Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
You Y, Uboh CE, Soma LR, Guan F, Li X, Rudy JA, Liu Y, Chen J.An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method for fast-throughput analysis of eight anabolic and androgenic steroids (AAS) in equine plasma is reported. Analytes were recovered by liquid-liquid extraction using methyl tert-butyl ether, separated on a 1.9 microm C(18) reversed-phase column, and analyzed in positive electrospray ionization mode on a triple quadrupole mass spectrometer with selected reaction monitoring (SRM) and full product ion scans. Two SRM ion transitions were monitored for each AAS during screening to obtain highly selective screenin...
Duffy CW, Morrison LJ, Black A, Pinchbeck GL, Christley RM, Schoenefeld A, Tait A, Turner CM, MacLeod A.African animal trypanosomiasis, or Nagana, is a debilitating and economically costly disease with a major impact on animal health in sub-Saharan Africa. Trypanosoma vivax, one of the principal trypanosome species responsible for the disease, infects a wide host range including cattle, goats, horses and donkeys and is transmitted both cyclically by tsetse flies and mechanically by other biting flies, resulting in a distribution covering large swathes of South America and much of sub-Saharan Africa. While there is evidence for mating in some of the related trypanosome species, Trypanosoma brucei...
Hanly BK, Stokes AM, Bell AM, Johnson JR, Keowen ML, Paulsen DB, Sod GA, Moore RM.To determine the feasibility of performing serial laminar and skin biopsies on sedated horses and whether sampling affected adjacent tissues. Methods: 6 horses. Methods: Laminar tissues were harvested via biopsy through the hoof wall from healthy conscious horses via sedation and regional anesthesia. Eight specimens were collected at 4 time points during 24 hours from a single foot. Laminar biopsy specimens were harvested with a 6-mm-diameter biopsy punch after burring through the horny corium to the stratum medium. Skin biopsy specimens were collected from an area proximal to the coronary ban...
Sanada Y, Senba H, Mochizuki R, Arakaki H, Gotoh T, Fukumoto S, Nagahata H.To establish a reliable diagnostic measure for equine Anoplocephala perfoliata infection, the impact of deworming was examined in 12 Thoroughbreds to which bithionol (5-10 mg/kg body weight) was administered and feces were examined by the modified Wisconsin method using sucrose solution. One day after the administration, cestode eggs were detected in previously fecal egg-negative 3 horses and increased in the other 9 horses. The optimum time for post-deworming egg detection was examined in following horses: 17 mares were administered bithionol and 10 mares were used as controls. The fecal egg ...
Ducharme NG, Fortier LA, Kraus MS, Hobo S, Mohammed HO, McHugh MP, Hackett RP, Soderholm LV, Mitchell LM.To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses. Methods: 6 horses. Methods: Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase...
Capponi L, Schmitz A, Thormann W, Theurillat R, Mevissen M.To investigate cytochrome P450 (CYP) enzymes involved in metabolism of racemic and S-ketamine in various species and to evaluate metabolic interactions of other analgesics with ketamine. Methods: Human, equine, and canine liver microsomes. Methods: An analgesic was concurrently incubated with luminogenic substrates specific for CYP 3A4 or CYP 2C9 and liver microsomes. The luminescence signal was detected and compared with the signal for negative control samples. Ketamine and norketamine enantiomers were determined by use of capillary electrophoresis. Results: A concentration-dependent decrease...
Stewart AA, Barrett JG, Byron CR, Yates AC, Durgam SS, Evans RB, Stewart MC.To compare viability and biosynthetic capacities of cells isolated from equine tendon, muscle, and bone marrow grown on autogenous tendon matrix. Methods: Cells from 4 young adult horses. Methods: Cells were isolated, expanded, and cultured on autogenous cell-free tendon matrix for 7 days. Samples were analyzed for cell viability, proteoglycan synthesis, collagen synthesis, and mRNA expression of collagen type I, collagen type III, and cartilage oligomeric matrix protein (COMP). Results: Tendon- and muscle-derived cells required less time to reach confluence (approx 2 weeks) than did bone marr...
Nieto JE, Snyder JR, Vatistas NJ, Jones JH.To develop a protocol to induce and maintain gastric ulceration in horses and to determine whether gastric ulceration affects physiologic indices of performance during high-speed treadmill exercise. Methods: 20 healthy Thoroughbreds. Methods: Each horse was acclimatized to treadmill exercise during a 2-week period. Subsequently, baseline data were collected (day 0) and each horse began an incrementally increasing exercise training program (days 1 through 56). Beginning on day 14, horses were administered omeprazole (4 mg/kg, PO, q 24 h until day 56) or no drug (10 horses/group) and underwent a...
Dart AJ, Perkins NR, Dart CM, Jeffcott LB, Canfield P.To evaluate the effect of a non-occlusive dressing incorporated in a 3-layer bandage on second intention healing of wounds of the distal portion of the limb. Methods: Untreated wounds in 33 adult horses used in four studies using the same wound-healing model conducted over 5 years. Methods: Standardised, full-thickness wounds were made in the skin overlying the dorsomedial aspect of the mid-metacarpus; 17 horses were bandaged with a non-occlusive dressing covered by gauze-coated cotton wool that was compressed with adhesive tape; 16 horses were left unbandaged. Wounds were photographed weekly ...
Cilliers I, Williams J, Carstens A, Duncan NM.Four horses were presented to the Onderstepoort Veterinary Academic Hospital with histories of facial asymmetry, nasal discharge or obstruction of normal nasal passage airflow. Radiographic examination of the maxillary sinuses of 2 cases revealed well circumscribed, unilateral, mineralised masses; the other 2 cases showed less mineralisation. The masses were accessed for further investigation by surgically created frontonasal bone flaps or trephination of the maxillary sinuses. Diagnosis of osteoma was confirmed histopathologically in 3 of the cases and of ossifying fibroma in the 4th. Two hor...
Larenza MP, Ringer SK, Kutter AP, Conrot A, Theurillat R, Kummer M, Thormann W, Bettschart-Wolfensberger R.To compare anesthesia recovery quality after racemic (R-/S-) or S-ketamine infusions during isoflurane anesthesia in horses. Methods: 10 horses undergoing arthroscopy. Methods: After administration of xylazine for sedation, horses (n = 5/group) received R-/S-ketamine (2.2 mg/kg) or S-ketamine (1.1 mg/kg), IV, for anesthesia induction. Anesthesia was maintained with isoflurane in oxygen and R-/S-ketamine (1 mg/kg/h) or S-ketamine (0.5 mg/kg/h). Heart rate, invasive mean arterial pressure, and end-tidal isoflurane concentration were recorded before and during surgical stimulation. Arterial blood...
Bowers JR, Slocombe RF.A 4-year-old crossbred, Welsh Mountain Pony gelding was presented with multiple, thick, round, raised, 3 to 8 mm diameter nodular lesions on the medial aspects of both ears. The nodules did not involve the epidermis and were observed to develop over several months. Punch biopsies were taken and histopathological examination returned a diagnosis of auricular chondrosis. Neither auricular chondrosis nor auricular chondritis has been reported in horses, although it has been recorded in cats, dogs, laboratory animals and humans.
Groesel M, Gfoehler M, Peham C.In this paper, an alternative method is presented to convert computed tomography (CT)-scans into 3D biomodels. The CT-data of an equine spine was converted into TIF format to work with it in a 2D CAD program. Then the bony structure has been marked manually with closed splines and saved as IGS files for the next procedure with 3D CAD software to create virtual biomodels of every single bone. Therefore, the different layers of the CT-scans were positioned in correct distance and then a closed surface was created to cover all spline-curves. Finally, the cover was filled up with material to creat...
Cheetham J, Pigott JH, Hermanson JW, Campoy L, Soderholm LV, Thorson LM, Ducharme NG.The equine upper airway is highly adapted to provide the extremely high oxygen demand associated with strenuous aerobic exercise in this species. The tongue musculature, innervated by the hypoglossal nerve, plays an important role in airway stability in humans who also have a highly adapted upper airway to allow speech. The role of the hypoglossal nerve in stabilizing the equine upper airway has not been established. Isolated tongues from eight mature horses were dissected to determine the distal anatomy and branching of the equine hypoglossal nerve. Using this information, a peripheral nerve ...
de Graaf-Roelfsema E, Veldhuis PP, Keizer HA, van Ginneken MM, van Dam KG, Johnson ML, Barneveld A, Menheere PP, van Breda E, Wijnberg ID....The influence of intensified and reduced training on nocturnal growth hormone (GH) secretion and elimination dynamics was studied in young (1.5 yr) Standardbred geldings to detect potential markers indicative for early overtraining. Ten horses trained on a treadmill for 32 wk in age-, breed-, and gender-matched fixed pairs. Training was divided into four phases (4, 18, 6, and 4 wk, respectively): 1) habituation to high-speed treadmill trotting, 2) normal training, in which speed and duration of training sessions were gradually increased, 3) in this phase, the horses were divided into 2 groups:...
Lopes MS, Diesterbeck U, da Câmara Machado A, Distl O.Navicular disease or podotrochlosis is one of the main causes of progressive forelimb lameness in warmblood horses. The objective of this study was to refine a quantitative trait locus on horse chromosome 2 for radiological alterations in the contour of the navicular bone (RAC) in Hanoverian warmblood horses. Genotyping was performed in 192 Hanoverian warmblood horses from 17 paternal half-sib groups. The marker set was extended to 58 informative microsatellites including nine newly developed microsatellites. QTL for RAC could be delineated at 32.50-43.13 Mb and a further new QTL for RAC could...
Ginther OJ, Siddiqui MA, Beg MA.The hypotheses were tested that prostaglandin F2alpha (PGF) travels from the uterus to the ovaries via a systemic route in mares, as opposed to a local route in ruminants, and that one pulse of PGF produces only partial luteolysis. Intravenous (i.v.) and intrauterine (i.u.) infusions of PGF were performed 8 days after ovulation at a constant rate for 2 h. Plasma concentrations of PGF were assessed by assay of 13,14-dihydro-15-keto-PGF2alpha (PGFM). Total doses administered were as follows: 0, 0.05, 0.1, 0.5 and 1.0 mg, i.v., PGF and 0 and 0.5 mg, i.u., PGF (n=4 mares per group). In addition, P...
De Santis T, Casavola V, Reshkin SJ, Guerra L, Ambruosi B, Fiandanese N, Dalbies-Tran R, Goudet G, Dell'Aquila ME.The extracellular calcium-sensing receptor (CASR) plays an important role in cells involved in calcium (Ca2+) homeostasis by directly sensing changes in the extracellular Ca2+ ion concentration. We previously reported the localization and quantitative expression of CASR protein in human oocytes. In this study, we examined the expression and the functional role of CASR during oocyte meiotic maturation in a large mammal animal model, the horse. As in humans, CASR protein was found to be expressed in equine oocytes and cumulus cells. Western-blot analysis revealed a single 130 kDa band in denuded...
Ginther OJ, Gastal EL, Gastal MO, Duarte LF, Beg MA.The effect of the ovarian follicles on plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) before versus after the expected emergence of the ovulatory follicular wave was studied on Days 0 to 18 (Day 0=ovulation) in four groups of mares (n=6/group). In addition to a control group, all follicles >/=6mm in diameter were ablated on Days 0.5, 6.5, or 12.5 in a herd of mares with reported emergence at 6mm of the future ovulatory follicle on mean Day 10.5. Concentrations of FSH were not different between the Day-0.5 or Day-6.5 ablation groups and the correspon...
Chesen AB, Dabareiner RM, Chaffin MK, Carter GK.To determine clinical signs, ultrasonographic findings, and outcome of horses with tendinitis of the proximal portion of the superficial digital flexor tendon (SDFT; group A horses) and to compare signalment, horse use, and outcome in these horses with that of horses with tendinitis of the midmetacarpal region of the SDFT (group B horses). Methods: Retrospective case series. Methods: 12 group A horses and 22 group B horses. Methods: Medical records were reviewed for signalment, horse use, and outcome information; data for group A horses also included severity of lameness, diagnostic results, a...
Bonneau S, Maynard L, Tomczuk K, Kok D, Eun HM.In this blinded randomized and controlled study, the anthelmintic efficacy of a tablet formula of ivermectin-praziquantel was evaluated in horses experimentally infected with three species of Strongylus larvae. Eighteen previously dewormed horses were inoculated on study day 0 with third-stage larvae of Strongylus vulgaris, Strongylus equinus, and Strongylus edentatus. The horses were randomly allocated to three groups (n = 6): test-drug (tablet formula), positive-control (reference gel), and negative-control (placebo tablet). On day 56, the horses were treated once with the respective drugs. ...
Schwarzwald CC, Schober KE, Berli AS, Bonagura JD.Noninvasive assessment of left-ventricular (LV) function is clinically relevant, but is incompletely studied in horses. Objective: To document the feasibility, describe the techniques, and determine the reliability of 2D speckle tracking (2DST) for characterization of LV radial and circumferential wall motion in horses. Methods: Three Standardbreds, 3 Thoroughbreds; age 8-14 years; body weight 517-606 kg. Methods: Observational study. Repeated 2-dimensional echocardiographic examinations were performed in unsedated horses by 2 observers and subsequently analyzed by 2DST. Test reliability was d...
Hart KA, Slovis NM, Barton MH.Transient hypothalamic-pituitary-adrenal (HPA) axis dysfunction occurs frequently in critically ill humans and impacts survival. The prevalence and impact of HPA axis dysfunction in critically ill neonatal foals are not well characterized. Objective: (1) HPA axis dysfunction occurs in hospitalized neonatal foals, and is characterized by inappropriately low basal serum cortisol concentration or inadequate cortisol response to exogenous adrenocorticotropic hormone (ACTH); (2) hospitalized foals with HPA axis dysfunction have more severe disease and are less likely to survive than hospitalized fo...
Modrá H, Svobodová Z.This article reports the most frequent cases of poisoning in farm animals, horses, cats, dogs, wild animals, fish and honey-bees in the Czech Republic. At present, there are fewer cases of acute poisoning caused by high doses of toxic substances but there are more and more cases of chronic poisoning as a consequence of environmental pollution.
Tobari H, Yamagishi K, Noda H, Tanigawa T, Iso H.Prevention of horse-related injuries is considered difficult because horse behavior is unpredictable. Therefore, risk factors for injuries related to professional horse racing need to be investigated. We conducted a study to determine whether body mass index (BMI) and gamma-glutamyltransferase (GGT) levels are associated with professional horse racing-related injuries. Methods: A baseline healthy survey of 546 male grooms and exercise riders aged 40-70 yr working at Miho Training Center, the largest racing-horse training facility in Japan, was performed in May 2003. A total of 93 occupational ...
Causey RC, Artiushin SC, Crowley IF, Weber JA, Homola AD, Kelley A, Stephenson LA, Opitz HM, Guilmain S, Timoney JF.Attenuated Salmonella enterica serovar Typhimurium MGN707, expressing the SzP protective protein of the MB9 serovar of Streptococcus equi subspecies zooepidemicus (SzP-MB9) was tested for its safety and efficacy as a nebulised intranasal vaccine against streptococcal uterine infections in mares. In a preliminary study, vaccinated mares (n=5) displayed serum, nasal and uterine responses (P<0.05) to S. Typhimurium lipopolysaccharide (St-LPS). Subsequently, vaccinated mares (expressor group, n=7), but not mares vaccinated with the vector only (control group, n=7), displayed significant increas...
Raisis AL, Mosing M, Hosgood GL, Secombe CJ, Adler A, Waldmann AD.Electrical impedance tomography (EIT) provides clinically useful lung images; however, it would be an advantage to extract additional cardiovascular information from the data. The aim of this study was to evaluate if cardiac-related changes measured by EIT can be used to measure pulse rate (PR) under physiological as well as high and low blood pressure states in anaesthetised horses. Electrical impedance tomography data and PR from seven horses anaesthetised in dorsal recumbency were recorded over 1 min during mechanical ventilation and 1 min of apnoea. Data were collected at four measurement ...
Herszberg B, McCue ME, Larcher T, Mata X, Vaiman A, Chaffaux S, Chérel Y, Valberg SJ, Mickelson JR, Guérin G.Glycogen storage diseases or glycogenoses are inherited diseases caused by abnormalities of enzymes that regulate the synthesis or degradation of glycogen. Deleterious mutations in many genes of the glyco(geno)lytic or the glycogenesis pathways can potentially cause a glycogenosis, and currently mutations in fourteen different genes are known to cause animal or human glycogenoses, resulting in myopathies and/or hepatic disorders. The genetic bases of two forms of glycogenosis are currently known in horses. A fatal neonatal polysystemic type IV glycogenosis, inherited recessively in affected Qu...
Steffey EP, Kelly AB, Farver TB, Woliner MJ.Circulatory and respiratory effects of intravenously administered acetylpromazine (0.033 and 0.067 mg/kg) and xylazine (0.5 and 1.0 mg/kg) were studied in drug cross-over fashion in eight laterally recumbent horses anesthetized only with halothane (1.06%, end-tidal) in O2. Both doses of acetylpromazine caused a significant and sustained elevation in cardiac output via a rise in stroke volume. Xylazine produced an initial significant fall in cardiac output followed by a return to control levels. Halothane anesthesia did not prevent xylazine-related atrioventricular conduction block. All treatme...
Biermann NM, McClure JT, Sanchez J, Saab M, Doyle AJ.Currently, the World Health Organization recommends the use of alcohol-based hand rubs (ABR) for surgical hand preparation in human surgery. When disinfecting soaps are used, a rubbing technique causes less skin irritation than brush scrubbing. Based on a recent survey, most equine surgeons still use disinfecting soap. The efficacy of scrubbing vs. rubbing and the use of sole ABR compared with chlorhexidine (CHx)- based products has not been evaluated in the equine surgical setting. Objective: To compare four surgical hand antisepsis techniques in equine surgery for reduction of aerobic bacter...
Schramme MC, Boswell JC, Hamhougias K, Toulson K, Viitanen M.Numerous different techniques for injection of the navicular bursa have been described but there is little conformity between these descriptions. A literature review was performed and techniques for injection of the navicular bursa were categorised into 5 approaches. This study was performed to evaluate the reproducibility of each technique and to assess which technique was consistently most successful. Five inexperienced operators performed each technique on 5 cadaver forelimbs. Once a needle had been placed, a radiograph was taken to confirm placement was in accordance with the description o...
Arrighi S.Occurrence of a solitary cilium was an unexpected discovery while studying the ultrastructure of epididymal epithelium in equidae. Primary cilia were detected in epididymal basal cells of all individuals of the equines studied - horses, donkey and mules - independently from age and tract of the duct, emerging from the basal cell surface and insinuating into the intercellular spaces. More rarely solitary cilia occurred also at the luminal surface of the principal cells. The ciliary apparatus was constituted by a structurally typical basal body continuous with the finger-like ciliary shaft exten...
Jordan VJ, Ireland JL, Rendle DI.It is accepted among equine practitioners that glucocorticoid treatment is a risk factor for the development of laminitis. However, there is little published evidence of a link between glucocorticoids and laminitis. Objective: To determine whether horses receiving oral prednisolone are at increased risk of laminitis. Methods: Retrospective case-control study. Methods: Clinical records of horses registered with the ambulatory service at Liphook Equine Hospital between January 2001 and November 2014 were reviewed retrospectively to identify horses that had received treatment with oral prednisolo...
Hunt RJ, Allen D, Moore JN.Using a pump-perfused extracorporeal isolated digital preparation, the effects of a 30-minute infusion of either saline solution (control) or endotoxin on equine digital hemodynamics and microvascular function were determined. Digital blood flow and arterial, venous, and capillary pressures were recorded at 15-minute intervals for 150 minutes. From these data, total vascular resistance and pre- and postcapillary resistances were calculated. Isogravimetric capillary filtration coefficient, vascular compliance, and the osmotic reflection coefficient were determined after the last hemodynamic mea...
Cartmill JA, Thompson DL, Gentry LR, Pruett HE, Johnson CA.In experiment 1, nine light horse geldings (three 3 x 3 Latin squares) received dexamethasone (DEX; 125 microg/kg BW, i.m.), glucose (0.2 g/kg BW, i.v.), or nothing (control) once per day for 4 days. DEX increased (P < 0.001) glucose, insulin, and leptin concentrations and resulted in a delayed increase (P < 0.001) in IGF-I concentrations. In experiment 2, mares were similarly treated with DEX (n = 6) or vehicle (n = 6). DEX again increased (P < 0.01) glucose, insulin, and leptin concentrations; the delayed elevation in IGF-I concentrations occurred on day 10, 12, and 19, relative to ...
Haluska GJ, Currie WB.Concentrations of plasma progesterone were similar to values reported in the literature except that a significant decrease in progesterone during the last day, but before parturition, was detected by systematic, high-intensity blood sampling. Mean concentrations of oestradiol-17 beta increased sharply and significantly, plateaued for 132.8 +/- 1.5 days (mean +/- s.e.m., N = 9), then declined sharply in each mare. There was obvious variation between the mares in when these increases and decreases in oestradiol-17 beta occurred, with the events being related closely to ambient photoperiod condit...
Geburek F, Deegen E, Hewicker-Trautwein M, Ohnesorge B.In the present field study the skin of the feet of 37 heavy draught horses of different breeds showing verrucous pastern dermatitis was examined clinically. Included were the degree of severity of the disease and the prevalence of anatomically normal structures associated with the skin: fetlock tufts of hair ("feathering"), ergots, chestnuts, bulges in the pastern region, cannon circumference. Each horse was examined for Chorioptes sp. skin mites. Information was also collected on the development of the skin alterations and housing conditions and feeding. These individual data were correlated ...
Witkowski M, Pardyak L, Pawlicki P, Galuszka A, Profaska-Szymik M, Plachno BJ, Kantor S, Duliban M, Kotula-Balak M.Cryptorchidism in horses is a commonly occurring malformation. The molecular basis of this pathology is not fully known. In addition, the origins of high intratesticular estrogen levels in horses remain obscure. In order to investigate the role of the G-protein-coupled membrane estrogen receptor (GPER) and establish histological and biochemical cryptorchid testis status, healthy and cryptorchid horse testes were subjected to scanning electron microscopy analysis, histochemical staining for total protein (with naphthol blue black; NBB), acid content (with toluidine blue O; TBO), and polysacchar...
Walker M, Geiser D.Heart rate, blood velocity, volumetric blood flow, and arterial diameter for 10 horses given acetylpromazine were determined from measurements of the dorsal metatarsal artery 3 (the great metatarsal artery), using 2-dimensional real-time and gated pulsed Doppler ultrasonography. Acetylpromazine induced significant increases in arterial diameter (P less than 0.01) and volumetric flow rate (P less than 0.05)--all compatible with adrenergic blockade. There was a trend indicating that there was increased blood velocity. Heart rate was unchanged.
Plotka ED, Foley CW, Witherspoon DM, Schmoller GC, Goetsch DD.Concentrations of progesterone and estrogen were measured in peripheral blood plasma samples from mares around the time of ovulation. Samples were collected every 2 hours from 36 hours before, to 26 hours after, ovulation and assayed by radioimmunoassay. Progesterone concentrations were between 60 and 100 pg/ml for the period 24 hours before ovulation through 8 hours after ovulation. By 10 hours after ovulation, concentrations increased to 140 pg/ml and, by 26 hours after ovulation, reached 346 pg/ml. Plasma estrogen concentrations did not change significantly throughout the same period.
Olszewski MA, Robinson NE, Yu MF, Derksen FJ.During acute bouts of recurrent airway obstruction (heaves) in horses, neutrophils that are capable of increased production of reactive oxygen species accumulate in the airways. In the study reported here, the effect of hydrogen peroxide (H2O2; 1 microM to 0.1M), one of these reactive oxygen species products, on the responses of isolated trachealis muscle of horses was determined. Before and after incubation with H2O2, contractile responses to acetylcholine, electrical field stimulation (EFS), 127 mM KCl, and relaxation responses to isoproterenol and activation of the nonadrenergic noncholiner...
Byrne BA, Rand CL, McElliott VR, Samitz EM, Brault SA.Dermatophilosis caused by Dermatophilus congolensis causes exudative dermatitis in a variety of species. The infection is generally limited to the cutaneous tissues, where infection is acquired from the environment and bacteria penetrate into keratinized epithelium through epithelial disruption. A 3-year-old pony filly was examined for enlarging mandibular lymph nodes during the preceding 10 months. Biopsy of the node revealed mixed and granulomatous inflammation and thick, filamentous Gram-positive bacteria. Dermatophilus congolensis, confirmed by biochemical testing and sequencing of the rib...
Greenhaff PL, Harris RC, Snow DH, Sewell DA, Dunnett M.Six thoroughbred horses exercised on a motorised treadmill on two separate occasions at a speed of 11 or 12 m.s-1 for up to 2 min. 4 h prior to exercise each horse was given a 21 test solution of sodium bicarbonate (NaHCO3; 0.6 g.kg-1 body mass) or a control solution of water by nasogastric intubation, the order of administration of the two solutions was randomised. Blood samples (n = 15) were obtained before and during the 4 h after intubation, during exercise and for 30 min after exercise. NaHCO3 ingestion resulted in changes in pre-exercise acid-base status. The changes in blood lactate and...
Froydenlund TJ, Dixon PM, Smith SH, Reardon RJ.The morphology of the dorsal conchal bulla (DCB) and ventral conchal bulla (VCB) are poorly described. The recent recognition that these bullae can become infected, causing chronic unilateral nasal discharge, has stimulated interest in these structures. Fourteen cadaveric horse heads were transected sagittally midline and dissected to expose the nasal conchal bullae. The dimensions of each bulla, the number and orientation of drainage apertures, and cellulae septae were recorded. Randomly selected samples were examined histologically. The mean DCB and VCB lengths were 78 and 57 mm, respec...
Mair TS, Sherlock CE.Six mature horses with large abdominal abscesses (defined as an abscess >15-20 cm in at least one dimension) were treated by surgical drainage and post operative lavage. The abscess was associated with previous intestinal surgery in one horse, and with Streptococcus equi spp. equi infection in the other 5. A Foley catheter was used to drain and lavage the abscess in all cases. The abscess was accessed by a ventral midline laparotomy in 5 cases and by standing flank laparoscopy in one. Two horses were subjected to euthanasia within 7 days due to persistent or recurrent colic. The other 4 hor...
MacKinnon MC, Bonder D, Boston RC, Ross MW.There is limited information regarding the impact of training track surface on the occurrence of stress fractures. Objective: To evaluate the impact of training track surface on the proportion of long bone and pelvic stress fractures associated with lameness in Thoroughbred horses in flat race training undergoing nuclear scintigraphic examination. Methods: Retrospective study. Methods: Scintigraphic examinations of Thoroughbred flat racehorses were evaluated from 2 hospitals (hospital A [Toronto Equine Hospital], 2003-2009, and hospital B [George D. Widener Hospital for Large Animals, Scho...
Wilson DA.The equine practitioner can positively influence wound healing by dispensing appropriate treatment in the first few hours after injury. Positive actions in the early period include hemostasis, meticulous cleansing and debridement of the wound, the use of effective but nonirritating products to disinfect the wound, closure (if indicated)with minimal tension on the suture line, the judicious use of drains,and ensuring adequate tetanus protection. Furthermore, a thorough assessment of the wound and the patient in the initial period after trauma provides pertinent information on prognosis. Finally...
Choi YH, Velez IC, Macías-García B, Hinrichs K.In nuclear transfer (NT), exposure of donor cell chromatin to the ooplast cytoplasm may aid reprogramming; however, the length of exposure feasible is limited by the developmental life span of the oocyte. We examined the effect of duration of nucleus-cytoplasmic exposure before activation and of in vitro maturation (IVM) in equine NT. In experiment 1, 24 h IVM and a delay of 2, 5, or 8 h between reconstruction and activation yielded 4%, 15%, and 11% blastocysts, respectively. In experiment 2, a 5-h activation delay yielded 17% and 22% blastocysts with two donor cell lines. In experiment 3, usi...
Tilley P, Simões J, Sales Luis JP.From previous studies, the International Society for Equitation Science has advised that further research be conducted on the physiological/psychological effects of less-exacerbated poll flexion angles. We aimed to evaluate the effects of two riding poll flexion positions with a difference of only 15° on the respiratory systems and behaviour of horses through an evaluation of dynamic airway collapse via over-ground endoscopy, the pharyngeal diameter, pleural pressure, arterial oxygenation and lactate, HR/RR, and the occurrence of conflict behaviours. Twenty high-level dressage and twenty show...
Henderson B, Diaz M, Martins C, Kenney D, Baird JD, Arroyo LG.Medical records of 20 horses with a confirmed diagnosis of valvular endocarditis at the Ontario Veterinary College between January 1, 1993 and February 3, 2020 were reviewed. The diagnosis was based on physical examination findings, complete blood (cell) count (CBC), serum biochemistry, echocardiography, blood culture, and post-mortem findings. Common presenting signs included tachycardia, pyrexia, weight loss, lameness/joint distension, and a heart murmur. Clinicopathological findings included leukocytosis, anemia, hypoalbuminemia, hyperglobulinemia, and elevated inflammatory markers. Culture...
Ward J, Hovey A, Brownlee K.Across mental health professionals, there is growing interest in the field of Equine-Assisted Therapy (EAT). Preliminary evidence suggests EAT is beneficial for a wide spectrum of client populations. EAT programs may be based on groundwork alone, where participants interact with the horses from the ground only, or they may incorporate mounted activities. It remains unclear whether mounted activities add therapeutic benefits to the EAT experience for participants. This scoping review explored whether mounted activities, specifically where the client rides the horse, contribute to distinct thera...
