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.
Spurlock SL, Spurlock GH, Donaldson LL.A 3-year-old Thoroughbred mare with signs of acute abdominal pain and chronic pneumonia was found to have pneumothorax. A single application of suction was successful in resolving the pneumothorax. The underlying pneumonia was treated with long-term antibiotic administration selected on the basis of results of bacteriologic culture and antimicrobial susceptibility testing of a transtracheal aspirate. The pneumonia resolved, and the mare returned to competition as a show hunter.
Taylor FG, Mair TS, Brown PJ.Equine steatitis is a rare condition which is usually reported in foals. A case of generalised steatitis in an adult pony mare is described and compared with steatitis in other species. It is concluded that the condition resembled that recorded in foals but that its aetiopathogenesis remains obscure.
Allen BV.The influence of plasma proteins on erythrocyte aggregation was studied in a population of young thoroughbred racehorses, using the 60 minute erythrocyte sedimentation rate (ESR) with and without haematocrit standardisation. The ESR was correlated inversely with the haematocrit, but directly with fibrinogen, plasma viscosity and serum total globulins. When ESR values were standardised to a common haematocrit the correlation coefficients for the same plasma protein factors were increased. Albumin levels showed a strong direct relationship with haematocrit which accounted for the inverse correla...
Tobin T, Tai HH, Tai CL, Houtz PK, Dai MR, Woods WE, Yang JM, Weckman TJ, Chang SL, Blake JW.We have developed and evaluated a one step enzyme-linked immunosorbent assay (ELISA) test for fentanyl as part of a panel of pre- and post-race tests for narcotic analgesics in racing horses. This ELISA test detects fentanyl with an I-50 of about 100 pg/ml. The test is economical in that it can be read with an inexpensive spectrophotometer, or even by eye. The test is rapid, and ten samples, a normal pre-race complement, can be analyzed in about twenty minutes. The test readily detects the presence of fentanyl or its metabolites in equine blood and urine from two and twenty-four hours respecti...
Morris DD.This article reviews normal hemostasis in order to provide the reader with the basis for understanding the pathogenesis and manifestations (both clinical and laboratory) of disseminated intravascular coagulation (DIC) in horses. DIC is subsequently discussed. The diagnosis and treatment of DIC in horses are also described.
Anderson WI, Picut CA, Georgi ME.Heavy renal infection in a pony with Klosiella equi resulted in moderate diffuse tubular nephrosis and tubular rupture. Multifocal non-suppurative interstitial nephritis was associated with ruptured tubules. Ultrastructural examination of sporoblasts demonstrated both the presence of a bilaminated membrane encasing organisms and nuclear budding. Endogenous corticosteroid production probably led to the development of an immune-compromized state and subsequent extensive parasitic replication.
Fischer AT.After surgical correction of the underlying abdominal disorder, careful postoperative care is the most important factor resulting in increased survival rates. Intensive care of the postoperative patient can be done practically and economically.
Lloyd KC.Despite clinical signs compatible with obstruction or ischemia of the gastrointestinal tract, the clinician occasionally is unable to identify a gastrointestinal cause for colic. In this article, disorders not originating from obstruction or ischemia of the gastrointestinal tract but causing real or apparent abdominal pain are presented as alternative causes of colic. In addition, colic of gastrointestinal origin may be the primary inciting factor or a secondary complication of an alternative disorder, causing colic-like signs. Recognition of alternative diagnoses relies on a thorough and cons...
Kohn CW, Muir WW.Comparison of the visceral analgesic effects of xylazine, morphine, butorphanol, pentazocine, meperidine, dipyrone, and flunixin in a cecal distention model of colic pain indicated that xylazine produces the most relief from abdominal discomfort. Repeated administration of xylazine may reduce visceral pain so effectively that the seriousness of abdominal disease is obscured. Xylazine decreased propulsive motility in the jejunum and pelvic flexure of healthy ponies. Morphine and butorphanol also gave relief from visceral pain in the cecal distention model. Morphine may inhibit colonic, and buto...
Reed SM, Hegreberg GA, Bayly WM, Brown CM, Paradis MR, Clemmons RM.A severe and progressive neuromuscular disorder accompanied by clinical, electrophysiological, and pathological features resembling human dystrophia myotonica was observed in three foals. This disorder was apparent as early as 1 month of age and involved progressive skeletal muscle dysfunction, initially characterized by proximal muscle hypertrophy and hypertonicity with subsequent muscle stiffness, weakness, and atrophy. Multisystem involvement was manifested in one case by testicular hypoplasia, early cataract formation, and borderline glucose intolerance. Prolonged dimpling of these large r...
Rose J, Rose E.This article discusses some of the rationales for the medical management of colic during the initial treatment period. The issue of colic pain control and the masking of clinical signs that may indicate severe gastrointestinal disease is addressed. Therapeutic considerations related to dehydration, metabolic imbalances, hemostatic disorders, antimicrobial therapy, fecal consistency, gastrointestinal decompression, and regulation of intestinal motility are reviewed.
Bessent C, Ginther OJ.The caracteristics of early intrauterine mobility of the conceptus were compared between ponies (n = 9) and donkeys (n = 9). The extensive mobility of the early conceptus, previously reported for ponies and horses, was found in donkeys as well. There were no significant differences between donkeys and ponies in the characteristics or patterns of mobility. However, the mean day of fixation was approximately one day later (P<0.05) in donkeys (Day 15.6 +/- 0.3) than in ponies (Day 14.7 +/- 0.2).
Bain FT, Brock KA, Koterba AM.High-frequency jet ventilation was performed on a premature foal for respiratory difficulty attributable to in utero-acquired pneumonia. The procedure involves delivery of compressed gas through a small-bore cannula at frequencies up to 400 cycles/min. Ventilation settings of drive pressure, frequency, and FIO2 were varied to optimize PaO2 and PaCO2 values. The foal was ventilated with this equipment for 14 hours. Evidence of a favorable response to this method of ventilation was observed in the form of improvement in arterial blood gas values as well as the foal's attitude and degree of respi...
Mendel VE, Witt MR, Gitchell BS, Gribble DN, Rogers QR, Segall HJ, Knight HD.Nine adult horses were fed alfalfa hay cubes containing approximately 10% Senecio vulgaris until all horses had consumed approximately the same amount of toxic components of S vulgaris, pyrrolizidine alkaloids (PA). The amount of PA consumed was determined by the amount that induced clinical signs of PA toxicosis in 3 horses. The 6 other horses were given similar amounts per kilogram of body weight. An initial decrease of feed intake was observed when horses' diets were changed from alfalfa cubes to alfalfa/Senecio cubes, and feed intake was decreased further over 89 to 98 days. From 50 to 159...
Ducharme NG, Lowe JE.Based on the clinical impression and the current knowledge of the clinical variables (rectal examination, abdominal distention, abdominal fluid, intractable pain) most likely to differentiate between medical and surgical cases, three decision trees are provided as a guide to making the management decision in a horse with abdominal pain. Prior elimination of horses with limited life expectancy because of age or function or where financial constraints are present is understood. It must be emphasized that most of the information presently available originates from referral centers where the preva...
Markel MD.Peritonitis and adhesions in the horse are best managed through prevention. Perioperative antimicrobial therapy, nonsteroidal anti-inflammatory therapy, experienced personnel, and good surgical techniques should minimize complications after surgery. Despite preventative measures, some horses still develop peritonitis after surgery. Immediate, intensive treatment is necessary to enhance their chances for survival.
Anderson WI, King JM.Lumbar polyradiculopathy, characterized by ballooning myelin sheaths was diagnosed in multiple aged mammalian species including two horses, a cow, a squirrel, a woodchuck, a rabbit, a guinea pig, a hamster, and a mouse. The lesion was subclinical, and considered an incidental, age-related finding.
Greiner EC, Fadok VA, Rabin EB.Twenty-three species of Culicoides were trapped near pruritic horses during a 2-year survey in Florida. Nearly 99% of the biting midges collected were represented by Culicoides insignis Lutz, C. edeni Wirth and Blandon, C. stellifer (Coquillett), C. niger Root and Hoffman, C. haematopotus Malloch and C. venustus Hoffman. The relative contribution to the total catch by each of these species varied among collection sites. Seasonally, different species attain their largest population sizes at different times. Association of species collected in light traps with the seasonality of lesion developme...
Cohen ML, Ming RH, Gogel HK, Davis M, Pitcher JL.Phenylbutazone (PBZ) is a nonsteroidal antiinflammatory drug (NSAID) that is not commonly prescribed due to the high incidence of serious adverse reactions. However, it is still used extensively in equine medicine, and is readily available to those employed in the care and management of horses. Such persons may take the drug indiscriminately, without medical supervision. We present a 33-year-old male race horse track worker who took phenylbutazone horse pills for a chronic toothache and subsequently suffered a major hemorrhage from a gastric ulcer. Human use of phenylbutazone horse pills shoul...
Shappell KK, Stick JA, Derksen FJ, Scott EA.Between 1981 and 1986, permanent tracheostomy was performed in 46 ponies and 1 adult Quarter Horse. Tracheostomies of 19 ponies and the horse were examined in June 1986 and evaluated for vertical length of stomal orifice (mean = 25.0 +/- 4.7 mm in the ponies and 55 mm in the horse), degree of tracheal obstruction (0/20), regrowth and apposition of epidermis (3/20), and whether or not stomal airflow occurred with nasal occlusion (20/20). In addition, the animals were evaluated to determine whether dyspnea developed during exercise. Records of 27 ponies were evaluated. Six of the 27 were not dys...
Plotka ED, Eagle TC, Gaulke SJ, Tester JR, Siniff DB.Blood was collected from 486 feral horses of mixed sex and age classes captured from three wild horse management areas in Nevada and Oregon from December 1985 to February 1986. Males were significantly outnumbered by females in the Flanigan area, but both sexes were represented in approximately equal numbers in the Wassuk and Beaty's Butte areas. Hematology and chemistry values averaged 16.4 +/- 0.11, 46.3 +/- 0.28, 9.9 +/- 0.07, 6.9 +/- 0.10, 47.1 +/- 0.24, 16.6 +/- 0.09, 35.2 +/- 0.09, 10.4 +/- 0.14 and 23.4 +/- 0.25 for hemoglobin (HGB), hematocrit (HCT), red blood cells (RBC), white blood ...
Firth EC, Goedegebuure SA.The long bone ends of foals with infectious disease were sawn into sagittal slabs, washed and inspected. Tissue suspected to be abnormal on the basis of change of colour and consistency was radiographed, and then decalcified and examined histologically. The exact site of 140 focal osteomyelitis lesions from 18 foals was determined. There were more lesions in the epiphysis than the metaphysis. Epiphyseal lesions were in specific sites within a given epiphysis, and in most epiphyses the lesions were at the site of thickest cartilage. Metaphyseal lesions in the metacarpal, metatarsal and distal r...
Narinx F, Monclin S, Sauvage A, Vercruysse E, Heimann M, Alloway E, Vandersmissen M, Grauwels M.To describe the clinical presentation and treatment of an ectopic periorbital lymph node in two young horses. Two warm-blood horses were presented at the equine clinic of the University of Liège with a periorbital non-painful mass. Differential diagnosis included neoplasm (lymphoma), (sterile) abscess, cyst, ectopic lacrimal gland tissue, hematoma, adipose tissue, or ectopic lymphoid tissue. Information collected included physical and ophthalmic examination findings, results of the ocular and periocular ultrasound, surgical procedure, histopathology, and follow-up. Masses of 2 × 2 cm and 3 Ã...
Lees MJ, Bowen CV, Fretz PB, Leach DH.Areas of skin vascularized by large axial vessels potentially suitable for microvascular anastomosis were investigated in 10 horse cadavers. Eleven such areas were dissected, and the skin over the flank region vascularized by the deep circumflex iliac artery was most suitable. The anatomy of this area was further defined, using angiography and latex injection studies on 10 cadavers.
Hansen S, Laustsen L, Otten ND, Skovgaard K, Bech R, Byrgesen S, Hopster-Iversen C, Fjeldborg J.Alternative treatment options to glucocorticoids for equine asthma is desirable due to withdrawal time. The objective was to evaluate if serum and Respiratory Gene Technology (RGT), a commercial kit to produce autologous conditioned serum, was effective in reducing bronchoalveolar lavage (BAL) neutrophils and mast cells in racehorses with cytological evidence of mild equine asthma . Thirty-six Standardbred trotters in active training were enrolled in this randomized clinical trial; a healthy control group (n=11), a RGT group (n=12) and a serum group (n=13). Endoscopy including tracheal wash (T...
Harkiss GD.An isotype-specific microELISA is presented for the measurement of antibodies to equine antithymocyte globulin in human heart transplant recipients. The assay conditions were optimized and evaluated in serial samples from 40 patients receiving a cardiac allograft. The results demonstrate that despite steroid immunosuppression and T cell cytopenia the majority of patients receiving antithymocyte globulin develop significant antibody responses, with some producing very high titres. IgM and IgG isotypes tended to predominate, with peak antibody responses occurring during the second and third week...
Kriegshäuser G, Cullinane A, Kuechler E, Skern T.Equine rhinitis B virus 1 (ERBV1), genus Erbovirus, family Picornaviridae, is a pathogen of horses which causes clinical and subclinical infection of the upper respiratory tract in horses. The virus is widespread in European horse populations and the current standard method for the detection of antibody against ERBV1 is by virus neutralisation (VN). VN tests, however, are labour-intensive and time-consuming, require tissue culture facilities, and generally do not provide same-day results. In this study, a protocol for the high-level expression and purification of recombinant virion protein 1 (...
Platt JP, MacDonald DG, Selberg K, Jackman BR.A 14-year-old American Paint Horse mare was referred for further evaluation of a firm mass with an associated draining tract at the base of the left ear suspected to be a dentigerous cyst. Approximately three months prior, the draining tract had been excised under the presumed diagnosis of an abscess with no improvement. Physical examination revealed a firm mass palpable at the base of the left ear with a draining tract that did not elicit any pain response on palpation. Digital radiographs revealed a 6x11cm mineral mass in the left temporal region. Medially, there were two projections that ex...
Raggio I, Lefebvre RC, Poitras P, Vaillancourt D, Goff AK.Multiple pregnancies are still an important cause of noninfectious abortion, stillbirth, neonatal mortality, and significant delays in reproductive performance in mares. Despite new management techniques, reduction in multiple pregnancies is an ongoing preoccupation and challenge for the equine veterinarian. The aim of the present study was to establish a twin pregnancy experimental model in the mare to study the effectiveness of a transvaginal ultrasound-guided embryonic vesicle injection. Mares in heat were inseminated and then received an embryo at day 7 of the estrous cycle. At days 14 and...
Thomson JR, McPherson EA, Lawson GH, Wooding P, Brown R.The chymotrypsin activity of seven batches of Micropolyspora faeni and of five batches of Aspergillus fumigatus culture extracts, prepared for inhalation challenge in horses, was assayed and was found to range between 0.29 and 1.45 units/mg protein and 0.02 and 0.20 units/mg protein respectively. Horses affected with chronic obstructive pulmonary disease (COPD) were challenged with two batches of each antigen which had different chymotrypsin activities and no significant correlations were found between the degree of response to challenge and the chymotrypsin activity of the antigens. Inhalatio...
Heath SE, Bell RJ, Clark EG, Haines DM.Clinical signs of generalized granulomatous disease in a horse included depression, generalized lymphadenopathy, scaly skin, and dependent edema. Diagnosis was confirmed histopathologically by diffuse granulomas in more than one organ system (lymph nodes and skin), and by ruling out etiologic agents. Response to treatment with corticosteroids was favorable. The clinical features and response to treatment in this horse were different from classic textbook descriptions of equine generalized granulomatous disease. Equine granulomatous disease appears to be comparable to human sarcoidosis. To avoi...
el Hasnaoui H, el Harrak M, Tber A, Fikri A, Laghzaoui K, Bikour MH.An indirect fluorescent antibody (IFA) technique was used to screen and quantify antibodies against African horse sickness virus (AHSV) in equine sera. Results obtained with the IFA assay were compared directly with those obtained with standard complement fixation (CF) and virus neutralisation (VN) tests using horse sera from experimental studies and samples from the field. Positive fluorescent antibody titres were detected from as early as 7 days after primary vaccination and persisted for at least six months. The IFA technique offers a clear advantage over CF tests, where the antibodies are ...
Bedenice D.One of the fundamental skills required for practicing evidence-based medicine is the development of a well-built clinical question, which specifies the patient group or problem, intervention, and outcome of interest. For this purpose, various "levels of evidence" have been developed in the human literature, which rank the validity of evidence. Our established conclusions and advice are thus supported by specific "grades of recommendations," which are intended to give an indication of the "strength" of a clinical recommendation. This article was compiled with these principles in mind.
Sokół R, Raś-Noryńska M, Michalczyk M, Jasiecka A, Ziółkowski H, Jaroszewski J.The aim of the present study was to determine the efficacy of ivermectin against Cyathostominae infections and to describe the drug's pharmacokinetic parameters during two seasonal deworming treatments in horses. The study was performed on warm-blooded mares aged 3-12 years weighing 450-550 kg. A single bolus of an oral paste formulation of ivermectin was administered at a dose of 0.2 mg/kg BW in spring and autumn. Fecal samples were tested before treatment and 1, 2, 3, 4, 6, 10, 20, 30, 40, 50, 60, 75 days after treatment. Ivermectin concentrations in blood samples collected before treatment,...
Dik KJ, Nemeth F.Six cases of patella fractures are reported. Three horses presented an avulsion fracture of the medial patellar angle. For a precise diagnosis of this fracture a radiographic skyline view was indispensable; lateral views were not diagnostic. One of these horses recovered after three months' rest but radiographically the fracture remained visible. One horse with a comminuted fracture recovered after five months' rest. A case with a contaminated longitudinal patella fracture was destroyed. The sixth horse had a chip fracture of the dorsomedial part of the patella. The outcome of this case is unk...