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.
Bentz BG, Granstrom DE, Stamper S.To determine seroprevalence of Sarcocystis neurona-specific antibodies in a population of horses residing in Chester County, Pa. Methods: Prevalence survey. Methods: 117 serum samples from selected members of a population of 580 Thoroughbred horses. Methods: Serum was analyzed for antibodies to Sarcocystic neurona, using a western blot. Information regarding age, sex, and housing of horse was obtained by questionnaire. Data were analyzed, using multivariable logistic regression. Results: Seroprevalence was 45.3% (95% CI, 36.3 to 54.3%). A relationship was not found between seroprevalence and s...
de la Cueva FI, Rigau T, Bonet S, Miró J, Briz M, Rodríguez-Gil JE.Although hypoosmotic tests are widely used to assess spermatozoal quality in different species, they have not been used extensively in the stallion. Moreover, the role of the Na (+)K (+), ouabain sensitive-ATP-ase in the response of equine sperm to hypoosmotic shock is not well understood. This study tests two hypotheses: 1) that equine spermatozoa will respond to a hypoosmotic medium by swelling of the tail, and 2) that addition of ouabain will increase the percentage of swollen sperm tails. Ejaculates from 3 stallions were collected with an artificial vagina and diluted in Kenney's medium (T...
Griffin LV, Gibeling JC, Gibson VA, Martin RB, Stover SM.Experiments and analyses were performed to determine the cause of a nonlinear force-deflection response observed in four-point flexural fatigue of beams of cortical bone machined from the mid-diaphysis of the equine third metacarpus. Observable grooves which formed on the beam surface at supports and load noses were found to be the primary cause of the nonlinearity. An additional geometric nonlinearity at large deflections revealed by finite element modeling may be minimized by using the smallest diameter supports and load noses recommended in ASTM 790. However, frictional constraint of the be...
Escande F, Vallee E, Aubart F.The isolation of Pasteurella caballi from an horse-bite wound in a 56-year-old man is reported. Biochemical characteristics are described and compared with the other species representing the genus Pasteurella. This strain probably represents the first human isolate of P. caballi in France.
Watt BC, Beck BE.Diagnosis and removal of a nasal polyp in a horse using standing chemical restraint and readily available equipment are described. Histopathology of the polyp and differential diagnoses are discussed.
Blanchard TL, Johnson L.Thirty adult stallion testes were selected with high (n = 15) and low (n = 15) Daily Sperm Production (DSP)/testis. Parenchymal samples were prepared for morphometric analysis, and the numbers of germ cells and Sertoli cells were determined. Testicular samples were homogenized, and germ cells and Sertoli cells were enumerated using phase contrast microscopy. Numbers of germ cells and Sertoli cells and potential DSP during spermatogenesis were determined. Significant correlations existed between morphometric and homogenate determinations of number per testis of preleptotene, leptotene plus zygo...
Martínez-Torrecuadrada JL, Díaz-Laviada M, Roy P, Sánchez C, Vela C, Sánchez-Vizcaíno JM, Casal JI.Fifteen horses were experimentally infected with African horse sickness virus (AHSV) serotype 4. To learn more about the time course of production and specificity of AHSV-specific antibodies, sera were analyzed by immunoblot analysis. Only animals that survived for more than 9 days were able to develop a humoral immune response detectable by immunoblotting. The earliest serological markers corresponded mainly to VP5, VP6, and NS2 and to a lesser extent to VP3, NS1, and NS3. Neutralizing antibodies to VP2 were not detected by immunoblotting, suggesting that they are mostly conformation dependen...
Sams RA, Gerken DF, Ashcraft SM.The respiratory stimulant prethcamide is a mixture of equal parts of crotethamide and cropropamide. A specific and sensitive gas chromatographic method for the determination of crotethamide and cropropamide in horse plasma and urine is described. Both components of prethcamide were extracted from plasma and urine into dichloromethane. The extracts were analyzed by capillary gas chromatography with thermionic detection in the nitrogen-specific detection mode. The lower limits of quantitation were 4.0 ng ml-1 of plasma and 10.0 ng ml-1 of urine. Calibration curves were linear from 2.0-100 ng ml-...
Hawkins DL, Stover SM.To investigate the effect of late gestation, age, and parity on material properties of third metacarpal (MCIII) cortical bone in mares. Methods: 8 healthy mares (treatment group) that died or were euthanatized within 24 hours after parturition because of foaling complications and 6 age-matched, healthy, nonpregnant mares (control group). Methods: After random assignment for mechanical testing and microradiography, the dorsal half of transverse mid-diaphyseal sections of each MCIII bone was divided into lateral, dorsal, and medial regions. Cylinders of bone from each of the 3 regions were teste...
Lány P, Pospísil Z, Zendulková D, Cíhal P, Jahn P.A mild outbreak of acute respiratory infection was reported in racing horses in the fall of 1995. Four studs were investigated for the sources and routes of infection. In five horses from two herds, virus isolates were obtained which, in preliminary typing experiments, were identified as the influenza A/equi 2 virus. The presence of this illness in all the examined herds was confirmed by a rise in specific antibody titres. The affected animals included both older vaccinated horses and young horses not yet vaccinated. Epidemiological studies suggested that the spread of infection occurred in si...
Fenger CK, Granstrom DE, Gajadhar AA, Williams NM, McCrillis SA, Stamper S, Langemeier JL, Dubey JP.Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four labora...
Journal of mass spectrometry : JMSFebruary 1, 1997
Volume 32, Issue 2 152-158 doi: 10.1002/(SICI)1096-9888(199702)32:2<152::AID-JMS456>3.0.CO;2-W
Anderson MA, Wachs T, Henion JD.A method based on ionspray liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed for the determination of reserpine in equine plasma. A comparison was made of the isolation of reserpine from plasma by liquid-liquid extraction and by solid-phase extraction. A structural analog, rescinnamine, was used as the internal standard. The reconstituted extracts were analyzed by ionspray LC/MS/MS in the selected reaction monitoring (SRM) mode. The calibration graph for reserpine extracted from equine plasma obtained using liquid-liquid extraction was linear from 10 to 5000 pg ml-1 and t...
Todhunter RJ, Fubini SL, Freeman KP, Lust G.To determine whether keratan sulfate concentrations in plasma or synovial fluid from clinically normal horses were different from concentrations in horses with joint disease and whether concentrations varied with type of joint disease. Methods: Case-control study. Methods: 67 clinically normal horses, 10 clinically normal foals, and 160 horses with joint disease. Methods: ELISA was used to measure keratan sulfate concentrations. Results: Mean plasma keratan sulfate concentration (mean +/- SEM, 580 +/- 124 ng/ml) in foals peaked at 10 weeks of age. Mean plasma keratan sulfate concentration in c...
Raidal SL, Taplin RH, Bailey GD, Love DN.To evaluate the administration of procaine penicillin prior to or during confinement with head elevation as a means of reducing the associated accumulation of inflammatory lower respiratory tract secretions and increased numbers of bacteria within the lower respiratory tract of confined horses. Methods: Two experiments were conducted to evaluate the efficacy of different dose rates and dosing frequencies. In experiment A a single low dose (15,000 IU/kg) of procaine penicillin was administered to four horses immediately prior to confinement with head elevation for 48 hours. The systemic leucocy...
Wood SC, Fedde MR.Splenic contraction in racing horses increases the hematocrit (hct), thereby increasing blood viscosity. We tested as to whether racing also affects the elastic properties of blood. Mares and geldings were studied for thus purpose. After racing, there was: (i) an increased erythrocyte count independent of gender and race distance (0.32 to 1.7 km): (ii) an increased mean erythrocyte volume in both sexes; (iii) an increased heterogeneity of RBC size in both sexes; (iv) an increased plasma fibrinogen concentration and erythrocyte sedimentation rate in both sexes; and (v) an increased elastic yiel...
Vodela JK, Dalvi RR.This study was conducted to determine and compare the activities of glutathione-S-transferase (GST) in red blood cells of cattle, horses, pigs, goats, dogs, rabbits, rats and mice. The highest GST activity was found in mouse red blood cells followed by that of rats, dogs, cattle, pigs, goats and horses with the lowest activity in rabbits. There were significant differences between the GST activities from these various species. The species differences in GST activities correlate with the reported variable responses of the different species to different toxicants since erythrocyte GST plays a si...
Kingston JK, Geor RJ, McCutcheon LJ.To compare dew-point hygrometry, direct sweat collection, and measurement of body water loss as methods for determination of sweating rate (SR) in exercising horses. Methods: 6 exercise-trained Thoroughbreds. Methods: SR was measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km, with a 15-minute rest at the end of each 15-km phase. Each horse completed 2 exercise trials. Dew-point hygrometry, as a method of local SR determination, was validated in vitro by measurement of rate of evaporative water loss. During exercise, local SR was determined ev...
Kaneene JB, Ross WA, Miller R.A prospective study was designed to document the frequencies of equine health problems in the state of Michigan, USA. A total of 2469 horses from a random sample of 138 equine operations were monitored in the study in two 12-month periods: 1992-1993 and 1993-1994. All the major breeds of horses in the state were proportionately represented in the sample. Using weighted annual incidence densities as measures of disease frequencies, the 10 most frequently observed groups of health problems were (from most to least frequent) leg lameness, dermatological problems, respiratory problems, hoof and fo...
Orme CE, Harris RC.The aim of the study was to develop a model for the pre-exercise elevation of plasma free fatty acids in the horse, with a view to its future use in investigations of fat metabolism during exercise. A comparison of the lipase releasing and anticoagulative effects of heparin and a related substance pentosan polysulphate was investigated. Furthermore, the ability of heparin and pentosan polysulphate to affect an increase in plasma free fatty acid concentration, when co-administered with-a triglyceride emulsion, was quantified. Doses of 0.39 and 1.3 mg kg-1 body wt of heparin and pentosan polysul...
Ronéus N, Essén-Gustavsson B.To determine whether performance capacity in a group of young trained Standardbreds is related to skeletal muscle characteristics and metabolic response to exercise. Methods: 13 clinically normal 2-year-old Standardbreds. Methods: Venous blood and middle gluteal muscle biopsy samples were obtained from each horse within 1 to 2 minutes after trotting at high speed for 1,600 m. Results: There was a positive correlation between plasma lactate and muscle glucose-6-phosphate (G-6-P) concentrations and trotting speed. There was a negative correlation between muscle adenosine triphosphate concentrati...
Parker JE, Rakestraw PC.A 5-year-old Quarter Horse stallion was admitted for cryptorchidectomy. Abnormalities were not found on physical examination, except for an undescended left testis. Cryptorchidectomy was performed, using an inguinal approach. The tail of the epididymis was in the inguinal canal, and the testis was adjacent to the internal inguinal ring. The testis was dark reddish purple to black, resulting from torsion at the level of the body of the epididymis. On histologic examination, the left testis was necrotic, except for the tunica albuginea and tunica vaginalis visceralis covering the testis. Intra-a...
Thompson JC, Ellison RS, Kirk J.Total thyroxine and total tri-iodothyronine concentrations were measured in the sera from 125 horses of mixed age, breed and sex, and varied clinical histories. While low serum thyroxine concentrations were detected in 35 horses, the majority of those horses had serum thyroxine values within the reference range when retested. Only one horse had a mildly decreased serum tri-iodothyronine concentration. Those horses in which the serum thyroxine concentration was low when retested had a normal thyrotropin releasing hormone stimulation test. Hypothyroidism was not diagnosed in any horses in this s...
Holman PJ, Hietala SK, Kayashima LR, Olson D, Waghela SD, Wagner GG.A horse with no prior clinical history of equine piroplasmosis tested negative for Babesia caballi and Babesia equi in the complement fixation test before importation into the United States from France. After 5 years in residence in the United States, the animal tested serologically positive for B. equi by the complement fixation test, the immunofluorescent antibody test, and Western blot analysis. The carrier status of the horse was confirmed by culture of B. equi parasites. In vitro culture offers an efficient and comparatively inexpensive method to determine the carrier status of horses sus...
Newton JR, Wood JL, Dunn KA, DeBrauwere MN, Chanter N.During an outbreak of strangles on a farm with approximately 1500 horses, the spread of Streptococcus equi infection was monitored by repeated nasopharyngeal swabbing and culture. In order to control the infection and prevent new introductions of strangles on to the premises, a system of quarantine and swabbing of cases and all incoming animals was instituted. Long-term carriage of the organism was detected in four clinically healthy convalescent animals, and in two of 350 new ponies; it persisted for between seven and 39 months, but it was detected only intermittently by the culture of swabs ...
Fordyce PS, Edington N, Bridges GC, Wright JA, Edwards GB.In 27 potential neuropathies an enzyme-linked immunosorbent assay, using P2 preparations from either bovine or equine myelin, detected all cases of cauda equina neuritis in which there was caudal involvement. The test was of limited value in differentiating neuropathies involving only cranial or other peripheral nerves.
Kennedy SA, Constable PD, Sen I, Couëtil L.To determine effects of syringe type and storage conditions on blood gas and acid-base values for equine blood samples. Methods: Blood samples obtained from 8 healthy horses. Methods: Heparinized jugular venous blood was equilibrated via a tonometer at 37°C with 12% O(2) and 5% CO(2). Aliquots (3 mL) of tonometer-equilibrated blood were collected in random order by use of a glass syringe (GS), general-purpose polypropylene syringe (GPPS), or polypropylene syringe designed for blood gas analysis (PSBGA) and stored in ice water (0°C) or at room temperature (22°C) for 0, 5, 15, 30, 60, or 120 ...
Mizobe F, Mori M, Nagata SI, Yamashita S, Okada J, Kusano K.Ever since 'One Health' concept was introduced in early 2000s, judicious use of antimicrobials by veterinarians has become an issue of great concern. Recently, findings of anti-inflammatory effects in certain types of antimicrobials have raised a subject for discussion among racing authorities. Regulatory framework of antimicrobials in racing should be based on best interest of horse welfare and doping control perspective, but basic data on prevalence of antimicrobials are lacking. Analysis of 100 postrace urinary samples collected from 10 Japanese racecourses by targeting 21 antimicrobials us...
Swain O'Fallon EA.Foal emergencies can be intimidating to manage in the field, yet many conditions will respond well to the supportive care possible on the farm. Triage of the foal targets focused supportive care to stabilize the foal before referral to a hospital or to facilitate the management in the field. There are many diagnostic and therapeutic options available in the field setting to support a successful outcome on the farm.
Sellon DC, Sanz M, Kopper JJ.Little is known about the acquisition and use of equine analgesic drugs by horse owners in the United States (US). Objective: To determine factors associated with possession of analgesic drugs by horse owners in the US or with analgesic drug acquisition from sources noncompliant with a valid veterinarian-client-patient (VCPR) relationship. Methods: Cross-sectional survey. Methods: An internet-based questionnaire included items related to experiences with horses and equine analgesic drugs. Factors associated with possession of ≥5 types of analgesic drugs and with the acquisition of drugs from...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare monotonic biomechanical properties and fatigue life of a broad locking compression plate (LCP) fixation with a broad limited contact dynamic compression plate (LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Methods: Cadaveric adult equine MC3 bones (n=12 pairs). Methods: MC3 were divided into 3 groups (4 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bending cyclic ...
Wagner PC, DeBowes RM, Grant BD, Kaneps AJ, Watrous BJ.Proximal growth plate fractures of the tibia in 4 foals were treated surgically. A medial approach was utilized in 3 cases and a lateral approach in the fourth. Bone screw fixation was achieved with cancellous screws and washers. In 3 cases, the screw shaft crossed the proximal tibial growth plate with no adverse effects. In all animals, there was rapid and cosmetic healing. At 8 to 18 months after surgery, all horses were sound at a walk, trot, and canter.
Kleijn WM, Sloet van Oldruitenborgh-Oosterbaan MM.Measuring the height of ponies at the withers is currently a prerequisite at Fédération Equestre Internationale (FEI) competitions. A pony measured at a competition site must not measure more than 151 cm with, or 150 cm without horse shoes. When a pony exceeds the regulated height, it is excluded from participation in the competition. Moreover, the sale value of a pony can decrease dramatically if by height measurement it is designated as a 'horse'. The aim of this study was firstly to determine whether measuring ponies at the withers with a laser device is repeatable; secondly, to evaluate ...
Granstrom DE.This article reviews recent advances in laboratory diagnosis of equine parasitic diseases. Laboratory diagnosis of most equine parasitic diseases continues to rely on standard methods. Only laboratory diagnostic tests for EPM, cryptosporidiosis, and giardiasis were included. The criteria for testing and interpretation of results for each new diagnostic method were explained. Western blot and PCR testing for EPM and immunofluorescent staining with monoclonal antibodies for cryptosporidiosis and giardiasis were reviewed.
Tinkler SH, Couëtil LL, Kennedy SA, Constable PD.To determine whether plasma total CO(2) concentrations would vary with the size of the evacuated tube used to collect blood samples. Methods: Randomized crossover study. Methods: Convenience sample of 20 healthy adult horses. Methods: Jugular venous blood was collected from horses in random order into 8 types of evacuated tubes: 2-mL glass, 2- or 3-mL plastic or plastic plasma separator, 4- or 6-mL plastic, and 10-mL glass or plastic. Total CO(2) concentrations in plasma were measured with a biochemistry analyzer. Data were analyzed via repeated-measures ANOVA and multivariate regression. Resu...
Townsend WM.Examination of the lens is critical, particularly when evaluating horses with visual impairment or performing prepurchase examinations. To adequately evaluate the lens, the pupil must be pharmacologically dilated. A cataract is any lens opacity. The size, density, and position of a cataract determine the impact on vision. Cataracts may be congenital or inherited or occur secondary to trauma or equine recurrent uveitis. Surgical removal is the only treatment option for vision impairing cataracts, but careful selection of surgical candidates is critical for successful outcomes.
McKane SA, Rose RJ, Evans DL.Twenty-four Thoroughbred and twelve Standardbred racehorses aged between 2 and 6 years, presented for reported poor racing performance, underwent clinical exercise testing. During the last 10 s of exercise at each speed throughout an incremental speed exercise test on a treadmill inclined at a 10% slope, samples of arterial blood and expired gases were collected. Maximum oxygen uptake and the partial pressures of oxygen and carbon dioxide in arterial blood were determined. These values were compared between the two breeds of horses and also with reference to cytological findings of bronchoalve...
Watson ED.Outbreaks of contagious equine metritis in Britain during 1996 emphasised the importance of preventing the disease through full and widespread implementation of the Horserace Betting Levy Board's code of practice. The provision of satisfactory samples for testing represents an integral part of applying the code. Here, in an article commissioned by the British Equine Veterinary Association, Dr Elaine Watson describes the techniques involved.
Canola PA, Cardenas JJ, Sá GC, de Paula VB.To evaluate the feasibility of performing needle arthroscopy of the scapulohumeral joint and bicipital bursa in standing horses by using the thoracic limbs of euthanized horses. To that purpose, this experimental study was designed. Ten thoracic limbs, five left and five right from euthanized horses were retained in an upright position to simulate a standing horse. The craniolateral and lateral scapulohumeral arthroscopic portals were used to access the articular structures. A third (caudal) portal was also identified and described. The degree of difficulty in accessing the articular space and...
Kornaś S, Cabaret J, Nowosad B.Faecal egg counts were performed in 187 foals of a large Polish stud farm between February and September 2007. Eggs of Parascaris equorum were present in faeces of 7% and those of cyathostomins in 13% of the foals aged less than 194 days. Information dealing with age of foals and/or efficiency of ivermectin treatment as well as the nematode parasite prepatent periods, it can be conducted that most of the infections recorded on the basis of faecal egg counts were false-infections in animals up to the age of six months, probably due to the ingestion of infected faeces of their dam or some other ...
Todhunter RJ, Brown CM, Stickle R.Five horses with retropharyngeal (RP) infections had clinical signs of dysphagia and/or dyspnea. Diagnosis was confirmed, using pharyngeal endoscopy and lateral radiography of the pharynx. One horse responded to surgical drainage of a RP abscess and was sound at light work. One horse responded to medical management after the site of infection was surgically explored. Two horses recovered after medical management; the RP abscess of 1 of these 2 horses ruptured spontaneously into the pharynx and the other horse became racing sound. The fifth horse remained dysphagic and had left laryngeal hemipl...
Green JH, Bolin RC, Carver RK, Gross H, Pigott N, Harrell WK.The serological response in burros and horses to the viable LVS strain of Pasteurella tularensis was studied. High-titered agglutinating antisera and fluorescent-antibody conjugates were obtained in both groups of animals. Maximum titers were obtained in horses 14 to 21 days after the start of vaccination and in burros 21 to 28 days after the start of vaccination. The use of Woodhour's adjuvants or booster inoculations did not result in increased titers.
Snowden RT, Schumacher J, Blackford JT, Cypher EE, Cox SK, Sun X, Whitlock BK.To determine whether therapeutic concentrations (> 0.5 to 1.0 μg/mL) of polymyxin B (PB) were achieved in the tarsocrural joint of horses when the drug was administered by IV regional limb perfusion (IV-RLP) via a saphenous vein at doses of 25, 50, and 300 mg and to describe any adverse systemic or local effects associated with such administration. Methods: 9 healthy adult horses. Methods: In the first of 2 experiments, 6 horses each received 25 and 50 mg of PB by IV-RLP via a saphenous vein with at least 2 weeks between treatments. For each treatment, a tourniquet was placed at the midmetata...
Dill SG, Gleed R, Matthews NS, Erb HN, Miller TK.The acupuncture point Governing Vessel (GV-26) is used commonly in the Orient to treat shock in human beings and other species. The cardiovascular effects of stimulation of GV-26 were studied in healthy ponies during 2 episodes of halothane anesthesia. During one anesthetic episode, electrical stimulation (electrostimulation) of GV-26 was performed, and during the other anesthetic episode, heat stimulation (moxibustion) of GV-26 was performed. The order of the stimulations was random. A nonacupuncture point was selected for comparable control stimulation during each experiment. Control and acu...