"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.
Dorph K, Haughan J, Robinson M, Redding LE.To characterize antimicrobial use on four racetracks in the eastern US during the peak racing 2017-2018 seasons. Handwritten daily treatment sheets provided by attending veterinarians who listed treatments administered to horses stabled at the racetrack were obtained. Information contained in the treatment sheets included the date, name of the horse and its trainer, type of treatment, and a brief (usually 1-word) indication for treatment. The handwritten data listed on the racetrack treatment sheets were manually transcribed and analyzed. A total of 2,684 antimicrobial prescriptions were recor...
Bravo-Barriga D, Serrano-Aguilera FJ, Barrasa-Rita R, Habela MÁ, Chacón RB, Ezquerra LJ, Martín-Cuervo M.Endurance is an increasingly popular equestrian sport. However, in southern Europe, there is a high prevalence of horses that are asymptomatic carriers of equine piroplasmosis (EP), a tick-borne disease that could affect their performance. This study aimed to evaluate the impact and influence of EP on the performance of endurance horses. Blood samples were collected from 40 horses in Extremadura, Spain, before and after a race, in different national elite horse endurance competitions. Hematological and biochemical parameters and EP seroprevalence were analysed by competitive enzyme-linked immu...
Belotta AF, Mayer MN, Waldner CL, Sidhu NP, Robinson KA, Carmalt JL, Freitas FP, Koehncke NK.The objectives of this study were to investigate scattered radiation doses to the hands of equine workers holding the cassette and the x-ray tube by hand, for both limb and vertebral column studies, and to compare the scattered radiation attenuation of lead with radiation protection lead-free gloves. Radiation doses to the hands of the cassette holder in the primary beam were also investigated. Methods: A whole-body horse cadaver. Methods: A portable x-ray unit was used to simulate 6 radiographic study types in the horse cadaver. Doses were measured with no shielding and, for cassette holders,...
Enke N, Brinkmann L, Südekum KH, Tholen E, Gerken M.Horses lose high amounts of Na through excessive sweating. These fluid losses can often not be replaced completely by voluntary water intake, requiring saline solutions as rehydration therapy to regain electrolyte balance. The experiment aimed to evaluate the sensitivity and tolerance of Shetland ponies towards different Na concentrations in their drinking water and contained three phases: (1) control: only fresh water provided; (2) pairwise-preference test: choice between fresh water and saline solution with stepwise increasing sodium chloride (NaCl) concentration (0.25%, 0.5%, 0.75%, 1.0%, 1...
Uldahl M, Bundgaard L, Dahl J, Clayton HM.This study addresses the presence and location of natural pigmentation, potentially pathological changes in pigment, interruptions of the natural lining (scars), roughness, and erosions/contusion (bruising) in and around the corners of the lips of 206 horses presented to a veterinarian for routine preventative dental treatment. After sedation, photographs were taken and later evaluated for the presence of lesions. During the photographic analysis, the Oral Commissure Assessment (OCA) protocol was developed to map precisely the areas of skin and mucosa around the corners of the lips, and the pr...
Derisoud E, Auclair-Ronzaud J, Palmer E, Robles M, Chavatte-Palmer P.Although puberty can occur as early as 14-15months of age, depending on breed and use, the reproductive career of mares may continue to advanced ages. Once mares are used as broodmares, they will usually produce foals once a year until they become unfertile, and their productivity can be enhanced and/or prolonged through embryo technologies. There is a general consensus that old mares are less fertile, but maternal age and parity are confounding factors because nulliparous mares are usually younger and older mares are multiparous in most studies. This review shows that age critically affects c...
Jurek KA, Schoonover MJ, Williams MR, Rudra P.To determine the influence of perfusate volume on synovial fluid amikacin concentrations in the joints of the hind limb after standing saphenous intravenous regional limb perfusion (IVRLP). Methods: Randomized crossover design. Methods: Six adult horses. Methods: Saphenous IVRLP was performed in 6 standing horses with 1 g of amikacin diluted with 0.9% NaCl to volumes of 10 ml, 60 ml, and 120 ml. Samples of synovial fluid from the tarsocrural, metatarsophalangeal, and hind limb distal interphalangeal joints were collected at 15 and 30 min after perfusate administration. Concentrations ...
Uldahl M, Bundgaard L, Dahl J, Clayton HM.This study addresses the presence and location of oral lesions in 342 dressage, show jumping, and eventing horses examined at an obligatory veterinary inspection before competing in the Danish National Championship in 2020. Ulcers in the lip commissures were photographed for subsequent pathological analysis. If a lesion was found at the lip commissures on one side, there was an increased risk of finding a similar lesion on the other side (ulcer: p < 0.0001; scarring/depigmentation: p < 0.0001; fissure: p = 0.002; erosion/contusion: p < 0.0001). At the lip commissures, external (cutaneous) ulce...
Russi RC, Garcia L, Cámara MS, Soutullo AR.Equine infectious anaemia (EIA) is controlled by the identification of seropositive animals. The official diagnostic method is the agar gel immunodiffusion (AGID) test, which detects antibodies against a viral core protein (p26). Although AGID is inexpensive and specific, the report of results takes considerable time and the test has low analytical sensitivity. Objective: To validate our in-house indirect ELISA , following the World Organization of Animal Health (OIE) criteria. Methods: Test validation. Methods: Synthetic peptides gp90 and gp45 were used as antigens in ELISA . Tests used for v...
Tong P, Duan R, Palidan N, Deng H, Duan L, Ren M, Song X, Jia C, Tian S, Yang E, Kuang L, Xie J.EHV-1 is one of the most serious viral pathogens that frequently cause abortion in horses around the world. However, so far, relatively little information is available on EHV-1 infections as they occur in China. In January 2021, during an abortion storm which occurred in Yili horses at the Chinese State Studs of Zhaosu (North Xinjiang, China), 43 out of 800 pregnant mares aborted. Results: PCR detection revealed the presence of EHV-1 in all samples as the possible cause of all abortions, although EHV-4, EHV-2 and EHV-5 were also found to circulate in the aborted fetuses. Furthermore, the parti...
Hall S, Smith R, Ramzan PHL, Head M, Robinson N, Parker R.Rib fractures in adult horses are poorly documented. Objective: To describe the presenting signs, diagnosis, treatment and outcome of horses diagnosed with rib fracture. Methods: Retrospective case series. Methods: The clinical records and diagnostic images of all adult horses diagnosed with a rib fracture at three referral centres over a 15-year period were reviewed. Results: Seventy-three horses met the inclusion criteria. Horses presented due to either resistance to ridden work and poor performance (n = 41), lameness (n = 21) or trauma (n = 7). In four horses, the presenting complaint...
Viljanto M, Kaabia Z, Taylor P, Muir T, Habershon-Butcher J, Bailly-Chouriberry L, Scarth J.Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. However, in certain situations, it is endogenous or is believed to be formed by microbes in urine, and therefore, an approach for the differentiation is required. Following the identification of Δ1-progesterone and 20(S)-hydroxy-Δ1-progesterone as potential biomarkers of microbial activity, the presence of six steroids was investigated in the postrace urine of castrated male horses (geldings, n = 158). In line with endogenous findings from several other species when ultrasensitive methods are employed, bolde...
Lawton KOY, Arthur RM, Moeller BC, Barnum S, Pusterla N.More and more studies are reporting on the natural transmission of SARS-CoV-2 between humans with COVID-19 and their companion animals (dogs and cats). While horses are apparently susceptible to SARS-CoV-2 infection based on the homology between the human and the equine ACE-2 receptor, no clinical or subclinical infection has yet been reported in the equine species. To investigate the possible clinical role of SARS-CoV-2 in equids, nasal secretions from 667 horses with acute onset of fever and respiratory signs were tested for the presence of SARS-CoV-2 by qPCR. The samples were collected from...
Biedrzycki AH, Morton AJ, Perez-Jimenez EE, Elane GL, Roe HA, Trolinger-Meadows KD.To report the technique, surgical approach, and postoperative features in horses treated via a 3-dimensional (3D) printed guide-assisted keratoma resection created using computed tomography (CT) or magnetic resonance imaging (MRI)-based segmentation. Methods: Five client-owned horses. Methods: Short case series. Methods: Horses were placed under general anesthesia for imaging (CT and MRI) and underwent a second anesthesia for surgery. Two horses had guides created from CT-based imaging, 3 horses had guides created from MRI. Various sized nonarbored hole saws were used to create accurate and pr...
Yamada T, Aoi S, Adachi M, Kamimura T, Higurashi Y, Wada N, Tsuchiya K, Matsuno F.Horses use the transverse gallop in high-speed running. However, different animals use different gaits, and the gait preference of horses remains largely unclear. Horses have fore-aft asymmetry in their body structure and their center of mass (CoM) is anteriorly located far from the center of the body. Since such a CoM offset affects the running dynamics, we hypothesize that the CoM offset of horses is important in gait selection. In order to verify our hypothesis and clarify the gait selection mechanisms by horses from a dynamic viewpoint, we developed a simple model with CoM offset and inves...
Winter JC, Thieme K, Eule JC, Saliu EM, Kershaw O, Gehlen H.Primary photosensitization rarely occurs in horses and can easily be misinterpreted. Descriptions of the disease in horses after ingestion of parsnip are lacking. The aim of this case series was to describe the dermatological and ocular changes due to photosensitization and to raise awareness of parsnip being a possible aetiologic agent. Methods: Nine horses from three different stables in Berlin and Brandenburg, Germany, presented variable degrees of erythema, scaling, crusting and necrosis of unpigmented skin at the head and prepuce. Horses were of different breeds with a median age of 15 ...
Jasiński T, Zdrojkowski Ł, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Domino M.Endometritis is an important issue decreasing mares' fertility. In the case of endometritis, both inflammatory cells infiltration and proinflammatory molecules production are regulated by various cellular and gene regulatory mechanisms, including the nuclear factor-κB (NF-κB)-dependent pathway. NF-κB-signalling pathway has been recently studied in the equine endometrium in the context of endometrosis. Thus, this study aimed to determine gene transcription of NF-κB subunits (RelA; NF-κB1; NF-κB2), proinflammatory molecules (MCP-1; IL-6) and hyaluronan synthases (HAS 1; HAS 2; HAS 3) in en...
Ang L, Vinderola G, Endo A, Kantanen J, Jingfeng C, Binetti A, Burns P, Qingmiao S, Suying D, Zujiang Y, Rios-Covian D, Mantziari A, Beasley S....Domesticated horses live under different conditions compared with their extinct wild ancestors. While housed, medicated and kept on a restricted source of feed, the microbiota of domesticated horses is hypothesized to be altered. We assessed the fecal microbiome of 57 domestic and feral horses from different locations on three continents, observing geographical differences. A higher abundance of eukaryota (p < 0.05) and viruses (p < 0.05) and lower of archaea (p < 0.05) were found in feral animals when compared with domestic ones. The abundance of genes coding for microbe-...
Annand EJ, Horsburgh BA, Xu K, Reid PA, Poole B, de Kantzow MC, Brown N, Tweedie A, Michie M, Grewar JD, Jackson AE, Singanallur NB, Plain KM, Kim K....We identified and isolated a novel Hendra virus (HeV) variant not detected by routine testing from a horse in Queensland, Australia, that died from acute illness with signs consistent with HeV infection. Using whole-genome sequencing and phylogenetic analysis, we determined the variant had ≈83% nt identity with prototypic HeV. In silico and in vitro comparisons of the receptor-binding protein with prototypic HeV support that the human monoclonal antibody m102.4 used for postexposure prophylaxis and current equine vaccine will be effective against this variant. An updated quantitative PCR dev...
Dyson S, Pollard D.The Ridden Horse Pain Ethogram (RHpE) was applied to 1010 competition starts at British Eventing (BE) 90, 100 and Novice one-day events and compared with performance. The overall median RHpE score was 4/24 (IQR 2,6; range 0,12). There were moderate positive correlations between RHpE scores and dressage penalties (Spearman’s rho = 0.508, 0.468, 0.491, all p < 0.001 for BE 90, 100 and Novice, respectively). There were weak positive correlations between RHpE scores and final placings (Spearman’s rho = 0.157, p = 0.033, BE90; rho = 0.263, p < 0.001, BE 100; rho = 0.123, p = 0.035, Novice). In ...
Júnior ÂMCA, da Silva AH, Bastos FL, Seidner JT, Filho LAJM, Faleiros RR, Gobesso AAO.This study evaluated the incidence of gastritis in foals subjected to different weaning management methods. Sixteen crossbreed foals [230 ± 35 kg], were enrolled in an experiment with a randomized block design. After weaning, foals were housed in either individual pens or a group pen. Gastritis in the foals was evaluated through gastroscopy. Data were submitted to analysis of variance by the non-parametric Friedman test at 0.05 significance level. Before weaning, gastritis was observed in 87.5% of the foals, and the scores for the number of gastric lesions were 2.10 and 1.56 for foals housed ...
José Antonio G, Jim S, Ramés SJ, Rohrbach BW, Alejandro Rodríguez M, Laura Romero R, Robert D.To examine changes occurring in normal pelvic suspensory ligaments (SLs) of horses after denervating these ligaments and to investigate the effect chronic inflammation might have on these changes. Methods: 10 horses. Methods: The SL of 1 randomly selected pelvic limb of each of 5 horses was injected with collagenase to induce desmitis, and 42 days later, the proximal aspect of both pelvic SLs were denervated. The SLs were harvested 120 days after being denervated, and the morphological and histological characteristics of each collagenase-injected, denervated SL were compared with those of the ...
Kaiser-Thom S, Gerber V, Collaud A, Hurni J, Perreten V.Many contributing factors are involved in the development of equine pastern dermatitis (EPD). Among the most frequently suspected is Staphylococcus aureus, known for its pathogenic potential in skin and soft tissue infections. We therefore investigated the association between S. aureus carriage and EPD. Results: One hundred five EPD-affected horses and 95 unaffected controls were examined for the presence of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA) on the pastern skin and in the nostrils. S. aureus isolates were cultivated from swab samples on selective MSSA...
Depuydt E, Broeckx SY, Chiers K, Patruno M, Da Dalt L, Duchateau L, Saunders J, Pille F, Martens A, Van Hecke L, Spaas JH.The use of mesenchymal stem cells (MSCs) for the treatment of equine tendon disease is widely investigated because of their regenerative and immunomodulatory potential. However, questions have been raised concerning the immunogenic properties of allogeneic MSCs. Therefore, two studies were conducted to assess the safety of equine allogeneic peripheral blood-derived tenogenic primed MSCs (tpMSCs). The objective was to evaluate if a single and repeated tpMSC administration induced a cellular and humoral immune response in horses suffering from tendon injuries. Horses enrolled in the first study ...
Bennell AJ, Wright RJH, Malalana F, Senior JM.Catastrophic fractures or luxations (FoL) sustained during recovery from general anesthesia are a significant cause of mortality during equine anesthesia. There is a lack of evidence regarding potential risk factors for a FoL occurring in the immediate anesthetic recovery period. A single center, retrospective, case-matched study was performed to identify risk factors for sustaining a catastrophic FoL during recovery from general anesthesia. Clinical data were obtained for horses which sustained a catastrophic FoL when recovering from general anesthesia from January 2011 to June 2020 in a sing...
Van Steenkiste G, Delhaas T, Hermans B, Vera L, Decloedt A, van Loon G.In human cardiology, the anatomical origin of atrial premature depolarizations (APDs) is derived from P wave characteristics on a 12-lead electrocardiogram (ECG) and from vectorcardiography (VCG). The objective of this study is to differentiate between anatomical locations of APDs and to differentiate APDs from sinus rhythm (SR) based upon VCG characteristics in seven horses without cardiovascular disease. A 12-lead ECG was recorded under general anaesthesia while endomyocardial atrial pacing was performed (800−1000 ms cycle length) at the left atrial free wall and septum, right atrial free ...
Van Steenkiste G, Delhaas T, Hermans B, Vera L, Decloedt A, van Loon G.In human cardiology, the anatomical origin of ventricular premature depolarizations (VPDs) is determined by the characteristics of a 12-lead electrocardiogram (ECG). Former studies in horses had contradictory results regarding the diagnostic value of the 12-lead ECG and vectorcardiography (VCG), which results were attributed to the different cardiac conduction system in this species. The objective of this study was to determine if the anatomical origin of pacing-induced VPDs could be differentiated in horses based upon VCG characteristics. A 12-lead ECG was recorded in seven horses under gener...
Sellon DC, Sanz M, Kopper JJ.Little is known about the acquisition and use of equine analgesic drugs by horse owners in the United States (US). Objective: To determine factors associated with possession of analgesic drugs by horse owners in the US or with analgesic drug acquisition from sources noncompliant with a valid veterinarian-client-patient (VCPR) relationship. Methods: Cross-sectional survey. Methods: An internet-based questionnaire included items related to experiences with horses and equine analgesic drugs. Factors associated with possession of ≥5 types of analgesic drugs and with the acquisition of drugs from...
Zhang C, Ni P, Ahmad HI, Gemingguli M, Baizilaitibei A, Gulibaheti D, Fang Y, Wang H, Asif AR, Xiao C, Chen J, Ma Y, Liu X, Du X, Zhao S.Animal domestication gives rise to gradual changes at the genomic level through selection in populations. Selective sweeps have been traced in the genomes of many animal species, including humans, cattle, and dogs. However, little is known regarding positional candidate genes and genomic regions that exhibit signatures of selection in domestic horses. In addition, an understanding of the genetic processes underlying horse domestication, especially the origin of Chinese native populations, is still lacking. In our study, we generated whole genome sequences from 4 Chinese native horses and combi...
Wiggers N, Nauwelaerts SL, Hobbs SJ, Bool S, Wolschrijn CF, Back W.Left-right symmetrical distal limb conformation can be an important prerequisite for a successful performance, and it is often hypothesized that asymmetric or uneven feet are important enhancing factors for the development of lameness. On a population level, it has been demonstrated that uneven footed horses are retiring earlier from elite level competition, but the biomechanical consequences are not yet known. The objectives of this study were to compare the functional locomotor asymmetries of horses with uneven to those with even feet. Hoof kinetics and distal limb kinematics were collected ...
Walton TE, Alvarez O, Buckwalter RM, Johnson KM.Ten horses (Equus caballus) were vaccinated with strain TC-83 Venezuelan equine encephalomyelitis (VEE) virus vaccine. Febrile responses and leukopenia due to a reduction of lymphocytes and neutrophils were observed in all animals. Viremias were demonstrable in eight horses, with a maximum of 10(3.5) median tissue culture infectious dose units per ml of serum in two horses. Clinical illness with depression and anorexia were observed in five horses. Neutralizing (N), hemagglutination-inhibiting, and complement-fixing antibodies to the vaccine virus were demonstrable by 5, 6.5, and 7 days, respe...
Corbin LJ, Kranis A, Blott SC, Swinburne JE, Vaudin M, Bishop SC, Woolliams JA.Despite the dramatic reduction in the cost of high-density genotyping that has occurred over the last decade, it remains one of the limiting factors for obtaining the large datasets required for genomic studies of disease in the horse. In this study, we investigated the potential for low-density genotyping and subsequent imputation to address this problem. Results: Using the haplotype phasing and imputation program, BEAGLE, it is possible to impute genotypes from low- to high-density (50K) in the Thoroughbred horse with reasonable to high accuracy. Analysis of the sources of variation in imput...
Theoret CL, Barber SM, Moyana TN, Gordon JR.To determine whether transforming growth factor (TGF)-beta1 and -beta3 expression differs between equine limb wounds healing normally and those healing with experimentally induced exuberant granulation tissue (EGT). Methods: Six wounds were created on the lateral aspect of both metacarpi of each horse; one forelimb was untreated, and the other was bandaged to stimulate the development of EGT. Sequential wound biopsies allowed comparison of growth factor expression between the two types of wound. Methods: Four horses (2 to 4 years of age; 350 to 420 kg). Methods: Wounds were assessed grossly, h...
Heleski CR, McGreevy PD, Kaiser LJ, Lavagnino M, Tans E, Bello N, Clayton HM.Unsteady hand position can cause discomfort to the horse, potentially leading to conflict behaviours (CB) such as head tossing or tail lashing. Some instructors feel that martingales or elastic rein inserts can reduce discomfort caused by inexperienced and unsteady hands. Others consider these devices to be inappropriate 'crutches'. Four horses and nine riders were tested under three conditions in random order: plain reins, adjustable training martingales (TM), and elasticised rein inserts (RI). Rein-tension data (7s) and behavioural data (30s) were collected in each direction. Rein-tension da...
Fenger CK, Granstrom DE, Gajadhar AA, Williams NM, McCrillis SA, Stamper S, Langemeier JL, Dubey JP.Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four labora...
Mehdizadeh Gohari I, Unterer S, Whitehead AE, Prescott JF.The role of type A in canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis is poorly characterized. However, a highly significant association between the presence of novel toxigenic and these specific enteric diseases has been described. These novel toxigenic strains produce 3 novel putative toxins, which have been designated NetE, NetF, and NetG. Although not conclusively demonstrated, current evidence suggests that NetF is likely the major virulence factor in strains responsible for canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis. NetF is a be...
Marois P, Boudreault A, DiFranco E, Pavilanis V.Rhesus monkeys and ferrets were exposed to intranasal inoculation of several strains of egg-adapted avian, equine and human influenza viruses and to strains of mouse-adapted equine influenza viruses. Local replication of virus and seroconversion were observed in the majority of these animals. However, clinical infection was observed only in ferrets.
Cook VL, Jones Shults J, McDowell M, Campbell NB, Davis JL, Blikslager AT.Absorption of endotoxin across ischaemic-injured mucosa is a major cause of mortality after colic surgery. Recent studies have shown that flunixin meglumine retards mucosal repair. Systemic lidocaine has been used to treat post operative ileus, but it also has novel anti-inflammatory effects that could improve mucosal recovery after ischaemic injury. Objective: Systemic lidocaine ameliorates the deleterious negative effects of flunixin meglumine on recovery of mucosal barrier function. Methods: Horses were treated i.v. immediately before anaesthesia with either 0.9% saline 1 ml/50 kg bwt, flun...
Kang H, Zsoldos RR, Sole-Guitart A, Narayan E, Cawdell-Smith AJ, Gaughan JB.Healthy adult horses can balance accumulation and dissipation of body heat to maintain their body temperature between 37.5 and 38.5 °C, when they are in their thermoneutral zone (5 to 25 °C). However, under some circumstances, such as following strenuous exercise under hot, or hot and humid conditions, the accumulation of body heat exceeds dissipation and horses can suffer from heat stress. Prolonged or severe heat stress can lead to anhidrosis, heat stroke, or brain damage in the horse. To ameliorate the negative effects of high heat load in the body, early detection of heat stress and im...
Vallance SA, Entwistle RC, Hitchens PL, Gardner IA, Stover SM.Identification of exercise history patterns that are related to catastrophic scapular fracture will facilitate prevention of racehorse fatalities. Objective: To determine if exercise patterns are associated with scapular fracture in Thoroughbred (TB) and Quarter Horse (QH) racehorses. Methods: High-speed exercise histories for 65 TB and 26 QH racehorses that had a complete scapular fracture (cases) and 2 matched control racehorses were retrospectively studied. Exercise variables were created from lifetime race and official timed workout reports. Associations between exercise variables and scap...
Johnson AL, McAdams SC, Whitlock RH.The objective of the current retrospective study was to describe naturally occurring type A botulism in horses in the United States. In the past 10 years, the Botulism Laboratory at the University of Pennsylvania's School of Veterinary Medicine has identified 3 isolated cases and 8 outbreaks of type A botulism in horses via samples positive for Clostridium botulinum type A toxin or spores using the mouse bioassay test. Additional information was obtained by review of submission forms and by telephone or email interviews. Almost all type A cases and outbreaks occurred in the western United Stat...
Timoney JF, Kumar P.Little is known about entry and subsequent multiplication of Streptococcus equi following exposure of a susceptible horse. This information would have value in design of intranasal vaccines and understanding of shedding and protective immune responses. Objective: To determine entry points and sites of subsequent replication and dispersion of S. equi at different times after intranasal infection or commingling exposure. Methods: Previously unexposed horses and ponies were subjected to euthanasia 1, 3, 20 or 48 h following intranasal inoculation with biotin labelled or unlabelled S. equi CF32. S...
Foland JW, McIlwraith CW, Trotter GW, Powers BE, Lamar CH.Osteochondral fragments were created arthroscopically on the distal aspect of both radial carpal bones in 12 horses. On day 14 after surgery, one middle carpal joint of each horse was injected with 2.5 mL Betavet Soluspan (3.9 mg betamethasone sodium phosphate and 12 mg betamethasone acetate per milliliter) and the contralateral joint was injected with 2.5 mL saline as a control. Intra-articular treatments were repeated on day 35. On day 17, six horses began exercising 5 days per week on a high-speed treadmill. The other six horses were kept in box stalls throughout the study as nonexercised c...
Tumas DB, Hines MT, Perryman LE, Davis WC, McGuire TC.The immune control of chronic equine infectious anaemia (EIA) lentiviral infection was investigated by specifically depleting CD5+ T lymphocytes in vivo with monoclonal antibody (MAb) or by immunosuppression with corticosteroids. MAb was given at 25 to 50 mg/day intravenously for 11 days. Murine IgG1 anti-equine CD2 MAb (n = 2 horses) or IgG1 (n = 2) and IgG2a control MAb (n = 2 normal; 2 EIA-infected) did not deplete CD2+ T lymphocytes in horses. Horses given murine IgG2a anti-CD5 MAb HB19A (n = 4 normal; 5 EIA-infected) had depletion of peripheral blood CD5+ T lymphocytes during treatment. T...
Steffey EP, Howland D.Circulatory and respiratory effects of alveolar concentrations of 1.31, 1.97, and 2.62 vol% of isoflurane in oxygen were studied in eight young, healthy horses during spontaneous and controlled ventilation. These isoflurane concentrations were equivalent, respectively, to 1.0, 1.5, and 2.0 times the minimal alveolar concentration of isoflurane, which prevents movement in horses in response to a standard pain stimulus. Results of the isoflurane studies were compared with similarly derived findings in these same horses during equipotent halothane in oxygen anesthesia. Isoflurane, similar to halo...
Proops L, Rayner J, Taylor AM, McComb K.It has been suggested that the process of domestication, at least in some species, has led to an innate predisposition to be skilled at reading human communicative and attentional cues. Adult domestic horses (Equus caballus) are highly sensitive to subtle bodily cues when determining if a person is attending to them but they are less adept at using human communicative cues in object choice tasks. Here we provide the first study into the ontogeny of such skills in order to gain insights into the mechanisms underlying these abilities. Compared with adult horses, youngsters under the age of three...
Sánchez de Medina A, Serrano-Rodríguez JM, Díez de Castro E, García-Valverde MT, Saitua A, Becero M, Muñoz A, Ferreiro-Vera C....Intravenous pharmacokinetics and oral bioavailability of cannabidiol (CBD) with different formulations have not been investigated in horses and may represent a starting point for clinical studies. Objective: To describe pharmacokinetics after intravenous and oral administrations with oil and micellar formulations and simulate different treatments. Methods: Single intravenous experiment and two-way randomised oral experiments, Latin-square design. Methods: Eight healthy horses received intravenous CBD at 1.00 mg/kg dose, oral CBD in sesame oil and in micellar formulation, both at 10.00 mg/k...
Wagner B.Since the initial characterization of IgE by Ishizaka et al. (1966), IgE was described in several mammalian species. In horses, a single gene encoding the IgE heavy chain constant region (IGHE gene) exists per haploid genome and several allelic variants of the equine IGHE gene were found. IgE occurs in its soluble form in equine serum and physiological concentrations of total IgE are around 1000-fold higher in normal horse than in normal human serum. Maternal IgE is enriched in the colostrum and transferred to the neonatal foal after birth. Foals do not produce detectable concentrations of end...
Nuñez CM, Adelman JS, Rubenstein DI.Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP's effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. Results: To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births...
Nielsen MK, von Samson-Himmelstjerna G, Kuzmina TA, van Doorn DCK, Meana A, Rehbein S, Elliott T, Reinemeyer CR.This guideline have been developed to assist in the design, execution, and interpretation of studies to assess the efficacy of anthelmintic drugs against internal parasites of equines, including nematodes, cestodes, and larval instars of Gasterophilus spp. The design and execution of critical and controlled studies are outlined, and their advantages and disadvantages are discussed. Unique considerations for specific target parasites are included. Information is also provided on selection of animals, procedures for randomization, housing, feeding, dosage titration, dosage confirmation and field...
Meijer MC, van Weeren PR, Rijkenhuizen AB.The condition of septic arthritis was treated in 12 foals with 21 affected joints (Group I) and in 27 adult horses. The adult horses were divided into three groups, based on aetiology of the condition: haematogenous (Group II, n = 6), iatrogenic (Group III, n = 6), and perforating trauma (Group IV, n = 15). The treatment consisted of an initial systemic antibiotic that anticipated the microbial agents that were considered most likely per group, repeated through-and-through joint lavages every other day and non-steroidal anti-inflammatory drugs. The antibiotics were adjusted to the results of b...
Dyson S, Murray R, Schramme M, Branch M.Foot pain is a common cause of equine lameness and there have been significant limitations of the methods available for the diagnosis of the causes of foot pain (radiography, nuclear scintigraphy and ultrasonography). Until recently, magnetic resonance imaging (MRI) in the horse has been limited to examination of cadaver limbs. Objective: Our purpose was to 1) describe MRI of the foot in live horses, 2) describe MRI findings in horses with foot pain in which a definitive diagnosis could not be established by alternative means and 3) correlate MRI findings with other methods of clinical investi...
Raspa F, Dinardo FR, Vervuert I, Bergero D, Bottero MT, Pattono D, Dalmasso A, Vinassa M, Valvassori E, Bruno E, De Palo P, Valle E.Horses reared for meat production are fed high amounts of cereal grains in comparison with horses raised for other purposes. Such feeding practice may lead to risk of poor welfare consequences. The aim of this study was to investigate the effects of two feeding practices on selected metabolic parameters and production aspects. Nineteen Bardigiano horses, 14.3 ± 0.7 months of age, were randomly assigned to two groups-one fed with high amounts of cereal grains (HCG; n = 9; 43% hay plus 57% cereal grain-based pelleted feed) vs. one fed with high amounts of fibre (HFG; n = 10; 70% hay plus...
Clausen PH, Chuluun S, Sodnomdarjaa R, Greiner M, Noeckler K, Staak C, Zessin KH, Schein E.From May to July 2000, a cross-sectional study was conducted to estimate the prevalence of Trypanosoma equiperdum in the horse population of the central province (Tuv aimag) of Mongolia. On average, four herds were selected from each of the 29 aimag subdivisions (119 herds). From each herd, 10 horses were sampled in proportion to sex and age categories in the respective herds (1190 horses). Sera from 1122 horses were analysed for T. equiperdum antibodies using two serological assays, the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA). The crude estimate of the...
Kelmer G, Keegan KG, Kramer J, Wilson DA, Pai FP, Singh P.To characterize compensatory movements of the head and pelvis that resemble lameness in horses. Methods: 17 adult horses. Methods: Kinematic evaluations were performed while horses trotted on a treadmill before and after shoe-induced lameness. Lameness was quantified and the affected limb determined by algorithms that measured asymmetry in vertical movement of the head and pelvis. Induced primary lameness and compensatory movements resembling lameness were assessed by the Friedman test. Association between induced lameness and compensatory movements was examined by regression analysis. Results...
Kim H, Lee T, Park W, Lee JW, Kim J, Lee BY, Ahn H, Moon S, Cho S, Do KT, Kim HS, Lee HK, Lee CK, Kong HS, Yang YM, Park J, Kim HM, Kim BC, Hwang S....The modern horse (Equus caballus) is the product of over 50 million yrs of evolution. The athletic abilities of the horse have been enhanced during the past 6000 yrs under domestication. Therefore, the horse serves as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. The structure and function of skeletal muscle show remarkable plasticity to the physical and metabolic challenges following exercise. Here, we reveal an evolutionary layer of responsiveness to exercise-stress in the skeletal muscle of the racing horse. We analysed differentia...
