Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Horses
"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Genetic parameters for earnings in Quarter Horse. In this study, we estimated the heritability (h(2)) of earnings in the Quarter Horse in order to evaluate the inclusion of this trait in breeding programs. Records from 14,754 races of 2443 horses from 1978-2009 were provided by Sorocaba Hippodrome, São Paulo, Brazil. All ancestors of the registered horses were included in the pedigree file until the 4th generation. Log-transformed performance measures (LPM) were analyzed for animals aged 2, 3, and 4 years and during their entire career. The h(2) estimates were obtained using a multi-trait model and Gibbs sampling that included the effects of...
Pituitary pars intermedia dysfunction does not necessarily impair insulin sensitivity in old horses. Equine pituitary pars intermedia dysfunction (PPID) has been associated with reduced insulin sensitivity in comparison with younger adult horses; however, the difference in insulin sensitivity between horses with PPID and aged-matched controls has not been well characterized. The objective of the study was to determine if aged horses with PPID had reduced insulin sensitivity and alterations in the insulin-mediated signaling pathways in the skeletal muscle when compared with healthy aged horses. Isoglycemic hyperinsulinemic clamp procedures were conducted in 12 horses that were classified as ei...
Correlation between dichromatic colour vision and jumping performance in horses. There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red-green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences. In the indoor arena, significantly more touches and faults were made on blue fe...
Histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals. Computer-based digital image analysis of tissue samples shows promise both to reduce the subjectivity of traditional manual tissue assessments and potentially to shorten the time required to analyze each sample. The present study used digital image analysis to investigate the histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals. We hypothesized that the placentas of sick foals could have a different growth pattern and complexity that could be objectively estimated by their fractal dimension (FD). Fourteen placentas from 30 mares were selected i...
The DMRT3 ‘Gait keeper’ mutation affects performance of Nordic and Standardbred trotters. In a previous study it was shown that a nonsense mutation in the DMRT3 gene alters the pattern of locomotion in horses and that this mutation has a strong positive impact on trotting performance of Standardbreds. One aim of this study was to test if racing performance and trotting technique in the Nordic (Coldblood) trotters are also influenced by the DMRT3 genotype. Another aim was to further investigate the effect of the mutation on performance in Standardbreds, by using a within-family analysis and genotype-phenotype correlations in a larger horse material than in the previous study. We gen...
Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil. Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. Methods: From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; p...
Computed tomographic imaging of subchondral fatigue cracks in the distal end of the third metacarpal bone in the thoroughbred racehorse can predict crack micromotion in an ex-vivo model. Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic in...
An equine pain face. The objective of this study was to investigate the existence of an equine pain face and to describe this in detail. Methods: Semi-randomized, controlled, crossover trial. Methods: Six adult horses. Methods: Pain was induced with two noxious stimuli, a tourniquet on the antebrachium and topical application of capsaicin. All horses participated in two control trials and received both noxious stimuli twice, once with and once without an observer present. During all sessions their pain state was scored. The horses were filmed and the close-up video recordings of the faces were analysed for alterat...
A study of measurement of noninvasive blood pressure with the oscillometric device, Sentinel, in isoflurane-anaesthetized horses. To assess accuracy of noninvasive blood pressure (NIBP) measured by oscillometric device Sentinel compared to invasive blood pressure (IBP) in anaesthetized horses undergoing surgery. To assess if differences between the NIBP measured by the Sentinel and IBP are associated with recumbency, cuff placement, weight of the horse or acepromazine premedication and to describe usefulness of the Sentinel. Methods: Prospective study examining replicates of simultaneous NIBP and IBP measurements. Methods: Twenty-nine horses. Methods: Invasive blood pressure was measured via a catheter in the facial arte...
The influence of nutrition on the insulin-like growth factor system and the concentrations of growth hormone, glucose, insulin, gonadotropins and progesterone in ovarian follicular fluid and plasma from adult female horses (Equus caballus). Feed intake affects the GH-IGF system and may be a key factor in determining the ovarian follicular growth rate. In fat mares, the plasma IGF-1 concentration is high with low GH and a quick follicular growth rate, in contrast to values observed in thin mares. Nothing is known regarding the long-term effects of differential feed intake on the IGF system. The objective of this experiment was to quantify IGFs, IGFBPs, GH, glucose, insulin, gonadotropin and progesterone (P4) in blood and in preovulatory follicular fluid (FF) in relation to feeding levels in mares. Methods: Three years prior to the...
Biomechanical evaluation of a novel subcuticular skin stapling device for use in equine abdominal surgeries. To compare the in vitro biomechanical properties of a novel subcuticular stapling device to current methods of abdominal skin closure for equine abdominal surgery. Methods: In vitro randomized, matched design. Methods: Equine ventral median abdominal skin specimens (n = 24 horses). Methods: Subcuticular absorbable staples (SAS), metallic staples (MS), polyglyconate suture (PG), and nylon monofilament (NYL) were applied to longitudinally transected portions of equine ventral midline skin. Loads that resulted in an initial failure point and the ultimate failure load and mechanism were record...
Comparison of healing in forelimb and hindlimb surgically induced core lesions of the equine superficial digital flexor tendon. Even though equine multi-limb tendinopathy models have been reported, it is unknown if fore- and hindlimb tendon healing behave similarly. The aim of this study was to compare the healing process of surgically induced superficial digital flexor tendon (SDFT) core lesions of fore- and hindlimbs in horses. Methods: Tendon core lesions were surgically induced in the SDFT of both fore- and hindlimbs in eight horses. One randomly assigned forelimb and one randomly assigned hindlimb were injected with saline one and two weeks post-surgery. The healing process was monitored clinically and ultrasonogr...
Antibodies reactive to Ehrlichia spp. are common in Oklahoma horses. Abstract Tick infestations and infection with tick-borne agents are commonly recognized in horses in North America, but equine infection with true Ehrlichia spp. has not been described. To determine the degree to which horses in the south-central United States are naturally exposed to and infected with tick-borne disease agents, serum samples were collected at random (n=240) or from horses with active tick infestations (n=73) and tested by immunofluorescence antibody assay (IFA) and/or enzyme-linked immunosorbent assay (ELISA) for evidence of antibodies reactive to Ehrlichia spp., Anaplasma sp...
The effect of the ‘Gait keeper’ mutation in the DMRT3 gene on gaiting ability in Icelandic horses. A nonsense mutation in DMRT3 ('Gait keeper' mutation) has a predominant effect on gaiting ability in horses, being permissive for the ability to perform lateral gaits and having a favourable effect on speed capacity in trot. The DMRT3 mutant allele (A) has been found in high frequency in gaited breeds and breeds bred for harness racing, while other horse breeds were homozygous for the wild-type allele (C). The aim of this study was to evaluate further the effect of the DMRT3 nonsense mutation on the gait quality and speed capacity in the multigaited Icelandic horse and demonstrate how the freq...
Comparison of the bacterial community structure within the equine hindgut and faeces using Automated Ribosomal Intergenic Spacer Analysis (ARISA). The horse's hindgut bacterial ecosystem has often been studied using faecal samples. However few studies compared both bacterial ecosystems and the validity of using faecal samples may be questionable. Hence, the present study aimed to compare the structure of the equine bacterial community in the hindgut (caecum, right ventral colon) and faeces using a fingerprint technique known as Automated Ribosomal Intergenic Spacer Analysis (ARISA). Two DNA extraction methods were also assessed. Intestinal contents and faeces were sampled 3 h after the morning meal on four adult fistulated horses fed mea...
Proteomic analysis reveals age-related changes in tendon matrix composition, with age- and injury-specific matrix fragmentation. Energy storing tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT), are highly prone to injury, the incidence of which increases with aging. The cellular and molecular mechanisms that result in increased injury in aged tendons are not well established but are thought to result in altered matrix turnover. However, little attempt has been made to fully characterize the tendon proteome nor determine how the abundance of specific tendon proteins changes with aging and/or injury. The aim of this study was, therefore, to assess the protein profile of normal SDFTs ...
Evaluation of the length of competitive life in Hungarian sport horses. The aim of this study was to analyse the duration of the competitive life of jumping horses in Hungary to assess the potential for genetic evaluation and to get information about the risk factors affecting jumping performance of sport horses. The data set included lifetime performance in jumping competitions for 8475 horses born from 1992 onwards with records between 1996 and 2011 (32.7% were right-censored). Longevity was measured as the number of years spent in the competition. Discrete time survival model included fixed effects of gender, age at first competition, and the time-dependent eff...
Evaluation of regional limb perfusion with chloramphenicol using the saphenous or cephalic vein in standing horses. Regional limb perfusion (RLP) significantly decreases morbidity and mortality associated with distal limb injuries in horses. There is an urgent need for finding additional effective antimicrobial drugs for use in RLP. In this study, we tested the pharmacokinetics (PK) of chloramphenicol in RLP. Eight horses participated in the study, which was approved by the University Animal Care and Use Committee. The cephalic and the saphenous veins were used to perfuse the limbs. Synovial samples were collected from the metacarpo/metatarsophalangeal (MCP/MTP) joint. The Friedman Test was applied for asse...
Pharmacokinetic and pharmacodynamic analysis comparing diverse effects of detomidine, medetomidine, and dexmedetomidine in the horse: a population analysis. The present study characterizes the pharmacokinetic (PK) and pharmacodynamic (PD) relationships of the α2-adrenergic receptor agonists detomidine (DET), medetomidine (MED) and dexmedetomidine (DEX) in parallel groups of horses from in vivo data after single bolus doses. Head height (HH), heart rate (HR), and blood glucose concentrations were measured over 6 h. Compartmental PK and minimal physiologically based PK (mPBPK) models were applied and incorporated into basic and extended indirect response models (IRM). Population PK/PD analysis was conducted using the Monolix software implementing t...
Vasorelaxation responses to insulin in laminar vessel rings from healthy, lean horses. Hyperinsulinemia causes laminitis experimentally and is a risk factor for naturally occurring laminitis. The aim of this study was to investigate the effects of insulin on laminar vascular relaxation and to induce insulin-associated vascular dysfunction in vitro. Relaxation responses of isolated laminar arterial and venous rings to acetylcholine and insulin were evaluated. To alter vascular function in response to insulin, all vessel rings were incubated with insulin or vehicle, submaximally contracted, administered insulin again and relaxation responses recorded. Laminar arteries were also in...
Antioxidant activity of hyaluronic acid investigated by means of chemiluminescence of equine neutrophil bursts and electron paramagnetic resonance spectroscopy. Activated neutrophils (PMNs), the ROS/RNS released by PMNs and the derived inflammatory processes are involved in the pathogenesis and progression of human inflammatory airway diseases. Similar diseases are also present in horses which suffer from recurrent airway obstruction (RAO), exercise-induced pulmonary haemorrhage (EIPH) and inflammatory airway diseases (IAD). Hyaluronic acid (HA) plays numerous roles in modulating inflammatory processes. The aim of this study was to examine whether a preparation of HA (MW 900 000 Da) interferes with ROS/RNS during the course of equine PMN respiratory b...
First detection of co-circulation of West Nile and Usutu viruses in equids in the south-west of Tunisia. In the last fifteen years, West Nile Virus (WNV) has dramatically expanded its geographic range and is now considered the most widespread arbovirus in the world. In Tunisia, West Nile Fever (WNF) outbreaks were reported in humans in 1997, 2003 and 2012. Usutu Virus (USUV), which is a 'new' emerging Flavivirus antigenically close to WNV, has never been reported in Tunisia. A serological investigation in 284 equids was conducted in 2012 in the southern west region of the country to assess the presence and prevalence of the WNV and USUV infection. Of the 284 samples tested by competitive enzyme-l...
Diurnal modulation and sources of variation affecting ventricular repolarization in Warmblood horses. Irregularities in cardiac repolarization are known to predispose for arrhythmias and sudden cardiac death in humans. The QT interval is a quantitative measurement of repolarization, and clinically, the QTc (QT interval corrected for heart rate) and Tpeak to Tend intervals (TpTe) are used as repolarization markers. To support the use of these markers in horses, we sought to describe the possible influence of the environment, time of day, day-to-day effects, T wave conformation, age, body weight (BW), and horse-to-horse variation on repolarization measurements. Methods: 12 Warmblood geldings, ag...
Efficacy of a Parapoxvirus ovis-based immunomodulator against equine herpesvirus type 1 and Streptococcus equi equi infections in horses. The efficacy of Zylexis®, an immunomodulator in horses based on inactivated Parapoxvirus ovis (iPPVO), was assessed using an equine herpesvirus type 1 (EHV-1) challenge model in the presence of a natural infection with Streptococcus equi equi (S. equi). Eleven horses were treated with iPPVO and twelve were kept as controls. Six horses were challenged with EHV-1 and commingled with the horses on study. Animals were dosed on Days -2, 0 (just before commingling) and Day 7. On Day 11 significantly less nasal discharge, enlarged lymph nodes, EHV-1 shedding and lower rectal temperatures were observ...
Pharmacokinetics and pharmacodynamics of xylazine administered by the intravenous or intra-osseous route in adult horses. In certain situations, an alternate route for parenteral drug administration in horses may be useful. The intra-osseous (IO) route may provide a safe alternative to the intravenous (i.v.) route for administration of sedatives to horses when the i.v. route is inaccessible or undesirable. Six adult horses were administered xylazine i.v. or IO in a block-randomized crossover design. For the i.v. trial, both jugular veins were catheterized, and one was used for xylazine administration, while the other was used for blood collection. For the IO trial, one jugular vein was catheterized for blood coll...
Concentrations of stromal cell-derived factor-1 in serum, plasma, and synovial fluid of horses with osteochondral injury. To determine whether stromal cell-derived factor-1 (SDF-1) concentrations in serum, plasma, and synovial fluid differed among untrained, race-trained, and osteochondral-injured Thoroughbred racehorses. Methods: 22 racehorses without osteochondral injury and 37 racehorses with osteochondral injury. Methods: Horses without osteochondral injury were examined before and after 5 to 6 months of race training. Horses with osteochondral injury were undergoing arthroscopic surgery for removal of osteochondral fragments from carpal or metacarpophalangeal or metatarsophalangeal joints (fetlock joints). S...
Diagnostic sensitivity of bone scintigraphy for equine stifle disorders. Disorders of the stifle are a common cause of lameness in horses yet the accuracy of scintigraphy for diagnosis of stifle conditions is controversial. The aim of retrospective cross-sectional study was to determine the diagnostic sensitivity (Se) of bone scintigraphy in detecting stifle disease and to determine if two orthogonal scintigraphic images improve diagnostic Se. Horses that underwent scintigraphic examination during a two-year period were included. Horses were divided into two groups: group 1 (N = 23) had lameness that was localized to the stifle by intra-articular analgesia and grou...
Effects of clopidogrel on horses with experimentally induced endotoxemia. To evaluate the effects of clopidogrel on clinical and clinicopathologic variables in healthy horses with experimentally induced endotoxemia. Methods: 12 adult mares. Procedures-Horses were assigned with a randomization procedure to receive clopidogrel (4 mg/kg, once, then 2 mg/kg, q 24 h; n = 6) or a placebo (6) through a nasogastric tube. After 72 hours of treatment, horses received lipopolysaccharide (LPS; 30 ng/kg, IV). Heart rate, respiratory rate, rectal temperature, CBC variables, plasma fibrinogen concentration, serum tumor necrosis factor-α concentration, plasma von Willebrand factor...
