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.
Beutelspacher SC, Ardjomand N, Tan PH, Patton GS, Larkin DF, George AJ, McClure MO.In this study we compare the ability of self-inactivating Human Immunodeficiency Virus 1 (HIV-1) and Equine Infectious Anaemia Virus (EIAV)-based vectors to mediate gene transfer to rabbit and human corneas and to a murine corneal endothelial cell line. Both vectors were pseudotyped with vesicular stomatitis virus-G (VSV-G) envelope and contained marker transgenes under the control of an internal CMV promoter. For specificity of action, the heterologous promoter in the EIAV-vector was exchanged for an inducible E-Selectin promoter, previously shown to regulate gene-expression in a plasmid syst...
Gustås P, Johnston C, Roepstorff L, Drevemo S, Lanshammar H.The transmission of shockwaves following hoof impact is proposed to be one major source of stress to the limb. In the forelimb, there are indications that the period of horizontal deceleration of the hoof is related to the attenuation of shockwaves. In the hindlimb, information about the hoof deceleration has been lacking. Objective: To compare hoof deceleration patterns between the fore- and hindlimbs. Methods: Seven Standardbreds were trotted by hand over a force plate covered with sand, with triaxial accelerometers mounted on the fore and hind hooves. Variables representative of deceleratio...
Wennerstrand J, Johnston C, Roethlisberger-Holm K, Erichsen C, Eksell P, Drevemo S.Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. Objective: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. Methods: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Ra...
Peham C, Schobesberger H.Knowledge of load effects is crucial for the understanding of the aetiology and pathogenesis of equine back problems. Objective: To investigate different load scenarios of the equine back, such as being ridden or increased muscle tone, using biomechanical simulations. Methods: Kinetic and kinematic data of 15 sound horses and the electromyelograph of their long back muscles were recorded. A biomechanical simulation model was used for simulations under different biomechanical scenarios (ridden/unridden, localised increased stiffness) using ADAMS. Results: The vertical forces acting through a ri...
Keegan KG, Arafat S, Skubic M, Wilson DA, Kramer J, Messer NM, Johnson PJ, O'Brien DP, Johnson G.Subjective neurological evaluation in horses is prone to bias. An objective method of spinal ataxia detection is not subject to these limitations and could be of use in equine practice and research. Objective: Kinematic data in the walking horse can differentiate normal and spinal ataxic horses. Methods: Twelve normal and 12 spinal ataxic horses were evaluated by kinematic analysis walking on a treadmill. Each body position signal was reduced to a scalar measure of uncertainty then fuzzy clustered into normal or ataxic groups. Correct classification percentage (CCP) was then calculated using m...
Davies HM, Merritt JS.Bone strains quantify skeletal effects of specific exercise and hence assist in designing training programmes to avoid bone injury. Objective: To test whether compressive strains increase on the lateral surface of the inside third metacarpal bone (McIII) and the medial surface of the outside McIII in a turn. Methods: Rosette strain gauges on dorsal, medial and lateral surfaces of the midshaft of the left McIII in 2 Thoroughbred geldings were recorded simultaneously during turning at the walk on a bitumen surface. Results: Medial surface: Compression peaks were larger in the outside limb. Tensi...
Degueurce C, Chateau H, Denoix JM.Sacroiliac joint (SIJ) disease is associated with poor hindlimb action, lameness and poor performance in horses. However, little is known about the biomechanics of this low-motion joint. Objective: To determine in vitro the capacities of movement of the SIJ in the sagittal plane, and to test the effect of a sacrosciatic and sacrotuberal desmotomy on its stabilisation. Methods: Six anatomical specimens underwent cycles of flexion-extension of the lumbosacral joint (LSJ) before and after desmotomy. Kinematic triads were linked rigidly to the sacrum, spinous process of vertebra L5 and iliac wing....
Sha DH, Mullineaux DR, Clayton HM.Surface markers are usually used to track bone movement. However, skin movement related to the bone has a large effect on the analysis of skeletal kinematics. A 2-dimensional (2D) skin displacement correction model has been successfully developed, but no 3D skin displacement model exists. Objective: To develop a 3-dimensional (3D) skin displacement model for the equine radial segment during trot. Methods: The 3D trajectories of 6 skin-based markers and a bone-fixed triad were captured at trot in 4 horses. Skin displacements in the bone-based coordinate system were calculated using a singular-v...
Licka T, Kapaun M, Peham C.Equine lameness is commonly evaluated when the horse is being ridden, but the influence of the rider on the lameness has not been documented. Objective: To document the effect of 2 riders of different training levels on the vertical movement of the head and croup. Methods: Twenty mature horses were ridden at trot by an experienced dressage rider and a novice rider, as well as trotted in hand. Kinematic measurements of markers placed on the horse's head and sacral bone were carried out. The asymmetries of the vertical head and sacral bone motion were calculated as lameness parameters and compar...
Hobbs SJ, Mather J, Rolph C, Bower JA, Matuszewski B.Strains during stance on the hoof wall surface have been measured by a number of authors in vitro and in vivo. Histological structure and mechanical properties vary through the wall thickness (radially); radial strain measurements may therefore aid the understanding of mechanical function of the capsule and adjacent tissues. Objective: To develop instrumentation capable of measuring internal hoof strain, and to carry out a preliminary comparison of normal and laminitic hooves. Methods: Six forelimbs from 4 horses, including 2 with laminitis from the same horse, were tested using an Instron tes...
Kicker CJ, Peham C, Girtler D, Licka T.Support boots are thought to reduce tension on the superficial digital flexor tendon (SDTF) of the horse and are frequently recommended for horses convalescing after tendonitis, but evidence of their effectiveness is conflicting. Objective: To document the effects of 4 different types of support boots on fetlock joint angle in comparison to the unprotected fetlock. Methods: In 26 horses, the kinematics of the forelimb fetlock joint angle was measured at walk and trot on a treadmill when wearing 3 different types of support boots and 1 protective boot, as well as without boots. As outcome param...
Chateau H, Degueurce C, Denoix JM.Understanding of the biomechanical effects of heel elevation remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints. Objective: To quantify the effects of 6 degree heel wedge on the 3-dimensional movements of the 4 distal segments of the forelimb in the walking horse. Methods: Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three-dimensional rotations of the digital joints were calculated by use of a 'joint coordinate system' (JCS...
Ramón T, Prades M, Armengou L, Lanovaz JL, Mullineaux DR, Clayton HM.Athletic taping is used frequently by human athletes to stabilise, maintain or strengthen soft tissue structures, but empirical evidence supporting any changes in equine kinematics is lacking. Objective: To assess the effects of athletic taping of the fetlock applied by an experienced athletic trainer on forelimb mechanics in healthy horses. Objective: That athletic taping of the distal forelimb reduces 1) hyperextension of the fetlock joint during stance, 2) flexion of the fetlock joint during swing and 3) ground reaction forces during stance. Methods: Ground reaction force and kinematic data...
Wickler SJ, Hoyt DF, Clayton HM, Mullineaux DR, Cogger EA, Sandoval E, McGuire R, Lopez C.It is well known that adding a load to a horse's back increases its energetic costs of locomotion, but the magnitude of increase obtained by loading the most distal portion of limb has not been measured. Objective: To measure oxygen consumption in horses with mass added to the back and hooves. Because such mass distribution alters inertial parameters of the limbs, kinematic measurements were made to quantify the magnitude of change in limb movement. Methods: Steady-state oxygen consumption was measured in 6 horses with a load of 2.4 kg. The load was either carried on the back or distributed eq...
Ensink JM, Voermans M, Bartels JH, Passon-Vastenburgen MH, Loeb E.A 14-year-old Haflinger mare was presented with a wound on the right metatarsus which it had sustained 3 years earlier. The wound had never completely healed but had only recently become a problem. Over a period of several months, the wound became larger, produced a lot of exudate, and the horse became lame on the affected limb. Clinical examination and radiographs failed to reveal the cause of the deterioration. Histological evaluation of tissue removed during debridement of the wound revealed squamous cell carcinoma. Because the tumour had already invaded the bone, the prognosis was unfavour...
Bidwell LA, Brown KE, Cordier A, Mullineaux DR, Clayton HM.Perineural analgesics are used for lameness diagnosis but the duration of effect, knowledge of which would provide valuable information when performing subsequent blocks, is unknown. Objective: To evaluate the duration of a palmar digital nerve block using force plate measurements. Methods: Ten horses diagnosed with unilateral navicular syndrome were trotted at range of 3 +/- 0.15 m/sec over a force plate to record ground reaction forces for 5 trials of each forelimb. Data were recorded before nerve block, and then at 15 mins, 1, 2 and 24 h post nerve block. Results: Before nerve block, peak v...
Fruehwirth B, Peham C, Scheidl M, Schobesberger H.Basic information about the influence of a rider on the equine back is currently lacking. Objective: That pressure distribution under a saddle is different between the walk, trot and canter. Methods: Twelve horses without clinical signs of back pain were ridden. At least 6 motion cycles at walk, trot and canter were measured kinematically. Using a saddle pad, the pressure distribution was recorded. The maximum overall force (MOF) and centre of pressure (COP) were calculated. The range of back movement was determined from a marker placed on the withers. Results: MOF and COP showed a consistent ...
Khumsap S, Lanovaz JL, Clayton HM.Techniques for 3D analysis have recently been developed. This study applied 3D kinematic analysis to describe the effects of lameness in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints; complex joints such as this may show measurable amounts of movement outside the sagittal plane that may change in response to pathological conditions. Objective: Three-dimensional motions of the tarsal joint change after the induction of synovitis at the DIT and TMT joints. Methods: Twelve retroreflective markers, attached on the skin over the right limb, were used to develop 3D coordinate systems...
Wijnberg ID, Back W, de Jong M, Zuidhof MC, van den Belt AJ, van der Kolk JH.Systematically performed EMG needle examination of muscles provides essential information about the functional aspects of the motor unit. However, clinical studies in which information is given on the diagnostic and discriminative values of electromyography (EMG) in the horse are scarce. Objective: To determine to what extent inclusion of EMG analysis in clinical examination contributes to determination of type and localisation of abnormality. Methods: EMG analysis, complete clinical examination and diagnosis of 108 horses (mean +/- s.d. age 75 +/- 3.8 years; bodyweight 548 +/- 86 kg; height 1...
Khumsap S, Lanovaz JL, Clayton HM.Kinematic studies are usually based on tracking markers attached to the skin. However, complex joints, such as the tarsal joint, function in 3-dimensions (3D), and have therefore necessitated application of the invasive bone pin technique, limiting kinematic studies to the research laboratory. This study investigates the feasibility of using skin-based markers for 3D analysis of tarsal joint motion. Objective: Three-dimensional motions of the tarsal joint can be measured with an acceptable degree of accuracy using skin markers. Methods: Retroreflective markers were attached over the tibial and...
Schlacher C, Peham C, Licka T, Schobesberger H.Mechanical properties of the equine back are the bases for realistic modelling of the back, which is recognised as an important step towards improved understanding of the pathogenesis of equine back conditions. Objective: The stiffness of the equine back depends on the direction of the applied force and on the position of the spine. Methods: Fourteen dissected spines were tested in a tensile testing machine. In 3 different positions, simulating dorsoventral, laterolateral and dorsoventral-30 degree rotated movement, force was applied on the dorsal spinous process of T12 to reach an excursion o...
van der Meulen KM, Pensaert MB, Nauwynck HJ.West Nile virus (WNV), an arthropod-borne virus belonging to the family Flaviviridae, had been recognized in Africa, Asia and the south of Europe for many decades. Only recently, it has been associated with an increasing number of outbreaks of encephalitis in humans and equines as well as an increasing number of infections in vertebrates of a wide variety of species. In this article, the data available on the incidence of WNV in vertebrates are reviewed. Moreover, the role of vertebrates in the transmission of WNV, the control of WNV infections in veterinary medicine as well as future perspect...
Ekman S, Skiöldebrand E, Heinegård D, Hultenby K.One of the most common causes of lameness in racehorses is osteoarthritis (OA). Pathogenesis is not clear and pathological processes of the different joint tissues interact in often progressive events. The interface between cartilage and newly synthesised bone has been shown to be particularly enriched in bone sialoprotein (BSP), a cell-binding matrix protein. Objective: To establish whether changes in the concentration of BSP may serve as a marker for early biochemical changes of the subchondral bone. Methods: Articular cartilage, cartilage/bone interface and subchondral bone of the proximal ...
van den Boom R, van der Harst MR, Brommer H, Brama PA, Barneveld A, van Weeren PR, DeGroot J.Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting horses and leads to degeneration of articular cartilage. Diagnosis is based on clinical signs in combination with radiography, which is relatively insensitive and provides only an indication of accumulated damage. Alternative methods, such as molecular markers, are therefore needed that can quantitatively, reliably and sensitively detect osteoarthritic changes in the joints at an early stage of the disease. If such markers are to be used reliably, it is important to know the relationship between marker ...
Swanstrom MD, Zarucco L, Stover SM, Hubbard M, Hawkins DA, Driessen B, Steffey EP.The superficial (SDF) and deep digital flexor (DDF) muscles are critical for equine forelimb locomotion. Knowledge of their mechanical properties will enhance our understanding of limb biomechanics. Muscle contractile properties derived from architectural-based algorithms may overestimate real forces and underestimate shortening capacity because of simplistic assumptions regarding muscle architecture. Therefore, passive and active (=total - passive) force-length properties of the SDF and DDF muscles were measured directly in vivo. Muscles from the right forelimbs of four Thoroughbred horses we...
Rhodin M, Johnston C, Holm KR, Wennerstrand J, Drevemo S.A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. Objective: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. Methods: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the posit...
Bettschart-Wolfensberger R, Freeman SL, Bowen IM, Aliabadi FS, Weller R, Huhtinen M, Clarke KW.Currently available sedatives depress cardiopulmonary function considerably; therefore, it is important to search for new, less depressive sedatives. The study was performed to assess duration and intensity of cardiopulmonary side effects of a new sedative, dexmedetomidine (DEX), in horses. Objective: To study pharmacokinetics and cardiopulmonary effects of i.v. DEX. Methods: Pharmacokinetics of 3.5 microg/kg bwt i.v. DEX were studied in a group of 8 mature (mean age 4.4 years) and 6 old ponies (mean age 20 years). Cardiopulmonary data were recorded in mature ponies before and 5, 10, 20, 30, 4...
Klebe EA, Holcombe SJ, Rosenstein D, Boruta D, Bartner LR, Tessier C.Dysfunction of the glossopharyngeal nerve has been implicated as a cause of dysphagia in horses. However, recent studies have indicated that this is not the case. Objective: To determine whether bilateral glossopharyngeal nerve anaesthesia would cause dysphagia in horses or result in measurable alterations in the timing, function, or sequence of swallowing. Methods: Swallowing was evaluated in 6 normal horses with and without bilateral glossopharyngeal nerve anaesthesia. Swallowing dynamics were assessed subjectively and objectively based on time from prehension of food until swallowing, numbe...
Watkins JP, Auer JA, Morgan SJ, Gay S.The effect of pulsing electromagnetic field (PEMF) therapy on the healing of surgically created defects in equine superficial digital flexor tendons was evaluated. Defects were created in both front superficial digital flexor tendons of 20 horses. The defect in 1 limb was exposed to a PEMF for 2 hours daily. The other limb served as a control. Histologic and immunofluorescent evaluations were done in horse killed at postsurgical weeks 2, 4, 8, 12, and 24. Therapy with the PEMF significantly (P less than 0.05) delayed the maturation of the tissue formed within the defect at postsurgical weeks 8...
McArthur CL, Handel IG, Robinson A, Hodgkinson JE, Bronsvoort BM, Burden F, Kaplan RM, Matthews JB.Cyathostomins are the most prevalent parasitic pathogens of equids worldwide. These nematodes have been controlled using broad-spectrum anthelmintics; however, cyathostomin resistance to each anthelmintic class has been reported and populations insensitive to more than one class are relatively commonplace. The faecal egg count reduction test (FECRT) is considered the most suitable method for screening anthelmintic sensitivity in horses, but is subject to variation and is relatively time-consuming to perform. Here, we describe a larval migration inhibition test (LMIT) to assess ivermectin (IVM)...
Isola M, Piccinotti C, Magro M, Fasolato L, Vianello F, Menandro ML, Memarian P, Rossi M, Falomo ME.The presence of bacteria of various origins on horse hoofs enables the onset of infections following trauma or even post-surgical wounds. Thus, the analysis of new antibacterial substances is of fundamental importance. In this study, the antibacterial efficacy of Iron Animals (IA), a stable colloidal suspension of iron oxide, organic acids, and detergents, was tested in vitro and in vivo. In vitro assays were performed to test the unspecific inhibitory effect of IA on both gram-positive and gram-negative bacteria monitoring the microorganism growth by spectrophotometry (optical density OD600) ...
Alm CC, Sullivan JJ, First NL.Dexamethasone (100 mg/day) injected from Days 318 to 324 of pregnancy induced parturition. Progesterone (500 mg/day) administered daily from Day 318 of pregnancy also shortened gestation while oestrogen (50 mg/day) administered on the same schedule as progesterone had no such effect. Dexamethasone treatment superimposed on the oestrogen or progesterone treatments shortened gestation. Prostaglandin F2alpha alone did not induce parturition, unlike PGF2alpha with dexamethasone, or PGF2alpha given to ovariectomized mares.
Geor RJ, Weiss DJ, Smith CM.Hemorheologic alterations induced by incremental treadmill exercise were examined in 5 Thoroughbreds. Blood viscosity; PCV; RBC filterability, density gradient profile, and shape; serum and RBC electrolyte concentrations; and plasma total solids and lactate concentrations were measured before exercise, at treadmill speeds of 9 and 13 m/s, and 10 minutes after exercise. Exercise was associated with significant (P < 0.05) increases in PCV, blood viscosity, and plasma total solids concentration. After adjustment of PCV to 40% by adding or removing each horse's own plasma, blood viscosity ...
King WA, Bezard J, Bousquet D, Palmer E, Betteridge KJ.Confusion exists as to whether the oocytes of the domestic horse are ovulated at the first meiotic metaphase (MI) or the second (MII). In this study eight oocytes were collected from the preovulatory follicles of 16 mares 36 h after human chorionic gonadotropin CG treatment. Six of the eight oocytes were judged to be at MII by the presence of the first polar body and this judgement was confirmed by semithin sectioning in one. Of the two that had no polar body, one was found to be at MII after fixation for chromosomal analysis and the meiotic stage of the other remained undetermined. Since all ...
Meyerholz DK, Caston SS, Haynes JS.An Appaloosa filly was born with a ventral midline, approximately 8 x 12 x 15 cm subcutaneous cervical mass. The nonencapsulated mass was composed of interlacing and haphazard bundles of spindle cells on moderate to abundant loose myxomatous stroma. A moderate number of cells showed cross striations with minor nuclear variation and a low mitotic rate. Immunohistochemical staining for myoglobin, desmin, actin, vimentin, and S-100 was positive and negative for glial fibrillar antigen and keratin. Rhabdomyomas are rare benign tumors of striated muscle. Rhabdomyomas described previously in the vet...
Chong YC, Duffus WP, Field HJ, Gray DA, Awan AR, O'Brien MA, Lunn DP.Over a period of two years, a total of 22 full term foals from Welsh Mountain pony mares were raised in conditions that were free from infection by Equid herpesvirus (EHV-1/4). Parturition dates were predicted by monitoring colostrum electrolytes, and the mares allowed to foal naturally under supervision or following induction with intravenous oxytocin. Immediately following birth, foals were separated from their dams and transferred to a specially built, positive pressure isolation unit. They were given antibiotic prophylaxis and fed bovine colostrum during the first 24 h, and then mare's mil...
Lang DC.A beam of pulsed ultrasound was used to treat musculoskeletal disorders in 53 horses and 143 dogs and cats. The cases were spread over seven years and 533 separate insonations were made. Doses, which varied according to the lesion, ranged from 0.2 to 3 watts/cm2 for five minutes in each treatment. In 63 per cent of the cases, rapid and complete resolution occurred.
Derossi R, Miguel GL, Frazílio FO, Nunes DB, Kassab TA.Bupivacaine is available as a racemic mixture of its enantiomers, d-bupivacaine and l-bupivacaine (LB). The aim of this randomized, double-blind study was to investigate the clinical efficacy and safety of S(-)-bupivacaine compared with standard racemic bupivacaine (RB) in horses under caudal epidural analgesia. Two treatments were administered to each horse, with a 2-week interval between subsequent treatments. Treatment 1 consisted of 0.5% LB at a dose of 0.06 mg/kg of body weight, and treatment 2 consisted of 0.5% RB at a dose of 0.06 mg/kg of body weight. Epidural injections were given in ...
Christen G, Gerber V, van der Kolk JH, Frey CF, Fouché N.Pituitary pars intermedia dysfunction (PPID) has been associated with diminished immune response in aged horses. This prospective study hypothesised that this may result in increased strongyle egg shedding in affected animals and that horses treated with pergolide would have reduced fecal egg counts (eggs per gram, EPG) compared to placebo-treated animals. Adrenocorticotropic hormone (ACTH) concentrations and EPG were tested in 48 horses. There were no significant differences in baseline EPG between horses with pre-clinical PPID and healthy controls. There was no significant difference in EPG ...
Serteyn D, Pincemail J, Mottart E, Caudron I, Deby C, Deby-Dupont G, Philippart C, Lamy M.This preliminary study demonstrated the existence of a free radical generation during an experimental postischemic muscular reperfusion in a halothane anesthetized horse. The authors used alpha-phényl-N-tert-butylnitrone as a spin trap agent and the electronic paramagnetic resonance method to observe in vivo a free radical generation. This preliminary study demonstrated the existence of a free radical generation during an experimental postischemic muscular reperfusion in a halothane anesthetized horse. The authors used alpha-phényl-N-tert-butylnitrone as a spin trap agent and the electronic ...
Marycz K, Smieszek A, Grzesiak J, Nicpoń JE.Disorders of the locomotive system, especially those occurring due to degenerative changes of the joints, are serious problems in daily veterinary medical practice. Steroid injections are the main way of treating these disorders. However, this approach brings usually only temporary effects of pain relief, and may cause many side effects. Alternative therapies focus on regeneration of damaged tissue using adult mesenchymal stem cells (MSCs). Since 2002, the great plasticity and immunomodulatory properties of MSCs isolated from adipose tissue (AdMSCs) have been used successfully in the treatment...
Huseman C, Walker N, McCorkle DA, Hanselka D, Cater M, Zoller J.The COVID-19 pandemic affected the economic status of all sectors of the global economy including the horse show industry. Reporting the impact of COVID-19 on in-person horse shows and an early assessment of its impact on the economy was the objective of this study. A Qualtrics survey instrument was disseminated to horse show participants through social media pages and email (n = 251). A majority of respondents were females (95.6%) representing a cross-section of the United States (84.0%). Participants reported planning to attend an average of 9.7 (SD = 7.15) in-person horse shows in 2020...
Fairbairn SM, Marr KA, Lees P, Cunningham FM, Page CP.Antigen challenge is known to cause the recruitment of neutrophils to the lungs of horses with chronic obstructive pulmonary disease (COPD). To evaluate a possible role of platelet activating factor (PAF) in this process, the effects of PAF on the distribution of radiolabelled neutrophils were compared in normal horses and asymptomatic horses with COPD. Changes in lung function, heart rate and the distribution of platelets and eosinophils were also measured. PAF (5 ng kg-1 intravenously) caused immediate but transient increases in the number of radiolabelled neutrophils in the lungs and a conc...
Oikawa M, Ohnami Y, Koike M, Park CH, Oyamada T.To evaluate the effects of endotoxin on the morphology of the equine central, autonomic and enteric nervous system and intestinal muscularis, six Thoroughbred horses with experimentally induced endotoxaemia were examined. The lesions in the central nervous system consisted of perivascular oedema around arterioles, suggesting brain oedema, and ring haemorrhages around veins, similar to those in human patients with septic shock. In the cranial mesenteric ganglia, neuronal cell bodies became pink or red, with shrinkage of cytoplasm indicative of ischaemic changes; intramural and perivascular infi...
Seabaugh KA, Hubert JD, Kawcak CE, McGilvray KC, Santoni BG, Rao S, Baxter GM.To quantify changes in biomechanical stability and stiffness within the equine carpus after removal of 50%, 80%, and 100% of the second metacarpal bone (MC2). Methods: In vitro biomechanical study. Methods: Cadaveric equine forelimbs (n = 16) were evaluated. Intact constructs were loaded in axial compression from 0 to 5000 N and compression + torsion (5000 N ± 20°) for 5 cycles. This was repeated after removal of 50%, 80%, and 100% of MC2. The primary biomechanical outcome variables were the compressive stiffness and compressive + torsional stiffness of the carpus. Relative kinematic motion ...
Drudge JH, Lyons ET.This review cites recent advances in the knowledge pertaining to infections of large strongyles in equids. Emphasis is placed on Strongylus vulgaris and attention is focused on pathogenesis of clinical manifestations of infections and treatment and control, including chemotherapy of migrating larvae and drug resistance.
Hinz A, Fischer AT.To compare the accuracy of ultrasonographic and radiographic examination for evaluation of articular lesions in horses. Methods: Cross-sectional study. Methods: Horses (n = 137) with articular lesions. Methods: Radiographic and ultrasonographic examinations of the affected joint(s) were performed before diagnostic or therapeutic arthroscopic surgery. Findings were recorded and compared to lesions identified during arthroscopy. Results: In 254 joints, 432 lesions were identified by arthroscopy. The overall accuracy was 82.9% for ultrasonography and 62.2% for radiography (P < .0001) with a se...
Littlewood JD, Rose JF, Paterson S.A single blind controlled clinical trial of oral ivermectin paste at a dose rate of 0.1 mg/kg daily for seven days for the treatment of chorioptic mange in horses was carried out. There was a statistically significant reduction in the numbers of mites in the samples taken from the treated horses compared with the untreated horses, but the mites were not eliminated from all the treated animals. Two further groups of horses were treated, one at a dose rate of 0.1 mg/kg daily for 10 days and the other with two doses of 0.2 mg/kg given two weeks apart. There were no statistically significant diffe...
de Macêdo LB, Mouta AN, Araújo-Silva G, Urizar JTP, de Paula VV.Metamizole (MT), also known as dipyrone, is an analgesic and antipyretic drug labeled for use in humans and domestic animals in some countries. As with other drugs, the administration of MT in donkeys is based on studies carried out with horses. In the present report, we aimed to determine the pharmacokinetics of the two main metamizole active metabolites (N-methyl-4-aminoantipyrine [MAA] and 4-aminoantipyrine [AA]) following 10 (M ) and 25 mg/kg (M ) IV metamizole doses in Northeast Brazilian donkeys (n = 10). Blood was collected at predetermined times within over 48 h; MAA and AA plasma ...
Duarte PC, Morley PS, Traub-Dargatz JL, Creekmore LH.To identify factors associated with development of vesicular stomatitis (VS). Methods: Case-control study. Methods: 138 livestock premises and 118 horses suspected of having VS in Texas, New Mexico, and Colorado. Methods: Premises with >or= 1 animal with clinical signs and laboratory confirmation of infection were classified as case premises. Premises where laboratory confirmation results were negative were control premises. Among equine premises, case and control horses were selected on the basis of premises status. A survey was conducted to identify factors associated with VS for premises an...
Seabaugh KA, Selberg KT, Valdés-Martínez A, Rao S, Baxter GM.To investigate tissue diffusion of anesthetic agent following administration of low palmar nerve blocks (LPBs) in horses. Methods: Randomized clinical trial. Methods: 12 adult horses. Methods: In 9 horses, mepivacaine hydrochloride-iohexol (50:50 dilution) injections were administered bilaterally (2 or 4 mL/site) to affect the medial and lateral palmar and palmar metacarpal nerves (4 sites). Lateral radiographic views of both metacarpal regions were obtained before and at 5, 15, 30, 60, 90, and 120 minutes after block administration; proximal and distal extents of contrast medium (and presumab...
Easton-Jones CA, Madigan JE, Barnum S, Maxwell LK, Taylor SD, Arnesen T, Pusterla N.Equine herpesvirus-5 is commonly isolated from the lungs of horses with EMPF, suggesting an etiological link. Valacyclovir is used empirically to treat EMPF; however, no data is available concerning its impact on EHV-5 viral kinetics. Objective: To determine the effect of oral administration of valacyclovir on EHV-5 viral load measured by qPCR in blood, nasal secretions (NS) and BALF in horses with EMPF. Methods: Six horses diagnosed with EMPF. Methods: A prospective clinical trial was performed. Horses received 10 days of PO administered valacyclovir (loading dose 30 mg/kg, maintenance dose 2...
Vandeplassche M, Bouters R, Spincemaille J, Bonte P.Eight cases of severe dropsy of the fetal sacs have been observed in mares. All were in multiparous mares whose ages ranged from five to 20 years and who were 7 1/2 to 10 3/4 months pregnant. Abortion started spontaneously in four cases and had to be induced in the remaining four by manual dilation of the cervix, rupture of the tough allantochorion and the siphoning off of 120 to 220 litres of allantoic fluid. The amnion was normal. Dystocia, due to uterine inertia, occurred in all eight cases, one hydrocephalic fetus needing fetotomy. All fetuses were alive at delivery although four were tera...