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.
Lloyd KC, Stover SM, Pascoe JR, Baggot JD, Kurpershoek C, Hietala S.The concentration of gentamicin in plasma and synovial fluid of normal adult horses was measured periodically for 24 hours after IV (2.2 mg/kg of body weight), intra-articular (IA; 150 mg), and simultaneous IV and IA administrations. Gentamicin also was buffered with sodium bicarbonate (3 mEq) and then was administered IA and simultaneously IV and IA. Synovial fluid specimens were obtained via an indwelling catheter placed into the antebrachiocarpal joint. The peak mean plasma gentamicin concentration (8.30 micrograms/ml) after IV administration was significantly (P less than 0.05) greater tha...
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...
Ellis L.A 19-year-old appendix mare was presented with severe, acute right forelimb lameness and a history of significant hoof wall defect. The defect began as progressive toe separation affecting the dorsal hoof wall, which was eventually resected by a farrier. Placement of bar shoes by a farrier to stabilize the hoof was ineffective. Radiographs showed hoof wall separation, palmar rotation, and displacement of the coffin bone, consistent with failure of the laminar structures. Treatment included phenylbutazone, radiographic-guided therapeutic farriery consisting of derotation with a wedge shoe, and ...
de la Fuente A, Omyla K, Cooper C, Daels P, Meyers S, Dini P.Morphokinetic evaluation of embryo development has allowed the discovery of events occurring during blastulation. Here, we describe equine embryo pulsing, determined as continued expansion and contraction of both in vivo and in vitro produced blastocysts. Using time-lapse imaging, we demonstrated that pulsing starts during early blastocyst development of in vitro-produced embryos in horses. The median time for a complete contraction was 0.22h (0.08h-2h; min-max) where embryos reduced their sizes around 12.0% (median; 2.3%-27.0%) and the median time for an expansion was 3.3h (0.75-9.0h) where e...
Lester GD, DeMarco VG, Norman WM.To evaluate the efficacy of inhaled nitric oxide (NO) in anesthetized healthy newborn foals with experimentally induced pulmonary hypertension. Methods: Five 1- to 3-day-old foals. Methods: Anesthesia was induced and maintained with propofol, and foals were intubated and mechanically ventilated. Systemic pressure and pulmonary arterial pressure (P(PA)) were recorded every 30 seconds. Hypertension was induced via a hypoxic gas mixture or chemical vasoconstriction, using the thromboxane mimetic U46619. Nitric oxide was added at a concentration of 80 parts per million (ppm) for 6 minutes under ba...
Zhang J, Boyle MS, Smith CA, Moore HD.The acrosome of the stallion spermatozoon was visualized by indirect immunofluorescence with monoclonal antibody (18.6) which recognized an integral acrosomal membrane component. Localization was confirmed by electron microscopy using peroxidase labelled antibody. In fresh semen samples (n = 19), 73.9 +/- 9.1% of the spermatozoa from five fertile stallions displayed a uniform bright fluorescence over their acrosome region. In two semen samples from an infertile stallion only 28% and 35% of spermatozoa showed the same pattern of fluorescence. Spermatozoa from fertile stallions incubated for up ...
Kelmer G, Kramer J.Shortening of the deep digital flexor tendon was performed by tenotomy, overlapping and anastomosis. The procedure was performed on a two-year-old Quarter Horse Mare with distal interphalangeal joint hyperextension with subluxation and metatarsophalangeal joint hyperextension. These problems originated from damage to the digital flexor tendons, presumably due to previous distal limb trauma. The procedure markedly improved the mare's level of comfort, degree of ambulation and limb conformation. Two years following surgery the mare was comfortable at pasture.
Ganjam VK, Kenney RM, Flickinger G.The disappearance rate of progesterone from blood plasma of an ovariectomized mare was rapid and occurred in three phases. The half-life of the first component was 2-5 min and that of the second was 20 min; the half-life of the much slower third component was not measured. Progesterone, administered to ovariectomized and deeply anoestrous mares at the rate of 150 or 300 mg/day, maintained maximal peripheral levels of 6 to 8 ng/ml. Physiological levels were reached in 21 days using a dose of 150 mg and in 11 days with 300 mg daily. After withdrawal, circulating levels dropped rapidly. Blood pla...
Araujo GH, Rocha Filho AN, Lopes EP, Moya CF, Alvarenga MA.The effects of a low dose of equine purified FSH (eFSH) on incidence of multiple ovulations and embryo recovery rate in mares were studied. During the physiological breeding season in Brazil (19 degrees 45'45'S), 14 Mangalarga Marchador donor mares were used in a crossover study and another 25 mares of the same breed, between 3 years and 12 years of age were used as recipients for the embryo transfers. Donors were monitored during two consecutive oestrus cycles, an untreated control cycle followed by a treated cycle, when eFSH was administered. In both cycles, after an embryo collection attemp...
Donato GG, Appino S, Bertero A, Poletto ML, Nebbia P, Robino P, Varello K, Bozzetta E, Vincenti L, Nervo T.Mares' subfertility represents a complex diagnostic and therapeutic challenge and both clinical and subclinical endometritis are considered major causes of impaired fertility. Thanks to its properties, ozone has a big potential as a treatment for equine endometritis. Therefore, the aim of this study is to describe the safety and the effects on endometrium and reproductive parameters of mares of a commercial ozone foam preparation (Riger Spray®). Twenty-four mares were treated during estrus: ozone group with an intrauterine instillation of ozone foam preparation (OG, n=16) and control group wi...
Arthur RM.Racetracks are ideal environments for the promotion of lower respiratory disease. The stabling is close and unclean, the population is nationally and internationally mobile, and the work the racehorse performs is traumatic to the respiratory tract. The running horse must complete a respiratory cycle with each stride. This relationship requires 130-150 breaths a minute in the running horse. Minute volume has been measured at 1300 L per minute and peak flow rates of 60 L/second in horses traveling at a modest 8 meters per second. As a comparison, the fastest running horse approaches 18 meters pe...
Ito A, Imai S, Ogimoto K, Nakahara M.The composition of intestinal ciliates excreted in the feces of 20 Tokara native ponies kept in Iriki farm of Kagoshima University was surveyed. Eleven genera consisting of 18 species were identified based on the description of Strelkow. One new genus including a new species, Wolskana tokarensis n. gen., n. sp., of the family Buetschliidae was recognized and described. The average ciliate density of all horses was 13.8 x 10(3)/ml. Those of stallions (n = 5), mares (n = 11) and foals (n = 4) were 3.9, 16.1 and 43.3 x 10(3)/ml respectively. The value of stallions was significantly lower and that...
Moorthy AR, Spradbrow PB.Mycoplasmas were isolated from two of 43 nasal swabs taken from live horses, and from one of 28 tracheal swabs taken from slaughtered horses. The slaughtered horse that yielded mycoplasmas had no gross pathological changes in the respiratory tract, but the nasal isolations were made from horses with rhinitis. The three mycoplasmas could be distinguished by cultural characteristics, and probably they represent three different species.
Terblanche HM.Parturition was induced in 6 mares between Day 327 and 346 of pregnancy using oxytocin (Group I) and in 6 mares between Day 315 and 330 of pregnancy with fluprostenol in combination with oxytocin (Group II). A third group of 4 mares which served as controls were allowed to go to full term (322-340 days) and foal down normally. Parturition occurred within 24-102 min (mean = 61,4; SD = 31,6) in 5 of the Group I mares and within 160-185 min (mean = 173; SD = 10,86) in the mares of Group II. Expulsion of the afterbirth took place between 7 and 206 min (mean = 79; SD = 76,38) and between 7 and 73 m...