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.
Assessment of olfactory sensitivity in horses using positively conditioned scent. Differences in the ranges and capacities of sensory modalities cause horses to perceive their surroundings differently than humans. To date, the horses' sense of smell has been studied mainly regarding social and reproductive behaviour. The role of olfaction in horse management and use also seems to be of utmost importance. The aim of this study was to determine the response to a scent of different intensities by horses of different sexes and types (warmblood horses vs ponies). The study involved 21 adult mares and geldings, of which 15 subjects learned how to complete the required task and we...
Morphometric changes in overweight horses following 10-week weight loss programs. Up to 70% of horses in domestic equine populations are overweight. Promotion of weight loss is an important component of limiting the detrimental co-morbidities associated with excess adipose tissue. The use of a body condition score (BCS) can help equine caregivers track their horse's weight-status. However, this single score doesn't reflect changes in individual adipose depots. The purpose of this study was to characterize morphometric changes (including 8 anatomic BCS measurements that make up the whole-BCS) in horses during 3 different weight-loss programs over 10 weeks. Methods: Thirty-tw...
Effect of N-Butylscopolammonium Bromide and Metamizol Sodium on Heart Rate, Blood Pressure, and Echocardiographic Measurements in Warmblood Horses With Aortic and Mitral Valve Regurgitation. Administration of N-butylscopolammonium bromide (NBB) with metamizol sodium (NBBM) causes tachycardia and hypertension, and has been associated with accentuated cardiac murmurs. Objective: To evaluate the effect of a pharmacological challenge using NBBM on valvular regurgitation and cardiac murmurs in horses with aortic (AR) and mitral valve regurgitation (MR). Methods: Twenty Warmblood horses with AR and 20 with MR. Methods: Cardiac auscultation and two-dimensional (2D), M-mode, color flow, pulsed wave Doppler flow, and tissue Doppler echocardiography were performed with simultaneous ECG reco...
Laser fenestration of the dorsal pharyngeal recess does not correct experimentally induced dorsal nasopharyngeal collapse in horses. To quantify the impact of experimentally induced dorsal nasopharyngeal collapse (NPC) on respiratory performance parameters and assess the efficacy of laser fenestration of the dorsal pharyngeal recess as a treatment option for experimentally induced NPC. Methods: Experimental interventional study. Methods: Six adult Standardbreds (one with naturally occurring disease). Methods: After an 8 week conditioning program, baseline parameters (V̇Omax, pharyngeal pressure, peak airflows, upper airway resistance) and dynamic endoscopy videos were collected in a high-speed treadmill test (T1). Dorsal N...
Effects of the Sodium-Glucose Cotransporter-2 Inhibitor Velagliflozin on Insulin Concentrations in Horses With Insulin Dysregulation. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are promising treatments to manage hyperinsulinemia in horses with insulin dysregulation (ID). Objective: The SGLT2i velagliflozin decreases insulin concentration in horses with ID. Methods: Privately-owned adult horses (n = 37) with laboratory-confirmed ID (low-dose oral sugar test insulin concentration > 75 μIU/mL). Methods: Double-blind randomized placebo-controlled trial. Horses received placebo (n = 19) or velagliflozin 0.3 mg/kg PO q24h (n = 18) for 20 weeks (Study Period 1, SP1) immediately followed by a 20-week ope...
Influence of Extended Photoperiod Using Blue Light Masks on Hypertrichosis, Coat Condition and General Health Parameters in Horses with Pituitary Pars Intermedia Dysfunction. Fifty-two horses aged >15 years, diagnosed with pituitary pars intermedia dysfunction (PPID), and displaying hypertrichosis were recruited via an online survey of PPID horse owners. From mid-December, group T ( = 29) wore Equilume light masks extending photoperiod to 15 h daily, while group C1 ( = 23) remained under natural photoperiod. As 85% (44/52) of recruited study horses received pergolide medication, a second unmedicated PPID research herd (C2; = 17) was recruited and remained under natural photoperiod. Hair coat samples, shedding and body condition scores were collected monthly by own...
Modified stapled jejunocecostomy in horses. To develop a modified stapled (MS) jejunocecostomy (JC) in healthy horses. Methods: In vivo experimental study. Methods: Six healthy adult horses underwent ventral midline celiotomy, a jejunal resection, and an MS. Methods: Time to complete anastomosis and anastomotic length at necropsy were recorded. Horses were assessed by physical examination every 6 h for 5 days after surgery, then once daily until euthanasia at 7 days. A group of seven horses that had a stapled side-to-side JC and were euthanized 28 days postoperatively was used as an historical control (SS). Results: All MS horse...
Cervical epidural catheter for administration of detomidine and morphine in a model of carpal synovitis in the horse. To determine the analgesic effects of detomidine and morphine administered by cervical epidural catheter (CEC) on a model of thoracic limb pain. Methods: Prospective, randomized, blinded crossover study. Methods: Five adult horses. Methods: Cervical epidural catheters were placed under ultrasound guidance, followed by induction of lipopolysaccharide (LPS)-mediated carpal synovitis. Horses received either saline or detomidine/morphine (DM; 10 μg/kg, 0.1 mg/kg, respectively) via CEC 4 h after synovitis. After a 7 day washout, synovitis was induced in the contralateral carpus, and the alternate ...
Ultrasonographic Assessment of Caudal Vena Cava Collapsibility Index, Caudal Vena Cava-to-Aorta, and Femoral Vein-to-Artery Ratios in Healthy Sedated Adult Horses. (1) Background: Ultrasonography of major vessels helps evaluate fluid status and responsiveness in critical human and canine patients. Aims: transrectal and inguinal ultrasonography of caudal vena cava (CVC), aorta (Ao), and femoral artery (FA) and vein (FV) in horses; calculate CVC collapsibility index (CI CVC) and vein-to-artery ratios; compare B- and M-mode; and evaluate repeatability and reproducibility. (2) Methods: B-mode and M-mode video loops were recorded twice by transrectal (Ao, CVC) and inguinal ultrasonography (FV, FA) by two operators on 17 healthy, sedated adult horses. Diameter...
Multiple Catheter Recording in Horses to Investigate Atrial Depolarization Pattern During Sinus Rhythm and Induced Premature Atrial Complexes. Detailed characterization of arrhythmias can be performed by multiple catheter mapping; but this has not yet been explored in horses. Objective: Perform ultrasound-guided multiple catheter mapping of the right heart during sinus rhythm and right and left atrial pacing to identify activation patterns characteristic of the origin of ectopy. Obtain His signals and effective refractory periods (ERP). Methods: Eight healthy adult horses. Methods: Experimental study. Recording catheters were placed at the terminal crest, intervenous tubercle, caudal vena cava, and coronary sinus. Right atrial pacing...
Assessment of thermal imaging to objectively body condition score mature horses and multiparous gestating beef cows. This study explored whether thermal imaging could provide an objective means of body condition scoring (BCS) horses and multiparous, gestating beef cows. This study consisted of two parts: one part assessed BCS in horses of the Quarter Horse or Thoroughbred breed types while the other evaluated BCS of gestating beef cows. Ground truth BCS were assigned by five to eight trained scorers for each animal. Thermal images were also collected from one or both sides of the body and analyzed for surface temperature. Surface temperature and BCS were evaluated with the whole body, and for five (cows) or ...
Quantification of immune cells in full thickness and mucosal biopsies of the duodenum and rectum in a group of slaughter horses. Limited data are available on immune cells in the intestinal wall of healthy horses, hampering interpretation of results in case of disease. Objective: Characterize and quantify the immune cell populations and their distribution in duodenal and rectal biopsies of horses without gastrointestinal disease; compare immune cell counts (ICCTs) between full thickness- and mucosal biopsies. Methods: Twenty horses fit for slaughter, slaughtered for meat production. Methods: Full-thickness and endoscopic forceps obtained mucosal biopsies were taken within 30 min after slaughter from the duodenum and rec...
Effects of mixed polyphenol supplementation on lower airway inflammation in horses with Equine Asthma Syndrome. Equine Asthma Syndrome (EAS) is a chronic inflammatory respiratory disease of adult horses. While dietary polyphenols have shown anti-inflammatory effects in human asthma, their use in equine asthma has not been studied. Objective: To evaluate the effects of a mixed polyphenol supplement on systemic and pulmonary inflammation, bronchoalveolar lavage (BAL) cytology, and clinical respiratory signs in healthy and asthmatic horses. We hypothesized that polyphenol supplementation would decrease systemic and pulmonary inflammation in both healthy and asthmatic horses and would improve BAL cytology a...
Clinical and ultrasonographic findings in horses with desmopathy of the palmar/plantar abaxial ligaments of the proximal interphalangeal joint: 20 cases. To describe the clinical and ultrasonographic findings in horses with desmopathy of the abaxial palmar/plantar ligament (APL) of the proximal interphalangeal joint and the prevalence of concurrent musculoskeletal injuries in the pastern and foot. Unassigned: Horses presenting to New Bolton Center between March 2017 and November 2022 with an age ranging from 5 to 20 years that underwent lameness evaluation in which lameness was localized to the distal limb and had an ultrasonographic diagnosis of APL desmopathy. Unassigned: Horses included were those that (1) presented for a lameness examinatio...
A cohort study of nutritional secondary hyperparathyroidism in horses in Hawai’i. Equine nutritional secondary hyperparathyroidism (NSHP, Bighead Disease) is a consequence of diets with abnormal calcium: phosphorus ratios. With the widespread availability of fortified feeds and legume forage, the disease has largely disappeared. The Hawaiian Islands are unique in that legume forage is largely unavailable and pastures have high oxalate concentrations. This was a cohort study that included seventeen adult horses imported from the continental US to the Waiki'i region, Hawai'i that grazed on kikuyu grass pastures. Plasma ionized calcium and parathyroid hormone concentrations at...
Effects of Sedation on Rectal Temperature During Equine Dental Procedures Performed in Cold to Warm Ambient Temperatures. Sedation is important for safe equine dental procedures, but it is unknown if there is a higher risk of sedation causing hypothermia in procedures performed during cold months. The authors hypothesize that sedation for a dental procedure will significantly decrease rectal body temperature in cold as compared to warm ambient temperatures. Adult equids ( = 246), from a private equine dentistry practice, that underwent dental equilibration, were selected for the study. Each horse's weight was estimated and sedation was administered intravenously (0.01 mg/kg detomidine and 0.01 mg/kg butor...
Retrospective Evaluation of Neutrophil-to-Lymphocyte Ratio in Horses That Required Emergency Laparotomy: 341 Cases of Noninfectious Causes of Gastrointestinal Colic (2019-2024). To (1) compare total nucleated cell count (TNCC) and neutrophil-to-lymphocyte ratio (NLR) at admission between horses with medically managed, large intestinal (LI) and small intestinal (SI) surgical colic; (2) compare TNCC and NLR between survivors and nonsurvivors; and (3) investigate associations between TNCC, NLR, surgical intervention, and outcome. Methods: Case-control study. Methods: Single, academic institution. Methods: A total of 341 adult horses diagnosed with noninfectious medical or surgical colic. Results: Admission TNCC did not differ between the medical and combined surgical gro...
Scoping review of comminuted fractures of the proximal phalanx in horses. Comminuted fractures of the proximal phalanx (CFPP) occur in adult horses. Various treatments have been described. It remains uncertain which is the best therapeutic option. Objective: This study aims to review systematically the existing literature on CFPP in horses, evaluate treatment modalities, synthesise outcomes to assess treatment efficacy and survival rates, and identify knowledge gaps for future research. Methods: Scoping review. Methods: A literature search was conducted using online databases. The bias quality of each article was evaluated. Chi-squared analysis was used to detect di...
Effect of Fluorescence Biomodulation on Dermal Healing in an Equine Experimental In Vivo Wound Model. This study aimed to determine the safety and macroscopic/microscopic effects of fluorescence biomodulation (FBM) on experimentally induced, full-thickness, distal limb wounds in horses.This was an experimental study ( = 6 horses). Two full-thickness wounds were created on both dorsal metacarpi of six adult horses. Each forelimb was randomly allocated to either control (no FBM) or treatment (FBM) and randomly allocated to visual or histological assessment of healing. Wounds were treated within each experimental group every 7 days for four treatments. Fluorescence biomodulation wounds were ...
Inflammatory response following intra-articular injection of decellularized porcine amnion/chorion in horses. The objective of the study was to evaluate effects of intra-articular decellularized porcine amnion/chorion suspension (dPACLS) in horses. Methods: Controlled, randomized, prospective study. Methods: A total of 10 adult horses. Methods: One randomly selected radiocarpal joint (RCJ) was injected with a high dose (HD) of 50 mg (n = 5) or low dose (LD) of 5 mg of dPACLS (n = 5). The contralateral RCJ received saline as control. Systemic serum amyloid A (SAA), synovial fluid analysis (including SAA) and subjective lameness evaluation were performed prior to injection (time 0) and 24, 4...
Oral cannabidiol increases thermal threshold in horses without physiologic adverse effects. To investigate the effect of cannabidiol (CBD) on thermal and mechanical thresholds and physiologic variables in horses. Unassigned: 6 horses (3 geldings and 3 mares) were enrolled in a prospective, randomized, masked crossover design from March 18 through May 3, 2025. Horses received 3.48 mg/kg CBD oil or placebo (sesame oil) orally every 24 hours for 3 days. Thermal and mechanical thresholds were determined at baseline and 4 and 12 hours after treatment administration on each day. Physiologic variables, including heart rate, respiratory rate, and rectal temperature, were recorded at the same...
Flow-controlled expiration improves gas exchange in anaesthetised horses undergoing orthopaedic surgery. Flow-controlled expiration (FLEX) has been shown to significantly enhance oxygenation in horses under laboratory conditions. Objective: This study aims to corroborate these findings by evaluating the effects of FLEX on gas exchange in a randomised clinical trial involving a large population of clinical horses undergoing orthopaedic surgery. Methods: Prospective randomised clinical trial. Methods: A total of 406 healthy adult horses scheduled for elective orthopaedic procedures were recruited for this prospective clinical trial. Horses were randomly assigned to FLEX or VCV (volume-controlled ve...
Synovial Fluid Biomarker Profile After Intra-Articular Administration of Neosaxitoxin in Horses: A Feasibility Study. Osteoarthritis (OA) is an inflammatory joint disease and the leading cause of musculoskeletal disability affecting human and veterinary patients. New therapeutics halting inflammation while preserving joint homeostasis remain a critical need. Voltage-gated sodium (NaV) channels regulate the pro-inflammatory response of macrophages in the synovium, the central driver of joint homeostasis. Neosaxitoxin (NeoSTX) is a phycotoxin that blocks NaV channels, conferring a unique potential to regulate joint inflammation. This study evaluated the safety of intra-articular administration of NeoSTX in hors...
Exploratory Study of the Urine Protein-to-Creatinine Ratio in Apparently Healthy Horses. Currently, there is relatively little published information on the urine protein-to-creatinine (UPC) ratio in horses, a parameter commonly used in dogs and cats. The aim of this study was to determine the reference range of UPC in urine samples of apparently healthy horses and to assess the influence of age and sex. Urinalysis and the determination of urinary protein and creatinine concentrations and ratios were performed. A total of 118 urine samples from apparently healthy horses were included in the study: 10 from foals younger than 6 months and 108 from horses older than 1 year. The median...
Optimizing equine standing sedation: continuous infusion of detomidine and butorphanol enhances stability but prolongs ataxia. This study aimed to compare the sedation quality and cardiorespiratory and behavioral effects of detomidine administered intravenously, either in intermittent boluses or as a continuous rate infusion, with butorphanol in horses pre-medicated with acepromazine for odontoplasty procedures. Unassigned: A prospective clinical study was conducted with fifteen adult horses randomly assigned to two groups: Bolus group (BG, = 7) and Infusion group (IG, = 8). Both groups received acepromazine premedication, followed by detomidine administration (bolus or infusion). Butorphanol was administered either...
Hemoperfusion with a polymer-based column alters inflammatory responses in lipopolysaccharide-treated horses in vivo. To determine the effect of hemoperfusion with a polymer-based column on systemic cytokine concentrations and neutrophil dysfunction in lipopolysaccharide-treated horses in vivo. Unassigned: 6 university-owned horses received 60 ng/kg lipopolysaccharide, IV, as a bolus and then 60 ng/kg, IV, as a constant rate infusion over 1 hour. Endotoxemia was confirmed by clinical signs and neutropenia. In a crossover model that was completed from January 2024 through July 2024, hemoperfusion was performed for 4 hours with either a sham or polymer column. Blood was collected at 5 time points over a 72-hour...
Road transportation is associated with decreased intestinal motility in horses. Transportation of horses has been associated with colic and changes to the gastrointestinal microbiome. Percutaneous abdominal ultrasonography using wireless, point-of-care transducers can be used to assess gastrointestinal motility in field settings. Unassigned: Characterization of intestinal motility and salivary cortisol responses of horses completing commercial transportation of 10-12h. Unassigned: Prospective observational study of 30 horses with diverse signalment and transport histories. Clinical parameters, sonographic assessment of intestinal motility and saliva samples, were collecte...
Comparison of Gait Characteristics for Horses Without Shoes, with Steel Shoes, and with Aluminum Shoes. Differences in horseshoe materials may have effects on gait that could change perceived esthetic qualities. Objective information regarding effects of shoeing on gait characteristics of horses is scant. The aim of this study was to determine differences in gait characteristics for horses under various experimental shoeing conditions (barefoot, aluminum shoes, steel shoes) on two surfaces (asphalt and soft footing) using body- and hoof-mounted sensors. We hypothesized that shoeing would affect hoof arc height during early (arc height a) and late (arc height b) swing phases but would not affect ...
Primary Jejunal Impactions Resolved via Exploratory Celiotomy in Six Horses: 2017-2023. Impactions of the jejunum are rarely described in the literature. The current case series describes six cases of adult horses with jejunal impactions with feed material diagnosed by exploratory celiotomy. Horses underwent exploratory celiotomy based off of their degree of pain despite medical management and concerns for a primary strangulating small intestinal lesion. All jejunal impactions were relieved via manual decompression of the impaction into the cecum. None of the cases underwent a resection or anastomosis at the site of impaction. All horses were treated with gastroprotectants (omepr...
Retrospective Evaluation of Synchronous Diaphragmatic Flutter in Horses: 37 Cases (2004-2022). To describe the clinical presentation of horses with synchronous diaphragmatic flutter (SDF) and identify clinical and laboratory variables associated with survival. Methods: Retrospective study from January 2004 to September 2022. Methods: Five large animal referral hospitals in the United States. Methods: Thirty-seven horses of various breeds and ages presenting with clinical signs of SDF, excluding animals participating in an endurance competition. All horses were >1 year of age. Methods: None. Results: Variables recorded and analyzed included signalment, clinical and laboratory data, trea...