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.
New Perspectives in Equine Intestinal Parasitic Disease: Insights in Monitoring Helminth Infections. Regular anthelmintic treatment has contributed to anthelmintic resistance in horse helminths. This mass anthelmintic treatment was originally developed owing to a lack of larvicidal drugs against Strongylus vulgaris. The high prevalence of anthelmintic resistance and shortening of strongyle egg reappearance period after avermectins/moxidectins requires epidemiologically appropriate and sustainable measures. Selective anthelmintic treatment is a much-needed deworming approach: More than 50% of adult horses manifest no strongyle egg excretion. In this article, selective anthelmintic treatment pr...
Equine Dysautonomia. Equine dysautonomia (ED; also known as equine grass sickness) is a neurological disease of unknown cause, which primarily affects grazing adult horses. The clinical signs reflect degeneration of specific neuronal populations, predominantly within the autonomic and enteric nervous systems, with disease severity and prognosis determined by the extent of neuronal loss. This review is primarily focused on the major clinical decision-making processes in relation to ED, namely, (1) clinical diagnosis, (2) selection of appropriate ancillary diagnostic tests, (3) obtaining diagnostic confirmation, (4)...
Comparison of the oral and rectal mucosal and colonic serosal microcirculations of healthy, anesthetized horses. The objectives of the study were to: i) determine baseline microvascular perfusion indices (MPI) and assess their repeatability in healthy horses under general anesthesia, and ii) compare the MPIs of 3 microvascular beds (oral mucosa, colonic serosa, and rectal mucosa). Healthy adult horses were anesthetized and sidestream dark field microscopy was used to collect video loops of the oral mucosa, rectal mucosa, and colonic serosa under normotensive conditions without cardiovascular support drugs; videos were later analyzed to produce MPIs. Baseline MPI values were determined for each site, whic...
Molecular Characteristics of the Equine Periodontal Ligament. The equine periodontal ligament (PDL) is a fibrous connective tissue that covers the intra-alveolar parts of the tooth and anchors it to the alveolar bone-it, therefore, provides a similar function to a tendinous structure. While several studies have considered the formation and structure of tendons, there is insufficient information particularly on the molecular composition of the PDL. Especially for the equine PDL, there is limited knowledge concerning the expression of genes commonly regarded as typical for tendon tissue. In this study, the gene expression of, e.g., (, and fibrocartilage m...
Pharmacokinetics of the anticonvulsant levetiracetam in neonatal foals. Seizures are a common manifestation of neurological disease in the neonatal foal and are an important cause of morbidity and mortality in this population. Current antiepileptic options are effective, but often have undesirable adverse effects, short duration of action and high cost. Levetiracetam has an ideal safety and pharmacokinetic profile in multiple species, including the adult horse, and may be a safe and cost-effective alternative anticonvulsant in neonatal foals. Due to differences in drug disposition and clearance dosages in neonates, dosing recommendations in other species or adult ...
Estimation of dietary threonine requirement using plasma amino acid concentrations in mature thoroughbreds. The experiment was conducted to estimate dietary threonine (Thr) requirement using plasma amino acid concentrations as a criterion in mature thoroughbreds. Four adult thoroughbreds were used, and a 4 × 4 Latin square design was used for four dietary Thr levels. Plasma Thr concentration was constant until 0.41%, and then increased rapidly with increasing dietary Thr levels. The Thr requirement was estimated to be 67% of lysine with plasma Thr concentration at four Thr levels.
Normal reference intervals and the effects of sample handling on dynamic viscoelastic coagulometry (Sonoclot) in healthy adult horses. To determine reference intervals and the effect of sample agitation and rest time on Sonoclot analysis in healthy adult horses. Methods: Original prospective study. Methods: University veterinary medical teaching hospital. Methods: Sixty healthy adult horses. Methods: Blood was collected for assessment of complete blood count, serum biochemical analysis, and Sonoclot analysis. Results: Horses were determined to be healthy based upon physical examination, CBC, and serum biochemistry analysis. Blood was analyzed in a glass bead-containing cuvette using the Sienco Sonoclot analyzer following 2 re...
Effects of priming with cytokines on intracellular survival and replication of Rhodococcus equi in equine macrophages. Rhodococcus equi is a common cause of pneumonia in foals and an opportunistic pathogen in immunosuppressed people. The ability of R. equi to survive and replicate in macrophages is the basis of its pathogenicity. Limited knowledge about the role of cytokines in host defense against R. equi comes from studies in mice and the role of cytokines in intracellular survival of R. equi in equine macrophages is unknown. The objectives of this study were to determine the effect of priming with interferon (IFN)-γ, interleukin (IL)-1β, IL-4, IL-6, IL-10, or tumor necrosis factor (TNF)-α at various conc...
Pharmacokinetics of intravenous lithium chloride and assessment of agreement between two methods of lithium concentration measurement in the horse. Pharmacokinetics of lithium chloride (LiCl) administered as a bolus, once i.v. have not been determined in horses. There is no point-of-care test to measure lithium (Li ) concentrations in horses in order to monitor therapeutic levels and avoid toxicity. Objective: To determine the pharmacokinetics of LiCl in healthy adult horses and to compare agreement between two methods of plasma Li concentration measurement: spectrophotometric enzymatic assay (SEA) and inductively coupled plasma mass spectrometry (ICP-MS). Methods: Nonrandomised, single exposure with repeated measures over time. Methods: ...
Protein biomarker of cell proliferation determines survival to discharge in cases of equine large colon volvulus. Progenitor cells play critical roles in epithelial repair following ischaemic injury. Protein biomarkers have been used to identify intestinal progenitor cell subpopulations. This study aims to determine if a critical number of intestinal progenitor cells can predict tissue viability and survival to discharge of large colon volvulus (LCV) cases. Objective: The objectives were to 1) identify intestinal progenitor cell subpopulations using biomarkers: proliferating cell nuclear antigen (PCNA), sex determining region Y box 9 (SOX9), phospho-histone H3 (PHH3) and Ki-67, 2) define cut-off values fo...
Objective evaluation of the systemic effects of topical application of 1% atropine sulfate ophthalmic solution in healthy horses. OBJECTIVE To determine the safety of topical administration of 1% atropine ophthalmic solution in healthy horses by objectively measuring gastrointestinal transit time. DESIGN Randomized, masked, controlled crossover study. ANIMALS 6 adult geldings. PROCEDURES Horses were randomly assigned (3/group) to first receive topical treatment of the left eye with 1% atropine or artificial tears solution; the right eye was left untreated. After 24 hours of treatment every 6 hours, 200 nontoxic beads were administered to each horse via nasogastric intubation and treatment frequency was decreased to every...
Enteric coronavirus infection in adult horses. A new enteric virus of adult horses, equine coronavirus (ECoV), has recently been recognized. It is associated with fever, lethargy, anorexia, and less frequently, colic and diarrhea. This enteric virus is transmitted via the feco-oral route and horses become infected by ingesting fecally contaminated feed and water. Various outbreaks have been reported since 2010 from Japan, Europe and the USA. While the clinical signs are fairly non-specific, lymphopenia and neutropenia are often seen. Specific diagnosis is made by the detection of ECoV in feces by either quantitative real-time PCR, electron...
Effect of dietary carbohydrates and time of year on ACTH and cortisol concentrations in adult and aged horses. Diagnosis of equine pituitary pars intermedia dysfunction (PPID) remains a challenge as multiple factors (stress, exercise, and time of year) influence ACTH and cortisol concentrations. To assess endocrine status in a study designed to evaluate the effects of age and diet on glucose and insulin dynamics, we performed thyrotropin-releasing hormone (TRH) stimulation tests and overnight dexamethasone suppression tests in March, May, August, and October on 16 healthy Thoroughbred and Standardbred mares and geldings. Horses were grouped by age: adult (mean ± SD; 8.8 ± 2.9 yr; n = 8) and aged (20...
Pulmonary disposition and pharmacokinetics of minocycline in adult horses. OBJECTIVE To determine pharmacokinetics and pulmonary disposition of minocycline in horses after IV and intragastric administration. ANIMALS 7 healthy adult horses. PROCEDURES For experiment 1 of the study, minocycline was administered IV (2.2 mg/kg) or intragastrically (4 mg/kg) to 6 horses by use of a randomized crossover design. Plasma samples were obtained before and 16 times within 36 hours after minocycline administration. Bronchoalveolar lavage (BAL) was performed 4 times within 24 hours after minocycline administration for collection of pulmonary epithelial lining fluid (PELF) and BAL ...
Equine Exercise in Younger and Older Adults: Simulated Versus Real Horseback Riding. Horseback riding is an effective exercise for improving postural control and balance. To reduce costs and improve accessibility, simulated horseback riding has been developed; but no differential effects of simulated and real horseback riding on muscle activation patterns in older adults have been studied. Thus, we compared muscle activation patterns for older and younger adults engaged in real and simulated horseback riding exercises, using surface electromyography recordings of the erector spinae, rectus abdominis, internal oblique abdominis, and rectus femoris muscles. We recorded muscle ac...
Right dorsal colon ultrasonography in normal adult ponies and miniature horses. The aim of this study was to determine the normal location, wall thickness and motility of the right dorsal colon in adult ponies and miniature horses. The abdominal ultrasonography examination was performed in a study group consisting of 23 ponies and miniature horses and in a control group comprising ten Thoroughbred horses. The procedure was performed in unsedated standing animals. The location and the thickness of the right dorsal colonic wall was examined on the right side of the abdomen between the 10th and the 14th intercostal space. The contractility was recorded in the 12th intercosta...
Comparative Study of rhPDGF-BB Plus Equine-Derived Bone Matrix Versus rhPDGF-BB Plus β-TCP in the Treatment of Periodontal Defects. The purpose of this study was to evaluate the efficacy and safety of equine-derived bone matrix as a carrier for recombinant human platelet-derived growth factor BB (rhPDGF-BB) versus beta-tricalcium phosphate (β-TCP) for the treatment of intraosseous periodontal defects in adult patients. This study was performed on 32 adults with advanced periodontal disease. Eligible subjects were randomized in 1:1 ratio into a test (rhPDGF-BB-coated equine-derived bone matrix) or control group (rhPDGF-BB-coated β-TCP). Probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), a...
Influences of different dietary contents of macrominerals on the availability of trace elements in horses. In this study, influences of a reduced macromineral intake on the trace element metabolism in horses at maintenance were investigated. Background of this study is the revised recommendation on the macromineral supply for horses (GfE ). Balance studies on three adult pony geldings with body weights of 405 / 348 / 384 kg were performed to obtain data on apparent digestibility (aD), retention and serum concentrations of different trace elements (Cu, Zn, Se) at different dietary macromineral levels. A mineral supplement or a complementary feed-with a reduced macromineral content-was added to a ha...
Encapsulation of Equine Endothelial Colony Forming Cells in Highly Uniform, Injectable Hydrogel Microspheres for Local Cell Delivery. A common challenge in cell therapy is the inability to routinely maintain survival and localization of injected therapeutic cells. Delivering cells by direct injection increases the flexibility of clinical applications, but may cause low cell viability and retention rates due to the high shear forces in the needle and mechanical wash out. In this study, we encapsulated endothelial colony forming cells (ECFCs) in poly(ethylene glycol)-fibrinogen (PF) hydrogel microspheres using a custom-built microfluidic device; this system supports rapid encapsulation of high cell concentrations (10 million c...
Ex vivo comparison of single-layer and double-layer laparoscopic closure of equine bladders with 2 types of barbed sutures. To compare laparoscopic single-layer versus double-layer closure of experimental, full-thickness incisions in adult equine urinary bladders using unidirectional and bidirectional barbed suture. Methods: Experimental, ex vivo, surgical study. Methods: Thirty adult equine cadaver urinary bladders. Methods: Bladders were randomly divided into 5 groups (n = 6): intact controls, bladders sutured with unidirectional or bidirectional barbed suture in a single-layer closure, and bladders sutured with unidirectional or bidirectional barbed suture in a double-layer closure. A 5-cm apical incision wa...
Retrospective evaluation of 155 adult equids and 21 foals with tetanus from Western, Northern, and Central Europe (2000-2014). Part 2: Prognostic assessment. To identify prognostic variables for adult equids and foals with tetanus. Methods: Multicenter retrospective study (2000-2014). Methods: Twenty Western, Northern, and Central European university teaching hospitals and private referral centers. Methods: One hundred fifty-five adult equids and 21 foals with tetanus. Methods: None. Results: Variables from history and clinical examination were statistically compared between survivors and nonsurvivors (adults: 49 survivors, 85 nonsurvivors; foals: 7 survivors, 10 nonsurvivors). Cases euthanized for financial reasons were excluded. Mortality rates i...
Retrospective evaluation of 155 adult equids and 21 foals with tetanus in Western, Northern, and Central Europe (2000-2014). Part 1: Description of history and clinical evolution. To describe clinical data of hospitalized adult equids and foals with tetanus. Methods: Multicenter retrospective study (2000-2014). Methods: Twenty Western, Northern, and Central European university teaching hospitals and private referral centers. Methods: One hundred fifty-five adult equids (>6 months) and 21 foals (<6 months) with tetanus. Methods: None. Results: Information on geographic, annual and seasonal data, demographic- and management-related data, clinical history, clinical examination and blood analysis on admission, complications, treatments, and outcomes were described and stati...
Histologic and immunohistochemical evaluation of biocompatibility of castor oil polyurethane polymer with calcium carbonate in equine bone tissue. OBJECTIVE To evaluate the efficacy of castor oil polyurethane polymer with calcium carbonate for use in a unicortical ostectomy on the dorsal surface of the third metacarpal bone of horses. ANIMALS 6 adult horses. PROCEDURES A unicortical ostectomy was created on the dorsal surface of both third metacarpal bones of each horse. Castor bean (Ricinus communis) oil polyurethane polymer with calcium carbonate was implanted into the ostectomy on 1 limb, and the ostectomy of the contralateral limb was left unfilled and served as a control sample. Ostectomy sites were evaluated histologically 120 days...
Effect of topical application of 2% lidocaine gel on corneal sensitivity of clinically normal equine eyes. To assess the degree and duration of corneal anaesthesia provided by topical application of a non-ophthalmic 2% lidocaine gel in horses. Methods: Experimental, 'blinded', randomized prospective study. Methods: Twelve adult horses without relevant ocular abnormalities. Methods: Baseline corneal touch threshold (CTT) measurements were obtained bilaterally by use of a Cochet-Bonnet aesthesiometer just prior to topical treatment. A volume of 0.2mL of 2% lidocaine gel was administered in one randomly selected eye and the same volume of a viscous lubricant in the other eye to serve as control. The C...
Effect of age and dietary carbohydrate profiles on glucose and insulin dynamics in horses. Glucose and insulin dynamics may be different in adult and aged horses. Objective: To determine the effects of age and dietary carbohydrates on glucose and insulin dynamics in healthy horses. Methods: Balanced Latin square with four isocaloric diets: CONTROL (hay plus restricted-starch-and-sugar fortified pellets), STARCH (control plus kibbled corn), FIBER (control plus unmolassed sugar beet pulp/soybean hull pellets) and SUGAR (control plus dextrose powder). Methods: A total of 16 healthy Thoroughbreds and Standardbreds divided into two age groups: ADULT (8.8 ± 2.9 years; n = 8) and AGE...
Effect of feeding on the pharmacokinetics of oral minocycline in healthy adult horses. Minocycline is commonly used to treat bacterial and rickettsial infections in adult horses but limited information exists regarding the impact of feeding on its oral bioavailability. This study's objective was to compare the pharmacokinetics of minocycline after administration of a single oral dose in horses with feed withheld and with feed provided at the time of drug administration. Six healthy adult horses were administered intravenous (2.2 mg/kg) and oral minocycline (4 mg/kg) with access to hay at the time of oral drug administration (fed) and with access to hay delayed for 2 hr after ...
Atlanto-axial malformation in an adult Quarter horse gelding. An adult gelding was evaluated for bilateral intermittent forelimb lameness of approximately 2 years duration. The horse was found to have grade 2/5 upper motor neuron-general proprioception ataxia with no cranial nerve deficits. During radiographic and gross necropsy examinations a novel atlanto-axial malformation of possible congenital etiology was found. Un hongre adulte a été évalué pour une boiterie intermittente de la jambe avant présente depuis environ 2 ans. On a constaté que le cheval avait une ataxie de proprioception générale des motoneurones supérieurs de grade 2/5 sans d...
Effect of feed deprivation on selected parameters of lipid mobilisation and hepatic function in healthy Akhal Teke horses. Gastrointestinal and other systemic diseases of Equidae are often characterised by partial or complete inappetence. The catabolic processes may lead to lipid mobilisation and other metabolic disturbances. Evidence from earlier studies has revealed that during feed deprivation/inappetence, the conjugation of bilirubin is reduced causing a substantial rise of the total bilirubin and its unconjugated fraction. Objective: We hypothesised that during feed deprivation, the serum concentration of free fatty acids (FFA), triglycerides (TG), blood urea nitrogen (BUN), total bilirubin (tBIL), total bile...
The effects of multiple anaesthetic episodes on equine recovery quality. Although rare, 70% of equine fatalities during recovery from general anaesthesia (GA) are due to catastrophic fractures from poor recovery quality. Objective: To determine the effect of repeated GA recovery on GA recovery quality. Methods: Experimental blinded trial. Methods: Eight adult horses underwent six GA events on sevoflurane for distal limb MRI examination over a 14-week period. Prior to GA recovery, xylazine was administered. Randomly ordered video-recorded GA recoveries were scored by three blinded board certified veterinary anaesthesiologists, unaware of patient identity or GA event...