"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.
Gilger BC, Stoppini R, Wilkie DA, Clode AB, Pinto NH, Hempstead J, Gerding J, Salmon JH.To describe the use of episcleral silicone matrix cyclosporine (ESMC) drug delivery devices in horses with immune-mediated keratitis (IMMK) with evaluation of tolerability and efficacy in long-term control of inflammation. Methods: Retrospective study. ESMC implants (1.2 cm length, 30% wt/wt cyclosporine (CsA) in silicone; with approximately 2 μg/day steady-state release for at least 400 days) were used. Results: Nineteen horses (20 eyes) received two or more ESMC implants for superficial stromal (n = 9), midstromal (n = 3), or endothelial (n = 5) IMMK. Three additional horses received two or...
Marjamäki PH, Contasti AL, Coulson TN, McLoughlin PD.Movement away from an area or social group in response to increasing density (density-dependent dispersal) is known for most species; why it evolves is fundamental to our understanding of ecology and evolution. However, we have yet to fully appreciate how individuals of varying conditions (e.g., age and sex) might differently consider effects of density (quorum) when deciding to disperse or not, and scale dependence in their sense of quorum. We tracked movements of all individuals of a naturalized population of feral horses (Equus ferus caballus; Sable Island National Park Reserve, Nova Scotia...
Rumpler MJ, Kandala B, Vickroy TW, Hochhaus G, Sams RA.Glycopyrrolate (GLY) is an antimuscarinic agent that is used in humans and domestic animals primarily to reduce respiratory tract secretions during anesthesia and to reverse intra-operative bradycardia. Although GLY is used routinely in veterinary patients, there is limited information regarding its pharmacokinetic (PK) and pharmacodynamic (PD) properties in domestic animals, and an improved understanding of the plasma concentration-effect relationship in racehorses is warranted. To accomplish this, we characterize the pharmacokinetic-pharmacodynamic (PK-PD) actions of GLY during and after a 2...
Peacock RE, Smart L.A dog was presented for acute abdominal distension after inadvertent access to a large amount of dry dog food and possibly horse feed consisting of chaff, pony cubes and vitamin, mineral and yeast supplements. Results: A marked hyperchloraemia and decreased anion gap on blood electrolyte analysis prompted a review of the patient's history for potential ingestion of bromide. It was revealed that the horse feed was supplemented with potassium bromide. The serum bromide level was 23.6 mmol/L. The dog recovered uneventfully. Conclusions: This case report highlights the importance of knowing common...
Schauer SN, Sontakke SD, Watson ED, Esteves CL, Donadeu FX.Previous evidence from in vitro studies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle...
König von Borstel U, Bernhard V.The objective of this study was to compare the impact of health disorders and reasons for culling on the functional and biological longevity of warmblood breeding stallions using semi-parametric survival analysis accounting for competing risks. Complete breeding records were collected from 455 warmblood stallions serving between 1975 and 2010 at Marbach State Stud in Germany. The median length of life (18.0 years) was twice as long as the median length of service (9.0 years). However, both figures increased significantly over the time period examined (e.g., functional longevity increased from ...
Coleman SJ, Zeng Z, Hestand MS, Liu J, Macleod JN.Sequencing of equine mRNA (RNA-seq) identified 428 putative transcripts which do not map to any previously annotated or predicted horse genes. Most of these encode the equine homologs of known protein-coding genes described in other species, yet the potential exists to identify novel and perhaps equine-specific gene structures. A set of 36 transcripts were prioritized for further study by filtering for levels of expression (depth of RNA-seq read coverage), distance from annotated features in the equine genome, the number of putative exons, and patterns of gene expression between tissues. From ...
Donadeu FX, Schauer SN.Relatively little is known about the physiological roles of microRNAs (miRNAs) during follicular development. Previous evidence from in vitro studies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to gain insight on the involvement of these miRNAs during follicle maturation. Follicular fluid was aspirated from dominant follicles (>32 mm) during the ovulatory season (July to October) and the anovulatory season (January to M...
Brinkschulte M, Bienert-Zeit A, Lüpke M, Hellige M, Staszyk C, Ohnesorge B.The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three-dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2-25 years, were analyzed by the use of separate semi-automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris ros...
Théon AP, Pusterla N, Magdesian KG, Wilson WD.There is no information on the use of doxorubicin in horses with tumors. Objective: To determine dose-limiting toxicosis (DLT) and maximum tolerated dose (MTD) of doxorubicin in tumor-bearing horses. Methods: Seventeen horses with 34 localized or multicentric advanced tumors. Methods: Two-stage dose-ranging design involving intrapatient and interpatient dose escalation. Treatment protocol included 6 treatment cycles given at 3-week intervals with dosages ranging from 40 to 85 mg/m(2). Clinical signs, hematologic, and nonhematologic changes were evaluated. Results: Total doses ranged from 1,127...
Ninomiya S, Anjiki A, Nishide Y, Mori M, Deguchi Y, Satoh T.In stabled horses, behavioral responses to frustration are often observed, especially around feeding time. These behavioral responses are a useful indicator of their welfare. In this study, we investigated the association between this behavioral indicator and DRD4 gene polymorphisms in stabled horses. Twenty one horses housed in two stables were used. The horses were observed for approximately 4 h around feeding over three or more days using focal-sampling and instantaneous-sampling. Horses were genotyped for the A-G substitution in the DRD4 gene. The effects of the A-G substitution (with or w...
Ghosh S, Taniguchi K, Aida S, Ganesh B, Kobayashi N.Equine group A rotaviruses (RVA) are a major cause of severe diarrhea in foals. The whole genomes of only six common and three unusual equine RVA strains have been analyzed so far. To date, there are no reports on whole genomic analyses of equine RVAs from Asian countries. We report here the whole genomic analyses of three common (strains RVA/Horse-tc/JPN/BI/1981/G3P[12], RVA/Horse-tc/JPN/HH-22/1989/G3P[12] and RVA/Horse-tc/JPN/CH-3/1987/G14P[12]) and an unusual (RVA/Horse-tc/JPN/OH-4/1982/G6P[5]) equine RVA strains isolated from diarrheic foals in Japan. Strains BI, HH-22 and CH-3 shared a la...
Pereira GR, Lorenzo PL, Carneiro GF, Ball BA, Bilodeau-Goeseels S, Kastelic J, Pegoraro LM, Pimentel CA, Esteller-Vico A, Illera JC, Granado GS....The objectives of this study were to evaluate the effects of equine growth hormone (eGH) on nuclear and cytoplasmic maturation of equine oocytes in vitro, steroid production by cumulus cells, and expression and subcellular localization of eGH-receptors (eGH-R) on equine ovarian follicles. Cumulus-oocyte complexes (COCs) were recovered by aspirating follicles <30 mm in diameter from abattoir-derived ovaries. The COCs were morphologically evaluated and randomly allocated to be cultured in either a control maturation medium or supplemented with 400 ng/mL eGH, for 30 h at 38.5°C in air with 5%...
Nieto JE, Maher O, Stanley SD, Larson R, Snyder JR.To determine the effects of domperidone on in vivo and in vitro measures of gastrointestinal tract motility and contractility in healthy horses. Methods: 18 adult horses and tissue samples from an additional 26 adult horses. Methods: Domperidone or placebo paste was administered to healthy horses in a 2-period crossover study. Gastric emptying was evaluated after oral administration of domperidone paste (1.1 or 5.0 mg/kg) or placebo paste by means of the acetaminophen absorption test in 12 horses. Frequency of defecation, weight of feces produced, fecal moisture, and stomach-to-anus transit ti...
Ferreira TH, Brosnan RJ, Shilo-Benjamini Y, Moore SB, Hollingsworth SR.To assess the effects of ketamine hydrochloride, propofol, or compounded thiopental sodium administration on intraocular pressure (IOP) and qualities of induction of and recovery from anesthesia in horses. Methods: 6 healthy adult horses. Methods: Horses were sedated with xylazine hydrochloride (0.5 mg/kg), and anesthesia was induced with guaifenesin followed by ketamine (2 mg/kg), propofol (3 mg/kg), or thiopental (4 mg/kg) in a crossover study with ≥ 1 week between treatments. For each horse, IOP in the right eye was measured with a handheld applanation tonometer before and after xylazine ...
Constable PD, Tinkler SH, Couëtil LL.To determine the degree of agreement between 2 analyzers for measurement of total CO₂ concentration (ctCO₂) in equine plasma. Methods: 6 healthy untrained horses, 6 trained Standardbreds undergoing a simulated race protocol, and 135 trained Standardbreds at a racetrack. Methods: Jugular venous blood samples were obtained from all horses. Two analyzers (commonly used analyzer A and less expensive analyzer B) were used to measure plasma ctCO₂ in each sample. Validation of both analyzers was conducted in accordance with guidelines established by the Clinical and Laboratory Standards Institu...
Lallemand E, Trencart P, Tahier C, Dron F, Paulin A, Tessier C.To evaluate pharmacokinetic-pharmacodynamic variables and local tolerance at injection-site of marbofloxacin administered via regional intravenous limb perfusion (RIVLP) in standing horses. Methods: Adult horses (n = 6). Methods: RIVLP were performed with rubber tourniquets applied to the forelimbs of standing sedated horses. Marbofloxacin (0.67 mg/kg) was randomly injected in 1 forelimb, with the contralateral limb serving as a control (0.9% NaCl solution). Samples of jugular blood and synovial fluid from the radiocarpal joint of the marbofloxacin-perfused limb were collected before and...
Muniz E, Lobo Ladd AA, Lobo Ladd FV, da Silva AA, Kmit FV, Borges AS, Teixeira R, da Mota LS, Belli CB, de Zoppa AL, da Silva LC, de Melo MP, Coppi AA.Ileocolonic aganglionosis (ICA) is the congenital and hereditary absence of neurons that constitute the enteric nervous system and has been described in various species including humans - Hirschsprung's disease - and horses - overo lethal white syndrome (OLWS). Hirschsprung's disease affects circa 1 in 5,000 live births. At best, this disease means an inability to absorb nutrients from food (humans). At worse, in horses, it always means death. Despite our general understanding of the functional mechanisms underlying ICA, there is a paucity of reliable quantitative information about the structu...
Ziegler U, Angenvoort J, Klaus C, Nagel-Kohl U, Sauerwald C, Thalheim S, Horner S, Braun B, Kenklies S, Tyczka J, Keller M, Groschup MH.West Nile virus (WNV) is a mosquito-borne viral pathogen of global importance and is considered to be the most widespread flavivirus in the World. Horses, as dead-end hosts, can be infected by bridge mosquito vectors and undergo either subclinical infections or develop severe neurological diseases. The aim of this study was to detect WNV specific antibodies in horses in Germany as an indicator for an endemic circulation of WNV. Sera from more than 5,000 horses (primarily fallen stock animals) were collected in eight different federal states of Germany from 2010 to 2012. Sera were screened by a...
McCluskey BJ, Pelzel-McCluskey AM, Creekmore L, Schiltz J.Vesicular stomatitis is a viral disease primarily affecting horses and cattle when it occurs in the United States. Outbreaks in the southwestern United States occur sporadically, with initial cases typically occurring in Texas, New Mexico, or Arizona and subsequent cases occurring in a northward progression. The viruses causing vesicular stomatitis can be transmitted by direct contact of lesioned animals with other susceptible animals, but transmission is primarily through arthropod vectors. In 2012, an outbreak of vesicular stomatitis in the United States occurred that was caused by Vesicular...
Gordon ME, Edwards MS, Sweeney CR, Jerina ML.The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeas...
Olsen E, Pfau T, Ritz C.Over ground motion analysis in horses is limited by a small number of strides and restraints of the indoor gait laboratory. Inertial measurement units (IMUs) are transforming the knowledge of human motion and objective clinical assessment through the opportunity to obtain clinically relevant data under various conditions. When using IMUs on the limbs of horses to determine local position estimates, conditions with high dynamic range of both accelerations and rotational velocities prove particularly challenging. Here we apply traditional method agreement and suggest a novel method of functional...
Back H, Nyman A, Osterman Lind E.A case-control study was performed to investigate the association between colic of all types in Swedish horses and infection with the equine tapeworm Anoplocephala perfoliata. Colic cases were defined by clinical signs consistent with the presence of abdominal pain, and the control horses had no signs of colic within the last year but attended a clinic for other reasons. Blood and fecal samples were collected by veterinarian from 67 horses with signs of colic and 67 control horses. The sera were analyzed using serodiagnostic assay anti-12/13 kDa IgG(T) ELISA. The fecal samples, 30 g from each ...
Pawlak EA, Geor RJ, Watts MR, Black SJ, Johnson PJ, Belknap JK.Hypoxia-inducible factor-1α (HIF-1A) is an important protein in the regulation/induction of many genes in the cellular and tissue response to hypoxia and a central mediator in inflammatory signalling. As both hypoxia and inflammatory events are purported to occur in the lamellar epidermis in sepsis-related laminitis in the equid, HIF-1A may play a central role in this disease process. Objective: To assess the regulation of HIF-1A and HIF-1A-related genes in the equine keratinocyte in vitro and in the lamellar tissue of horses with sepsis-related laminitis. Methods: In vivo and in vitro experi...
Teixeira RB, Rendahl AK, Anderson SM, Mickelson JR, Sigler D, Buchanan BR, Coleman RJ, McCue ME.Both graying and melanoma formation in horses have recently been linked to a duplication in the STX17 gene. This duplication, as well as a mutation in the ASIP gene that increases MC1R pathway signaling, affects melanoma risk and severity in gray horses. Objective: To determine if melanoma susceptibility in gray Quarter Horses (QH) is lower than gray horses from other breeds because of decreased MC1R signaling resulting from a high incidence of the MC1R chestnut coat color allele in the QH population. Methods: A total of 335 gray QH with and without dermal melanomas. Methods: Blood or hair roo...
Townsend WM, Langohr IM, Mouney MC, Moore GE.Based on the current literature, neither medical, surgical nor combination therapy adequately controls equine glaucoma for many horses. Aqueous shunts have been useful in other species to control glaucoma. Objective: To determine whether aqueous shunts in normal equine eyes significantly reduce intraocular pressure (IOP) without causing vision threatening complications. Methods: Prospective experimental trial. Methods: Aqueous shunts were placed in 7 normal eyes of 4 horses. The shunts were placed dorsotemporally. Examinations were initially performed daily for 7 days and after that every 3 da...
Knych HK, Harrison LM, Casbeer HC, McKemie DS.Methylprednisolone acetate (MPA) is commonly administered to performance horses, and therefore, establishing appropriate withdrawal times prior to performance is critical. The objectives of this study were to describe the plasma pharmacokinetics of MPA and time-related urine and synovial fluid concentrations following intra-articular administration to sixteen racing fit adult Thoroughbred horses. Horses received a single intra-articular administration of MPA (100 mg). Blood, urine, and synovial fluid samples were collected prior to and at various times up to 77 days postdrug administration a...
Taylor KG, Paessler S.Equine encephalids have high mortality rates and represent a significant zoonotic public health threat. Of these the most pathogenic viruses to equids are the alphaviruses in the family Togaviridae. The focus of this review Venezualen equine encephalitis virus (VEEV) has caused the most widespread and recent epidemic outbreaks of disease. Circulation in naturally occuring rodent-mosquito cycles, results in viral spread to both human and equine populations. However, equines develop a high titer viremia and can transmit the virus back to mosquito populations. As such, the early recognition and c...
Zhang J, Wu M, Ma Z, Zhang Y, Cao H.Donkey-hide gelatin is an important traditional Chinese medicine made from donkey skin. Despite decades of effort, identifying the animal materials (donkeys, horses, cattle and pigs) in donkey-hide gelatin remains challenging. In our study, we aimed to identify marker peptides of donkey-hide gelatin and its adulterants and develop a liquid chromatography-tandem mass spectrometry method to identify them. Theoretical marker peptides of four animals (donkeys, horses, cattle and pigs) were predicted and verified by proteomic experiments, and 12 species-specific marker peptides from donkey-hide gel...
Gerhardt R.The accidental introduction of West Nile Virus into New York City from the Old World in 1999 resulted in an epidemic in humans, horses, and birds that swept to the west coast in just 3 years. The virus is transmitted by infective mosquitoes among susceptible native birds, which serve as amplifying hosts. Clinical disease occurs in humans and horses, but not enough virus is produced in their blood to infect other mosquitoes; therefore, humans and horses are considered dead-end hosts. Humans can best protect themselves by remaining indoors during periods of high mosquito activity and/or by using...
Scott GS, Crawford WH, Colahan PT.To determine arthroscopic findings in lame horses with subtle radiographic lesions of the medial femoral condyle. Methods: Retrospective study. Methods: 15 horses examined because of lameness that had subtle radiographic evidence of osteochondral lesions involving the medial femoral condyle in at least 1 joint. Methods: Medical records were reviewed, and results of physical examination, radiography, and arthroscopy were recorded. Follow-up information was obtained through reexamination of the horses or telephone conversations with the referring veterinarians, owners, or trainers. Results: Lame...
Falcão MVD, Laroucau K, Vorimore F, Deshayes T, Santana VLA, Silva KPC, do Nascimento SA, de Castro RS, Araújo FR, Mota RA.Glanders is an infectious zoonosis caused by Burkholderia (B.) mallei that mainly affects equids. The objective of this work was to provide additional knowledge on the diversity of the strains circulating in Brazil. Six Burkholderia mallei isolates obtained during necropsies of glanderous horses between 2014 and 2017 in two different states (Pernambuco and Alagoas) were analyzed by polymerase chain reaction-high-resolution melting (PCR-HRM). While four strains (9902 RSC, BM_campo 1, BM_campo 3 and UFAL2) clustered in the L3B2 branch, which already includes the Brazilian 16-2438_BM#8 strain, tw...
Gross I, Hadar A, Bala M, Hashavya S.Horse riding has become increasingly popular in recent years and is a common activity among children. As a result, pediatric horse-related injuries are frequently encountered in emergency departments. Objective: To examine the characteristics of horse-related injuries in the pediatric population. Methods: We collected and analyzed the data on all pediatric horse-related injuries presented to a tertiary hospital, level one trauma center, during the years 2006-2016. Results: A total of 53 children with horse-related injuries were documented. Forty-two patients were male (79%) and their mean age ...
Jiménez BLM, Elghandour MMMY, Adegbeye MJ, Tirado González DN, Tirado Estrada G, Salem AZM, Pacheco EBF, Pliego AB.In the race against deadly diseases, multiple drugs have been developed as a treatment strategy in livestock. Each treatment is based on a specific mechanism to find a suitable drug. Antibiotics have become a fundamental part of the equine industry to treat bacterial diseases. These antibiotics have specific doses and side effects, and understanding each parameter allows veterinarians to avoid or limit the adverse effects of such drugs. Use of antibiotics causes microbial imbalance, decreased microbial diversity and richness in both cecal and fecal samples. Antibiotics reduced metabolites prod...
Tiago G, Júlio C, António R.Pseudomonas aeruginosa may cause venereal disease and infertility in horses. A Pseudomonas aeruginosa - carrier stallion, often unresponsive to artificial vagina collection, was used to naturally breed mares. Semen collected from the same stallion was also used to perform artificial inseminations. Pregnancy rates, embryo quality and incidence of uterine infection were compared between inseminated or naturally-bred mares. Methods: P. aeruginosa was isolated from swabbing of the penis, prepuce and distal urethra of the stallion. Before being bred or inseminated, clitoral/vestibular samples were ...
Macon EL, Harris P, Bailey S, Caldwell Barker A, Adams A.Identifying intake levels of nonstructural carbohydrates (NSCs) that limit the postprandial insulinaemic response in the insulin dysregulated (ID) horse may help reduce hyperinsulinaemia-associated laminitis (HAL) risk. Objective: To determine if ID horses have thresholds for pure sources of starch and sugar, above which there is an augmented insulin response. Methods: Randomised crossover experiment. Methods: Fourteen adult horses (6 ID and 8 noninsulin dysregulated, NID; matched for bodyweight) were randomly fed eight dietary treatments. Dietary treatments were formulated using a base of low...
Netherwood T, Binns M, Townsend H, Wood JL, Mumford JA, Chanter N.During a survey of foal diarrhoea between 1991 and 1994, Clostridium perfringens was significantly associated with disease with 56% of cases infected [1]. The contribution of enterotoxigenic C. perfringens to this association, was assessed by use of the reverse passive latex agglutination test for enterotoxin (RPLA; Oxoid Unipath) and vero cell toxicity neutralized by antitoxin on stored faecal samples and sporulated faecal isolates of C. perfringens. Polymerase chain reaction (PCR1) based on the DNA sequence for the whole enterotoxin gene [2] yielded a fragment from an equine isolate of the a...
Kellon EM, Gustafson KM.Hyperinsulinemia associated with equine metabolic syndrome and pituitary pars intermedia dysfunction is a risk factor for laminitis. Research in other species has shown elevated body iron levels as both a predictor and consequence of insulin resistance. In humans, this is known as dysmetabolic hyperferritinemia. To explore the relationship between equine hyperinsulinemia and body iron levels. We reviewed case histories and laboratory results from an open access database maintained by the Equine Cushing's and Insulin Resistance Group Inc. (ECIR). We identified 33 horses with confirmed hyperinsu...
Ayala-Valdovinos MA, Lemus-Flores C, Galindo-García J, Bañuelos-Pineda J, Rodríguez-Carpena JG, Sánchez-Chiprés D, Duifhuis-Rivera T.Theileria equi infection prevalence was calculated from 1000 blood samples obtained from apparently healthy horses in western Mexico. Samples were sent to the Animal Biotechnology Laboratory of the University of Guadalajara (Mexico) for T. equi diagnosis. Nested polymerase chain reaction (nPCR) was used as a diagnostic method to detect pathogen DNA. Using primers for the merozoite antigen-1 (EMA-1) gene, 19.70±2.47% of the horses (95% CI, 17.23-22.17%) tested positive for T. equi. There was no significant association between gender and T. equi infection. However, prevalence was higher among s...
Hasebe R, Kimura T, Nakamura K, Ochiai K, Okazaki K, Wada R, Umemura T.Equine herpesvirus 1 (EHV-1) shows endotheliotropism in the central nervous system (CNS) of infected horses. However, infection of endothelial cells has not been observed in the CNS of infected mice. To explore the basis for this difference in endotheliotropism, we compared the susceptibility of equine brain microvascular endothelial cells (EBMECs) and mouse brain microvascular endothelial cells (MBMECs) to EHV-1 infection. The kinetics of viral growth in EBMECs was typical of a fully productive infection whereas viral infection in MBMECs seemed to be nonproductive. Immunofluorescence microsco...
Negro Rama S, Valera M, Membrillo A, Gómez MD, Solé M, Menendez-Buxadera A, Anaya G, Molina A.The association of five candidate genes with sporting performance in young and adult Spanish Trotter horses (STHs) was performed according to a previous selection based on quantitative analysis of the trait time per kilometre (TPK). A total of 334 516 records of TPK from 5958 STHs were used to estimate the estimated breeding values (EBVs) at different age groups (young and adults horses) throughout the range of distances (1600-2700 m) using a bicharacter random regression model. The heritability estimated by distance ranged from 0.16 to 0.40, with a different range for the two age groups. Co...
Hurcombe SD, Fox JG, Kohn CW.A 2-year-old quarterhorse was evaluated for chronic diarrhea and weight loss of 5 weeks duration after numerous diagnostic tests failed to identify an underlying cause. Historically, the horse was housed at pasture where human household waste vehicles were routinely cleaned and the effluent could run onto the field. Physical examination revealed poor body condition and frequent high-volume diarrhea. Diagnostic testing for Salmonella spp., endoparasites, Cryptosporidium spp., Clostridium spp., and diffuse infiltrative bowel disease were negative. Rectal tissue histopathology failed to identify ...
Elbrønd VS, Thomsen MB, Isaksen JL, Lunde ED, Vincenti S, Wang T, Tranum-Jensen J, Calloe K.The Purkinje fibers convey the electrical impulses at much higher speed than the working myocardial cells. Thus, the distribution of the Purkinje network is of paramount importance for the timing and coordination of ventricular activation. The Purkinje fibers are found in the subendocardium of all species of mammals, but some mammals also possess an intramural Purkinje fiber network that provides for relatively instantaneous, burst-like activation of the entire ventricular wall, and gives rise to an rS configuration in lead II of the ECG. To relate the topography of the horse heart and the dis...
Knottenbelt DC, Hetzel U, Roberts V.A 14-year-old gray gelding was presented for investigation of a visible, pale-colored ocular mass in the right eye. An intraocular mass was identified clinically and ultrasonographically as originating from the superior nasal quadrant of the ciliary body and retina. The mass occupied the majority of the vitreous chamber and some of the superior anterior chamber of the eye. The affected eye was blind. Following exenteration, a primary intraocular primitive neuroectodermal tumor (i.e. a retinoblastoma/medulloepithelioma), a rarely described intraocular mass in adult horses, was identified by pat...
Bernard WV, Bolin C, Riddle T, Durando M, Smith BJ, Tramontin RR.Leptospirosis was documented as the cause of abortion in a 5-year-old mare. Leptospires were detected in tissue specimens from fetal kidneys and from placenta by histologic evaluation of silver-stained sections. Antibodies against Leptospira interrogans serovar pomona were detected in fetal serum at a titer of 1,600 by use of a microscopic agglutination test. The mare had serum titers of 6,400; 0; 400; 800; 3,200; and 6,400 to L interrogans serovars bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona, respectively. A serologic survey identified titers of at least 6,400...
Russell KE, Perkins PC, Hoffman MR, Miller RT, Walker KM, Fuller FJ, Sellon DC.Thrombocytopenia is a consistent finding and one of the earliest hematological abnormalities in horses acutely infected with equine infectious anemia virus (EIAV), a lentivirus closely related to human immunodeficiency virus. Multifactorial mechanisms, including immune-mediated platelet destruction and impaired platelet production, are implicated in the pathogenesis of EIAV-associated thrombocytopenia. This study was undertaken to investigate whether regenerative thrombopoiesis and platelet destruction occurred in ponies acutely infected with EIAV. Circulating large, immature platelets were in...
Bouhali O, Bensmail H, Sheharyar A, David F, Johnson JP.Great advances have been made in human health care in the application of radiomics and artificial intelligence (AI) in a variety of areas, ranging from hospital management and virtual assistants to remote patient monitoring and medical diagnostics and imaging. To improve accuracy and reproducibility, there has been a recent move to integrate radiomics and AI as tools to assist clinical decision making and to incorporate it into routine clinical workflows and diagnosis. Although lagging behind human medicine, the use of radiomics and AI in veterinary diagnostic imaging is becoming more frequent...
Clouser JM, Swanberg JE, Bundy H.Although farm management may understand agriculture's risks, they may not provide personal protective equipment (PPE). This study describes thoroughbred farm management's risk perceptions, provision of PPE, and factors that influence its provision. Methods: Thirty-five representatives from 26 farms participated in a 1-4hr semi-structured interview covering perceived risks associated with horse work and perspectives and provision of PPE. Interviews were audio-recorded, transcribed, entered into ATLAS.ti, and analyzed by three coders. Results: Management cited horse-related tasks as most dangero...
Canisso IF, Gallacher K, Gilbert MA, Korn A, Schweizer CM, Bedford-Guaus SJ, Gilbert RO.The major objective of this study was to determine whether short-term preovulatory progestagen treatment of mares could effectively delay ovulation. Secondary objectives were to determine the effect such supplementation had on signs of estrus, follicular growth, postovulatory luteal function and pregnancy rate. Thirteen cyclic mares of different breeds were used in this study during the natural breeding season. Once mares were confirmed in estrus with a follicle of 35 mm in diameter, they were assigned in random order to receive no treatment (control), placement of a progesterone-impregnated c...
Gold JR, Grubb TL, Cox S, Malavasi L, Villarino NL.The repeated administration of high doses of gabapentin may provide better analgesia in horses than current clinical protocols. Objective: Administration of gabapentin at 40 and 120 mg/kg PO q 12 h for 14 days will not alter serum biochemistry findings or cause adverse effects. Our objectives were to evaluate the effect of gabapentin on serum biochemistry, physical examination, and plasma pharmacokinetics of gabapentin. Methods: Six healthy adult mares. Methods: Horses received 40 and 120 mg/kg of gabapentin orally q 12 h for 14 days. Horses were examined and scored for ataxia and ...
Rush BR, Worster AA, Flaminio MJ, Matson CJ, Hakala JE.To determine alteration in adrenocortical function in horses with recurrent airway obstruction (heaves) after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively. Methods: 6 horses with inducible and reversible heaves. Methods: Episodes of heaves were induced by exposure to moldy hay and straw for 7 days (natural challenge). Horses then underwent treatment (aerosolized beclomethasone, parenterally administered dexamethasone, and aerosolized propellant) for 7 days. Horses remained in the mold-contaminated environment for 7 days after discontinuat...
Carpio MM, Iversen JO.Leptospira interrogans serotype pomona antibody titres of 1:100 or greater were detected in 12.8% of 408 adult horses from seven of eight sampled herds in Saskatchewan. The geographical distribution of the seropositive horses was widespread throughout the agricultural area of the province. The geographical distribution and the cumulative increase in prevalence with age suggested that serotype pomona is enzootic in the equine population of Saskatchewan.
Power MM.Two unrelated chromosome abnormalities were found in equine half sibs. The proposita, Case 1, which was short in stature and infertile, had a de novo unbalanced X;15 translocation involving loss of Xp. Replication studies indicated that the translocated X was preferentially late replicating and that this late replication spread variably into the autosomal segment. Case 2, a half brother of the proposita, was short in stature, had cryptorchidism, and was trisomic for chromosome 28. Cytogenetic analysis of the dam, the sire of Case 1, and two other phenotypically normal half sibs revealed normal...
Shingleton WD, Mackie EJ, Cawston TE, Jeffcott LB.Cartilage canals have been described in most mammals and contain the vascular elements necessary for the maintenance of epiphyseal growth cartilage. The presence and longevity of cartilage canals in developing articular/epiphyseal cartilage of horses is described for the first time. Growth cartilages from 30 normal horses (from 130 days gestation to age 2 years) and 6 cases of dyschondroplasia (age 6 months. Cartilage canals were associated with retained cartilage of dyschondroplastic lesions found in animals age < 15 months. The presence of cartilage canals in association with dyschondrop...
Semevolos SA, Nixon AJ, Fortier LA, Strassheim ML, Haupt J.The purpose of this study was to determine changes in the expression of regulatory molecules in normal equine articular cartilage throughout development up to 18 months of age. The hypothesis was that expression of these regulatory molecules would decrease from birth to postpubescence. Cartilage was harvested from normal femoropatellar or scapulohumeral joints from 34 fresh horse cadavers. Horses were placed in four age groups [prenatal (n = 5); prepubertal, 0-6 months (n = 11); pubertal, 7-14 months (n = 13); and postpubertal, 15-18 months (n = 5)]. Indian hedgehog (Ihh), Gli1, Gli3, Patched1...
Goachet AG, Julliand V.Measurements of respiratory exchanges in genuine exercise conditions are undoubtedly of interest to further define the energy needs of endurance horses. However, the equine K4b2, the gas exchanges portable device validated for equines, has not been used in Arabian endurance horses yet. Therefore, the objective of this study was to implement field cardio-respiratory measurements in such horses using the equine K4b2 in order to assess energy expenditure (EE). Measurements of heart rate (HR), oxygen uptake (VO2), carbon dioxide production (VCO2), respiratory frequency (RF), tidal volume (VT) and ...
