Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Hodgkinson JE, Freeman KL, Lichtenfels JR, Palfreman S, Love S, Matthews JB.The efficacy of five daily fenbendazole (FBZ) treatments was tested against benzimidazole-resistant cyathostomins in naturally infected horses (n=13). Horses were treated with pyrantel embonate (PYR) to remove adult strongyles followed, 7 days later, by a 5-day course of FBZ. The PYR treatment produced an average faecal egg count reduction of 98%. All samples were negative by faecal egg count 7 days after the start of the FBZ treatment. Positive egg counts were observed from 28 days after the start of FBZ treatment and all horses displayed positive faecal egg counts by 77 days after treatment....
Gustafson-Seabury A, Raudsepp T, Goh G, Kata SR, Wagner ML, Tozaki T, Mickelson JR, Womack JE, Skow LC, Chowdhary BP.High-resolution gene maps of individual equine chromosomes are essential to identify genes governing traits of economic importance in the horse. In pursuit of this goal we herein report the generation of a dense map of horse chromosome 22 (ECA22) comprising 83 markers, of which 52 represent specific genes and 31 are microsatellites. The map spans 831 cR over an estimated 64 Mb of physical length of the chromosome, thus providing markers at approximately 770 kb or 10 cR intervals. Overall, the resolution of the map is to date the densest in the horse and is the highest for any of the domesticat...
Xu J, Lasry JB, Svaren J, Wagner B, Darien BJ.P-selectin glycoprotein ligand-1 (PSGL-1, CD162) is a dimeric, mucin-like, transmembrane glycoprotein constitutively expressed on leukocytes. A high baseline level of P-selectin expression in circulating equine platelets suggests a primed state toward inflammation and thrombosis via P-selectin/PSGL-1 adhesion. To investigate the potential role of equine P-selectin in these events, we first identified the cDNA sequence of equine PSGL-1 (ePSGL-1) using degenerate PCR and RACE-PCR and then compared the predicted sequence with that of human PSGL-1 (hPSGL-1). ePSGL-1 protein subunit is predicted to...
Gibson VA, Stover SM, Gibeling JC, Hazelwood SJ, Martin RB.We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4 x 10 x 100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thorou...
Estrada-Franco JG, Navarro-Lopez R, Freier JE, Cordova D, Clements T, Moncayo A, Kang W, Gomez-Hernandez C, Rodriguez-Dominguez G, Ludwig GV....Equine epizootics of Venezuelan equine encephalitis (VEE) occurred in the southern Mexican states of Chiapas in 1993 and Oaxaca in 1996. To assess the impact of continuing circulation of VEE virus (VEEV) on human and animal populations, serologic and viral isolation studies were conducted in 2000 to 2001 in Chiapas State. Human serosurveys and risk analyses indicated that long-term endemic transmission of VEEV occurred among villages with seroprevalence levels of 18% to 75% and that medical personnel had a high risk for VEEV exposure. Seroprevalence in wild animals suggested cotton rats as pos...
Pollock RV.Advances in digital technology have vastly increased the speed and content of information transfer. Equine practitioners of the future should be in contact with their office and other information resources at all times through an array of digital networks. Patients and practitioners alike should benefit from better information access.
Frisbie DD, McIlwraith CW.The field of equine veterinary practice is in an ever-evolving state, requiring current technologies to be constantly evaluated for new applications. The specific use of gene therapy in the horse is a novel application. The authors want to help familiarize the equine practitioner with the concept of gene therapy, and introduce its use and potential future benefits for the equine industry in the treatment of osteoarthritis.
Miller RM.For decades after the discipline of psychiatry had been established as an accepted specialty, many medical schools continued to fail to train their students in the fundamentals of this discipline. Medical students all have at least cursory exposure to psychiatric principles and basic psychology. Unfortunately, the veterinary profession has lagged behind human medicine in this regard. Until recently, veterinary students received no training in animal behavior, and there were no available residencies within our schools for developing board-certified behavioral specialists.
Marr CM.The digital storage and transfer of images coupled with the development of the Internet have revolutionized diagnostic imaging. With the press of a button, practitioners can exploit the diagnostic skills of specialists anywhere in the world and enlist their help with challenging cases. This easy transfer of images and digital data should stimulate a greater number of multicenter studies so that the sensitivity and specificity of ultrasonographic techniques can be established in larger and more meaningful cohorts of patients. There is now no doubt that we can identify a plethora of conditions o...
Martinelli M.Digitization of clinical data is becoming increasingly important in veterinary medicine. Current veterinary applications range from digital cameras to computed radiography. The opportunity for increased productivity and diagnostic capabilities makes the computerization of veterinary medicine especially exciting. Future trends seem to indicate that more veterinarians should have better technology available in their practices and more veterinarians should be connected to experts, clients, and each other.
Sansom J, Featherstone H, Barnett KC.Six horses with keratomycosis were examined and three different clinical expressions of the disease were recognised. The diagnostic work-up and response to treatment is described.
Gutmann S, Zawatzky R, Müller M.Interferon-gamma (IFN-gamma) is a key cytokine in cell-mediated immunity. To measure IFN-gamma production of equine lymphocytes (eqIFN-gamma), we developed a quantitative ELISA. Monoclonal antibodies (mAb) were produced against bacterially derived eqIFN-gamma. The mAbs recognised recombinant and lymphocyte-derived eqIFN-gamma in ELISA, Western blotting, as well as flow cytometric and microscopic analysis. In contrast to bacterially derived material, mammalian and insect cell-derived eqIFN-gamma was biologically active but could be neutralised by one of the monoclonal antibodies. Unexpectedly, ...
Fenger CK.Technology promises to improve the lifestyle and life quality of humankind. As a rule, wherever human medicine goes, veterinary medicine is sure to follow. Nevertheless, the promise of technologic advances does not shine as bright for veterinarians as for human physicians. This trend is echoed in the business of animal health as pharmaceutic company after pharmaceutic company spins off or otherwise eliminates their animal health division. Instead, a small group of strictly animal health-oriented companies compete for the animal health dollar, promising that fewer and fewer expensive technologi...
Cowles RR, Mitchell JS.As equine practices move forward in the 21st century, we feel increasing pressure to manage our businesses like business people. This requires outside expertise, in-house business-trained managers, and continuing education on various aspects of practice life. Aside from the AAEP, several other organizations are providing continuing education in management, including the Association of Veterinary Practice Managers, the Veterinary Management Institute offered at Purdue University Krannert Graduate School of Management, the American Animal Hospital Association through (The Virginia-Maryland Regio...
Wyant LA.The Internet is a fast-growing technology that allows information (text as well as images) to be shared across the world in an instant. As computer systems, software, and Internet services become less expensive options, the world becomes more experienced and comfortable with these technologies. In the foreseeable future, equine veterinarians are likely to be better educated about diseases and treatments, better connected with specialists for consultations on difficult cases, able to respond to client communications more efficiently, able to accurately educate clients, and able to communicate w...
Tozaki T, Hirota K, Hasegawa T, Tomita M, Kurosawa M.Linkage disequilibrium (LD) mapping is often used in searches for genes governing economically significant traits and diseases. The D' coefficient is a commonly used measure of the extent of LD between all possible pairs of alleles at two markers. This study aimed to test the utility of the D' coefficient for LD mapping of a trait in a thoroughbred population. Microsatellite genotype data and grey coat colour as a trait model in a thoroughbred population were used to assess the extent of LD. We demonstrated that LD mapping was a reasonable approach for initial genome-wide scans in a thoroughbr...
Johnson NL, Galuppo LD, Stover SM, Taylor KT.To compare screw insertion variables and pullout mechanical properties between AO 6.5-mm cancellous and 7.3-mm cannulated bone screws in foal femoral bone. Methods: A paired, in vitro mechanical study. Methods: Seven pairs of femora from immature (1-7 months) foals. Methods: The 6.5 cancellous and 7.3-mm cannulated screws were inserted at standardized proximal and distal metaphyseal, and mid-diaphyseal locations. Insertion torque, force, and time to drill, tap (6.5-mm cancellous), guide wire insertion (7.3-mm cannulated), and screw insertion were measured. Screw pullout properties (yield and f...
Greene SK.The reintroduction and development of safe motorized instruments, the increased availability of continuing education, and the understanding and implementation of appropriate procedures allow practitioners to provide better dental care. Veterinarians realize that sedation, analgesia, a full-mouth speculum, and proper instrumentation are necessary to provide these services. Continued instrument design, future research, and new treatment and prophylactic protocols should have a positive impact on the future of equine dental health. New and rediscovered procedures for equilibrating equine occlusio...
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....
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...
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...
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...
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...
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...
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...
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...
van Heel MC, Barneveld A, van Weeren PR, Back W.Studies on hoof balance have, so far, only assessed the effects of strong and relatively unrealistic interventions due to technical limitations of measuring equipment. For the assessment of more subtle interventions, other techniques are necessary. Objective: To test a sensitive pressure measurement system during locomotion and to set a standard for further studies by using the system to evaluate the effects of trimming. Methods: Eighteen horses were measured before and after trimming with an interval of 4 weeks. Trimming was standardised to a straight hoof-pastern axis. The horses trotted ove...
Acland HM, Kenney RM.Twenty-three mares were infected with contagious equine metritis organism by intrauterine inoculation, and necropsied after intervals of two to 116 days. Severe diffuse subacute salpingitis was seen in one mare, and mild multifocal subacute salpingitis was common. Severe diffuse endometritis and cervicitis initially were acute and became more severe, subacute and predominantly plasmacytic by 14 days, then declined but persisted as mild diffuse or multifocal inflammation for the rest of the experimental period. Vaginitis arose in parallel but resolved after 70 days. There were no lesions in the...
Roberts GD, Graham JP.CR is a useful tool for the equine veterinarian and has many advantages. Its only major disadvantage is the initial cost, in dollars and time, for setup in one's practice. CR is already in use at several universities and private practices in the United States and around the world. In the future, as is the case with any computer-based technology, this modality should become more affordable and readily available to smaller practices. The potential of CR in veterinary medicine combined with saturation of the human market is driving the development of specialized software and algorithms for veteri...
Mason TA, Speirs VC, Maclean AA, Smyth GB.A technique for the surgical repair of a cleft soft palate in the horse is described. A symphysiotomy approach was employed to repair the anterior end of the cleft palate, and the posterior part was approached via a pharyingotomy incision.
Cardwell JM, Christley RM, Gerber V, Malikides N, Wood JL, Newton JR, Hodgson JL.The term 'inflammatory airway disease' (IAD) is often used to describe the syndrome of lower airway inflammation that frequently affects young racehorses in training around the world. In practice, this inflammation is generally diagnosed using a combination of endoscopic tracheal examination, including grading of amounts of mucus present and tracheal wash sampling. However, a recent consensus statement from the American College of Veterinary Internal Medicine concluded that bronchoalveolar lavage (BAL) sampling, rather than tracheal wash (TW) sampling, is required for cytological diagnosis of ...
Richardson DW, Evans LH, Tulleners EP.Rostral mandibulectomy with primary gingival closure was performed in 5 horses with rapidly growing or bleeding mandibular tumors. The technique involved preservation of the most caudal portion of the mandibular symphysis to maintain stability. There were no surgical complications or recurrences, and the cosmetic and functional results were good. The histopathologic diagnosis of all the tumors was ossifying fibroma. Rostral mandibulectomy affords a simple and effective technique of treating tumors of the rostral portion of the mandible in horses.
Estberg L, Case JT, Walters RF, Cardiff RD, Galuppo LD.The objectives of the current project were to: (1) identify limitations of search sensitivity and positive predictive value (PPV) for free-text surgical diagnoses included in electronic patient records maintained at the University of California, Davis, Veterinary Medical Teaching Hospital (VMTH), (2) develop procedural or programmable recommendations for removing these limitations, and (3) provide guidelines for effective search strategies for users performing aggregate searches using the VMTH clinical information system. Search sensitivity corresponds to detection sensitivity (the capacity of...
Secor EJ, Matychak MB, Felippe MJ.This study aimed to determine whether TNF-α is transferred to equine neonates via colostrum and the relationship between TNF-α and IgG concentrations in the equine neonate. Colostrum, presuckle and postsuckle foal serum samples were collected from healthy mares and their foals. Equine TNF-α ELISA and IgG SRID kits were used to determine the concentrations of TNF-α and IgG, respectively. Statistical analysis was performed using the Spearman rank correlation. TNF-α concentrations in all presuckle foal serum were below the limit of detection in 15/16 foals and increased in postsuckle foal se...
McClure JT.Leukoproliferative disorders reported in horses include lymphoma, lymphocytic leukemia, plasma cell myeloma, granulocytic leukemia, monocytic leukemia, myelomonocytic leukemia, and eosinophilic leukemia. Lymphoma affects horses of all ages, whereas leukemias often occur in younger horses. Clinical signs are often nonspecific including depression, anorexia, fever, and weight loss. Specialized diagnostic techniques such as cytochemistry and immunophenotyping better define the cellular origin of leukoproliferative disorders, which is essential for developing appropriate therapeutic protocols and ...
Leid RW, Coley SC, Blanchard DP, Perryman LE.The equine alternative complement pathway has been partially characterized and compared to the equine classical activation pathway. A dose-dependent lysis of RbRBC was observed with peak lytic values noted within 10 minutes at 37 degrees C when rabbit red blood cells (RbRBC) were used as an alternative pathway activator. Sheep red blood cells (SRBC) sensitized with rabbit hemolysin or partially purified equine IgM antibodies were equally sensitive to lysis. Dilution of the commercial hemolysin by 1/5 reduced lysis from 90% to 38% in the presence of constant cell numbers. Hemolysis of SRBC peak...
McLean JG, Lewis IM.The oxygen affinities of horse and human haemoglobins were compared in the absence and presence of the allosteric effector 2,3-diphosphoglycerate (2,3-DPG). Horse haemoglobin solutions showed significantly smaller responses to the presence of 2,3-DPG, and this difference may be due to different amino acid substitutions at position NA2(2)beta. Horse haemoglobin solutions from erythrocytes containing different ratios of the two different haemoglobin types showed similar oxygen affinities in the absence and presence of 2,3-DPG. Horse haemoglobins in solution were found to autoxidise to methaemogl...
McKinney AR, Suann CJ, Stenhouse AM.A method was developed for the analysis of the synthetic progestin 17alpha-hydroxyprogesterone caproate in equine plasma following its administration by intramuscular injection. The method employed a reversed-phase solid-phase extraction followed by enol-trimethylsilylation and analysis by gas chromatography/tandem mass spectrometry. The intact ester was detectable in the plasma for up to 2 weeks after a single therapeutic dose, and was found to be stable in equine whole blood for at least 2 months.
Black SJ.The structure and dynamic nature of extracellular matrix is discussed in the context of healthy and diseased tissues particularly the equine digital laminae.
Goodrich LR.Equine orthopedic pain management has become a growing area of interest. Its importance has been emphasized in many studies showing that better pain management results in decreased postoperative complications such as chronic pain, support-limb laminitis, gastric ulceration, and gastrointestinal disease. This review is meant for the surgeon managing orthopedic pain pre-, peri-, and postoperatively.
Freeman DE.Intravenous lidocaine is widely used to prevent or treat postoperative ileus in horses. Clinical studies that support this approach are flawed and contradicted by others. Also, physical obstruction could be more important in causing postoperative reflux than postoperative ileus in the horse. The antiinflammatory properties of lidocaine and the role of inflammation from intestinal handling in the genesis of postoperative reflux are questionable. Because of cost and questionable efficacy of lidocaine, a well-designed clinical trial is required to support its continued use. However, lidocaine cou...
Michalska J, Nowicka B, Wessely-Szponder J.We hypothesized that in horses with naturally occurring joint disorders, the neutrophil response, acute phase response (APR), and oxidative stress parameters elevated significantly and are markers of increased inflammatory response in these conditions. Therefore, the first aim of the study was to evaluate neutrophil response, oxidative status, and APR. The neutrophil activity was assessed on the basis of elastase, myeloperoxidase (MPO), and alkaline phosphatase release, whereas free radical generation was assessed on the basis of nitric oxide and superoxide production. Acute phase response was...
Scholl PJ, Chapman MR, French DD, Klei TR.In a trial designed to evaluate the efficacy of the recommended dosage of moxidectin 2% oral gel against the gastric stages of Gasterophilus spp., 14 ponies were selected from a herd on the basis of the inclusion criterion of the presence of Gasterophilus spp. eggs attached to their hair coats. After random allocation, the ponies were treated with 1 of 2 treatments, moxidectin 2% equine gel in a single dose at the commercial dosage of 400 microg moxidectin/kg body weight or placebo gel. The animals were necropsied 14 days posttreatment. Efficacies against second- and third-instar Gasterophilus...
Klei TR.Helminths are among the most significant parasites of horses in developed countries. This article examines immune responses against helminth parasites and the implications that immunologic investigations have on vaccine development, improvement of diagnostic procedures, and disease eradication.
Hance SR.Colopexy is a surgical procedure designed to create an adhesion from the ventral colon to the body wall to prevent recurrence of large colon volvulus or displacement, and is a useful technique to prevent recurrence of this disease. Colopexies usually are reserved for broodmares, because this is the population of horses that is most predisposed to recurrence of large colon volvulus.