Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Mahoney DF, Wright IG, Frerichs WM, Groenendyk S, O'Sullivan BM, Roberts MC, Waddell AH.A Babesia parasite, isolated from the blood of a horse at Bowral, New South Wales, was identified on the basis of its morphological features, host specificity and serological reactions, as Babesia equi (Laveran 1901). The case was originally reported by Churchill and Best (1976, Aust. vet. J. 52: 487) and is the first record of equine babesiosis in Australia. In preliminary studies, the organism produced only a mild disease in an intact horse, but caused the typical clinical syndrome of acute babesiosis in a splenectomised horse, which died 19 days after the intravenous inoculation of the para...
Duncan ID, Baker GJ, Heffron CJ, Griffiths IR.The larynges of 6 horses were examined endoscopically and the findings correlated with the gross and histological appearance of the intrinsic laryngeal muscles and their nerve supply. In all cases it appeared that the balance between abductor and adductor muscle groups had been lost due to preferential atrophy of individual muscles or groups of muscles. The laryngeal abnormalities recorded were asymmetry of the larynx with asynchronous left sided abduction and fluttering or trembling of the left vocal cord and arytenoid cartilage. It is suggested that these changes represent the early signs of...
Sumner-Smith G, Bell M, Manley P, Caddell E, Hoare J.The advances made by the use of a telemetric system in the study of bone strain in a free-moving horse are reported. A rosette strain gauge was bonded to the craniomedial aspect of the metacarpus of the horse. Attachment of a miniature FM transmitter to lead wires facilitated telemetric transmission of of resistance changes which corresponded to limb movement. During 3 different gaits, the trace pattern remained similar, although frequency and amplitude varied. The tracings were similar to those reported in other species in which nontelemetric transmission was used.
Strömberg B, Tufvesson G.Four autologous tendon grafting techniques, bipedicle, pedicle and free grafts of the deep digital flexor tendon and free grafts from the lateral digital extensor tendon were described. The vascularization and remodelling of the transplant and the reactions in the donor, as well as the recipient tendon, were studied by means of microangiographic and histochemical methods. The results indicated that regardless of the technique used the grafts were revascularized and replaced by a highly orientated and organized tendon. The use of free grafts may therefore be worthwhile in treatment of severe te...
Roberts MC.Progressive leukaemic changes and a persistent anaemia were demonstrated in the blood of a 7 year old gelding, which had shown early signs of lowered performance and unthriftiness, and later developed dependent oedema and became dull and listless. The total leucocyte count, initially within the normal range although reflecting an absolute lymphocytosis, increased fourfold in 6 days from excessive lymphoid production involving predominantly the more immature cell types; lymphoblasts, prolymphocytes and large lymphocytes. The severity of the condition was confirmed by bone marrow biopsy.
Glendinning SA.The author considers some of the difficulties the clinician may be faced with when giving an opinion on a horse with a cardiac abnormality. The 3 types of cardiological cases presented to the practitioner are described. The first 2 categories both exhibit a reduction in performance either with loss of bodily conduction or without it. The third group, which is the most troublesome for the clinician, involves the horse which shows a cardiological abnormality but is otherwise apparently normal.
Littlewort MC.This paper outlines the major problems in evaluating and assessing prognosis in horses with minor cardiac abnormalities. It emphasises that progress will only be made if adequate data on the "natural history" of equine cardiac disease can be collected. This will necessitate a long-term study of suitable cases and will require the collaboration of specialist institutions and general practitioners if it is to be successful.
O'Callaghan MW.The problem of transitory cardiac arrhythmias in equidae is discussed particularly with regard to the referral of suspect cases to specialist institutions for second opinion. Recently developed electro-stimulation techniques designed to uncover problem arrythmias, are briefly described and their potential in the analysis of cardiac electrical function under varying conditions is reviewed. The author cautions on the too rapid evaluation of the techniques for this purpose while remaining optimistic of the potential of electro-stimulation in the objective analysis of cardiac electric parameters.
Barstow LE, Young RS, Yakali E, Sharp JJ, O'Brien JC, Berman PW, Harbury HA.Horse heart cytochrome c can be split with cyanogen bromide into a heme peptide (residues 1-65) and a nonheme peptide (residues 66-104). In a process involving (i) complex formation between the two fragments and (ii) restoration of the severed peptide linkage, a fully active cytochrome c preparation can be re-formed. Use has been made of this process to couple the heme peptide to peptide 66-104 synthesized by the Merrifield solid-phase procedure. The semisynthetic product formed in this manner is indistinguishable from reconstituted cytochrome c prepared with nonsynthetic peptide 66-104.
Gay CC, Carter J, McCarthy M, Mason TA, Christie BA, Reynolds WT, Smyth B.Indirect arterial blood pressure was determined on 33 horses prior to surgical intervention for the diagnosis and/or correction of acute abdominal disorders and a relationship between low systolic blood pressure and non-survival was established. It is suggested that blood pressure determination should be used to augment other methods of clinical and laboratory examination in cases of equine colic.
Grelck H, Hörchner F, Wöhrl H.Ten pony foals were infected with Fasciola hepatica; five animals received up to 1000 metacercariae orally, the remaining animals received up to 80 specimens of 24 hours old adulescariae intraperitoneally. The rate of development of the parasites varied in a wide range between 0,2 and 41%. Most of the liverflukes were found in animals severely infected with strongyles in the same time. Only 22 weeks after oral infection, the flukes had reached a length of 20 mm and sexual maturity. Fasciola-eggs could not be detected in the feces.
Cazalet E.The paper examines the responsibilities of the veterinary surgeon in relation to the advances more recently made in the field of equine cardiology. Notwithstanding such advances it is stated that the normal established legal principles apply, in particular in relation to the preparation of certificates, namely that the veterinary surgeon must be sufficiently expert to give the opinion sought, that he must make himself fully aware of the purpose for which the certificate is required and that he must make clear the nature and limitations of any examination carried out.
Dusek J.Various sets of horses were examined in view of the necessity of widening the range of biochemical substances for diagnostic purposes in the field of veterinary medicine. The aim of the investigations was to obtain basic information on fibrinogen level and its variability. The average value stated was 280 mg% s = 89, sx = 12, V% = 32). The fibrinogen level in horses of the pronounced oxidation type was lower than in those with reduced metabolism, the difference being connected with the speed of sedimentation of erythrocytes. Repeated examination of a part of the set of horses (n = 10) on three...
Drudge JH, Lyons ET.The critical test is the primary method used for the efficacy evaluation of drugs against the major internal parasites (bots, ascarids, large strongyles, small strongyles, and pinworms) of the horse. The critical test determines: (1) spectrum of activity, (2) effectiveness of removal, (3) pattern of discharge, and (4) physical condition of each species of these parasites. General characteristics of the major parasitisms of the horse are discussed briefly. Criteria of the critical test also are considered including: (1) number of tests, (2) strain variation and drug resistance, (3) selection of...
Smith JS, Mayhew IG.The sympathetic nervous innervation of the head was surgically transected in the horse, cow, sheep and goat. The site of transection was preganglionic in all 4 species and ganglionic-postganglionic in 2 additional horses. The Horner's syndrome, manifested as a result of the iatrogenic lesion, varied with the species. Ptosis was the most constant sign in all species. Unilateral sweating over the face and proximal neck, particularly at the base of the ear, was the most prominent feature in the horse. The cow revealed distension of vasculature and cutaneous heat of the pinna, and a reduced produc...
Gerber JD, Marron AE, Bass EP, Beckenhauer WH.The cell-mediated immune response and antibody response of horses of varying ages and of pregnant horses to equine herpesvirus 1 antigen were examined. Six to eight month old horses showed either no increase or slight increases in anti-equine herpesvirus 1 serum neutralizing antibody following vaccination and revaccination with a modified live equine herpesvirus 1 vaccine. However, these same horses showed a marked increase in the cell-mediated immune response to equine herpesvirus 1 as measured by the lymphocyte transformation test. Eighteen to 21 month old horses showed four to 64-fold incre...
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Greatorex JC.The clinical manifestations, diagnosis and differential diagnosis of "verminous aneurysm" formation at the root of the cranial mesenteric artery and coeliac artery resulting from Strongylus vulgaris larvae migration are described. Forty-nine of 57 cases were successfully treated with low molecular weight dextran (dextran 70).
Blackmore DJ, Palmer A.Examination of tissues obtained from thoroughbred horses showed that the 'intestinal' phosphatase activity could be differentiated from other phosphatases by analysis at a pH of 9-5 and inhibition with 15 mM L-phenylalanine. A simple method for the measurement of 'intestinal' phosphatase in heparinised plasma or serum is described. Application of the technique to serum or plasma from normal and diseased horses indicates that the increase in the activity of 'intestinal' phosphatase is associated with cases showing clinical, biochemical and haematological evidence of intestinal damage.
Jahrling PB, Beall JL.Hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. Different conditions of pH and phosphate molarity were required to obtain satisfactory elution profiles and separations for Western equine encephalomyelitis virus strains, compared with Eastern equine encephalomyelitis virus and Semliki Forest virus strains. Raising the pH of the buffers effected earlier elutions of all viruses. Selection of phosphate gradients with more gentle slopes and adjustment to the proper pH effected better separations of virus subpopulations. Elution profiles ...
Hussein KH, Elmeligy E, Khalphallah A, Al-Lethie AA.This study was performed to investigate the effects of cyclopentolate on ultrasonographic parameters of eye structures, intraocular pressure (IOP), tear production, and pupil size in normal donkeys. Sixteen eyes of eight clinically healthy adult donkeys (2-2.5 years old) weighing 295 ± 34 kg (mean ± standard deviation) were used in this study. Cyclopentolate hydrochloride 1% was instilled in a randomly selected eye and the other eye received normal saline drops as a control. The effect of cyclopentolate was evaluated by ultrasonography. Additionally, changes in IOP and tear production were ...
Dusek J, Munk Z.In a set of mares of English Thoroughbred horse of the Napajedla stock the gravidity length in the time period from 1880 to 1972 was evaluated. The variability of the gravidity length was evaluated in sets which were put together by combination of two age groups with a division of the studied time period into ten-year stages. Variance and sample means of the gravidity lengths in these sub-groups are significantly different in the period under study. In order to eliminate the action of non-genetic influences qualifying the variability of the gravidity length, and to increase the objectivity of ...
Attenburrow DP.The development of a radio-stethoscope for horses is described. The equipment consisted of a sound transducer applied to the skin adjacent to the trachea and a radio transmitter attached to the saddle. The signals emitted were detected by telemetry and recorded on a magnetic tape-recorder. The recorder incorporated a monitor earphone so that sounds could be reproduced at the time of recording. The frequency response obtainable ranged from a few Hz to 4 KHz. This technique provided an objective means of studying the respiratory sounds generated during exercise although absolute values could not...
Klohnen A, Peroni JF.With the recent development of video-assisted thoracic surgery, visual inspection of the thoracic cavity has been used to provide a more accurate diagnosis and prognosis of thoracic diseases and to better manage these diseases. Equipment, techniques, and complications for standing thoracoscopy in horses are described.
Altmeyer P, Holzmann H, Stöhr L, Koch HJ.White horses are subject to age-dependent coat depigmentation. They are dark gray or black at birth and lose their coloring between their second and fourth year. Beginning at about age 10 their coat takes on a characteristic silver-gray coloring. The purpose of this paper was to find out to what extent the endogenic alpha-MSH level changes with the change in pigmentation. alpha-MSH plasma levels were determined by radioimmunologic analysis in 3 age groups of white Camarque horses: age group 1 consisted of dark horses with a mean age of 1.2 years and a mean alpha-MSH level of 106.4 pg/ml +/- 18...
Neuhauser S, Gösele P, Handler J.During the peripartal period, interpretation of basic clinical signs may be challenging. In the present study, heart rate (HR), respiratory rate (RR) and body temperature (BT) were evaluated in healthy mares of different breed types and compared to reference values for adult horses from the literature. Methods: During daily physical exams of periparturient mares, the HR, RR and BT were evaluated. Differences according to the horse's size were investigated and in large breeds, the influence of dystocia or retained placenta was analysed. Results: During the last weeks before parturition (a. p.),...
Bjorck G, Nilsson G.Sixteen cases of chronic hoof changes seen in Standardbred trotters are described. The chief defect is decomposition of the horn. The disease process usually commences on the weight-bearing surface and spreads to underrun both the sole and wall. Histopathological studies revealed marked swelling and vacuolation of the cells of the stratum corneum, increased proliferation in the stratum germinativum, and monocytic infiltration in the corium. Treatment comprised complete removal of underrun horn and exposure of the affected area. In severe cases, a course of penicillin is administered. The lengt...
Leung GN, Tang FP, Wan TS, Wong CH, Lam KK, Stewart BD.This paper describes the application of gas chromatography-mass spectrometry (GC-MS) for in vitro and in vivo studies of 6-OXO in horses, with a special aim to identify the most appropriate target metabolite to be monitored for controlling the administration of 6-OXO in racehorses. In vitro studies of 6-OXO were performed using horse liver microsomes. The major biotransformation observed was reduction of one keto group at the C3 or C6 positions. Three in vitro metabolites, namely 6alpha-hydroxyandrost-4-ene-3,17-dione (M1), 3alpha-hydroxyandrost-4-ene-6,17-dione (M2a) and 3beta-hydroxyandrost-...
Spoo W.Poisoning resulting from exposure to a wide variety of industrial chemicals is not a common occurrence in horses, but it does happen on occasion. A wide range of toxicosis can occur from a wide range of industrial pollutants, such as dioxin, carbon tetrachloride, and tetrachloroethylene, to heavy metals, such as cadmium and zinc. The equine practitioner must consider industrial chemical toxicosis in differential diagnoses and work with a reputable veterinary diagnostic laboratory to confirm or rule out industrial chemical poisoning.
Szczerba-Turek A, Siemionek J, Wasowicz K, Szweda W, Raś A, Platt-Samoraj A.BPV-1 is now recognized as a main etiological agent of equine sarcoids. The etiopathogenesis of the equine sarcoids is equivocal and is not yet fully understood. The aim of the present study was to analyse a partial sequence of the L1 gene of BPV associated with equine sarcoids in Polish horses. After clinical diagnosis, 40 skin lesions obtained from 29 horses were collected. The amplicons of a fragment of BPV L1 DNA were detected using PCR with MY09/MY11 primers in 31 specimens. All of them were recognized as BPV-1. Phylogenetic analysis has allowed the amplicons of partial L1 gene to be divi...
MacDougall DF.The proteins IgG and IgG(T) are the predominant immunoglobulins in equine colostrum. Their distribution and catabolism were studied in the newborn foal using an isotopic tracer technique. More precise quantitation of the absorption of these immunoglobulins from colostrum is now possible.
Lesser FR, Cowles RR.In this article, the author discusses the design of an equine ambulatory practice. He suggests a more systematic approach to the design of an ambulatory practice that should answer the needs of group and solo practices. Today's practitioners must actively manage their practices so that their resources can be leveraged in such a fashion that a return can be realized on their capital investment and the hours spent in practice.
Les CM, Stover SM, Willits NH.Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which...
Sanada Y, Noda H, Nagahata H.The blastogenic response of lymphocytes from 16 newborn foals naturally infected with Rhodococcus equi was investigated, in order to evaluate the relationship between R. equi infection and depressed host response. Naturally infected foals showed evidence of R. equi infection at 5-6 weeks of age, as determined by clinical, haematological, bacteriological and serological methods. The blastogenic response of lymphocytes against phytohaemagglutinin was significantly depressed (stimulation index < 1.80; P < 0.01, P < 0.05) in R. equi-infected foals at 5-6 weeks of age compared with those o...
Lavach D.Performance and pleasure horses depend upon their ability to see and assess the environment. Thus, the veterinarian must be able to examine the eyes and recognize abnormalities so that the owner or purchaser can be informed about the visual status and prognosis for the horse's vision. If the veterinarian encounters suspicious or abnormal findings during the examination, a more detailed examination and/or referral to a veterinary ophthalmologist can be recommended to the owner or purchaser.
Osame S, Ichijo S.Seven cases of thoroughbred foals kept on a farm in the Hidaka district of Hokkaido showed bilateral thyroid enlargement from 3 or 4 months after birth. Their serum T4 levels were remarkably low, whereas T3 levels were in the normal range. Serum T4 levels were also low in the other clinically normal foals and their dams kept together. Since the iodine content in pasture soil and grass was very low, iodine deficiency was supposed to be the cause of the disease.
Long CD, Galuppo LD, Waters NK, Hornof WJ.The aim of this study was to evaluate the diagnostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) by means of a retrospective review of its use in 14 horses that were evaluated for orthopedic infection as a cause of lameness. A total of 17 LS exams were performed in 14 horses. LS studies were positive in 10 of 14 horses. A bacterial infection was confirmed with cytology or culture in 9 of 10 positive horses. Negative LS studies occurred in 4 of 14 horses. Necropsy confirmed the lack of infection in 2 of the 4 horses. Other clinical data and a favorable clinical outcome supported a negative...
Hansmann F, Herder V, Ernst H, Baumgärtner W.This report is the first description of a spinal epidermoid cyst (EC) in a SJL mouse and gives an overview on the occurrence of ECs in animals including dogs, horses, mice and rats. The EC was not detected grossly and the mouse did not display clinical signs or an altered rotarod performance. Microscopically, there was an oval cyst lined by stratified squamous epithelium that was attached to the dorsolateral meninges and caused moderate compression of the adjacent lumbar spinal cord. ECs in mice and rats are mainly located in the caudal part of the spinal cord with a variable, strain-dependent...
Bailly-Chouriberry L, Pinel G, Garcia P, Popot MA, Le Bizec B, Bonnaire Y.Equine growth hormone (eGH) has been available since 1998 as an approved drug (EquiGen-5, Bresagen) containing recombinant eGH (reGH). It is suspected of being illegally administered to racehorses in order to improve physical performance and to speed-up wound healing. Thus it may be considered a doping agent which would require a sensitive and reliable method of identification and confirmation in order to regulate its use in racehorses. reGH differs from the native eGH by an additional methionine at the N-terminal (met-eGH) and has never been unambiguously detected in any type of biological ma...
Wilson DG, Mays MB, Colahan PT.Seven horses with canker had radical surgical debridement and various irritant substances applied to the wounds. Four of the horses were clinically normal in (mean) 3.6 months, 1 mare was lame, and 2 horses were euthanatized because of complications of their treatments. Seven horses that had minor surgical debridement and antimicrobial agents used systemically and topically were clinically normal in (mean) 1.4 months. Seemingly, canker in horses should be managed using minor surgical debridement and appropriate antimicrobial therapy.
Freeman KP, Roszel JF, Slusher SH, Kocan KM.Cells resembling those known as "repair cells" in gynecologic cytology specimens from women were identified in uterine cytology specimens from infertile mares treated with antibiotics using indwelling uterine catheters. This prompted a study of the effect on the equine uterus of indwelling catheterization without antibiotic infusion, using light microscopic examination of cytologic and biopsy specimens and electron microscopic examination of biopsy specimens. Cytologic and biopsy specimens had features within normal limits at the start of the study. Following five days of indwelling catheteriz...
Ainsworth DM, Ducharme NG, Hackett RP, Eicker SW, Snedden K.We examined the electromyographic activity of the costal portion of the diaphragm and the transverse abdominal and external oblique muscles in 6 chronically instrumented awake adult horses during eupneic breathing, during 2 levels of hypercapnia (fractional concentration of inspired CO2; FICO2 = 0.4 and 0.6), and during 2 levels of hypocapnic hypoxia (FIO2 = 0.15 and 0.12). Using the inert gas technique, we also measured the end-expiratory lung volumes of the 6 horses during eupnea, 6% CO2 challenge, and 12% O2 breathing. During eupneic breathing, phasic electrical activity of these 3 muscles ...
Casola C, Pot SA, Lavaud A, Voelter K.Corneal cross-linking should be considered as treatment option in Friesian horses with infectious keratitis and corneal dystrophy. Optical coherence tomography, giving information of corneal structure, can help for diagnosis and monitoring.
Marr KA, Lees P, Page CP, Cunningham FM.The leukotrienes (LT) LTD4 and LTB4 have been shown to cause bronchoconstriction and neutrophil accumulation, respectively, in horse lungs. Such changes are characteristic of the equine allergic respiratory disease, chronic obstructive pulmonary disease (COPD). To further investigate the role of these putative mediators in the pathogenesis of equine COPD the effect of a 5-lipoxygenase inhibitor, fenleuton, on antigen-induced changes in horses with this condition has been examined. Six horses with COPD underwent a series of four antigen challenges, one month apart, with placebo pre-treatment on...
Kero T, Kuussaari J.The purpose of this communication is to report the first diagnosed case of spinal ataxia in the horse in Finland. The horse was atactic and had a wobbling gait. Especially in turning and backing the rear legs tended to swing outwards. Macroscopical studies revealed malformation of the cervical vertebral articular facets and narrowing of the cervical vertebral canal. The vertebral malformation caused the degeneration of the spinal cord, through the compression of the cord. In this paper the macroscopial and microscopical findings are discussed and compared with the findings of other authors.
Lange L, Marett S, Maree C, Gerdes T.Suspected molluscum contagiosum was diagnosed in 3 horses in the Chingola district of Zambia. The horses were found to be suffering from a slow progressive skin disease with lesions on the chest, shoulders, inner and lateral aspects of the fore- and hindlimbs, the face, fetlocks, pasterns and on the lateral surfaces of the body. The lesions varied from 4 to 20mm in diameter, were hairless but covered by soft keratin projections which, when removed, left a raw elevated base tightly adherent to the epidermis. These lesions bled profusely when the animals were groomed. Older lesions were well cir...
Yilmaz O, Wilson RT.Mules are known to have been used as carriage and riding animals in Mesopotamia and Anatolia as early as the beginning of the second millennium BC but may have been first bred in Anatolia in the Third Century BC. They have thus contributed to Turkey's cultural, social and economic heritage for more than 4,000 years and were an ancient component of its guild of domestic animals and overall biodiversity. Once bred country-wide most mules are now introduced "illegally" to the southeast and east from Iraq and Iran. Mules are now bred only in one small area in north-central Turkey close to the Blac...
Breeze RG, Brown CM, Turk MA.3-methylindole was administered orally and intravenously to horses and ponies in order to determine the ability of this chemical to provide a model of equine pulmonary disease. Both routes produced a severe and sometimes fatal pulmonary disease, characterised by bronchiolitis. Clinical signs developed 48 to 72 h after dosing and were most severe between Days 4 and 10 post dosing. Intravenous administration of 3-methylindole produced lung injury more rapidly and at a lower dose rate than the oral route. It is suggested that the respiratory condition induced by this chemical could become a metho...
McGavin MD, Knake R.A 35-kg Duroc pig died 3 days after eating a ration containing aflatoxin B1, B2, G1, and G2. It had hemorrhagic enteritis and extensive midzonal necrosis in the liver. A 13-year-old Quarterhorse that died 2 days after eating moldy hay had hemorrhagic enteritis, fatty degeneration of the myocardium and renal tubules, and extensive total midzonal necrosis of the liver.
