Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Biomarkers
Biomarkers in horses are measurable indicators of biological processes, states, or conditions that can be used to assess health and disease. These biomarkers can be identified in various biological samples such as blood, urine, or tissue. They provide valuable information for diagnosing diseases, monitoring health status, and evaluating treatment responses in equine medicine. Common biomarkers in horses include enzymes, hormones, and metabolites, which may change in response to physiological or pathological conditions. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, quantification, and application of biomarkers in equine health and disease management.
Serial Postoperative Blood and Peritoneal Fluid Analysis and Ultrasonographic Assessment in Client-Owned Horses Undergoing Ventral Midline Exploratory Celiotomy for Colic. Postoperative monitoring, including evaluation of peritoneal fluid, is used to aid in the diagnosis and treatment plan for complications after colic surgery. The primary objective of this study was to determine serial venous and peritoneal postoperative variables, including L-lactate values in horses after ventral midline exploratory celiotomy. A secondary objective was to evaluate postoperative abdominal ultrasonography as a predictor of complications. A total of 36 client-owned horses with signs of colic undergoing ventral midline exploratory celiotomy were prospectively enrolled in the stud...
Centrifugation of peritoneal fluid improves visual assessment of strangulating lesions in equine colic. Early and accurate recognition of a strangulating lesion is essential to expedite surgical intervention in horses presenting with colic. Objective: To evaluate the use of a colour grading scale in the visual assessment of peritoneal fluid, before and after centrifugation, and assess its ability to predict the presence of a strangulating lesion. Methods: Prospective clinical study. Methods: Peritoneal fluid samples from 231 equids presenting with colic were visually analysed immediately after collection and assigned a numerical value based on a developed colour scale. Peritoneal fluid was centr...
Evaluating ex vivo toll-like receptor agonist response as a potential biomarker in equine gastric ulcer syndrome. Equine gastric ulcer syndrome (EGUS) is highly prevalent in horses. Despite its presumed painful nature, evaluation of objective biomarkers associated with EGUS presence and severity remains limited. The objective of this study was to investigate the potential of interleukin-1 beta (IL-1β) release by peripheral blood mononuclear cells (PBMCs) following ex vivo stimulation of toll-like receptors 2 and 4 (TLR2 and TLR4) as a potential biomarker for EGUS status, with gastric lesions used as a proxy for presumed EGUS-associated pain. Venous blood was collected from 77 horses, PBMCs were isolated ...
Circulating Cell-Free RNA Reflects Immune-Associated and Airway Remodeling Signatures in Equine Asthma. Circulating cell-free RNA (cfRNA) has emerged as a promising minimally invasive biomarker capable of capturing transcripts originating from multiple tissues and cell types, but its utility in chronic inflammatory airway diseases remains poorly understood. Equine asthma (EA), a naturally occurring respiratory disease that shares key clinical and immunopathological features with human asthma, provides a valuable comparative model for evaluating plasma cfRNA in this context. We performed transcriptomic profiling of plasma cfRNA from horses with EA and healthy controls and compared these findings ...
High molecular weight adiponectin as an adjunct biomarker for insulin dysregulation in equids. Total adiponectin concentration is associated with hyperinsulinemia and laminitis risk in ponies but the high molecular weight (HMW) multimer is a more sensitive indicator of metabolic disease in other species and could be a useful biomarker for insulin dysregulation (ID). Objective: To determine a cut-off value for using HMW adiponectin as an adjunct diagnostic tool for ID. Methods: Cohort of 127 privately and university-owned horses and ponies of various breeds with 55 classified as ID positive and 72 as ID negative. Methods: Cohort study. Baseline and postprandial blood samples from an in-f...
Serum physiology, fecal microbiota, and metabolome signatures associated with perinatal stage transitions in Mongolian mares. Lactation is a critical reproductive trait that influences offspring survival and livestock productivity in equine production. Characterizing physiological transitions during the perinatal period can improve our understanding of how mares adapt to late gestation, parturition, and early lactation. However, in horses-a typical monogastric herbivore with unique digestive characteristics-the associations between gut microbiota and perinatal physiological adaptation, as well as related stage-associated microbial and metabolic features, remain largely uncharacterized. Unassigned: In this study, para...
Equine Blood and Salivary Cortisol Levels While Exercising on a Water Treadmill with an Artificial River System. A water treadmill (WT) is used in equine rehabilitation and training. This study aimed to investigate whether varying water depths and using an active artificial river (AR) system during water treadmill exercise would affect physiological stress responses in leisure horses. Thirteen leisure horses participated in five 20 min WT sessions, including those with a treadmill with dry belt, fetlock-depth WT (with/without AR), and carpal-depth WT (with/without AR) at a walking speed of 1.25 m/s. Blood and salivary cortisol levels were measured before, immediately after, and 30 min after exercise. Blo...
Preliminary evaluation of beta-endorphin alone and in combination with adrenocorticotropic hormone for the diagnosis of pituitary pars intermedia dysfunction in equids. Limited published data exist regarding the diagnostic utility of beta-endorphin (β-END) for pituitary pars intermedia dysfunction (PPID), either compared with or in combination with adrenocorticotropic hormone (ACTH). Objective: To evaluate β-END as a potential diagnostic test for PPID in comparison with ACTH and to explore the diagnostic performance of combined tests. Methods: Ninety-eight equids aged 19-32 years, owned by the foundation "Stiftung für das Pferd," were included. Methods: A cross-sectional study was conducted in January 2025. Haircoat abnormalities were scored as absent, mi...
Horses with pituitary pars intermedia dysfunction have an altered fecal short-chain fatty acid profile. Pituitary pars intermedia dysfunction (PPID) is a prevalent endocrine disease in older horses sharing pathogenetic features with Parkinson disease, including dopaminergic neurodegeneration and α-synuclein aggregation. This study was conducted to determine whether horses with PPID exhibit changes in short-chain fatty acid (SCFA) profiles as described in Parkinson disease, providing further evidence for involvement of a microbiota-gut-brain axis in the pathogenesis of PPID. Unassigned: Prospective case-control study including 22 horses > 12 years of age. Diagnosis of PPID was based on clinical ...
Evaluation of a commercial multiplex immunoassay for assessing uterine inflammation in mares susceptible to persistent breeding-induced endometritis. Persistent breeding-induced endometritis (PBIE) is characterized by a prolonged and dysregulated uterine inflammatory response following breeding. Although inflammatory cytokines are central to the post-breeding immune response, their assessment in the equine uterus has historically relied largely on gene expression analyses. Multiplex immunoassays provide an opportunity to simultaneously quantify multiple cytokine proteins within uterine secretions; however, the application of equine-specific multiplex immunoassays utilizing the Luminex platform to low-volume uterine lavage (LVL) fluid remain...
Effects of omeprazole therapy administered via different routes on urinary parameters and selected interleukins in horses with equine gastric ulcer syndrome. Equine gastric ulcer syndrome (EGUS) is commonly treated with proton pump inhibitors such as omeprazole, administered orally or by injection. In humans, omeprazole has been associated with acute interstitial nephritis (AIN) and acute kidney injury (AKI), potentially linked to oxidative stress, and urinary interleukins may serve as early non-invasive markers. However, this association has not been established in horses. Objective: To evaluate the effects of oral and injectable omeprazole on basic urinary parameters and selected interleukin levels, with particular emphasis on the potential risk ...
Effects of Exercise on Ocular Parameters and Oxidative Stress Biomarkers in Saliva and Tear Fluid of Horses. Physical exercise is a physiological stressor in horses and may induce oxidative stress through increased production of reactive oxygen species. Saliva and tear fluid are accessible non-invasive matrices that may reflect oxidative balance, while ocular parameters including intraocular pressure (IOP), tear secretion (TS) and central corneal thickness (CCT) are key components of ocular homeostasis. Objective: To evaluate the effects of a standardised submaximal exercise session on IOP, TS and CCT, and on oxidative stress biomarkers (CAT, SOD, GSH, MDA, IMA) measured in saliva and tear fluid. Met...
Energy Metabolism Dysregulation in Horses and Foals. Dysregulation of energy metabolism occurs in horses and foals with transient systemic illness, malnutrition, or chronic metabolic diseases. The pathophysiologic processes resulting in energy dysregulation are important to interpret, understand, and appropriately monitor laboratory abnormalities associated with various disease states (hypoglycemia and hyperglycemia), as well as to aid in the management of energy dysregulation through nutritional and medical management.
Serum Osteocalcin and CTX-I in Fit-to-Race Thoroughbred Racehorses: Reference Intervals and Associations with Demographic, Training, and Lameness-Related Factors. Musculoskeletal injury remains a major welfare and performance concern in Thoroughbred racing, and biomarkers for early risk stratification are of scientific interest. This multicentre observational cohort study characterised serum concentrations of two bone turnover markers, osteocalcin/BGLAP (OC) and C-terminal telopeptide of type I collagen (CTX-I), in 1359 fit-to-race Thoroughbred racehorses sampled across New South Wales, Victoria, and Western Australia. Biomarker distributions, population-wide percentile ranges, demographic and training-related associations, and short-term soundness outc...
Evaluation of sequential serum amyloid A measurements for the prediction of sepsis and survival in critically ill neonatal foals. Single measurements of serum amyloid A (SAA) concentration at hospital admission has limited sensitivity for predicting sepsis and death. Objective: To determine whether differences in SAA during the first 2 days of hospitalization could predict sepsis and death in critically ill foals. Methods: One hundred twenty-seven critically ill neonatal foals, <14 days of age. Methods: Prospective cohort study. SAA was measured at hospital admission and on day 2 of hospitalization using a validated point-of-care test. Logistic regression was conducted to evaluate the predictive value of individual S...
Four Haylages, One Metabonome: Defining Diet Driven Metabolic Shifts in Ponies. Haylage is widely fed to all categories of stabled horses across Europe and New Zealand. Haylage can vary from high energy nutrient dense forage to low energy highly fibrous fodder, yet little is known about the impact different haylages have on metabolism in horses. This study provides the first direct comparison of feeding four different haylages: early cut (Lolium multiflorum), later cut (Lolium perenne) rye grass (R1 and R2); early and late cut meadow grass (M1 and M2), on urinary and faecal metabonomics, in ponies at maintenance. Using replicated Latin Square design, eight individually ho...
Detection and confirmation of hypoxia-inducible factor activating agents in equine plasma and urine by liquid chromatography coupled to mass spectrometry. Hypoxia-inducible factor (HIF) activating agents can promote the transcription of the erythropoietin gene, enhancing an athlete's performance, and are therefore prohibited in sports. A liquid chromatography coupled to high-resolution mass spectrometry (LCHRMS) method was developed for the detection and confirmation of 11 HIF-activating substances in equine plasma and urine. Ammonium formate added to the mobile phase system suppressed the responses of all the analytes in either positive or negative ion mode and thus was not used. The starting organic percentage in the mobile phase gradient and ...
The in vitro application of high-intensity laser therapy on equine platelet-rich plasma and autologous protein solution does not alter select cytokine and growth factor concentrations. To quantify the effects of high-intensity laser therapy (HILT) on the concentration of key immunomodulatory cytokines and growth factors in equine platelet-rich plasma (PRP) and autologous protein solution (APS). We hypothesized that HILT treatment of PRP and APS in vitro would increase the concentration of cytokines and growth factors compared to untreated controls. Unassigned: Whole blood was collected from 6 adult horses housed at the University of Pennsylvania in March 2025 and processed into PRP or APS using commercially available systems (Zoetis). Platelet-rich plasma and APS samples wer...
Oxidative Stress and Immunomarkers in Equine Dermal Melanomatosis: Single-Case Comparison with Healthy Individual. Dermal melanomatosis is a common tumor in grey horses, characterized by cutaneous/subcutaneous lesions with metastatic potential. While clinically well-described, oxidative stress involvement remains poorly understood. This case report compared oxidative stress markers and antioxidant enzymes' activities in total protein extracts from melanomatosis lesions (grey horse) versus healthy control skin (black horse), alongside histopathology and immunohistochemistry, to correlate oxidative imbalance and tumor behavior. Melanomatosis tissue exhibited decreased antioxidant defenses confirmed by catala...
Nonsteroidal anti-inflammatory drug administration alters crypt distribution of the peroxisomal marker acyl-coenzyme A oxidase 1 in the equine right dorsal colon. To characterize and compare the distribution of peroxisomal markers in the right dorsal colon (RDC) and left ventral colon (LVC) of healthy horses and horses treated with NSAIDs. Unassigned: Archived colonic tissues were evaluated from 10 horses (n = 5/group) administered phenylbutazone (4.4 mg/kg, PO, twice daily for 10 days) or placebo prior to euthanasia. Samples from the RDC and LVC were analyzed using immunofluorescence to assess peroxisomal biogenesis factor 14 (PEX14) and acyl-coenzyme A oxidase 1 (ACOX1) distribution. Marker abundance was quantified within colonic crypts and compared b...
Plasma Homocysteine Concentrations in Horses with Left-Sided Valvular Heart Disease. In human medicine, homocysteine, a sulfur-containing amino acid, is used as a biomarker reflecting endothelial dysfunction, inflammation, thrombogenesis, oxidative stress and cardiovascular disease. An automated enzyme-cycling assay for homocysteine, established for humans, has been validated and reference ranges have been created for horses. In this study the homocysteine assay was further evaluated by assessing short-term stability (whole blood and plasma samples stored at 4 °C and room temperature for 24 h), long-term stability (two years), the effect of different anticoagulants (lithium h...
The Transcriptomic and Proteomic Molecular Signatures of Equine Multiple-System Neuropathy (Grass Sickness). Equine grass sickness (EGS or equine dysautonomia) is a predominantly fatal multi-system neuropathy affecting grazing horses, likely caused by a neurotoxic phospholipase A2 (nPLA2) derived from a plant or microorganism. We studied neuronal tissue gene and protein expression patterns in EGS to elucidate the possible mechanisms of neurotoxicity and neurodegeneration. Tissue from the cranial cervical ganglion of eight EGS horses and six controls was examined histologically and used for transcriptomic analysis. These transcriptomic data were compared with previously published EGS-related proteomic...
Development and validation of a liquid chromatography-tandem mass spectrometry method for the quantification of twenty-five steroids in equine serum. Steroids are potential biomarkers for monitoring equine pregnancy. However, immunoassays currently used for their quantification suffer from cross-reactivity and limited specificity, thus requiring more accurate methods. This study reports the development and validation of a robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of 25 steroids covering the main biosynthetic pathways of progestogens, corticosteroids, androgens, and estrogens. Steroids were extracted by protein precipitation followed by evaporation, derivatization, and reconstitut...
Vasopressin stimulation testing in hospitalized foals. Hypothalamic-pituitary-adrenal gland axis (HPAA) dysfunction impairs survival and can be diagnosed with an arginine vasopressin (AVP) stimulation test. Objective: Adrenocorticotropic hormone (ACTH) and cortisol response to an AVP stimulation test will be attenuated in hospitalized foals compared to healthy foals and associated with severity of disease. Methods: Fifteen healthy and 45 hospitalized foals: 19 septic, 26 sick non-septic (SNS). Methods: A prospective, observational case-control design was utilized to assess HPAA function and compare corticotropin-releasing hormone, ACTH, and cortis...
High-Throughput Equine Plasma Profiling Using Laser-Assisted Rapid Evaporative Ionisation Mass Spectrometry. Remnants of erythrocyte removal from blood constitute therapeutic plasma-a water-based solution containing mainly platelets, extracellular vesicles (EVs), protein and lipid complexes and ions. Plasma-based therapies, including their use to accelerate wound healing in human and animal patients, are increasingly gaining prominence in regenerative medicine; however, methods for the optimal preparation of individual plasma are still under development. Rapid and accurate analysis of plasma composition is essential for the development of therapeutic applications and for ensuring the quality of plasm...
Evaluation of an Immunoturbidometric Assay for Measurement of Total Adiponectin Concentration in Equine Serum Samples. Total adiponectin (TA) is a marker of metabolic health in equids, with values below a critical decision point of < 7.9 μg/mL conferring increased risk of laminitis. Objective: To evaluate an IT assay to measure serum [TA] in equids and to assess its correlation with [high molecular weight adiponectin] (HMWA) measured by ELISA. Methods: Total serum adiponectin concentrations from 207 adult horses were measured using both an IT assay for TA and HMWA using a previously validated ELISA assay. Data were analyzed using Spearman correlation and Passing-Bablok regression. Intra- and inter-assa...
Preliminary Metabolomic Analysis: Serum Metabolomic Dynamics During Estrus Synchronization in Kazakh Mares. This study aimed to analyze the differences in serum metabolomes at different stages of estrus synchronization in Kazakh horses, to characterize dynamic changes in serum metabolites during estrus synchronization, and to screen potential metabolic markers and key regulatory pathways. Four sampling stages (M1: intravaginal device insertion; M3: device removal, labeled consistently with the pre-experiment timeline; P: 24 h post-PG injection; L: tertiary follicle emergence) were selected. The research results showed that 37 significantly different metabolites (DAMs) were identified in the M1-vs.-M...
Altered gene expression in the liver and small intestine of horses with equine neuroaxonal dystrophy. Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is the second most common diagnosis of spinal ataxia in horses in the United States. The disease develops due to a combination of vitamin E deficiency and an unknown genetic risk factor(s), and there currently is no effective treatment. Objective: We performed transcriptomic profiling of the liver and small intestine of horses with and without eNAD/EDM, as both tissues are the main locations for absorption, metabolism, and delivery of vitamin E to the nervous system. Methods: Case-control exploratory study. Methods: Post...
Reference interval for serum amyloid a in apparently healthy donkeys measured with a donkey-specific ELISA. Serum amyloid A (SAA) is a major acute phase protein used as an inflammatory biomarker in equine medicine. However, no universally accepted assay-specific reference interval (RI) exists for donkeys, and available literature remains limited, with only few studies using different donkey breeds and immunoassay platforms. This study aimed to establish an assay- and population-specific RI for serum SAA in apparently healthy donkeys using a species-specific double sandwich ELISA. Unassigned: Serum SAA concentrations were measured in 176 apparently healthy donkeys. RI estimation followed ASVCP/CLSI r...
