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.
Day MJ, Penhale WJ.Skin biopsies from 47 dogs, 6 cats and 5 horses with suspected autoimmune skin disease were submitted for immunofluorescence from 1978 to 1985. These cases were predominantly Western Australian in origin, although a number were also referred from Queensland and Victoria. In 5 dogs, 2 cats and 2 horses immunoglobulin binding to intercellular cement substance and/or basement membrane was demonstrated by direct immunofluorescence. Antinuclear antibody was also demonstrated in several of these cases. Immunofluorescence was used in combination with histopathological examination to confirm the clini...
Jacob RJ.Preliminary experiments have revealed that several laboratory and wild-type strains of the equine herpesvirus (EHV) triad were temperature-sensitive for growth when assayed at 39 degrees C. The efficiencies of plating (EOP) observed were 10(-2) for both EHV 1 and 2, and 1 X 10(-6) for EHV 3. The EOPs were determined by plaque assays which compared titrations at 34 degrees C and 39 degrees C on equine fetal dermal fibroblast cells. Growth yield experiments, assayed at 34 degrees C, reflected those EOP's, but did not indicate any difference in yields when infected cultures were incubated at 34 d...
Pan LG, Forster HV, Bisgard GE, Murphy CL, Lowry TF.We investigated arterial PCO2 (PaCO2) and pH (pHa) responses in ponies during 6-min periods of high-intensity treadmill exercise. Seven normal, seven carotid body-denervated (2 wk-4 yr) (CBD), and five chronic (1-2 yr) lung (hilar nerve)-denervated (HND) ponies were studied during three levels of constant load exercise (7 mph-11%, 7 mph-16%, and 7 mph-22% grade). Mean pHa for each group of ponies became alkaline in the first 60 s (between 7.45 and 7.52) (P less than 0.05) at all work loads. At 6 min pHa was at or above rest at 7 mph-11%, moderately acidic at 7 mph-16% (7.32-7.35), and markedly...
Juillerat MA, Taniuchi H.To investigate the role of evolutionarily invariant leucine 32 of horse cytochrome c, analogs of residues 28-38, (28-38), each containing a substituted amino acid at positions 32 or 35 were synthesized using Merrifield's method. Position 35 is leucine in horse cytochrome c but replaced by nonpolar amino acids in some species. The ability of the analogs to bind to the two-fragment complex of ferri- or ferro heme fragment (1-25)H and apofragment (39-104) was measured using gel filtration and equilibrium dialysis. Replacement of leucine 32 with isoleucine, for example, increased the dissociation ...
Hultgren BD.Pulmonary lobar hypertrophy was diagnosed in a 4-hour-old Quarter Horse full-term foal that had respiratory arrest shortly after birth. The gross and microscopic appearances were consistent with polyalveolar lobe, a congenital anomaly of human infants.
Hodson NP, Wright JA, Hunt J.Plasma levels of adrenocorticotropic hormone (ACTH), cortisol and catecholamines were used to study the role of the sympatho-adrenal system in equine grass sickness. Statistical evaluation determined differences of hormone levels between seven horses with grass sickness (one acute, five subacute and one chronic), six horses with colic (one with laminitis) and 16 control horses before and after mild stress. Plasma levels of the hormones were higher in horses with acute and subacute grass sickness than in the other groups. No differences were detected between horses with colic and stressed contr...
Garner DL, Pinkel D, Johnson LA, Pace MM.Spermatozoa from bulls, boars, dogs, horses, mice, and men were examined using a fluorogenic stain consisting of the membrane-permeant substrate carboxyfluorescin diacetate (CFDA) and the relatively membrane-impermeant nuclear stain propidium iodide (PI). Three distinct populations of spermatozoa were discernible in samples from each species upon microscopic examination. Individual spermatozoa, presumed to be viable because of their motility, retained products of the fluorescein chromophore throughout the cell. A second population of spermatozoa in which the nuclei stained red with PI retained...
Richardson DW.A technique involving internal fixation guided by arthroscopy was used to repair third carpal slab fractures in 23 horses. The technique allowed good reduction and compression of the fractures, with minimal surgical trauma. Ten of 17 horses with a 6-month or longer follow-up have returned to race successfully.
Yager JA, Foster SF, Zink MC, Prescott JF, Lumsden JH.Polymorphonuclear leukocytes from adult horses were separated from whole blood, using a 2-step Percoll gradient, and were tested for bactericidal function against Corynebacterium equi. Staphylococcus aureus, an organism against which equine neutrophils have proved efficacy, was a positive control. The percentage of uptake after a 15-minute preincubation of the neutrophils and bacteria in the presence of normal horse serum was also calculated. The results indicated that equine neutrophils effectively phagocytosed and killed C equi and S aureus. The percentage of uptake for S aureus (95% +/- 3%)...
Lyons ET, Drudge JH, Tolliver SC.Two controlled tests (experiments D and E) were done to evaluate a fenbendazole (FBZ) paste dosage regimen (10 mg/kg once a day for 5 days) for activity against naturally occurring infections of migrating Strongylus vulgaris and S edentatus in the mesenteric arteries and ventral abdominal wall, respectively. Data were also obtained on other internal parasites of the gastrointestinal tract and eyes in experiment E. Eight pony yearlings were used in experiment D (4 treated and 4 nontreated) and 6 horse weanlings were used in experiment E (3 treated and 3 nontreated). Intervals, expressed as days...
Rosendal S, Blackwell TE, Lumsden JH, Physick-Sheard PW, Viel L, Watson S, Woods P.Mycoplasma felis has been isolated from horses with pleuritis, and limited research indicates that mycoplasma pleuritis can be reproduced in horses. The serodiagnostic potential of the indirect hemagglutination and the metabolism-inhibition tests was evaluated by testing 177 horses for antibodies to M felis. Seven horses with M felis pleuritis developed antibodies, and 6 horses with sterile or bacterial pleuritis had high titers suggesting a previous M felis infection. Six horses with pleuritis (one sterile and five bacterial) had low or no titers to M felis. Only one of 30 horses with conditi...
Martin GS, Beadle RE, Haynes PF, Watters JW.The ventral-to-dorsal height of the rima glottidis was measured from lateral pharyngeal radiographs after correction for magnification. The rima glottidis height was used to enlarge accurately endoscopic photographs of 5 horses taken before and after transection of the left recurrent laryngeal nerve. Areas of the rima glottidis and aditus laryngis were measured, using a computerized digitizer. Mean area of the aditus laryngis was 1,908 mm2 before neurectomy and 1,346 mm2 after neurectomy (P = 0.025). Mean area of the rima glottidis was 1,198 mm2 before neurectomy and 805 mm2 after neurectomy (...
Yovich JV, LeCouteur RA, Stashak TS, Grandy JL, Whalen LR.Acute hemorrhagic myelopathy developed in the sixth cervical to the eighth thoracic spinal cord segments of a 1-year-old Quarter Horse colt that was castrated under general anesthesia while in dorsal recumbency. Clinical signs were consistent with severe transverse myelopathy caudal to the brachial enlargement and cranial to the lumbosacral enlargement of the spinal cord. Histologic examination of the spinal cord revealed hemorrhage in the gray matter, with multiple blood-filled clefts in otherwise normal neuropil. Hemodynamic changes in the spinal cord associated with anesthesia and dorsal re...
Thompson DL, Garza F, Ashley KB, Wiest JJ.Anestrous lighthorse mares were treated in December with dihydrotestosterone (DHT; 150 micrograms/kg of body weight), progesterone (P; 164 micrograms/kg), both DHT and P (DHT+P), testosterone (T; 150 micrograms/kg), or vehicle (n = 4/group). Daily blood sampling was started on Day 1, and on Day 4 all mares were administered a pretreatment injection of gonadotropin-releasing hormone (GnRH) and were bled frequently to characterize the responses of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations. Treatment injections were given on Day 4 and then daily through Day 17...
Cooley PL, Wyman M.Three horses were admitted with indolent-like corneal ulcers. All horses were treated topically with antibiotics. Two horses had ulcers with redundant epithelial borders, which were debrided with cotton-tipped applicators after topical anesthesia was induced. One ulcer healed after 2 debridements. Of 2 horses treated surgically, one had complications.
Heffner RS, Heffner HE.The ability of horses to use binaural time and intensity difference cues to localize sound was assessed in free-field localization tests by using pure tones. The animals were required to discriminate the locus of a single tone pip ranging in frequency from 250 Hz to 25 kHz emitted by loudspeakers located 30 degrees to the left and right of the animals' midline (60 degrees total separation). Three animals were tested with a two-choice procedure; 2 additional animals were tested with a conditioned avoidance procedure. All 5 animals were able to localize 250 Hz, 500 Hz, and 1 kHz but were complet...
Hornof WJ, Dunlop CI, Prestage R, Amis TC.Six horses were anesthetized and placed in lateral recumbency for 1 hour and then were turned to the opposite side for an additional hour. A short-lived radioactive gas, 81mKr, was used to determine the relative spatial distribution of ventilation (V) and perfusion (Q) in these horses. Effects of time, side down, and turning on the distribution were evaluated. A consistent gradient of V/Q was found at all times, with the highest V/Q values at the top (non-dependent) portion of the lung field and the lowest at the bottom (dependent). This gradient was also present within each lung, as well as b...
Yovich JV, McIlwraith CW.Arthroscopic surgery for osteochondral fractures of the proximal phalanx was performed on 74 fetlock joints of 63 horses for a total of 87 fractures during a 2-year period. The medial dorsal proximal aspect of the proximal phalanx of the forelimbs was most commonly involved (59 fractures), followed by the lateral aspect (26 fractures), and 2 fractures occurred in the fetlock joint of the right hindlimb. At surgery, 82 fragments were removed and 5 fragments that had healed or were embedded in the joint capsule were not removed. Of the fragments removed, 15 were fixed firmly to the proximal phal...
Richardson DW.Eikenella corrodens, a previously unrecognized pathogen in the horse, was isolated from the spinous process of the axis of a colt with signs of severe neck pain. Dorsal laminectomy (excising the infected spinous process and lamina) was performed and the colt was treated with antibiotics for 6 weeks. Recovery was uncomplicated.
Gordon BJ, Latimer KS, Murray CM, Moore JN.In a continuous-flow centrifugation apheresis technique adapted for blood-component separation and collection in horses, hydroxyethyl starch was not required for erythrocyte sedimentation. The efficacy and separation characteristics of whole blood from 10 horses were evaluated at various gravitational forces (700 to 1,500 rpm), using a constant withdrawal rate (100 ml/min). Maximum leukocyte collection occurred at 700 rpm (P less than 0.01), and optimal neutrophil collection occurred at 700 to 750 rpm (P less than 0.01). Although neutrophil counts decreased and lymphocyte counts remained const...
Smith JE, Cipriano JE, DeBowes R, Moore K.Values for serum ferritin, serum iron, and serum total-iron binding capacity were determined in 100 hospitalized horses. Six foals had iron deficiency, as indicated by low serum ferritin and iron concentrations. Twenty-eight horses had low serum iron content and normal or high serum ferritin content and were considered to have pseudo-iron deficiency, possibly in response to infection. Ten horses had serum ferritin concentrations that were quite high, probably indicating iron overload.
Nation PN, Klavano GG.This account describes two neonatal foals affected with osteopetrosis. One of these foals, a full term Peruvian Paso, was born alive, was bright and alert but was unable to stand and was euthanized at two days of age. The second foal, an Appaloosa, was also born alive at full term and was blind, weak, uncoordinated and unable to stand. Postmortem examination of both foals revealed generalized osteopetrosis and brachygnathia inferior. The osteopetrosis was characterized by failure of bone remodelling resulting in spicules of mineralized and nonmineralized cartilage covered by osteoid occupying ...
Caron JP, Barber SM, Bailey JV, Fretz PB, Pharr JW.Periorbital skull fractures were diagnosed in 5 horses, and were associated with ophthalmic complications including corneal ulceration, uveitis, and entrapment of the eye by retrobulbar bone fragments. Physical examination was of greater diagnostic use than radiography. Surgical repair was performed on all horses and was associated with a more favorable postoperative appearance in horses treated acutely; however, the cosmetic results were considered acceptable in all horses. Major postoperative complications were not observed.
Li XQ, Uboh CE, Soma LR, Guan FY, You YW, Kahler MC, Judy JA, Liu Y, Chen JW.A non-aqueous capillary electrophoresis-mass spectrometry (NACE-MS) method was developed for simultaneous separation and identification of 12 amphetamine and related compounds in equine plasma. Analytes were recovered from plasma by liquid-liquid extraction using methyl tertiary butyl ether (MTBE). A bare fused-silica capillary was used for separation of the analytes. Addition of sheath liquid to the capillary effluent allowed the detection of the analytes by positive electrospray ionization mass spectrometry using full scan data acquisition. The limit of detection (LOD) for the target analyte...
Denny HR.The current trends in equine fracture treatment are reviewed. Surgical approach, method of fixation, the advantages of Association for the Study of Internal Fixation (ASIF) implants and the complications of treatment are discussed with reference to 21 fracture cases. Normal limb function was restored in four horses with fractures of the olecranon and one with a mid shaft fracture of the tibia following stabilisation of the fracture with plates. A horse with a chip fracture of the distal radius and three other animals with fractures of the lateral condyle of the third metacarpal bone were also ...
Seltzer KL, Stover SM, Taylor KT, Willits NH.The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Bacon Miller C, Wilson DA, Martin DD, Pace LW, Constantinescu GM.A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the normally reported distance (13-15 cm), but was observed endoscopically during placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respiratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmortem examination revealed an aberrant le...
Krpan MK.Transtracheal aspiration is used to obtain samples for culture and cytologic examination of respiratory tract secretions and exudates. A 15-cm-long area of the ventral midcervical region is surgically prepared, a small site infiltrated SC with 2-3 ml lidocaine, and a stab incision made in the skin. A trocar with cannula is inserted through the incision and annular ligament into the trachea and the trocar removed. An 8-Fr polypropylene catheter is inserted about 35-40 cm down the trachea and attached to a 30-ml syringe, containing 20 ml sterile saline, with a 3-way stopcock . The saline is rapi...
Wright L, Puchalski SM, Kristoffersen M, Lindegaard C.To develop arthroscopic approaches to the atlanto-occipital (A-O) and describe associated arthroscopic anatomy. Methods: Experimental ex vivo study and clinical case report. Methods: Ten equine cadaver joints and 1 clinical case. Methods: CT arthrograms of 8 A-O joints were performed to determine the placement of an arthroscopic portal. Arthroscopy was performed via dorsal and/or ventral approaches (dorsal or ventral to the longissimus capitis tendon) in 10 cadaveric A-O joints and the A-O joint of a 2-week-old foal with septic arthritis. Accessible cartilage was debrided in 3 cadaver joints. ...
Groves L.An eighteen-month old quarter horse gelding was diagnosed with chip fractures from the distal lateral trochlear ridge of the talus. The horse presented with the symptom of persistent synovitis. The diagnosis was based on radiographic evidence. The horse was treated initially with arthroscopic surgery. He was given a non-steroidal anti-inflammatory agent, and a chondroprotective agent to prevent further damage to, and aid in the healing of, the damaged joint.
Doyle AJ, Saab ME, Lewis KM, McClure JT.An alcohol-based rub has been confirmed effective at reducing bacterial counts on equine skin. Skin sites with expected high bacterial burden have not been tested or has a comparison to a common protocol been performed. Objective: To determine if ethanol-based antisepsis reduces bacterial counts on the equine distal limb comparable to a current chlorhexidine scrub method and determine the most effective application technique for the product. Methods: Randomised trial. Methods: Forty-one horses were used in the study. By horse, each limb was randomly assigned to a treatment group: 5min scrub us...
Paik WK, Farooqui J, Gupta A, Smith HT, Millett F.The present observations are the continuation of our earlier study on the physicochemical mechanism of protein-lysine methylation. In this paper the electrophoretic behaviour (pI values) of two chemically modified horse heart cytochromes c at lysine-72 with trifluoromethylphenylcarbamoyl (neutral group) or carboxydinitrophenyl (acidic group) is compared with the enzymatically methylated cytochrome c. The results indicate that although both chemically modified cytochromes c have lower pI values than the unmodified cytochrome c, the enzymatic methylation appears to be much more efficient in lowe...
Roberts BL, Blake JW, Tobin T.Horses pretreated with 6.6 mg/kg of phenylbutazone were injected with 1 mg/kg of furosemide intravenously. Furosemide had no clinically significant effect on either plasma levels or plasma half-life of phenylbutazone. Furosemide reduced urinary levels of phenylbutazone 18-fold to concentrations which may result in inconsistent drug detection in routine screening tests. The results show that it is not possible to monitor compliance with phenylbutazone medication rules by means of urinalysis alone if the use of furosemide is permitted. Furosemide treatment, however, does not interfere with monit...
Demir C, Brereton RG, Dumasia MC.After oral administration of quinine sulfate to a thoroughbred mare, seven urine samples were obtained over a 45.5 h period. Using gas chromatography -electron impact ionization and positive-ion chemical ionization mass spectrometry, quinine and five putative metabolites were detected and tentatively identified in enzyme-hydrolysed post-administration urine; all metabolites involved some form of oxidation. The parent drug could be detected for about 16 h and some phase I biotransformation products for up to 40 h post-administration.
Alexander GR, Gibson KT.Two mares presented with life-threatening rectal tears were successfully treated with intensive medical management. Although surgery has been regarded as mandatory for grade 3 or 4 rectal tears in the past, recent reports have indicated the value of medical management alone. The case reports presented in this article detail the use of antibiotics, flunixin meglumine, laxative diets and faecal softeners in the medical management of two mares presented with grade 3 rectal tears.