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.
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...
Bioreactance noninvasive cardiac output monitoring in euvolemic adult horses subjected with 7.2% saline and 6% hydroxyethyl starch (130/0.4) solution infusions. To compare the ability of bioreactance noninvasive cardiac output (BR-NICO) with thermodilution cardiac output (TDCO) for the measurement of cardiac output (CO) in healthy adult horses receiving 2 different IV volume replacement solutions. Methods: Prospective randomized crossover study from September to November 2021. Methods: University teaching hospital. Methods: Six university-owned adult horses. Methods: Horses were randomly assigned to receive 7.2% hypertonic saline solution (HSS) or 6% hydroxyethyl starch (130/0.4) solution (HETA). BR-NICO and TDCO were measured simultaneously at baseli...
Oral trazodone results in quantifiable sedation but does not result in a xylazine-sparing effect in healthy adult horses. To evaluate sedation and IV xylazine requirements to achieve 45% of baseline head height above ground measurements following oral (PO) administration of 2 trazodone dosages. Methods: 8 healthy, adult mares of various weights and breeds belonging to a university teaching herd were utilized in a blinded, crossover study design. Horses were randomly assigned to 1 of 3 PO treatments: control (no trazodone), trazodone at 3 mg/kg (low dose [LD]), or trazodone at 6 mg/kg (high dose [HD]). Before treatment, cardiac auscultation, EquiSed sedation score, and head height above ground (HHAG; cm) measureme...
Ex vivo comparison of one-layer versus two-layer closures in end-to-end anastomoses in normal equine descending colon. The aim of the study was to evaluate time to closure, bursting pressures and luminal diameters of a single and double-layer end-to-end anastomoses in normal equine descending colon. Methods: Experimental study. Methods: Eight adult horses. Methods: Four segments of descending colon from each horse were randomly assigned to a control (n = 8, CON), one-layer (n = 12, group 1; continuous Lembert pattern), or two-layer group (n = 12, group 2; simple continuous oversewn with Cushing pattern). Anastomoses were performed, and time to closure and luminal diameter were measured. Bursting pr...
Early recognition of pain: improving colic outcomes in horses in Senegal. Limited knowledge exists on recognition and treatment of equine abdominal pain in low- and middle-income countries. This study aimed at finding indicators for recognizing abdominal pain, evaluating responses to clinical and behavioral changes, and assessing the impact of timely referral on colic outcomes in a suburban region of Senegal. The final goal was to identify factors that may be leveraged to improve the outcome of horses presented for abdominal pain in Senegal. Unassigned: Retrospective, observational cohort study. Unassigned: Data from 26 foals and 40 adult horses referred for acute a...
The impact of short-term transportation stress on insulin and oral sugar responses in insulin dysregulated and non-insulin dysregulated horses. It is unknown whether short-term transportation affects endocrine responses similarly in horses with and without insulin dysregulation (ID). Objective: To characterise the effect of short-term transportation on stress parameters and insulin responses to an oral sugar test (OST) in horses with and without ID. Methods: Longitudinal cohort study. Methods: Fourteen adult non-pregnant, non-PPID mares of mixed light breeds were grouped as either ID (n = 7) or non-ID (n = 7) based on endocrine testing. Over 2 weeks, horses were transported once, in groups of 3-4 in a horse trailer on a roun...
Increased packed cell volume alters point of care viscoelastic clotting parameters in horses. Polycythaemia and coagulopathy are identified risk factors for non-survival in critically ill horses. Assessment of coagulation is recommended for critical care monitoring but may be affected by concurrent polycythaemia. Objective: To evaluate the effects of induced polycythaemia on coagulation parameters as measured by a point-of-care viscoelastic coagulation device (VCM Vet™). Methods: Prospective interventional study. Methods: Healthy adult horses (n = 7) were given 6 mcg/kg of phenylephrine IV over 15 min to induce transient polycythaemia. Samples for packed cell volume (PCV), to...
Acute leptospirosis in horses: A retrospective study of 11 cases (2015-2023). Reports of leptospirosis in horses are limited. Objective: To describe the clinical and diagnostic findings of acute systemic leptospirosis in horses. Methods: Eleven client-owned horses presented to an equine hospital because of acute onset of disease between 2015 and 2023. Methods: Retrospective case series. Horses diagnosed with leptospirosis by 1 or more of urine PCR, serologic microscopic agglutination test (MAT), and histopathology. Results: Common clinical signs included lethargy (10), anorexia (10), fever (9), tachypnea (9), abnormal lung sounds (9), and epistaxis (6). Acute kidney inj...
Time to resolution of airway inflammation caused by bronchoalveolar lavage in healthy horses. Bronchoalveolar lavage (BAL) is a common procedure for evaluation of the equine lower airways. Time to resolution of post-BAL inflammation has not been clearly defined. Objective: Residual inflammation, evident by changes in immune cell populations and inflammatory cytokines, will resolve by 72 hours after BAL. Methods: Six adult, healthy, institution-owned horses. Methods: Randomized, complete cross-over design. Each horse underwent 3 paired BALs, including a baseline and then 48, 72, and 96 hours later, with a 7-day washout between paired BALs. Each sample underwent cytological evaluatio...
Oral T-cell-rich large B-cell lymphoma in a horse. Lymphoma is the most common tumor of hematopoietic origin in horses. The course of the disease and clinical signs vary greatly, depending on tumor location and extent. The aim of this report is to describe the occurrence of T-cell-rich oral large B-cell lymphoma with marked local infiltration in a 25-year-old Crioula mare. The mare showed an increase in volume on the right side of its face, dyspnea, anorexia, and progressive weight loss. The clinical assessment showed that the lesion was located in the rostral and caudal sinuses and was markedly invasive to adjacent structures. The autopsy rev...
Long-term use of an implantable loop recorder for ECG recording in horses. Potential arrhythmias recorded by cardiac monitors using the built-in human algorithm are as follows: total number of episodes, ventricular tachycardia, asystole, bradycardia, atrial tachycardia, atrial fibrillation and the percentage of time spent in atrial tachycardia or atrial fibrillation. Long-term use of an insertable cardiac monitor (loop recorder) has been reported in one horse earlier, but its accurate role as a diagnostic tool is still unclear. The aim of the present study was to investigate the long-term applicability of the Reveal XT cardiac monitor for recording cardiac arrhythmia...
Paraneoplastic Syndromes in Horses. This article discusses the reported paraneoplastic syndromes (PNSs) in horses, including the possible pathogenesis, diagnostic methods, and any treatment options. The more commonly reported PNSs in horses include cancer anorexia and cachexia, fever and increased acute phase protein concentrations, and hypercalcemia and monoclonal gammopathy. As these conditions can often be more commonly diagnosed in non-neoplastic conditions, the diagnosis of a PNS and the accompanying neoplasia can be challenging. As signs of a PNS may precede signs of the underlying neoplasia, it is important that the clini...
The effect of the fat to starch ratio in young horses’ diet on plasma metabolites, muscle endurance and fear responses. High-starch diets may affect equine hindgut microbiota and increase blood glucose levels, which may cause unwanted physiological changes, but may also elicit behavioural changes such as increased fear reactions. The purpose of the current study was to feed a high starch (300) and low fat (43; HS_LF) or a low starch (60) and high fat (85; LS_HF, g/kg of DM) concentrate within the available commercial range and investigate how muscle endurance and fear reactions of horses respond to different diets. Twenty Danish Warmblood stallions (4 years) were randomly allocated to two treatments: LS_HF (nâ€...
Aspergillus fumigatus antigen-reactive Th17 cells are enriched in bronchoalveolar lavage fluid in severe equine asthma. Equine asthma (EA) is a common disease of adult horses with chronic respiratory pathology and common neutrophilic airway inflammation. It presents with hyperreactivity to hay dust components such as molds, and underlying dysregulated T cell responses have been suggested. Thus far, T cells have been analysed in EA with conflicting results and the antigen reactivity of T cells has not been demonstrated. Serological and epidemiological data point to the relevance of as an antigen source in EA. Here, we aimed to identify and characterise antigen-reactive T cells in EA. Unassigned: Cryopreserved ...
Use of a new aiming compression device and technique for the repair of navicular bone fractures in horses: A cadaveric study. To assess the use of a newly developed aiming compression device (ACD) for screw insertion in non-fractured navicular bones (NB) in cadavers. Methods: Cadaveric study. Methods: A total of 10 cadaveric front limbs of adult horses. Methods: Placement of a 3.5 mm cortical screw in non-fractured NB under radiographic guidance was performed in 10 cadaver limbs in a standing position. An ACD was used to stabilize the NB and to guide the drilling process. Preparation and surgical time as well as the number of radiographic images were noted. A postoperative scoring system was used to assess screw pl...
Parasympathetic tone activity, heart rate, and grimace scale in conscious horses of 3 breeds before, during, and after nociceptive mechanical stimulation. Parasympathetic tone activity (PTA) in response to nociceptive stimulus in conscious non-sedated horses is unknown. Objective: Study PTA, heart rate (HR), and horse grimace scale (HGS) at rest and during mechanical nociceptive stimulation. Methods: Ninety healthy young adult horses (females, males): 30 each of Friesians, Quarter Horses, and Warmbloods. Methods: Prospective control study. The study consisted of habituation to equipment (Day 1), baseline recordings (Days 2 and 3), and nociceptive testing applying mild pressure to the metacarpus (Day 4). Parasympathetic tone, HR, and HGS were rec...
Use of extracorporeal hemoperfusion therapy in an adult horse with Clostridioides difficile colitis and severe systemic inflammatory response syndrome. An 8-year-old American Quarter Horse gelding was treated with extracorporeal hemoperfusion (HP) therapy for treatment of Clostridioides difficile (C. difficile) colitis-induced systemic inflammatory response syndrome (SIRS). The gelding developed C. difficile associated peracute colitis and severe SIRS as evidenced by a positive fecal C. difficile PCR and tachypnea, tachycardia, fever, neutropenia, altered mucous membrane color, and hyperlactatemia. Concurrent acute kidney injury in the horse limited the use of routine anti-inflammatory and anti-lipopolysaccharide treatments, including flunixi...
Effects of general anesthesia on airway immune cell function in an equine in vivo model. Complications from general anesthesia, including pneumonia and decreased wound healing, are influenced by changes in immune cell function secondary to sedatives and anesthetics. It was hypothesized that immune cell function would be depressed in the early postanesthetic period. The objective was to investigate airway immune cell function before and after a general anesthetic episode in an equine in vivo model using ex vivo cell stimulations with lipopolysaccharide (LPS) for assessment of immune function. Methods: Prospective experimental study. Methods: Six healthy, adult, institution-owned ...
Storage of equine faecal microbiota transplantation solution has minimal impact on major bacterial communities and structure. Management of diarrhoea in horses is usually non-specific and supportive. Faecal microbiota transplantations (FMT) are used to manage dysbiosis in horses with diarrhoea. There are few studies investigating the effects of storage on prepared FMT solutions. This study was an in vitro non-randomised controlled experiment that investigated the effects of FMT solution preparation and storage on the faecal microbiota. Fresh faeces were collected from five healthy adult horses and used for DNA extraction and preparation of FMT. From each FMT, seven aliquots were collected and DNA was extracted immedi...
Feasibility of transthoracic echocardiographic guidance for multicatheter electrophysiological mapping studies in horses. Improved characterization of arrhythmias is based on minimally invasive catheterizations. However, these catheterizations have been poorly explored in horses because apart from 3-dimensional (3D) mapping systems, continuous guidance of the catheter's position with adequate detail is difficult using current imaging modalities. Objective: Position multiple electrophysiology catheters simultaneously at predetermined strategical positions in the heart using transthoracic echocardiographic guidance. Methods: Eight adult healthy horses. Methods: Observational study. Two electrophysiological studies ...
Owner-reported health and disease in U.S. senior horses. Information on health care and health status of U.S. senior horses (≥15 years of age) is currently sparse. Objective: (A) Provide an overview of owner-reported (1) medical conditions, (2) management/treatment practices for equine metabolic syndrome and pituitary pars intermedia dysfunction (PPID), (3) frequencies of routine health care practices and (4) supplement and pharmaceutical use in U.S. senior horses (≥15 years of age). (B) Evaluate potential risk factors for certain medical conditions and for low routine health care. Methods: Online survey. Methods: Descriptive and inferential...
The Effects of Intra-Articular Triamcinolone and Autologous Protein Solution on Metabolic Parameters in Horses. Intra-articular corticosteroids are a popular treatment choice for joint-associated pain and inflammation in horses despite recent work on the metabolic effects of these drugs. The goal of this project was to compare metabolic effects between intra-articular (IA) triamcinolone acetonide (TA) and an autologous protein solution (APS). Five mixed-breed geldings (4-9 years) were utilized for this project. Three identical and consecutive 28-day treatment blocks were used, with metacarpophalangeal IA treatments consisting of equal volumes of saline, a commercially available APS, or 9 mg of TA. Regul...
Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment. Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking. Objective: To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks. Methods: Eleven healthy adult horses. Methods: Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Wee...
Prevalence of insulin dysregulation in the non-obese stock-type horse and relationship with morphometric neck measurements. Insulin dysregulation (ID), core to equine metabolic syndrome, may present without obesity. Testing for ID risk is commonly based on breed and obese phenotype but might be valuable for non-obese stock-type horses. This study aimed to determine the prevalence of ID in non-obese stock-type horses and evaluate if morphometric neck measurements (MNM) correlate with ID. Sixty-two, non-obese (BCS 5, range 2.5-6/9) stock-type horses were assessed for MNM: neck circumference at 25%, 50% (NC50), and 75% (NC75) length, and crest height. An oral sugar test (OST; 0.15 mL/kg BW corn syrup) was performed wi...
Roles of collagen cross-links and osteon collagen/lamellar morphotypes in equine third metacarpals in tension and compression tests. Many bones experience bending, placing one side in net compression and the other in net tension. Because bone mechanical properties are relatively reduced in tension compared with compression, adaptations are needed to reduce fracture risk. Several toughening mechanisms exist in bone, yet little is known of the influences of secondary osteon collagen/lamellar 'morphotypes' and potential interplay with intermolecular collagen cross-links (CCLs) in prevalent/predominant tension- and compression-loaded regions. Paired third metacarpals (MC3s) from 10 adult horses were prepared for mechanical test...
Hoof wall masses removal in 30 standing sedated horses: Surgical technique, postoperative complications and long-term outcome. To describe the surgical technique for removal of hoof wall masses in horses under standing sedation (SS) and local anesthesia (LA), and to report complications and long-term outcome following surgery. Methods: Observational retrospective study. Methods: Client-owned horses (n = 30). Methods: Horses undergoing keratoma removal under SS and LA in a single equine hospital between August 2016 and July 2023 were included in the study. Signalment, affected foot, history of lameness and/or foot abscesses, degree of lameness on admission, imaging findings (radiography and magnetic resonance imagi...
Changes of mRNA, miRNA and lncRNA expression contributing to skeletal muscle differences between fetus and adult Mongolian horses. The growth and development of myofibers, as the fundamental units comprising muscle tissue, and their composition type are indeed among the most crucial factors influencing skeletal muscle types. Muscle fiber adaptation is closely associated with alterations in physiological conditions. Muscle fiber types undergo dynamic changes in fetus and adult horses. Our aim is to investigate the mechanisms influencing the differences in muscle fiber types between fetal and adult stages of Mongolian horses. The study investigated the distribution of muscle fiber types within longissimus dorsi muscle of fe...
An updated description of bacterial pneumonia in adult horses and factors associated with death. Available descriptive studies on equine pneumonia are outdated or focus on specific horse or bacterial populations. Objective: To describe the clinical presentation and bacterial isolates of adult horses with bacterial pneumonia and identify factors associated with death. Methods: One hundred sixteen horses >2 years old with bacterial pneumonia. Methods: Retrospective case series. Data regarding history, physical examination, clinicopathologic features, treatment, bacterial culture and sensitivity, and outcome were collected and analyzed retrospectively. Results: Historical risk factors w...
Ultrasound-guided caudal cervical articular process arthrocentesis is accurate in live horses with and without arthropathy. Cervical articular process joint (CAPJ) therapy is advocated for horses with neck disorders. Several ultrasound-guided CAPJ techniques have been described in cadaver studies with 72%-89% intra-articular injection accuracy; however, the CAPJ injection accuracy in clinical equine practice has not been extensively reported. Objective: To describe a modified cranial approach for ultrasound-guided caudal CAPJ injections, to investigate the accuracy of this CAPJ injection technique in live horses, and to assess the effect of CAPJ injection location, laterality, operator, and radiographic CAPJ enlarg...