Equine Science encompasses the study of horses and their management, health, and performance. This field integrates various scientific disciplines such as biology, genetics, nutrition, physiology, and veterinary medicine to understand and improve the well-being and capabilities of horses. Areas of focus include equine anatomy, reproduction, behavior, and disease prevention. Research in equine science aims to enhance horse care, optimize training and performance, and address health challenges. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine science, providing insights into the latest advancements and methodologies in the field.
Berreta A, Burbick CR, Alexander T, Kogan C, Kopper JJ.Probiotics are defined as live microorganisms that confer a health benefit to the host when administered in adequate amounts, therefore the presence of viable microorganisms is essential. Previous studies reported inconsistencies when comparing contents of probiotics marketed for use in animals with label claims. However, to the author's knowledge the variability of the same product between different lots has yet to be evaluated. The objective of this observational study was to evaluate the content and inter-lot variability of commercial equine probiotic products using culture dependent and in...
Freitas NFQR, Otaka DY, Galvão CC, de Almeida DM, Ferreira MRA, Moreira Júnior C, Hidalgo MMMH, Conceição FR, Salvarani FM.In horses, Clostridium perfringens is associated with acute and fatal enterocolitis, which is caused by a beta toxin (CPB), and myonecrosis, which is caused by an alpha toxin (CPA). Although the most effective way to prevent these diseases is through vaccination, specific clostridial vaccines for horses against C. perfringens are not widely available. The aim of this study was to pioneer the immunization of horses with three different concentrations (100, 200 and 400 µg) of C. perfringens recombinant alpha (rCPA) and beta (rCPB) proteins, as well as to evaluate the humoral immune response ove...
Gastal EL, Pastorello M, Godoi DB, Gastal MO.This comparative study between postpartum lactating (PP Lactating) and non-postpartum cycling (N-PP Cycling) mares aimed to characterize reproductive patterns, types and frequencies of follicular waves, corpus luteum and endometrial echotexture dynamics, and the influence of season and body condition. Mares from each group were paired considering the day of parturition of a PP Lactating mare. The partum-ovulation interval (POI) and the postpartum interovulatory interval (PPIOI) were evaluated for PP Lactating mares, and 2 IOIs were evaluated for N-PP Cycling mares. The following observations w...
Huseman C, Walker N, McCorkle DA, Hanselka D, Cater M, Zoller J.The COVID-19 pandemic affected the economic status of all sectors of the global economy including the horse show industry. Reporting the impact of COVID-19 on in-person horse shows and an early assessment of its impact on the economy was the objective of this study. A Qualtrics survey instrument was disseminated to horse show participants through social media pages and email (n = 251). A majority of respondents were females (95.6%) representing a cross-section of the United States (84.0%). Participants reported planning to attend an average of 9.7 (SD = 7.15) in-person horse shows in 2020...
Wiebke M, Hensel B, Nitsche-Melkus E, Jung M, Schulze M.This review is part of the Festschrift in honor of Dr. Duane Garner and provides an overview of current techniques for cooled storage of semen from livestock animals. The first part describes the current state of the art of liquid semen preservation in boars, bulls, and stallions, including the diluents, use of additives, processing, temperature, and cooling of semen. The species-specific physiology and varying extents of cold shock sensitivity are taken into consideration. In addition, factors influencing the quality of cooled-stored semen are discussed. Methods, trends, and the most recent a...
Parés-Casanova PM.Morphological integration and modularity are concepts that refer to the covariation level between the components of a structure. Morphological modules are independent subsets of highly correlated traits. The horse skull has been studied as a whole functional structure for decades, but the integrative approach towards quantitative examination of modules is scarce. We report here the first evaluation of cranial modularity in the horse at basal level. For this, we studied the modularity hypothesis for splanchnocranium and basicranium modules in the horse, two phenotipic regions under local influe...
Zanker A, Wöhr AC, Reese S, Erhard M.Veterinary and human medicine are still seeking a conclusive explanation of the function of sleep, including the change in sleep behaviour over the course of an individual's lifetime. In human medicine, sleep disorders and abnormalities in the electroencephalogram are used for prognostic statements, therapeutic means and diagnoses. To facilitate such use in foal medicine, we monitored 10 foals polysomnographically for 48 h. Via 10 attached cup electrodes, brain waves were recorded by electroencephalography, eye movements by electrooculography and muscle activity by electromyography. Wireless ...
Brubaker L, Schroeder K, Sherwood D, Stroud D, Udell MAR.While human benefits of animal-assisted therapy programs have been documented, relatively little research has been conducted on behavioral factors that predict a successful equine-assisted services (EAS) horse. This study compares the behavior of experienced and non-experienced EAS horses as well as horses selected for future EAS work in a series of sociability and temperament tests. No significant differences were found between experienced and non-experienced horses in the sociability measures or for most of the temperament tests; however, significant differences were found between groups in ...
Ringhofer M, Trösch M, Lansade L, Yamamoto S.When interacting with humans, domesticated species may respond to communicative gestures, such as pointing. However, it is currently unknown, except for in dogs, if species comprehend the communicative nature of such cues. Here, we investigated whether horses could follow the pointing of a human informant by evaluating the credibility of the information about the food-hiding place provided by the pointing of two informants. Using an object-choice task, we manipulated the attentional state of the two informants during food-hiding events and differentiated their knowledge about the location of t...
Viafara JAS, Portilho RV, Maculan R, Souza Júnior JF, Silva CM, Rodrigues PG, El Azzi MS, Souza JC.This study evaluated the presence of polyunsaturated fatty acids in circulating blood and in the ovarian follicular fluid of mares, after supplementation of the diet with linseed oil. Six Mangalarga Marchador mares, weighing 397.00±31.89 kg, were kept on native pasture, and assigned to the current study. In a switch over design, mares were randomly allocated to receive 150 ml of vegetable oil daily, containing polyunsaturated fatty acids n3 (62.23 g ALA, 20.34 g LA, 2.27 g EPA, 2.32 g DHA), (n=3) or no supplementation (n=3) in two replicates. Blood and follicular fluid samples were taken on t...
Requena F, Campos MJAPM, Martínez Marín AL, Camacho R, Giráldez-Pérez RM, Agüera EI.In equine reproduction, accurate and timely detection of the moment of ovulation is of great importance. Power Doppler ultrasound technology is a non-invasive method that enables to assess the morpho-echogenic features and blood flow changes during the estral cycle in mares. The objective of the present study was to evaluate the influence of age on ultrasonographic parameters (follicular diameter, follicular blood flow-FBF, corpus luteum (CL) area and corpus luteum blood flow-CLBF) and blood plasma progesterone concentrations in cycling Spanish Purebred mares (15 less than 8 years old and 15 e...
Ginther OJ.The equine embryo or embryonic vesicle on Days 11-15 postovulation travels with profound physiologic purpose throughout the lumen of the two uterine horns and uterine body making 12 to 22 trips between the two uterine horns per day. This phenomenon is termed embryo mobility and is unique in equids among domestic species. Apparently, the embryo first reaches the uterine body on Days 8 or 9. Mobility increases to maximum by Days 11 or 12 and continues until an abrupt cessation of mobility (fixation) on Days 15 (ponies) or 16 (horses and donkeys). The embryo is propelled by uterine contractions i...
Poyato-Bonilla J, Laseca N, Demyda-Peyrás S, Molina A, Valera M.The Carthusian horse is a Pura Raza Español (PRE) strain (CS), bred as a closed population since its creation more than 500 years ago. The aim of this study was to analyse for the first time its population structure and situation of variability combining both genealogical (GEL) and genomic (GEN) data. The GEL data comprised 348,429 pedigree records (56,105 CS horses), while the GEN analysis included the high-density genotypes (670,804 SNPs) of 287 horses. Pedigree completeness demonstrated its accuracy, showing a good correlation of GEL (F) and GEN (F ) inbreeding coefficient in the case of ...
Rankins EM, Wickens CL, McKeever KH, Malinowski K.Little published information exists on the horses in equine-assisted services (EAS), particularly their selection, longevity, and retirement. The purpose of this study was to characterize horses and procedures used in EAS. A pilot survey was developed using focus group discussions and distributed to Professional Association of Therapeutic Horsemanship, International (PATH Intl) centers in Florida ( = 45, Part I) before further modification and distribution to members of PATH Intl., American Hippotherapy Association (AHA), eagala, and Certified Horsemanship Association (CHA) ( = 26,000, Part II...
Becsek A, Tzanidakis N, Blanco M, Schmicke M, Bollwein H.The aim of this study was to investigate the effects of maternal, hormonal, and fetal factors on early fetal volume (FV) measurements in mares obtained by three-dimensional (3D) ultrasound. Furthermore, postpartum parameters were explored in regard to their association with early FV. For this purpose, 149 German warmblood mares that were artificially inseminated and confirmed to be pregnant between days 14-16 of gestation, were examined transrectally at day 45 ± 1 of gestation with the portable 3D ultrasound device Voluson® i (GE, Zipf, Austria). FV was calculated by using the extension so...
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI.The Thoroughbred breed was formed by crossing Oriental horse breeds and British native horses and is currently used in horseracing worldwide. In this study, we constructed a single-nucleotide variant (SNV) database using data from 101 Thoroughbred racehorses. Whole genome sequencing (WGS) revealed 11,570,312 and 602,756 SNVs in autosomal (1-31) and X chromosomes, respectively, yielding a total of 12,173,068 SNVs. About 6.9% of identified SNVs were rare variants observed only in one allele in 101 horses. The number of SNVs detected in individual horses ranged from 4.8 to 5.3 million. Individual...
Alsing-Johansson T, Pedersen A, Bergström K, Sternberg-Lewerin S, Penell J, Bergh A.Equine dentistry has developed immensely and human dental equipment, such as handpieces, are often used. Measures to avoid the spread of infectious microorganisms are important, but this is challenging since handpieces are difficult to decontaminate. Thus, it is necessary to develop effective IPC measures in equine dentistry. The aim of this study was to contribute to the evidence needed for future evidence-based guidelines on IPC by investigating hygiene in equine dentistry. Used handpieces and dummies (i.e., handpieces not used during dental procedure, reflecting environmental bacterial cont...
Rodrigues JB, Garrett C, Norris SL, Albuquerque F, Queijo L, Cooke F, Judge A.Working donkeys represent an important source of energy worldwide. Poor working conditions and equipment affect their ability to work. Poorly designed, ill-fitted harness causes inefficient transfer of power and leads to health and welfare issues. Using technology to assess different types of collars provides a better understanding of those that are most efficient for working donkeys. Methods: Seven different collars were tested using pressure pads. Contact area, median, maximum and peak pressures were obtained for the whole collar and critical points. Eight donkeys pulled 20% and 40% of their...
Animals must attend to a diverse array of stimuli in their environments. The emotional valence and salience of a stimulus can affect how this information is processed in the brain. Many species preferentially attend to negatively valent stimuli using the sensory organs on the left side of their body and hence the right hemisphere of their brain. Here, we investigated the lateralisation of visual attention to the rapid appearance of a stimulus (an inflated balloon) designed to induce an avoidance reaction and a negatively valent emotional state in 77 Italian saddle horses. Horses' eyes are late...
Fernández-Hernández P, Marinaro F, Sánchez-Calabuig MJ, García-Marín LJ, Bragado MJ, González-Fernández L, Macías-García B.Equine fertilization cannot be performed in the laboratory as equine spermatozoa do not cross the oocyte's zona pellucida . Hence, a more profound study of equine oviductal fluid (OF) composition at the pre-ovulatory and post-ovulatory stages could help in understanding what components are required to achieve fertilization in horses. Our work aimed to elucidate the proteomic composition of equine OF at both stages. To do this, OF was obtained postmortem from oviducts of slaughtered mares ipsilateral to a pre-ovulatory follicle ( = 4) or a recent ovulation ( = 4); the samples were kept at -80°...
Brownlow MA, Brotherhood JR.Exertional heat illness (EHI) is a syndrome that occurs when metabolic heat production from muscular contraction exceeds the rate at which it can be dissipated. Core body temperature rises to critical levels, causing hyperthermia and central nervous system dysfunction. Best practice for the prevention of EHI centres around early detection, rapid response and aggressive cooling. Advance planning enables risk mitigation measures. The more that is known about EHI in horses, the better prepared those in the positions of responsibility can be to anticipate events in which the risk of EHI may be ele...
Bernor RL, Cirilli O, Bukhsianidze M, Lordkipanidze D, Rook L.The Equus datum has been established as a geochronologic 'instantaneous' migratory event of a North American Equus species into Eurasia at the beginning of the Pleistocene (2.58 Ma). A remarkable radiation of Equus followed across Eurasia and Africa. Dmanisi includes excellent remains of Equus, well calibrated between 1.85 and 1.76 Ma. Our morphologic and morphometric analyses of the augmented Dmanisi Equus sample support the co-occurrence of Equus stenonis and Equus altidens in the sequence. Dmanisi E. stenonis is found to be morphologically similar to the European E. stenonis populations a...
Menchetti L, Dalla Costa E, Minero M, Padalino B.Regulation EC 1/2005 has stricter rules for transportation of unbroken (untamed) vs. broken (tamed) horses, but does not provide adequate tools for their identification. This study aimed to develop and validate such a tool. A behavioural test (Broken/Unbroken Test (BUT)) based on approaching, haltering, and leading was applied to 100 horses. Physiological and additional behavioural data were also collected, and the horses' status (broken/unbroken) was assessed by the expert who administered the BUT. Each horse's behaviour during the BUT was scored by four trained observers blinded to the horse...
The Journal of heredityAugust 4, 2021
Volume 112, Issue 5 443-446 doi: 10.1093/jhered/esab037
Hammons V, Ribeiro L, Munyard K, Sadeghi R, Miller D, Antczak D, Brooks SA.Chestnut coat color in horses is determined by a missense mutation within the MC1R gene. However, the intensity of the chestnut color can vary widely within individuals possessing this genotype. Here, we investigated this variation using standardized photographs of 96 horses. Each horse was ranked lightest to darkest within the cohort for phenotype by 3 blinded observers. A genome-wide association study utilizing the relative shade ranking as the phenotype and using 268 487 single-nucleotide polymorphisms (SNPs) genotyped using the Affymetrix Equine 670k array identified a single significantly...
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota K, Kusano K, Nagata S.Gene doping is prohibited in horseracing. In a previous study, we developed a method for non-targeted transgene detection using DELLY, which is based on split-read (SR) and paired-end (PE) algorithms to detect structural variants, on WGS data. In this study, we validated the detection sensitivity of DELLY using artificially generated sequence data of 12 target genes. With DELLY, at least one intron was detected as a deletion in eight targeted genes using the 150 bp PE read WGS data, whereas all targeted genes were detected by DELLY using the 100 bp PE read data. The detection sensitivity was h...
Prieto AV, Ayupe KMA, Abreu ACA, Filho PJBG.Improvement in rider mobility represents an important functional gain for people with disabilities undergoing hippotherapy. However, there is no validated measuring instrument to track and document the rider's progress in riding activities. In this study, we aimed to develop and establish validity evidence for an instrument to assess hippotherapy participants' mobility on horseback. We report on this development through the stages of: (a) content validation, (b) construct validation, (c) inter- and intra-rater reliability and (d) internal consistency analysis. We evaluated its factor structure...
Pennington PM, Splan RK, Jacobs RD, Wang Y, Wagner AL, Freeman EW, Pukazhenthi BS.The reproductive cycle and early pregnancy represent dynamic physiological states in mammals, but mechanisms involved in early pregnancy in the domestic horse remain poorly understood. Proteins in uterine secretions have been studied, but the proteome of peripheral serum during various reproductive states has not been investigated. This study characterized and compared the serum proteome in the domestic horse during various reproductive states. Serum was collected from three mares during: (1) estrus (day [d] -1; d 0 = ovulation), (2) diestrus (d 12.5, non-mated), (3) early pregnancy (d 12.5,...
Yordanov G, Zlatanovic N, Palova N, Mehandjyiski I, Neov B, Radoslavov G, Hristov P.The objective of our study was to investigate the genetic structure of yet uninvestigated populations of three closely related horse breeds - the Danubian Horse, the Hungarian Nonius and the Serbian Nonius - in order to clarify their origin and genetic diversity. A 640-bp-long fragment of the mtDNA D-loop region was amplified and sequenced. The results showed that the investigated breeds have different genetic profiles although they share some common characteristics. We identified nine of the 17 haplogroups described in modern horses. Most of the obtained sequences fall into the M, L, G, and O...
Miller AB, Murphy BA, Adams AA.Blue light therapy can be used in horses to alter the natural photoperiod and inhibit winter hair coat growth. Seasonal increases in ACTH occur in the fall season but are exaggerated in horses with pituitary pars intermedia dysfunction (PPID). Additionally, PPID horses frequently present with hypertrichosis. Thus, blue light therapy was proposed as a potential management tool for hypertrichosis and for investigating the impact of photoperiod manipulation on ACTH. Eighteen PPID horses, aged 18 to 31 yr, from a university-owned research herd were selected and assigned to either the control group...
Tomonaga M, Kumazaki K, Camus F, Nicod S, Pereira C, Matsuzawa T.Mammals have adapted to a variety of natural environments from underwater to aerial and these different adaptations have affected their specific perceptive and cognitive abilities. This study used a computer-controlled touchscreen system to examine the visual discrimination abilities of horses, particularly regarding size and shape, and compared the results with those from chimpanzee, human and dolphin studies. Horses were able to discriminate a difference of 14% in circle size but showed worse discrimination thresholds than chimpanzees and humans; these differences cannot be explained by visu...
Burns EN, Finno CJ.Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy is an inherited neurodegenerative disorder affecting many horse breeds. Clinical signs include a symmetric ataxia and an abnormal stance at rest, similar to cervical vertebral compressive myelopathy, equine protozoal myeloencephalitis, and equine herpesvirus 1 myeloencephalopathy. This review will provide an update on the disease prevalence, management, impact, and ongoing research.
Roth LS, Balkenius A, Kelber A.Most mammals have dichromatic colour vision based on two different types of cones: a short-wavelength-sensitive cone and a long-wavelength-sensitive cone. Comparing the signal from two cone types gives rise to a one-dimensional chromatic space when brightness is excluded. The so-called ;neutral point' refers to the wavelength that the animal cannot distinguish from achromatic light such as white or grey because it stimulates both cone types equally. The question is: how do dichromats perceive their chromatic space? Do they experience a continuous scale of colours or does the neutral point divi...
Love S.In the horse, adenomata of the pairs intermedia of the pituitary gland have been associated with the distinct clinical entity of Cushing's disease which arises largely as a result of excessive secretion of adrenocorticotropin (ACTH) or other proopiomelanocortin (POMC) peptides. Pars intermedia peptide secretion is under dopaminergic control and compounds such as pergolide or bromocriptine, which are dopamine agonists, can palliate the clinical signs. A variety of endocrinological abnormalities, relevant to both pathogenesis and diagnosis, may be demonstrated in equine Cushing's disease, includ...
Dhorne-Pollet S, Barrey E, Pollet N.Mitochondrial DNA is remarkably polymorphic. This is why animal geneticists survey mitochondrial genomes variations for fundamental and applied purposes. We present here an approach to sequence whole mitochondrial genomes using nanopore long-read sequencing. Our method relies on the selective elimination of nuclear DNA using an exonuclease treatment and on the amplification of circular mitochondrial DNA using a multiple displacement amplification step. Results: We optimized each preparative step to obtain a 100 million-fold enrichment of horse mitochondrial DNA relative to nuclear DNA. We sequ...
Bailey SR, Marr CM, Elliott J.A large number of studies have been undertaken in recent years aimed at furthering our understanding of the complex mechanisms underlying the common and debilitating condition of acute laminitis in the horse. Many of these studies have either reinforced or cast doubt on previously held theories on the pathogenesis of this disease, while others have suggested new mechanisms which may play a key role in its development. This review seeks to put the current hypotheses into the context of this recent body of evidence. While a unifying theory may not yet seem to be achievable, this review demonstra...
Bjørnstad G, Nilsen NØ, Røed KH.Human populations of Central Asian origin have contributed genetic material to northern European populations. It is likely that migrating humans carried livestock to ensure food and ease transportation. Thus, eastern genes could also have dispersed to northern European livestock populations. Using microsatellite data, we here report that the essentially different genetic distances DA and (deltamu)2 and their corresponding phylogenetic trees show close associations between the Mongolian native horse and northern European horse breeds. The genetic distances between the northern European breeds a...
Rieder S.Colour phenotypes may have played a major role during early domestication events and initial selection among domestic animal species. As coat colours mostly follow a relatively simple mode of Mendelian inheritance, they have been among the first traits to be systematically analysed at the molecular level. As a result of the number of genetic tools developed during the past decade, horse coat colour tests have been designed and are now commercially available for some of the basic phenotypes. These tests enable breeders to verify segregation within particular pedigrees, to select specific colour...
Meier K, Jaguva Vasudevan AA, Zhang Z, Bähr A, Kochs G, Häussinger D, Münk C.Human myxovirus resistance protein B (hMXB) is a restriction factor of HIV-1 that also inhibits a variety of retroviruses. However, hMXB is not antiviral against equine infectious anemia virus (EIAV). We show here that equine MX2 (eMX2) potently restricts EIAV in vitro. Additionally, eMX2 inhibits HIV-1 and other lentiviruses, including murine leukemia virus. Previously, it was reported that hMXB repression is reduced in hMXB Δ1-25, but not in GTP-binding mutant K131A and GTP-hydrolysis mutant T151A. In contrast to this phenomenon, our study indicates that eMX2 restriction is not diminished i...
Muñoz A, Saitua A, Becero M, Riber C, Satué K, de Medina AS, Argüelles D, Castejón-Riber C.In recent years, exercise on a water treadmill has come to have great relevance in rehabilitation and training centres for sport horses. Its use exploits certain physical properties of water, related to the fundamental principles of hydrodynamics, such as buoyancy, viscosity, hydrostatic pressure, and water temperature. These properties together with deliberate specification of the depth of the water and the velocity of the treadmill provide a combination of parameters that can be varied according to the purpose of the rehabilitation or training programme, the disease to rehabilitate, or the h...
Essén B, Lindholm A, Thornton J.Fibre characteristics and enzyme activities were determined for the gluteus, semitendinosus, vastus lateralis and triceps brachii muscles of 55 Standardbred trotters of different ages. Four fibre types (I, IIA, IIB, IIC) were demonstrated by histochemical staining of myofibrillar adenosine triphosphatase after preincubation at different pH values. Type II fibres predominated in all the muscles and the type IIA/IIB ratio was higher in horses over 5 years than in younger horses, except in the vastus in which the IIA/IIB ratio did not change with age. The vastus had the highest proportion of type...
Prinsloo M, Hynd P, Franklin S, Weaver S, van den Boom R.Equine squamous gastric disease (ESGD) is common in horses and many factors, including stress, may play a role in lesion development. Hair cortisol concentration (HCC) provides a measure of medium to long-term stress and therefore, the relationship between HCC and ESGD was examined in this study. Hair samples were collected from 25 horses and gastroscopy was performed to determine the presence and severity of ESGD. Hair cortisol concentrations were lower in horses with ESGD (P = 0.014), and negatively correlated with lesion severity. Mares had lower HCC than geldings (P = 0.031), and a...
Whishaw IQ, Sacrey LA, Gorny B.An animal that has stepped over an obstacle with its forelimbs uses a memory of the obstacle to guide the hind limbs so that they also clear the obstacle, even in situations in which long pauses are introduced between forelimb and hind limb stepping. To further clarify the features of hind limb obstacle clearance memory, the present study examined hind limb obstacle clearance in the horse. A rider guided horses over obstacles and paused the horse over obstacles in tests that examined the relationship between forelimb and hind limb stepping, with the following results. First, the horses display...
Salamon Z, Tollin G.Complex formation between horse heart cytochrome c (cyt c) and bovine cytochrome c oxidase (cco) incorporated into a supported planar egg phosphatidylcholine membrane containing varying amounts of cardiolipin (CL) (0-20 mol%) has been studied under low (10 mM) and medium (160 mM) ionic strength conditions by surface plasmon resonance (SPR) spectroscopy. Both specific and nonspecific modes of cyt c binding are observed. The dissociation constant of the specific interaction between cyt c and cco increases from approximately 6.5 microM at low ionic strength to 18 microM at medium ionic strength, ...
Chowdhary BP, Raudsepp T.The map of the horse genome has undergone unprecedented expansion during the past six years. Beginning from a modest collection of approximately 300 mapped markers scattered on the 31 pairs of autosomes and the X chromosome in 2001, today the horse genome is among the best-mapped in domestic animals. Presently, high-resolution linearly ordered gene maps are available for all autosomes as well as the X and the Y chromosome. The approximately 4350 mapped markers distributed over the approximately 2.68 Gbp long equine genome provide on average 1 marker every 620 kb. Among the most remarkable deve...
Gillis C.Young elite athletes, particularly horses used for jumping, are at a relatively high risk for injury to the ligaments associated with the axial skeleton. Extreme back flexion appears to be a contributing factor to ligament damage. Back pain due to injury of the ligaments of the axial skeleton has often been considered to be secondary to lower limb injury, to the extent that a separate definitive diagnosis, treatment, and prognosis were unnecessary. Diagnostic imaging, ultrasound in particular, has demonstrated ligamentous damage that can be the limiting factor in return to previous athletic us...
Bertin FR, Sojka-Kritchevsky JE.Equine insulin resistance is important because of its association with laminitis. The insulin-response test is described to diagnose insulin resistance in clinical settings. Practitioners may be reluctant to perform this test because of the time needed for the test and the fear of inducing hypoglycemia. The objective of the study was to compare a 2-step insulin-response test with a complete insulin-response test. A complete insulin-response test was performed on 6 insulin-resistant horses and 6 controls. A 2-step insulin-response test consisting of an intravenous injection of 0.1 IU/kg human i...
Briski O, Salamone DF.During the past 2 decades, intracytoplasmic sperm injection (ICSI) has become a routine technique for clinical applications in humans. The widespread use among domestic species, however, has been limited to horses. In horses, ICSI is used to reproduce elite individuals and, as well as in humans, to mitigate or even circumvent reproductive barriers. Failures in superovulation and conventional in vitro fertilization (IVF) have been the main reason for the use of this technology in horses. In pigs, ICSI has been successfully used to produce transgenic animals. A series of factors have resulted in...
Dobrinsky JR.The development of embryo freezing technologies revolutionized cattle breeding. Since then, advancements in cryobiology, cell biology, and domestic animal embryology have enabled the development of embryo preservation methodologies for our other domestic animal species, including sheep and goats. Recently, technologies have been developed to cryopreserve pig embryos, notorious for their extreme sensitivity to cooling; horse embryo cryopreservation is in its infancy. While cryopreservation can enhance the utilization of in vitro embryo production technologies, cryosurvival of in vitro-produced ...
Slater JD, Herrtage ME.Echocardiographic examinations were performed on 41 clinically normal small ponies, large ponies and horses. Using standardised two-dimensional (2-D) echocardiographic images to guide M-mode studies, the interventricular septal thickness, left ventricular internal dimension and left ventricular wall in systole and diastole, and aortic diameter in diastole were measured. Normal values for these echocardiographic dimensions were obtained across a wide range of bodyweights. Although there was a trend for echocardiographic dimensions to increase with bodyweight across the whole range of animals ex...
Huthmann S, Staszyk C, Jacob HG, Rohn K, Gasse H.The forces generated during equine mastication influence the teeth, as well as the periodontium, the jaw bones, the temporomandibular joints and materials used in dental therapy. Due to the limited accessibility of the cheek teeth located farther caudal in the equine oral cavity the measurement of the masticatory forces on these teeth is virtually impossible. The calculation of such forces is an appropriate, indirect alternative to direct measuring. Hence, a mathematical model, which respects several morphological features of the equine dentition, e.g. the Curve of Spee, is presented. The rele...
Biswas B, Mukherjee D, Mattingly-Napier BL, Dutta SK.Genomic amplification by the polymerase chain reaction (PCR) was used to identify a unique genomic sequence of Ehrlichia risticii directly in DNA isolated from peripheral-blood buffy coat cells of E. risticii-infected horses (Potomac horse fever) and from infected cell cultures. A specific primer pair, selected from a cloned, species-specific, 1-kb DNA fragment of the E. risticii genome as a template, was used for the amplification of the target DNA of 247 bp. The optimal number of 40 PCR cycles, determined by analyzing an amplification profile obtained with a constant Taq polymerase concentra...
O'Grady SE, Poupard DA.Adherence to the basic principles of physiologic horseshoeing is essential to maintaining hoof health and soundness. Most horses do not require special trimming or shoeing techniques. Becoming familiar with a few basic concepts can help the veterinarian to recognize when changes in trimming or shoeing might be expected to help the performance of a sound horse or might help to restore the performance of one that is lame. Sound physiologic horseshoeing can only be achieved by a thorough knowledge of, strict adherence to, and skillful application of basic principles, such as hoof angle, HPA, and ...
Wickler SJ, Hoyt DF, Cogger EA, Myers G.Two studies have focused on potential triggers for the trot-gallop transition in the horse. One study concluded that the transition was triggered by metabolic economy. The second study found that it was not metabolic factors but, rather, peak musculoskeletal forces that determine gait transition speeds. In theory, peak musculoskeletal forces should be the same when trotting up an incline as when trotting at the same speed on the level. Assuming this is the case, we hypothesized that if peak forces determine gait transition speeds then horses should switch from a trot to a gallop at the same sp...