis revealed no significant differences between adult and senior horses in the three tests conducted at T1. However, a significant difference...
A systematic review of the prevalence of post-operative complications after general anaesthesia in adult horses (2000-2023). Equine post-operative morbidity represents a significant concern for both veterinary surgeons and horse owners. Objective: To estimate the prevalence of post-operative complications in horses after elective/non-abdominal surgery or colic surgery. Methods: Systematic review. Methods: A database search identified eligible studies which reported the prevalence of equine post-operative complications published as a full paper in English in a peer-reviewed journal between 2000 and 2023. Studies were evaluated using the JBI Critical Appraisal Checklist for Prevalence Studies and GRADE (Grading of Rec...
Investigating conditioned pain modulation in horses: can the lip-twitch be used as a conditioning stimulus? Study objective was to evaluate whether the application of a lip twitch could be proposed as conditioning stimulus in the context of a novel Conditioned Pain Modulation (CPM) assessment paradigm for use in horses. The study was a prospective, experimental, randomized trial. Twelve healthy horses were evaluated in two experimental sessions. The lip twitch was used as the conditioning stimulus in both sessions; electrical stimulation was used as the test stimulus in one session, while mechanical and thermal stimulations were used in the other. Differences between thresholds recorded before and d...
Effect of furosemide on comprehensive renin-angiotensin-aldosterone system activity of Thoroughbred horses. Furosemide, a commonly used diuretic, activates the renin-angiotensin-aldosterone system (RAAS) in other species. Little is known about RAAS peptide activation in horses. Objective: To evaluate equilibrium analysis as a practical method for RAAS quantification in horses and describe the RAAS response to a single dose of furosemide. We hypothesize that furosemide would cause transient increase in RAAS peptides in horses. Methods: 14 healthy adult thoroughbreds from a university teaching herd. Methods: Horses received either furosemide (1 mg/kg IV) or saline IV in a crossover study design. Pro...
Third eyelid cartilage eversion in an adult mare. To describe the first report of third eyelid cartilage eversion in an adult American Quarter Horse mare. Methods: A 22-year-old American Quarter Horse mare presented to the University of Missouri Veterinary Health Center Equine Hospital for a 2-week history of a third eyelid cartilage abnormality of the left eye with no known recent trauma. Complete ophthalmic examination revealed third eyelid cartilage eversion of the left nictitans. The abnormal scrolled cartilage was surgically excised using a handheld cautery unit and submitted for histopathologic evaluation. Results: Histopathologic findi...
Computed tomography of the equine caudal spine and pelvis: Technique, image quality and anatomical variation in 56 clinical cases (2018-2023). Cross-sectional imaging improves the diagnostic accuracy of complex anatomical regions. Computed tomography (CT) of the pelvis and caudal spine in a large group of live horses and ponies has not been previously reported. Objective: To describe the procedure for acquiring CT images of horses' caudal spine/pelvis under general anaesthesia (GA) and to detail the image quality, artefacts and anatomical variations in this region. Methods: Retrospective case series. Methods: Horses with CT of the caudal spine/pelvis were included. Horses under 6 months and CT examination performed post-mortem were...
Physiological and metabolic effects of short-term dopamine reduction in healthy horses using a tyrosine hydroxylase inhibitor (alpha-methyl-para-tyrosine). Alpha-methyl-para-tyrosine (AMPT) is a reversible inhibitor of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine synthesis. This study aimed to determine whether AMPT could reduce dopamine concentrations in horses. Six healthy adult Standardbred geldings were administered AMPT (40 mg/kg BW, orally) or placebo in a randomised crossover study design. Clinical examination findings were recorded, and blood samples were collected for up to 6 h after administration of AMPT or placebo, for measurement of blood glucose, plasma ACTH and cortisol concentrations, and plasma metabolomic anal...
Equine Enteric Glial Culture and Application to the Study of a Neural Inflammatory Mechanism in Equine Colic. Inflammatory postoperative conditions of equine colic (acute abdomen) contribute not only to increased client cost, patient discomfort, and hospitalization time, but in many cases, prove to be life-threatening. A unique population of intestinal cells, enteric glia, are increasingly acknowledged for their roles in sensing the gastrointestinal environment and communicating with surrounding cell types. Interactions between enteric glia and intestinal epithelia may prove critical in establishing how equine enteric glia can alter the mucosal barrier to modulate inflammation in health and colic. To ...
Equine intraocular melanocytic neoplasia. To describe the clinical appearance, histopathology, and treatment of equine intraocular melanocytic neoplasia in adult horses. Unassigned: A retrospective review of medical records was conducted. Data recorded included signalment, ocular examination findings, physical examination findings, therapeutic interventions, and case outcomes. Histopathologic characteristics of enucleated globes were evaluated. A Student's -test was used to evaluate differences in the interval from diagnosis to last known outcome between horses receiving therapeutic interventions and horses undergoing monitoring alone...
Metabolomic analysis of the impact of red ginseng on equine physiology. Red ginseng (RG), a traditional herbal remedy, has garnered attention owing to its diverse health benefits resulting from its complex composition. However, extensive research is needed to substantiate the efficacy of RG and understand the underlying mechanisms supporting these benefits. This study aimed to identify potential biomarkers and investigate the impact of RG on related metabolic pathways in horse plasma using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. Unassigned: Ten horses were divided into control and RG groups, with the latter administered RG at a dose of ...
A Comprehensive Analysis of the Genomic and Expressed Repertoire of the T-Cell Receptor Beta Chain in Equus caballus. In this paper, we report a comprehensive and consistent annotation of the locus encoding the β-chain of the equine T-cell receptor (TRB), as inferred from recent genome assembly using bioinformatics tools. The horse TRB locus spans approximately 1 Mb, making it the largest locus among the mammalian species studied to date, with a significantly higher number of genes related to extensive duplicative events. In the region, 136 TRBV (belonging to 29 subgroups), 2 TRBD, 13 TRBJ, and 2 TRBC genes, were identified. The general genomic organization resembles that of other mammals, with a V cluster o...
Does a relation between bone histomorphometry and fractures exist? The case of the equine radius and tibia. Fractures of long bones in limbs are rare traumatic events in horses. This study investigates whether the incidence and types of fractures can be related to the histomorphometric features of the radius and tibia, which experience different biomechanical stresses and exhibit varying incidences and types of fractures. Clinical observations suggest that, in adults, slightly transverse and comminuted fractures are present in the radius, while the tibia shows a higher frequency of longitudinal and spiral fractures. Microscopic observations reveal no apparent distinctive characteristi...
Grade IV gastric ulceration, pyloric aplasia, and an ectopic duodenal papilla in a 13-year-old Quarter Horse gelding evaluated for recurrent colic. The objective of this Case Report was to describe the clinical manifestation and postmortem findings of a horse evaluated for recurrent colic diagnosed with pyloric aplasia and an ectopic duodenal papilla. Methods: 13-year-old Quarter Horse gelding. Unassigned: The horse was presented to a referral center for signs of colic that were unresponsive to management on the farm. No abnormalities were noted on rectal palpation; however, upon passage of a nasogastric tube, 31 L of net gastric reflux was obtained. Gastroscopy noted grade IV squamous ulceration and moderate glandular ulceration, severe ...
Closed laceration of the trachea, esophagus and guttural pouches in a mare caused by blunt trauma. A mare was admitted for progressive swelling of the neck, lethargy and anorexia. Radiography revealed perilaryngeal, peritracheal, and periesophageal emphysema. Endoscopy revealed pharyngeal and tracheal roof collapse, and a small laceration on the trachea. Treatment with antimicrobials, fluids, and flunixin was initiated. To prevent exacerbation of the emphysema, temporary tracheostomy was performed. Clipping for the tracheostomy revealed a hoofprint mark on the ventral neck. Subsequent endoscopies revealed laceration of the esophagus and guttural pouch septum communicating with the visceral ...
Disseminated pleomorphic rhabdomyosarcoma in a horse. An 8-y-old National Show Horse mare was presented for evaluation of pneumonia and laminitis. Harsh bronchovesicular sounds were auscultated throughout both lung fields, and the mare had signs of moderately painful laminitis. Thoracic ultrasonography revealed lung consolidation throughout the dorsal aspect of both lungs, and radiography revealed an extensive diffuse-to-patchy bronchointerstitial lung pattern. The mare's clinical condition rapidly deteriorated, and euthanasia was elected. On postmortem examination, the lungs, omentum, spleen, liver, adrenal glands, kidneys, and femur contained 0...
A hybrid repair strategy for full-thickness cartilage defects: Long-term experimental study in eight horses. The objective of this study was to evaluate a non-resorbable implant for the focal repair of chondral defects in eight adult horses with 12-month follow-up. The bi-layered construct composed of a polycarbonate-urethane-urea biomaterial which was printed in 3D fashion onto a bone anchor was implanted into surgically created osteochondral defects into the femoropatellar joints of eight horses. The analysis of post-mortem outcomes were compared to defects treated with microfracture in the same animal on the contralateral femoropatellar jointfemoropatellar joint. The overall macroscopic scoring af...
Treatment of experimental hyperchloremic metabolic acidosis in horses with enteral electrolyte solution containing sodium acetate. In adult horses, the development and evaluation of enteral electrolyte solutions containing sodium acetate for correcting hyperchloremic metabolic acidosis are still lacking, although these electrolyte and acid-base imbalances are commonly observed. The objective of this study was to evaluate the alkalinizing effect of two enteral electrolyte solutions containing different concentrations of acetate, administered via nasogastric tube in continuous flow, in adult horses with experimental hyperchloremic metabolic acidosis. Unassigned: Six mares aged between 3 and 10 years were used in a 6×2 cr...