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.
Pringle JK, Ducharme NG, Baird JD.Ureterovesicular anastomosis resulted in resolution of the clinical signs of urinary incontinence in three horses with unilateral ectopic ureter. Follow-up of two of the horses ten months and three years later indicated no further urinary tract problems; the third horse died four days after surgery from intestinal infarction.Diagnosis can be readily confirmed by antegrade or retrograde ureterography, or endoscopic visualization of the ectopic ureteral openings. Nephrectomy appears indicated in cases of unilateral ectopic ureter with associated ipsilateral urinary tract infection or hydronephro...
Burns GA, Karcher LF, Cummings JF.A 4-year-old Standardbred mare was referred to the New York State College of Veterinary Medicine for colic evaluation. Physical examination revealed a small colon impaction which initially responded to conservative medical management. Her signs soon recurred, however, and an exploratory celiotomy was recommended. At surgery the small colon impaction was confirmed. The impaction was evacuated and a surgical biopsy was submitted for histopathologic evaluation. Microscopic examination of H&E and Trichrome sections revealed a massive mononuclear cell infiltration of the myenteric plexus. In additi...
Erzinclioglu YZ.The unusual structure of the mouth hooks of the third instar larvae of the species of Gasterophilus and Gyrostigma, parasites of the alimentary canal of Equideae and Rhinocerotidae respectively, is described.
Lane PJ, Lees P, Fink-Gremmels J.In a crossover study in seven New Forest ponies the actions of dexamethasone, at a dose rate of 0.06 mg kg-1 administered intravenously, were compared with those of a placebo treatment. Dexamethasone exerted expected effects on plasma and inflammatory exudate concentrations of cortisol and on blood glucose concentration and circulating leucocyte numbers, but it failed to affect exudate concentrations of the eicosanoids, prostaglandin E2, thromboxane B2, 6-keto-PGF1 alpha and leukotriene B4. These findings do not support the hypothesis that the anti-inflammatory actions of dexamethasone in the ...
Frey R, Lieb A.An outbreak of abortion due to the equine herpesvirus-1 (EHV-1) in the eastern part of Switzerland is reviewed. Seven of eleven pregnant mares aborted within twenty-three days in January 1989. Four weeks later another foal died a few minutes after parturition. Three mares delivered live foals in February, March and April without any complications. The examination of the eight dead foals revealed an EHV-1 Infection. The clinical signs and the pathology are discussed. Severe complications during the early post-parturient time are in contrast to the uncomplicated outcome mentioned by other author...
Hartley JW, Hahn AW, DeLorey M, Caldwell WM.We have developed and used a system for recording and analyzing the electrocardiogram (ECG) of the horse during exercise. The system consists of a commercial ECG transmitter telemetering a Z lead (base-apex) ECG from an exercising horse. The received data are then remodulated at an audio frequency and stored on a audio cassette recorder. Exercise protocols of up to 10 minutes are digitized using a Macintosh II computer. For rhythm analysis, a computer program to identify the various waves of the ECG uses a modification and refinement of the integrated-squared-derivative (ISD) technique. This t...
Bump KD, Lawrence LM, Moser LR, Miller-Graber PA, Kurcz EV.1. Muscle samples from the M. gluteus medius were obtained from six Quarter Horses (QH), six Thoroughbreds (TB), and five Standardbreds (SB) to determine carnosine values and fiber type percentages. 2. Muscle biopsies were for fiber type percentages and carnosine concentration. 3. QH had a lower percentage of slow twitch oxidative fibers and a higher percentage of past twitch glycolytic fibers than SB or TB. 4. Fast twitch oxidative-glycolytic fibers were lowest in the QH. 5. The QH had mean carnosine values significantly greater (P less than 0.01) than the mean values for SB and TB. 6. Across...
Rwambo PM, Issel CJ, Hussain KA, Montelaro RC.A neutralization escape mutant (A/1 E) of equine infectious anemia virus was isolated after 13 passages in cell culture in the presence of serum containing antibodies to type- and group-specific determinants of EIAV envelope glycoproteins. Loss of neutralization by the selecting serum correlated with loss of two epitopes in the major envelope glycoprotein gp90 of A/1 E which were present in a parallel variant isolated from a persistently infected pony.
Naden J, Amann RP, Squires EL.Puberty was studied using 15 colts of Quarter Horse phenotype. Total scrotal width was measured every 8 weeks from 48 to 96 weeks. Blood samples were taken from 8 colts at 8, 16 and 24 weeks and then every 4 weeks until 100 weeks to measure changes in LH, FSH and testosterone concentrations. Seminal collections were attempted monthly from 48 to 64 weeks and every 2 weeks thereafter until puberty resumed every 3rd day from 96 weeks for 15 ejaculates. For all collections, times to erection, mount and ejaculation and seminal characteristics were recorded. Age at puberty was defined as the first e...
Schmid DO, Ek N, Braend M.A silent allele in the transferrin locus (Tf) was observed in a Thoroughbred mare and in five of her offspring from three different matings. Evidence for the silent allele was obtained by quantitative immunodiffusion studies.
Adam A, Ong H, Sondag D, Rapaille A, Marleau S, Bellemare M, Raymond P, Giroux D, Loo JK, Beaulieu N.A monoclonal antibody was synthesized in mouse against the O-(3-carboxypropionyl) derivative of albuterol linked to bovine serum albumin. Isotyping of this material revealed the IgG1 class characterized by an affinity constant of 1.03 nM-1 and a density of sites of 0.55 nM. This antibody was found specific as its cross-reactivity to structurally related molecules was less than 1% except for clenbuterol (75%). A radioimmunoassay was set up with culture supernatant (final dilution 1/1000) and [3H] albuterol. The calibration curve was characterized by a maximum binding of 28%, an ED50 of 1.15 pmo...
Jann HW, Stein LE, Good JK.Size 3-0 polydioxanone was used as a single strand, single braid (3 strands), or double braid (6 strands) to create six suture material-pattern combinations for equine tenorrhaphy: single-strand locking loop, single-braid locking loop, double-braid locking loop, single-strand three-loop pulley, single-braid three-loop pulley, and double-braid three-loop pulley. Maximum load to failure for the single-strand locking loop (46.1 +/- 2.9 newtons [N]) was less than for all other sutures (range, 103-155 N). The load required to form a 2 mm gap between tendon ends was greater for the single-braid thre...
Robertson SA, Carter SW, Donovan M, Steele C.The effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature were investigated in six foals at 10 and 28 days of age. These variables were also measured in three foals at 19 days of age when saline alone was injected. Rectal temperature fell significantly after 30 mins in both groups of xylazine treated foals and was still depressed after 120 mins. Hypothermia did not occur in the saline control group. There was no significant change in blood glucose or plasma insulin concentrations during the 120 mins following either xylazine or saline administrat...
Richer CL, Power MM, Klunder LR, McFeely RA, Kent MG.The following decisions concerning the banded karyotype of the horse (Equus caballus) were made at the second International conference for Standardization of Domestic Animal Karyotypes, held at Jouy-en Josas, France, 22nd-26th May 1989: (1) numbering of the chromosomes was modified to correspond to an arrangement into only two groups (the non-acrocentrics and the acrocentrics) within which the autosomes are placed according to length alone; (2) a more compact karyotype arrangement was adopted: chromosomes 1 to 5 on the first row, 6 to 10 on the second, 11 to 13, and, at the far right, X and Y ...
Chaffin MK, Fuentealba IC, Schmitz DG, Read WK.An endometrial adenocarcinoma with metastases to the lung, liver, spleen, mesentery and serosal peritoneal surfaces was found in an 11-year-old Arabian mare. Clinical signs included generalized weight loss, depression, anorexia, ventral edema and abdominal distension. Ascites was due to thrombosis of the caudal vena cava. The diagnosis of endometrial adenocarcinoma was based on the histological appearance of uterine glandular epithelium and the presence of similar tissue in the metastatic tumors.
Cox JE, Redhead PH.The long term effect of a single injection of 6,000 iu of human chorionic gonadotrophin (hCG) was studied in two pony stallions. Peripheral plasma samples were analysed for testosterone and oestrone sulphate. Testosterone concentrations were markedly elevated for five days after injection in both stallions. No adverse effects of these high concentrations were observed on concentrations later in the experiment. There was an initial increase in oestrone sulphate in one stallion, after which concentrations decreased to below pre-injection levels. The other stallion (whose initial oestrone sulphat...
House C, Mikiciuk PE, Berninger ML.Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA describ...
van den Bogert AJ, van Weeren PR, Schamhardt HC.In movement analysis of the horse, large errors result from movements of the skin with respect to the underlying bones. A generally applicable, two-dimensional, method for correction of these skin-movement errors in kinematic data has been developed. It was tested on a kinematic analysis of the hindlimb in a walking pony. The results indicate that without correction for skin-movement errors, misreadings of up to 15 degrees in the knee angle and 30% in the moment arm of the gastrocnemius muscle can be expected.
Troedsson M, Concha C, Einarsson S, Holmberg O.From 6 mares with chronic uterine infection, polymorphonuclear neutrophils (PMNs) were obtained from the uterus. In order to recover an adequate number of viable PMNs, 0.1% oyster glycogen was infused into the uterus as a mild irritant 12 h prior to the uterine flushing. Phagocytosis and chemotaxis of the uterine derived PMNs were determined. The supernatant from the uterine flushing was compared with autologous serum for its capacity as an opsonin and chemoattractant. There was a significant increase of both phagocytosis and chemotaxis when autologous serum was used compared with the supernat...
Specht TE, Colahan PT.Eleven horses with acute or chronic incomplete cortical fractures of the left or right third metacarpal bone (McIII) were treated with surgical puncture (osteostixis). The fractures were diagnosed by physical examination and radiography. Four to eight holes, 2.7 or 3.5 mm in diameter, were drilled in the fractured bone. Radiographically, the fractures were healed by month 3, and the drill holes were inapparent by month 7. Nine horses (82%) returned to race competition, and two horses were retired, one the result of a surgical complication. The mean time between surgery and the first race was 9...
Hassanain MM, al-Afaleq AI, Soliman IM, Abdullah SK.Two 7-year old Arabian racing horses were reported to show typical AHS symptoms in Qatar and died shortly after. The horses had been vaccinated with formol inactivated vaccine approximately 10 days before the onset of the disease. Blood samples from these horses were collected and AHS virus isolated from one sample after intracerebral (i.c.) inoculation into suckling mice. The virus identity was confirmed by complement fixation test (CFT) using the virus antigen and reference type 9 of AHS virus hyperimmune serum. The serotype of the isolated virus was identified by serum neutralization test (...
McCarthy RN, Jeffcott LB, McCartney RN.Ultrasound speed, as measured by a transmission technique in equine cortical bone, was found to vary markedly with the direction of the ultrasound path through the bone. Using bone samples from the mid-site of the third metacarpus of 20 horses, the ultrasound speed was measured as 4125 m s-1 in the longitudinal direction, 3442 m s-1 in the circumferential or transverse direction, and 3428 m s-1 in the radial direction. These results confirm the anisotropic properties of compact bone. Ultrasound speed had a positive linear relationship when compared with bone specific gravity of cortical bone (...
Hahn NE, Fletcher M, Rice RM, Kocan KM, Hansen JW, Hair JA, Barker RW, Perry BD.Dermacentor variabilis, Rhipicephalus sanguineus, Amblyomma americanum, and Ixodes scapularis ticks were investigated for their ability to transmit Potomac horse fever. Larval and nymphal ticks were exposed to Ehrlichia risticii by feeding on mice inoculated with the organism. Molted exposed ticks were then allowed to feed on susceptible ponies or mice. No evidence of transmission, either clinically or by detection of antibodies to E. risticii in mice or ponies, was observed for any tick species examined.
Taylor FG, Cooke BJ.The fragility of erythrocytes is easily demonstrated by their ability to withstand osmotic swelling and lysis in solutions of increasingly hypotonic saline. In healthy animals a plot of percentage haemolysis against increasing hypotonicity produces a sigmoid curve. Using the same data a derivative curve calculated from haemolytic increments shows a normal distribution of fragility within samples. In enhanced fragility due to immune-mediated haemolytic anaemia, these profiles of haemolysis are markedly altered and the derivative curve becomes multiphasic, indicating the presence of subpopulatio...
Winder NC, Hermann M, Grünig G, Hulliger C, Von Fellenberg R.Thirty-nine horses and 3 ponies underwent a thorough respiratory examination and were grouped as follows: healthy (4 horses and 1 pony); mild chronic pulmonary disease (CPD 11 horses); moderate CPD (16 horses and 1 pony); and severe CPD (8 horses and 1 pony). Bronchoalveolar lavage (BAL) fluid collected from all animals and respiratory secretions (RS) obtained from 39 of these animals were evaluated cytologically and the results were compared. It was concluded that cytological examination of either BAL fluid or RS was useful in diagnosing various equine pulmonary diseases. The only advantage t...
Juzwiak JS, Slone DE, Santschi EM, Moll HD.The case records of 19 mares undergoing caudal ventral midline celiotomy for cesarean section were reviewed. Surgical exposure to the uterus was good, and the incisions healed by first intention in surviving mares. Seventeen mares (89%) survived to time of hospital discharge. Six foals (32%) were delivered alive, of which three were euthanatized because of severe deformity (1 died on day 6 and 2 survived to time of discharge). The most frequent postoperative complications were abdominal pain (13 mares), anemia (10 mares), and retained placenta (6 mares). Sixteen mares were bred during at least...
Schulz KS, Simmons TR, Johnson R.An 8-year-old mare was presented to the New York State College of Veterinary Medicine Large Animal Clinic for evaluation of anorexia, fever and icterus. The mare had a 5-day history of anorexia, depression and tongue protrusion. Diagnostic procedures included serum hepatic enzyme activities, serum bile acid concentrations, blood ammonia evaluations and hepatic ultrasound and ultrasound guided biopsy. The history, clinical pathology and histopathology in this case supported a probable diagnosis of primary septic cholangiohepatitis.
Gill KK, Kroeger EA.Equine airway smooth muscle is innervated by vagal efferents and, in addition, displays spontaneous mechanical activity. The preparation thus appears to contain at least two discrete excitable components, the cholinergic neural elements and the smooth muscle membrane. Indomethacin (INDO), a cyclooxygenase (CO) inhibitor, exerts a considerable potentiation of function in this preparation. The latter may be effected indirectly, through loss of the inhibitory effect of endogenous prostaglandin E2 (PGE2) on neural acetylcholine release and through direct effects on smooth muscle of the generally a...
Stern JA, Doreste YR, Barnett S, Lahmers SM, Baumwart RD, Seino KK, Bonagura JD.Sustained narrow-QRS tachycardia of three months duration and left ventricular systolic dysfunction were identified in a fifteen-year-old Quarter Horse. No underlying cause for the tachyarrhythmia was found and no predisposing structural cardiac lesions were evident by echocardiography. Intravenous diltiazem and lidocaine were administered without achieving successful conversion of the arrhythmia. Oral quinidine therapy converted the tachyarrhythmia to sinus rhythm. Ventricular systolic dysfunction and chamber dilatation subsequently resolved. As with other species, echocardiographic features ...
Van Hoogmoed LM, Snyder JR, Harmon FA.To evaluate the effect of 2 cyclooxygenase (COX)-2 inhibitors on contractile activity of the circular smooth muscle layer of the equine dorsal and ventral colon. Methods: Samples of the dorsal and ventral colon obtained from 10 healthy horses. Methods: Full-thickness tissue samples were collected from the dorsal colon in the area of the diaphragmatic flexure and the ventral colon in the area of the sternal flexure. Samples were cut into strips oriented along the fibers of the circular muscle layer and mounted in a tissue bath system for determination of contractile strength. Incremental amount...
Fazio F, Ferrantelli V, Piccione G, Caola G.In the athletic horse, the efficiency of physical exercise during activity is strictly
connected to several organic–functional characteristics. Among these, cardiovascular
function takes a primary role in determining the quality of performance. The morphological and functional changes occurring in the cardiovascular system during physical
exercise are due to the increasing demand required to deal with intense muscular
activity. Thus, the cardiovascular physiological response to physical exercise is characterized both by transitory modifications and adjustments that are similar in both
t...
Houghton E.The methylated xanthines caffeine and/or theobromine are commonly encountered in drug-positive samples from racehorses and their metabolism and excretion in the horse and their analysis in urinary extracts has been of particular interest in this laboratory. Due to their polar nature the dimethylxanthines theobromine, theophylline and paraxanthine give unsatisfactory gas chromatographic performance and require derivatization prior to analysis by gas chromatography mass spectrometry. The present paper describes a simple deuteromethylation procedure to render the compounds amenable to analysis by...
Careddu GM, Evangelisti MA, Columbano N, Masala G, Manunta ML, Passino ES.Progressive ethmoid hematoma is frequently reported among the pathologies of the upper airways in horses. While several hypotheses have been proposed such as repeated trauma, inflammatory processes and/or chronic infections, congenital phenomena, complication of hemangiomas, and neoplastic processes, the aetiology of this condition is yet unknown. Clinical symptoms are non-specific and includes haemorrhagic nasal discharge, respiratory noise not related to physical exercise and, in most severe cases, phenomena of coughing. The purpose of this case report is to contribute to a correct diagnosti...
Brown AE, Hansen PJ, Asbury AC.Uterine flushings collected from mares before and after bacterial-induced inflammation were assayed for ability to opsonize Streptococcus zooepidemicus for phagocytosis by polymorphonuclear leukocytes. Opsonization was measured as the peak phagocytic rate of bacteria preincubated with uterine flushings relative to the peak phagocytic rate of unopsonized bacteria. Flushings from four mares with noninfected uteri were unable to opsonize bacteria regardless of whether uteri were flushed at estrus or on day 10 postovulation. In a second experiment, 7 X 10(9) live S. zooepidemicus were inoculated i...
Brown VA, Wilkins PA.Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular ...
Içli S, Soleimani M, Oldenhof H, Sieme H, Wriggers P, Wolkers WF.Cryopreservation can be used to store equine oocytes for extended periods so that they can be used in artificial reproduction technologies at a desired time point. It requires use of cryoprotective agents (CPAs) to protect the oocytes against freezing injury. The intracellular introduction of CPAs, however, may cause irreversible osmotic damage. The response of cells exposed to CPA solutions is governed by the permeability of the cellular membrane towards water and the CPAs. In this study, a mathematical mass transport model describing the permeation of water and CPAs across an oocyte membrane...
Stokol T, Gold J, Johnson A, Ainsworth D.A 3-day-old filly was presented to the Cornell University Hospital for Animals with an umbilical hematoma and mild aspiration pneumonia. The foal underwent abdominal surgery for resection of the hematoma. Recovery was uneventful, but 3 days after surgery, the foal became progressively tachypneic. Imaging studies revealed bilateral pleural effusion and pleuropneumonia. Cytologic evaluation and bacterial culture of the pleural fluid from both sides of the chest revealed sterile exudates, consisting mostly of neutrophils, with fewer macrophages and lymphocytes. Pleural fluid macrophages contained...
You Y, Guan F, D'Ippolito R, Li X, Soma LR, Robinson MA.A hydrophilic interaction liquid chromatography-tandem mass spectrometry method (HILIC-MS/MS) was developed for the simultaneous determination of 28 amphetamine-type stimulants (ATSs) in equine plasma for doping control analysis. In this method, stimulants were recovered from equine plasma by liquid-liquid extraction (LLE) at pH 9.5 using methyl tert-butyl ether and detected on a Thermo Finnigan triple quadrupole mass spectrometer operating in positive-ion mode electrospray ionization. All stimulants were eluted within 7 minutes and baseline separation was achieved for isomeric and isobaric ...
Lea RG, Bolton AE.Two-dimensional crossed immunoelectrophoresis of sera from pregnant and non-pregnant horses, using antisera developed against early pregnant mare serum, revealed the presence of two immunologically related proteins one of which appeared to be specific to the pregnant state. This pregnancy-specific protein had beta 2-electrophoretic mobility and was first detectable at Day 6 after successful mating with a stallion. The second protein had gamma 2-electrophoretic mobility and was present in sera from pregnant and non-pregnant horses. The proteins were termed beta 2-horse pregnancy protein and gam...
Clem MF, DeBowes RM, Leipold HW.A mass originating from the dorsal rectal wall of a 4-year-old mare was diagnosed as a leiomyosarcoma. General anesthesia and meticulous surgical dissection were required to effect removal. In spite of incomplete excision, as indicated by histologic sections, the mass has not recurred in the 18 months since removal.
Jaeschke G, Lange W.In this paper three outbreaks of equine influenza in Berlin (Germany) in the years of 1988, 1989 and 1991 are discussed, reporting mainly clinical, hematological, virological and some epizootiological aspects. We have detected variations from the traditional pattern of equine influenza, whereby the main clinical symptoms like cough or fever were absent in several cases. If cough was found, it was moist. Furthermore a mucous nasal discharge was present in a number of cases for a period of 4-5 days. Extreme neutropenia, lymphocytosis and predominantly an unchanged level of monocytes were observe...