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.
Landgren GL, Gillespie JR, Fedde MR, Jones BW, Pieschl RL, Wagner PD.We studied mechanisms of O2 transport in 6 adult (2-5 year old) horses at rest and during steady-state exercise on a treadmill (0% slope) at 12 m/s (a submaximal gallop). Oxygen consumption was measured using an open-flow system. Arterial and mixed venous blood samples were simultaneously obtained for measurement of O2 content and hemoglobin concentration. VO2 increased from 1.5 +/- 0.2 L/min at rest to 46.2 +/- 4.8 L/min during exercise. HR increased from a resting value of 36.9 +/- 2.5 bpm to 196.5 +/- 10.9 bpm and the arterio-venous O2 content difference (a-v O2) increased from 4.2 +/- 0.8 ...
Cohen D, Bosler EM, Bernard W, Meirs D, Eisner R, Schulze TL.A serologic survey of horses in the New Jersey-Pennsylvania area demonstrated that about 10% (6.2-14.2%) have significant levels of serum antibody to Borrelia burgdorferi. However, in a highly endemic area of central New Jersey, up to 60% of the mares and yearlings samples on one farm were seropositive. In 1983, sera from this same farm exhibited only 12% positives in mares and 35% positives in yearlings. Longitudinal studies of paired sera obtained from individual yearlings over a 6-month period in 1985 showed that 34% of them declined during the period. A new clinical syndrome associated wit...
Pause B, Nolte I, Geiss V, Mayer H, Lasch HG.A thoroughbred horse, suffering from intermittent lameness was treated with streptokinase, urokinase and warfarin. The appearing fibrinolytic changes in coagulation were exhibited in a resonance thrombogram. In attendant coagulation studies fibrinogen- and fibrin-degradation products were demonstrated. The stallion does not show any lameness since the end of the treatment and is standing in a breeding station since March 1988.
Cochaux P, Van Sande J, Swillens S, Dumont JE.The characteristics of the iodide-induced inhibition of cyclic AMP accumulation in dog thyroid slices have been previously described [Van Sande, J., Cochaux, P. and Dumont, J. E. (1985) Mol. Cell. Endocrinol. 40, 181-192]. In the present study we investigated the characteristics of the iodide-induced inhibition of adenylate cyclase activity in dog and horse thyroid. The inhibition of cyclic AMP accumulation by iodide in stimulated horse thyroid slices was similar to that observed in dog thyroid slices. The inhibition was observed in slices stimulated by thyroid-stimulating hormone, cholera tox...
Jaussaud P, Courtot D, Guyot JL, Paris J.The main metabolite of flunixin, a hydroxylated product, has been identified by gas chromatography-mass spectrometry and 1H NMR spectroscopy in equine urine and plasma. The method also permits the qualitative monitoring of the urinary elimination of the drug and its metabolite. The two products are detected up to 175 and 54 h, respectively, after a single intravenous administration at the dose of 1 mg/kg. Simultaneous detection of the two compounds increases the reliability of anti-doping control analysis.
Sillerud CL, Bey RF, Ball M, Bistner SI.After the observation of 2 horses with uveitis on a horse farm in the Minnesota River valley, 100 horses from this geographic area were given ophthalmologic examinations and were evaluated serologically for leptospirosis. A statistically significant (P less than 0.001) association was observed between the finding of antibodies against Leptospira interrogans serovar pomona and uveitis.
Wyatt CR, Magnuson NS, Perryman LE.Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Steffey EP, Hodgson DS, Dunlop CI, Miller MF, Woliner MJ, Heath RB, Grandy J.Hemodynamic and respiratory effects of 5 h of unvarying 1.57%, end-tidal (1.2 MAC) isoflurane in O2 anesthesia were characterized in ten left laterally recumbent horses. Compared to base line values at 30 min of constant dose isoflurane, cardiac output, hematocrit, total plasma solids, PaCO2, and peak inspired gas flow progressively and significantly (P less than 0.05) increased over the course of study. Arterial blood pressure increased (P less than 0.05) during the first 2 h of constant dose of isoflurane then decreased and remained near base line values. Inspiratory time progressively decre...
Cowell RL, Tyler RD, Clinkenbeard KD, MacAllister CG.This article discusses collection, slide preparation, culture technique, fluid analysis and evaluation, and cytologic evaluation of peritoneal and pleural effusions. The morphologic characteristics of various effusions are described, and the physical characteristics (volume, color, turbidity) of effusions are discussed. An algorithm for classifying effusions as transudates, modified transudates, or exudates is included, and each category is discussed.
Hodgson DR.This article reviews what are considered the basic concepts of gas transport, blood gases, and acid-base physiology is most mammalian species. Techniques for the appropriate collection of blood samples for blood gas and acid-base determinations in the newborn foal are described. Guidelines for interpretation of these values in the normal foal and those animals undergoing respiratory and metabolic derangements are provided.
Cox JH, DeBowes RM.Discomfort manifested by colic-like clinical signs in 2 young mares was presumed to be attributable to ovarian pain associated with follicular enlargement and ovulation. Diagnosis was based on the lack of detectable evidence of gastrointestinal disease, the finding of a large ovarian follicle or recent ovulation, the repetition of signs during several subsequent estrual periods, and the clinical response to pharmacologic suppression of estrus and ovulation. The similarity of the clinical signs in these 2 mares to cyclic intermenstrual pain in women was considered.
Kannegieter NJ, Alley MR.A 20-month-old, Standard-bred colt was presented with an acute onset of hindlimb ataxia. Clinical and radiographic examination identified a compressive lesion affecting the spinal cord at the level of the 17th to 18th thoracic vertebrae. After euthanasia, post-mortem examination revealed a tumour in the epidural space, diagnosed histologically as a lymphosarcoma. Neoplastic lymphoid cells were also present in the abdominal lymph nodes and brain. Because of the disseminated nature of lymphosarcoma in the horse, involvement of the central nervous system is likely to be more common than is presen...
Labadia A, Rivera L, Costa G, García-Sacristán A.The presence of both alpha and beta adrenergic receptors in the caudal third ureter of the horse were studied in vitro under isometric conditions using adrenergic agonist and antagonist drugs. Isoprenaline and the beta 2- stimulating agent, salbutamol, elicited relaxation of the ureter smooth muscle strips. The responses were not affected by the beta 1- blocking agent, practolol, but were totally abolished by propranolol and the beta 2- blocking agent, butoxamine. The stimulation of alpha-adrenergic receptors with noradrenaline and phenylephrine evoked a contractile effect which was totally in...
Auer DE, Wilson RG, Groenendyk S, Filippich LJ.A case of pituitary dependent hyperadrenocorticism in a horse is reported. Clinical signs included hirsutism, polydipsia and general debility. The horse was persistently hyperglycaemic and glucose values were unchanged following subcutaneous administration of insulin. Resting cortisol values were normal, but dexamethasone suppression of cortisol concentration was shorter than normal. Plasma glucose, cortisol, insulin and glucagon concentrations were measured as part of an intravenous glucose tolerance test. The patient responses were different from those in a control pony.
Carpenter S, Evans LH, Sevoian M, Chesebro B.Equine infectious anemia virus was isolated from peripheral blood leukocytes collected during two early febrile cycles of an experimentally infected horse. RNase T1-resistant oligonucleotide fingerprint analyses indicated that the nucleotide sequences of the isolates differed by approximately 0.25% and that the differences appeared randomly distributed throughout the genome. Serum collected in the interval between virus isolations was able to distinguish the isolates by membrane immunofluorescence on live cells. However, no neutralizing antibody was detected in the interval between virus isola...
Illera JC, Illera M, Hamlin RL.Electrocardiograms were obtained from 100 male crossbred horses. In addition to standard limb leads, leads were taken from 12 points on the thorax. The QRS complexes were categorized into 1 of 8 forms on the basis of configuration and amplitudes of component deflections. Relative uniformity of QRS was determined for each lead, using the percentage of horses that possess a particular configuration. All unipolar thoracic leads, except those coplanar with the frontal plane, and lead aVR had great uniformity, with greater than 80% of the horses with a QRS of similar contour.
Roger T, Ruckebusch Y.The motor responses of the caecum and colon to stimulation of alpha 2-adrenoceptors by xylazine and detomidine at the recommended dose levels of 0.6 and 0.1 mg/kg were investigated in three ponies. The motor changes of the left ventral colon induced by continuous intra-arterial infusion of a prostaglandin (PGF2 alpha) were used to assess the relative inhibitory effects of xylazine and detomidine in a colic model. The administration of alpha 2-agonists inhibited the spiking activity on the whole of the large intestine for 20-30 min (xylazine) or 2-3 h (detomidine). However, the detomidine-induc...
Spensley MS, Carlson GP, Harrold D.During the growth interval encompassing age 2 days through 24 weeks, plasma, RBC, total blood, and extracellular fluid (ECF) volumes were determined in 7 healthy, resting foals. Evans blue dye and sodium thiocyanate were used to estimate plasma and ECF volumes, respectively. Absolute plasma volume remained stable from 2 days through 2 weeks of age, then increased progressively through 24 weeks of age. After decreasing between 2 days and 2 weeks of age, absolute RBC and total blood volumes progressively increased. Absolute ECF volume increased progressively from 2 days of age through 24 weeks o...
Tyler RD, Cowell RL, Clinkenbeard KD, MacAllister CG.Normal reference ranges and pertinent background information on equine hematology are presented and briefly discussed. Diagnostic interpretation of hematologic data is discussed and three diagnostic algorithms and two diagnostic tables are provided to facilitate the use of the presented information for diagnosis. Two cases are presented and the information presented in the article is used to interpret the case data.
de Waal DT, Potgieter FT.Rhipicephalus evertsi evertsi larvae were fed on the ears of rabbits. Seven days after larval infestation, unfed, newly moulted nymphae were manually removed to infest a splenectomized donkey showing a patent Babesia caballi infection. Engorged nymphae were collected from the donkey and the ensuing adult ticks were placed on a susceptible horse. The horse contracted a B. caballi infection showing a prepatent period of 19 days after tick infestation. A very low parasitaemia, (highest score 2), which was patent for only 10 days, was recorded. The lowest packed cell volume recorded was 16%.
Craig AM, Blythe LL, Appell LH, Slizeski ML.Dimethyl sulfoxide (DMSO) had been postulated to be a 'masking agent' when used concurrently with therapeutic or prohibited drugs in racing animals. Eight drugs (flunixin, furosemide, caffeine, apomorphine, phenylbutazone, lidocaine, cocaine, and acepromazine maleate) were administered to six horses singly and with concurrent intravenous DMSO. Urine samples were analyzed for the presence of the drugs and/or their metabolites by thin layer chromatography. Direct comparison of thin layer chromatograms of extracts of positive urine samples with and without DMSO verified that DMSO did not interfer...
Carnevale EM, Squires EL, McKinnon AO.Forty equine embryos collected 7 d post-ovulation were stored at 5 C for 24 h in one of two culture media (n = 20/group): 1) Ham's F10 + 10% heat-treated fetal calf serum (FCS) buffered by gassing with 5% CO2, 5% O2 and 90% N2 and 2) Ham's F10 + 10% FCS with Hepes buffer (25 mM). Embryos cultured in Ham's F10 + CO2 maintained a better quality score and had a larger average increase in diameter (+34.8 micron) than embryos stored in Hepes buffered Ham's F10 (-10.2 micron). Embryos were transferred surgically into recipient mares that ovulated -3 to +1 d in relation to the donor mare. Twenty embr...
Perryman LE, Bue CM, Magnuson NS, Mottironi VD, Ochs HS, Wyatt CR.Thirty-eight foals with combined immunodeficiency (CID) received transplanted fetal liver cells, fetal liver and thymus cells, histocompatible bone marrow cells, or equine lymphocyte antigen (ELA) haploidentical bone marrow cells in an attempt to reconstitute their deficient immune systems. Engraftment was infrequent, partial, and unpredictable when fetal cells were employed. Three of five CID foals receiving ELA haploidentical bone marrow cells demonstrated partial reconstitution, but engraftment was only temporary. Administration of histocompatible bone marrow cells resulted in rapid, full a...
MacDonald MH, Richardson DW, Morse CC.A 23-year-old Thoroughbred stallion was admitted to the hospital for treatment of acute esophageal obstruction. Clinical examination and contrast radiography confirmed the presence of an esophageal obstruction. The horse was euthanatized, and examination revealed a bolus of feed material occluding the esophageal lumen 6 cm caudal to the thoracic inlet, with underlying necrosis of the esophageal mucosa. A large pulsion diverticulum was identified in the caudocervical portion of the esophagus. Apparently, the phytobezoar was formed within the esophageal diverticulum and subsequently became dislo...
Roger T, Ruckebusch Y.The contractile activity of the equine large intestine exhibited a biphasic response to feeding: enhancement of migrating complexes passing along the colon and an increase of 50% in cyclic variations in smooth muscle at intervals of 20 min on the left ventral colon for a period of 5 to 7 h postfeeding. The cholinergic agonist, bethanechol (50 micrograms/kg subcutaneously), induced both the migrating complexes and the cyclic variations at intervals of 10-15 min. In contrast, the intra-arterial infusion of PGF2 alpha (3 micrograms/kg/min) increased the contractile activity during infusion, but w...
Morris CF, Robertson JL, Mann PC, Clark S, Divers TJ.A syndrome characterized clinically by oliguria, progressive severe azotemia, and edema of the abdomen and groin was seen in 2 horses. Treatment with fluids, diuretics, and corticosteroids administered intravenously was ineffective, and the horses were euthanatized. Microscopically, there was severe necrotizing angiopathy with profuse fibrin deposition in renal glomeruli and sinusoids of peripheral lymph nodes. The signs observed in the horses resembled hemolytic-uremic syndrome in human beings.
Collier MA, Lowe JE, Rendano VT.Materials fatigue and gross biocompatability of an implantable bone growth stimulator (BGS) were assessed in a 6-month trial using 6 ponies. The forelegs of each pony were implanted with a BGS; the right leg implant had the cathode and cathode lead preconnected by the manufacturer, and the left leg implant was connected at surgery. Evaluation was by radiographic and clinical examination at the beginning and end of the experimental period. Six of the 12 cathode leads (50%) and 7 of the 12 cathodes (58%) were broken at 6 months. All of the implanted preconnected cathode and insulated cathode lea...
Breen LJ, Coleridge MOD, O'Brien T.A 6-month-old thoroughbred colt foal was referred to a private equine referral hospital for evaluation of an acute onset, left hind limb lameness. On arrival the foal was 4/5 lame on the left hind at walk and there was diffuse swelling of the left hind pastern and fetlock region. The physical exam was otherwise unremarkable. Digital radiographs of the left hind pastern identified a Salter-Harris type-2 physeal fracture of the proximal phalanx. The fracture was initially treated conservatively using a cast, but the immobilization was not sufficient at achieving adequate reduction. As a result, ...
Iqbal J, Edington N.Equid herpesvirus 1 (EHV-1) is the most common cause of virus-induced abortion in horses. After primary infection the virus becomes latent predominantly in the respiratory tract lymph nodes and the genome can also be detected in the peripheral nervous system. The role of mouse as a feasible model for the establishment of latency and reactivation of EHV-1 was investigated. Intracerebral and intranasal infections of 3- and 17-day-old mice were made and virus replication was confirmed by virus isolation and detected by indirect immunofluorescence (IIF) in brain. For reactivation studies, the mice...
Osz E, Réthy L.The authors have compared the anaphylaxis due to active and passive sensitization of mice. In the case of active sensitizing, anti-mouse anti-thymocyte horse serum (ATS), and/or normal horse serum (NHS), whereas in the case of passive sensitizing, plasma, peripheral leukocytes, spleen cells and thymocytes of sensitized animals were used. Provocation of shock was carried out by intravenous administration of ATS or NHS. Irreversible anaphylaxis occurred in a significantly higher rate in the case of ATS than NHS sensitivity, produced either actively, or passively. Differences have been found also...
Firth EC.Bilateral neurectomy of the ventral branch of the spinal accessory nerve was performed in an attempt to control windsuckling. There was no permanent improvement in the eight cases described.
Power MM.The results of Y chromosome measurements in 31 horses are presented. The Y chromosome was identified using G-, R-, and C-banding techniques. From G-banded metaphase spreads, total X and Y chromosome and separate proximal (P) and distal (D) Y-band measurements were made. Within this group, the Y/X ratio (%) for each animal varied from 18.93 to 43.95, with an overall mean of 34.85 and a coefficient of variation (CV) of 16.12. The overall mean P/X ratio (%) was 23.57 with a CV of 20.57, compared with an overall mean D/X ratio (%) of 11.26 with a CV of 15.18. The group studied included 27 Thorough...
Hendrix DV, Newkirk KM.To determine whether epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are expressed in periocular squamous cell carcinomas (SCCs) of horses. Methods: Biopsy specimens of SCCs from 46 horses. Methods: Pathology records were searched retrospectively for biopsy specimens of periocular SCCs obtained from horses. Slides of the specimens were reviewed histologically to confirm the SCC diagnosis and stained for EGFR and HER2 by immunohistochemical methods. For both EGFR and HER2, the immunohistochemical staining intensity and percentage of stain-positive cel...
Ludders JW, Palos HM, Erb HN, Lamb SV, Vincent SE, Gleed RD.To determine if horses before undergoing anesthesia for surgical correction of colic would have lower plasma arginine vasopressin (AVP) concentrations than healthy horses undergoing anesthesia for arthroscopic surgery, and would not increase their plasma AVP concentrations in response to anesthesia and surgery. Methods: Prospective clinical study. Methods: University teaching hospital. Methods: Fourteen horses with colic and 8 healthy horses. Methods: Horses with colic underwent anesthesia and surgery for alleviation of colic, and healthy horses underwent anesthesia and surgery for arthroscopy...
Elyasi Gorji Z, Amiri-Yekta A, Gourabi H, Hassani S, Fatemi N, Zerehdaran S, Vakhshiteh F, Sanati MH.Follicle stimulating hormone (FSH) plays an essential role in reproductive physiology and follicular development. Objective: A new variant of the equine () gene was cloned, sequenced, and expressed in ) GS115 yeast expression system. Methods: The full-length cDNAs of the and chains were amplified by reverse transcription polymerase chain reaction (RT-PCR) using the total RNA isolated from an Iranian Turkmen-thoroughbred horse's anterior pituitary gland. The amplified chains were cloned into the pPIC9 vector and transferred into The secretion of recombined eFSH using expression system was...