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.
Hatheway CH, Snyder JD, Seals JE, Edell TA, Lewis GE.Serum levels of equine-botulism antitoxin to toxin types A, B, and E were measured in four type-A botulism patients who had received equine-botulism antitoxin. High circulating levels capable of neutralizing in excess of 1 X 10(8), 9 X 10(7), and 6 X 10(6) 50% mouse lethal doses of toxin of types A, B, and E, respectively, were detected. There was little depletion of type-A antitoxin even though two of the patients had circulating type-A toxin before treatment. The half-life for antitoxin persistence for one patient was calculated as being 6.5, 7.6, and 5.3 days for antitoxin types A, B, and E...
Musselman EE, LoGuidice RJ.A necropsy diagnosis of hypoplastic left ventricular syndrome was made in a day-old foal. The cardiac abnormalities included mitral and aortic valve atresia, patent ductus arteriosus, and a secundum atrial septal defect. The left ventricle was hypoplastic and nonfunctional. The brief survival of the foal was a consequence of left-to-right shunting through the atrial septal defect and right-to-left shunting through the patent ductus. The information is presented to demonstrate the existence of the syndrome as a congenital defect in the horse and to clarify the necropsy findings for the practiti...
Soma LR, Korber K, Anderson T, Hopkins J.The effects of furosemide (0.55 mg/kg IV) on the plasma and urinary fentanyl (PFE UFE) concentrations were studied during steady-state conditions. The PFE during the steady-state period was 0.31 +/- 0.027 ng/ml, with no significant changes occurring, even though the rate of excretion of fentanyl (EX) increased during the 1st hour from 112.0 +/- 21.6 to 534.5 +/- 82.9 ng/minute. The EX returned to control levels within 3 hours, as did the UFE. The injection of furosemide increased glomerular filtration rate from 1.97 +/- 0.21 to 3.81 +/- 0.75 ml/kg/min. The fractional reabsorption decreased fro...
Pan LG, Forster HV, Bisgard GE, Dorsey SM, Busch MA.We assessed cardiovascular variables and blood O2 contents in order to characterize O2 transport in ponies during treadmill exercise. In normal ponies at 1.8, 3, and 6 mph, respectively, cardiac output (Qc) increased from 12 l/min at rest to maximum levels of 19.7, 28.7, and 39.9 l/min between 30 and 60 s. Qc then decreased to steady-state levels of 18.2, 24.6, and 32.7 l/min by 4 min. Heart rate (HR) showed a similar biphasic response in the 1st min of exercise. Systolic and diastolic arterial blood pressure (BP) decreased at the onset of exercise by 20-25 Torr (P less than 0.05) and then inc...
Ludwig KG, Craig TM, Bowen JM.Six mares were treated on the day of parturition with an intramuscular injection of 0.2 mg kg-1 ivermectin and placed in a pasture free of equine parasites as soon as possible after foaling. The mares and their foals were compared with a similar group of untreated mares and foals on an adjoining pasture. The experimental data was derived from mare and foal fecal egg counts, foal necropsies and pasture larval counts. Ivermectin administered to mares on the day of parturition, when combined with movement to parasite-free pastures, significantly lowered the cyathostome (small strongyle) egg produ...
Vandeplassche M, Simoens P, Bouters R, De Vos N, Verschooten F.In 214 cases of severe dystocia in mares, of which 141 (66 per cent) were Draught horses, deviation of the head and neck, with or without torticollis, malformed head and limbs were found to be the cause of dystocia. No evidence of a genetic lethal factor was found and torticollis was often combined with scoliosis of the head and, frequently, with malformation of one or more limbs. This is considered evidence of a common aetiology and pathogenesis of the syndrome of malformation. The malformations were found to be associated with an increased incidence of caudal and, particularly, transverse pr...
Held JP, Blackford JT.Three cases of vaginal perforation after coitus are discussed. The most consistent clinical sign is a small amount of blood escaping from the vulvar lips immediately after breeding. Secondary infection and posttraumatic swelling may cause abdominal pain due to rectal impaction. Treatment with high levels of an appropriate antibiotic is important to reduce the risk of a severe infectious peritonitis. The use of artificial insemination or a breeding roll to prevent full intromission is recommended.
McCoy DJ, Shires PK, Beadle R.Atlantoaxial subluxation secondary to odontoid fracture in a 30-day-old foal was corrected by alignment of the atlantoaxial joint and stabilization with 2 ventrally placed dynamic compression plates. At 90 days after surgery, healing of the fracture, with adequate alignment of the atlantoaxial joint, was confirmed radiographically. The foal was only slightly tetraparetic at that time. At 1 year after surgery, the gait was normal. It was concluded that the technique has advantages over the use of Steinmann's pins or external coaptation for stabilization. The ventral approach allows decompressio...
Forster HV, Pan LG, Bisgard GE, Dorsey SM, Britton MS.We characterized the temporal patterns of pulmonary O2 consumption (VO2) and CO2 excretion (VCO2) in exercising ponies. We also assessed the cardiac, ventilatory, and hematologic contributions to the VO2-VCO2 changes during exercise. At five moderate treadmill work loads in normal ponies, VO2 and VCO2 generally increased progressively throughout the 1st min reaching, respectively, approximately 95 and 80% of steady state by 45-60 s. Between 1 and 1.5 min, Vo2 and Vco2 were either stable or they decreased 300-500 ml, but then each increased slightly, reaching steady-state levels between 3 and 5...
Powers JD, Powers TE, Varma KJ, Gabel AA, Spurlock SL.Quantification of the clinical manifestations of a disease has been a serious problem particularly as related to clinical trials or drug efficacy studies. Historically, this quantification has been limited to categorizing each patient into one of three or four groups, e.g. worse, no improvement, improved. This problem becomes serious when an investigation utilizes an experimentally induced animal disease model. A health index, which quantifies the clinical state of horses which have an experimentally induced beta-hemolytic streptococcal infection, is described. Aspects of experimental design a...
Goetz TE, Coffman JR.Ulcerative colitis, protein losing enteropathy and intestinal histoplasmosis-salmonellosis were diagnosed in a six-year-old Quarterhorse stallion. For six months before examination, the horse experienced a slow continual loss of weight. During the 17 day period of hospitalisation the horse developed progressive generalised oedema. On the 12th day of hospitalisation a severe profuse watery diarrhoea began; the horse was killed five days later.
Thurman JD, Johnson BJ, Lichtenfels JR.Arteriosclerosis caused by Dirofilaria immitis adult parasites was diagnosed in a 20-month-old Quarter horse stallion that died from cantharidin toxicosis. Microscopically, the pulmonary vascular changes were typical of those described as "proliferative endarteritis" in D immitis-infected dogs.
Corda M, Pellegrini M, Rinaldi A.Diamine oxidase was prepared from horse kidney by a procedure involving heat denaturation at 50 degrees C, ammonium sulfate fractionation, chromatography on hydroxyapatite and on G-200 Sephadex columns. This procedure gave about 1000 fold purification over the crude kidney cortex homogenate. The enzyme preparations thus obtained are stable only at high ionic strength. The effect on enzyme activity of salt concentration and various stabilizing agents have been investigated. The horse kidney diamine oxidase is irreversibly inhibited by carbonyl reagents and shows substrate specificity quite simi...
Ramey DW, Reinertson EL.A diagnosis of sand enteropathy was made in a 3 1/2-month-old Quarter Horse filly. Clinical signs included diarrhea and weight loss of 2 1/2 months' duration. Abdominal radiographs were useful in diagnosis of the condition and in evaluating response to therapy. The filly responded to treatment with psyllium hydrophilic mucilloid although full recovery took 2 months. Diagnosis and treatment of sand enteropathy is discussed.
van Amstel SR, Reyers F, Colly PA.Variable results were obtained when the starch digestion test was carried out on a suspected case of malassimilation in a horse. In order to re-evaluate this test, 15 starch digestion tests were carried out using 4 horses. Results showed a marked variation in the increase in plasma glucose levels between individual horses and especially between poor and good condition horses when the dose of starch was based on body mass. Results also suggest that a fixed dose of starch may give more consistent results.
Miller PJ, Holmes JR.The anatomy of the equine mitral valve and certain variations observed in 60 adult horses are described. The functional role of this valve, sited between the left atrium and the high pressure-generating left ventricle, is discussed in relation to its anatomical structure. A method of examining the left side of the heart post mortem is described.
Colbern GT, Moore JN.A patellar fracture was identified radiographically in the right stifle of a mature Tennessee Walking Horse stallion. The horse was markedly lame (grade IV/V) on the right hindlimb. Due to the articular nature and small size of the fragment, surgical removal via arthrotomy was selected. A dorsomedial approach to the femoropatellar joint was used. The horse recovered well and has returned to training as a show horse by 8 months following surgery.
Said AH, Khamis Y, Mahfouz MF, Hegazy A.Clinical and pathological changes following neurectomy were studied experimentally in 46 male and female equids. Sixty-three operations were performed using either the traditional or the Fackelman and Clodius methods of neurectomy. The effect of arteriovenous ligation was studied in 12 animals and 20 angiograms were performed post mortem to study the arterial pattern of the extremities of the operated limb. Neuroma formation (31 cases) and sloughing of the hoof (five cases) were the two main untoward sequelae. Neurectomy by the technique of Fackelman and Clodius proved superior to the traditio...
Horak IG, Biggs HC, Reinecke RK.Twelve Hartmann's mountain zebra, Equus zebra hartmannae, were shot for arthropod parasite recovery during the period June 1980-June 1981 on a farm in the Khomas Hochland region of South West Africa/Namibia. Four species of Gasterophilus larvae, 1 species of Rhinoestrus larvae and 3 ixodid tick species were recovered. The seasonal prevalence of the Gasterophilus species larvae and of Rhipicephalus evertsi mimeticus was determined. Three horses examined on the same farm were infested with larvae of 2 Gasterophilus species and with the same ixodid tick species as the zebras.
Muylle E, Nuytten J, Van den Hende C, Deprez P, Vlaminck DK, Oyaert W.The concentration of potassium in the red blood cells in 15 horses with severe diarrhoea was determined. The red blood cell potassium content (RBCK+) was low compared with levels obtained in normal horses. The decrease in the RBCK+ was used to evaluate the total body potassium deficit. This calculated amount was administered orally, following each RBCK+ determination. In those horses which recovered, RBCK+ content returned to normal levels. During treatment, refilling of the red blood cells with potassium occurred only gradually as long as the diarrhoea persisted. In each case, oral loading wi...
Kold SE, Hickman J.The results of surgical treatment of 10 subchondral bone cysts, all located in the medial femoral condyle, are presented. A cancellous bone graft was used in nine cases and a two component acrylic bone cement was used in the case of an extremely large cyst. Eight out of the 10 cases made a satisfactory clinical recovery.
Toutain PL, Brandon RA, de Pomyers H, Alvinerie M, Baggot JD.Pharmacokinetics of dexamethasone and prednisolone were studied in 6 horses given dexamethasone alcohol (IV or IM) or dexamethasone 21-isonicotinate as a solution IV or IM (50 micrograms/kg of body weight), prednisolone 21-sodium succinate IV or IM (0.6 mg/kg of body weight), or prednisolone acetate IM (0.6 mg/kg of body weight). Plasma concentrations were determined using a high-performance liquid chromatographic method. After dexamethasone alcohol (IV) or dexamethasone 21-isonicotinate (IV), the half-life of elimination was similar (53 minutes) for both formulations. After dexamethasone (alc...
Kulinski KM, Thompson DL, Capshaw EL, French DD, Oliver JL.This experiment assessed the effects of 12 mo of daily treatment of young horses with recombinant equine somatotropin (eST) on 1) carcass and internal organ traits at necropsy and 2) residual effects in live horses for 60 d after cessation of treatment. Seven horses received eST daily at 20 microg/kg BW; seven others received vehicle (controls). Four horses from each group were killed at the end of treatment. There were few effects of eST treatment on hematologic assessments or histopathologic evaluations of internal organs. Treatment with eST increased the weights of the right adrenal gland (...
Wong JKY, Leung DKK, Curl P, Schiff PJ, Lam KKH, Wan TSM.The detection of boldenone, nandrolone, 5(10)-estrene-3β,17α-diol, and 4-estrene-3,17-dione in a urine sample collected from a gelding having been treated with testosterone (500 mg 'Testosterone Suspension 100', single dose, injected intramuscularly) in 2009 led the authors' laboratory to suspect that these 'testicular' steroids could be minor metabolites of testosterone in geldings. Administration trials on six castrated horses with Testosterone Suspension 100 confirmed that low levels of boldenone, nandrolone, 5(10)-estrene-3β,17α-diol, and 4-estrene-3,17-dione could indeed be detected ...
Morel MC, Newcombe JR, Reynolds N.The mare's reproductive system is rarely capable of sustaining multiple pregnancies to term. Multiple pregnancies largely derive from multiple ovulations, most commonly double ovulations, hence, double ovulations are of significant concern to breeders/veterinarians. Double ovulations may be synchronous or asynchronous. Asynchrony of up to 96 hours may result in two embryonic vesicles of very different sizes, which are challenging to detect at early ultrasonic pregnancy detection. This study aims to (1) document the incidence of synchronous and asynchronous double ovulation and (2) determine ...
Williams S, Scott P.Meal contaminated by Datura stramonium seeds at the rate of 0.5% by weight was fed to two horses. Both horses showed clinical signs of depression, anorexia, weight loss, rapi heart and respiration rates, mydriasis, polyuria, polydipsia and diarrhoea. Both recovered with treatment. Maize screenings contaminated by the seeds had been used in the manufacture of the meal.
Stewart JH, Rose RJ, Young IH, Costas L.The distribution of ventilation-perfusion (VA/Q) ratios, before and after 100 per cent oxygen, was studied in an induced-premature foal at 4 h and again at eleven days of age, using the multiple inert gas elimination technique. The major finding was an absence of low VA/Q ratios when breathing air, indicating that low PaO2 in the neonatal period was totally attributable to the right-to-left shunt. At 4 h of age the PaO2 was 5.48 kPa and the right-to-left shunt represented 33.4 per cent of the cardiac output. At eleven days of age the PaO2 was 9.76 kPa and right-to-left shunt was 10.1 per cent ...
Pozio E, Celano GV, Sacchi L, Pavia C, Rossi P, Tamburrini A, Corona S, La Rosa G.Epidemiological investigations conducted during 10 trichinellosis outbreaks between 1975 and 1994 showed that horse-meat was the probable source of infection. Though hundreds of thousands of horses have been examined at abattoirs in America and Europe to detect Trichinella infection by artificial digestion or trichinelloscopy, an infected horse has never been detected during routine analysis, which consists of examining 1 g of tissue muscle from the diaphragm. In November 1996, a naturally infected horse imported from Romania was detected in Southern Italy. The parasite was identified as Trich...
Ainsworth DM, Dodds WJ, Brown CM.A 16-year-old gelding was examined because of weight loss, inappetence, and intermittent fever of 2 months' duration. Preliminary laboratory findings revealed anemia, hypoproteinemia, thrombocytopenia, and prolongation of the activated partial thromboplastin time. A deficiency or inhibition of coagulation factor XI, factor XII, or high molecular weight kininogen was diagnosed. This defect was not associated with a bleeding diathesis, but should be considered as a cause of prolongation of the activated partial thromboplastin time.
Hughes KJ, McGorum BC, Love S, Dixon PM.Six ponies and four horses with a mean (sd) age of 15.9 (6.0) years developed sudden-onset bilateral laryngeal paralysis (BLP) in association with hepatic dysfunction. Nine of them had been referred for the investigation of respiratory distress, and one pony had been referred for weight loss before BLP developed. Nine of the animals had clinicopathological evidence of liver disease, and nine had histological evidence of liver disease. All of the animals had one or more of the following: hepatic encephalopathy (in eight), hyperammonaemia (in six) and endoscopic evidence of BLP (in nine). Three ...
Paweska JT, Henton MM, van der Lugt JJ.Clinical, virological and serological responses were evaluated in 10 pregnant mares after different challenge exposures to the asinine-94 strain of equine arteritis virus (EAV). The outcome of maternal infection on the progeny was also investigated. Mares were inoculated intranasally (n = 4), intramuscularly (n = 2), intravenously (n = 1), or contract-exposed (n = 3). All inoculated mares developed pyrexia, 5 showed mild clinical signs related to EAV infection and 2 remained asymptomatic. Viraemia was detected in all the inoculated animals and shedding of virus from the respiratory tract occur...
Brosnan RJ, Steffey EP.We hypothesized that propofol can produce rapidly-reversible, dose-dependent standing sedation in horses. Methods: Prospective randomized, blinded, experimental trial. Methods: Twelve healthy horses aged 12 +/- 6 years (mean +/- SD), weighing 565 +/- 20 kg, and with an equal distribution of mares and geldings. Methods: Propofol was administered as an intravenous bolus at one of three randomized doses (0.20, 0.35 and 0.50 mg kg(-1)). Cardiovascular and behavioral measurements were made by a single investigator, who was blinded to treatment dose, at 3 minute intervals until subjective behavior s...