Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Sarazan RD, Starke WA, Krause GF, Garner HE.The cardiovascular effects of detomidine and xylazine were compared in six chronically instrumented, conscious ponies. Ponies were instrumented with a micromanometer in the left ventricular chamber, a Doppler flow probe on a coronary artery and sonomicrometer crystals in the left ventricular free wall. Heart rate, ventricular systolic pressure, stroke work, dP/dtmax, minute work and coronary blood flow were measured for 4 h following intravenous injection of detomidine at several doses or xylazine at 1.1 mg/kg. Both drugs caused a profound hypertensive response at 15 s post-injection. The magn...
Bertone AL.Second-intention healing (contraction and epithelization) is most appropriate for heavily traumatized, contaminated wounds that may have a prolonged debridement phase. Therapy during healing can promote rapid debridement and faster healing. Healing of lower limb wounds by second intention may be protracted, owing to poorer wound contraction and excessive granulation tissue production as compared with body wounds.
van Rensburg IB, Stadler P, Soley J.A bronchiolo-alveolar adenocarcinoma was diagnosed in the lungs of a horse which was euthanased after protracted respiratory disease and radiological evidence of pulmonary neoplasia. Multifocal, large, firm neoplasms occurred throughout both lungs. Neoplastic lesions were not found elsewhere. Histologically the bronchiolar and alveolar architecture was retained. The cuboidal cells lining neoplastic alveoli had very vacuolated cytoplasm, while some were ciliated. Electron microscopy identified the cells as Type II pneumocytes. Numerous distended myelinoid bodies in the tumour cells accounted fo...
Gift LJ, DeBowes RM.Nonhealing wounds can present a frustrating clinical challenge to the veterinary practitioner. In many cases, healing is delayed by the presence of a foreign body or sequestrum; a review of wounds complicated by the presence of osseous sequestration and penetrating foreign bodies is presented. The typical signs include delayed wound healing and the presence of serous to exudative drainage, which may vary from intermittent to continuous. The use of radiographic or sonographic imaging modalities is often of value in reaching a diagnosis. Removal of the sequestra or foreign body is generally cura...
Rice NR, Lequarre AS, Casey JW, Lahn S, Stephens RM, Edwards J.The amount and distribution of viral DNA were established in a horse acutely infected with the Wyoming strain of equine infectious anemia virus (EIAV). The highest concentration of viral DNA were found in the liver, lymph nodes, bone marrow, and spleen. The kidney, choroid plexus, and peripheral blood leukocytes also contained viral DNA, but at a lower level. It is estimated that at day 16 postinoculation, almost all of the viral DNA was located in the tissues, with the liver alone containing about 90 times more EIAV DNA than the peripheral blood leukocytes did. Assuming a monocyte-macrophage ...
Bertone AL.Exuberant granulation tissue is common in large, lower limb wounds of horses, particularly horses of large body size. Methods of control include chemical cautery, cryogenic surgery, and surgical resection. Surgical resection is preferred because it is easy to perform, provides tissue for histologic evaluation, and preserves the epithelial margin. Effective treatments to prevent the formation of granulation tissue include leaving granulating wounds open to the air or, possibly, bandaging with topical steroids. Bandaging or casting may promote exuberant granulation tissue in wounds in which it h...
Freeman DE, Kleinzeller A, Donawick WJ, Topkis VA.When sheets of mucosa from the cecum of clinically normal horses were incubated in vitro with radiolabeled L-alanine, they could accumulate this amino acid against an apparent concentration gradient after 60 to 150 minutes of incubation. The active transport system for L-alanine was on the serosal surface of the mucosal sheet only. L-Alanine accumulation at 60 minutes was partly inhibited by 20 mM glycine (P less than 0.01), 0.5 mM ouabain (P less than 0.05), and Na deprivation (P less than 0.02). Anoxia for 60 minutes increased L-alanine accumulation, but had adverse effects on cell structure...
Trotter GW.Although many wounds in horses heal successfully by second-intention healing or delayed closure, some wounds can be sutured primarily, with reasonably high expectations of first-intention healing. To expect to achieve these results, one needs to have a rational treatment plan. Such a plan should be based on a working knowledge of the biology of tissue repair and tissue infection. Treatment decisions should be based more on results of experimental and clinical trials rather than on testimonials of other practitioners.
Boyd EH, Allen WE.Plasma drug concentrations were measured after two commercially available potentiated sulphonamides, trimethoprim and sulfadoxine and trimethoprim and sulphadiazine, were infused daily for 2 and 3 days, respectively, into the uteri of pony mares which had been mated before ovulation. Intravenous administration of trimethoprim and sulfadoxine allowed uterine absorption of trimethoprim (23-43%) and sulfadoxine (29-34%) to be calculated. After intra-uterine administration trimethoprim and sulphadiazine were detected in the milk of a lactating mare. In order to maintain plasma concentrations likel...
Booth LC.Delayed closure is an underutilized technique that can produce a good cosmetic result in lower leg wounds and can significantly shorten the healing time. To be successful, the surgeon should be able to utilize tension-relieving techniques and manage dead space. Scar revision should be limited to simple elliptical excision or modifications thereof until experience is developed. Sliding skin flaps, Z-plasties, and W-plasties are used infrequently and require adequate preoperative planning.
Fessler JF.Major surgery for wounds of the foot, compared with other parts of the body, requires a more detailed preparation and a more persistent aftercare. To approach severe hoof wounds with a routine applicable to drainage of a subsolar abscess is doomed to failure! Yet, in dealing with referral cases of hoof wounds, particularly those that have become chronic, the author has observed that the principles have been ignored and/or the routines inadequate. The hoof has a suitable capacity to heal, with complete reformation of hoof structures, if a healing environment is maintained for a long enough peri...
Goetz TE, Munsiff IJ, McKiernan BC.The pharmacokinetic disposition of theophylline was determined by high-performance liquid chromatographic analysis of plasma samples from six healthy, adult horses following the administration of intravenous aminophylline (dosed at 9.94 mg/kg as theophylline), immediate-release aminophylline tablets (dosed at 9.94 mg/kg as theophylline), and sustained-release theophylline tablets (dosed at 20 mg/kg). The elimination rate constant (lambda z), apparent volume of distribution (Vz), and clearance (Cl) determined by compartmental analysis of the intravenous data were 0.07 +/- 0.01 h-1, 0.80 +/- 0.0...
Grandy JL, Hodgson DS, Dunlop CI, Chapman PL, Heath RB.The cardiopulmonary effects of intravenous (i.v.) administration of the sympathomimetic drug ephedrine during two different levels of halothane anesthesia [end-tidal concentration of 1.37% (light anesthesia) and 2.1% (deep anesthesia)] were studied in eight horses. Anesthesia was induced and maintained using only halothane in O2. Ventilation was controlled to maintain a Paco2 of 38-42 mmHg. Following instrumentation and stabilization of the horse at the halothane concentration being studied, baseline measurements of cardiac output (Q), arterial blood pressure (AP), pulmonary artery pressure, h...
Saari H, Konttinen YT, Tulamo RM, Antti-Poika I, Honkanen V.In addition to its well-known physicochemical properties, hyaluronate (HA) has recently been shown to have important biological and pathophysiologic regulatory effects on granulocytes, monocytes, fibroblasts, and endothelial cells, as well as on the healing of wounds and various joint disorders. Many of these effects depend on or are reflected in the concentration and degree of polymerization of HA. Therefore, high-performance liquid chromatography with size-exclusion column was used to characterize the concentration and degree of polymerization of HA in equine synovial fluid (SF). The mean (+...
Morris DD, Henry MM, Moore JN, Fischer K.In laboratory animals, the incorporation of alpha linolenic acid or other n-3 series fatty acids into the diet results in marked changes in cell membrane composition as well as arachidonic acid metabolism. The purpose of the present study was to determine whether endotoxin-induced thromboxane A2 (TxA2) and/or prostacyclin (PGI2) production by equine peritoneal macrophages was altered by feeding horses a diet containing 8% linseed oil as a source of alpha linolenic acid for 8 weeks. Peritoneal macrophages were cultured in vitro in the presence of endotoxin (LPS) (0.5-500 ng/ml) or calcium ionop...
Spurlock GH.The prognosis for returning horses with open joint injuries to athletic function is most closely related to the duration of the injury prior to treatment. Prompt diagnosis and appropriate therapy should yield a favorable result. Delayed diagnosis or inappropriate therapy that allow the wound to progress to an infected state makes the likelihood of return to athletic function poor. Refractory joint infection can occur despite early diagnosis and prompt appropriate therapy. The development of these infections is undoubtedly increased by tissue loss and gross contamination. Appropriate antibiotic...
Dumasia MC, Houghton E.The research investigates the biosynthesis of a particular isomer called 5(10)-estrene-3 alpha, 17 beta-diol in stallion testes and how it affects the formation of 19-nor steroids and oestrogens. Summary of […]
Schumacher J, Hanselka DV.Free autogenous skin grafting of the horse is indicated for wounds too large to heal by contraction and epithelization. Techniques of pinch, punch, tunnel, and sheet grafting are described. Allografting and storage of skin for delayed grafting are discussed.
Blancquaert AB, Colgan SP, Bruyninckx WJ.To identify the influence of technical factors on the in vitro motility of equine neutrophils towards streptococcus culture supernatant in an under-agarose assay, we studied the changes in eight cell migration parameters. The distances the phagocytes travelled by directed, random and spontaneous migration increased with incubation time, cell concentration and the gelatin and serum contents of the migration plates. The contribution of chemotaxis to the phagocyte migrations, however, decreased simultaneously. The directed and random, though not the spontaneous, migrations of the phagocytes incre...
Reis KJ.A hemolytic assay was developed for the measurement of functional equine complement activity. The assay utilizes antibody sensitized chicken erythrocytes as the target cell and was specific for classical pathway (antibody dependent) complement activity. The assay was found to be reproducible and more sensitive than previous reports using other species of target cells. Total serum complement (CH50) values were determined for five mares and their foals and followed over a period of 3 months.
O'Rourke KI, Perryman LE, McGuire TC.Antibody responses in horses with equine infectious anemia virus (EIAV) were examined to determine their cross-neutralizing capacity. Antibodies induced by infection with any of six biologically cloned variants of EIAV cross-neutralized multiple variants from the group. Anti-EIAV antibody was found in both the IgG and IgG(T) subclasses in plasmas with virus-neutralizing activity and the majority of antiviral antibody was of the IgG(T) subclass. Depletion of IgG(T) did not increase the neutralization indexes of either neutralizing or non-neutralizing plasma samples.
Jones RS, Lawrence TL, Veevers A, Cleave N, Hall J.Fifty-three horses, all but two of them over two years of age and varying in type, sex and liveweight (230 to 707 kg) were weighed and seven different body measurements were recorded in duplicate by a single operator. The best overall prediction of liveweight using an equation with two variables was found to be: liveweight (kg) = (umbilical girth [cm])1.78 X (length of body from tuber ischii to elbow [cm]0.97/3011). This equation had an adjusted R2 value of 94.9 per cent and was derived from the pooled data, because differences of sex, type and weight did not significantly affect the relations...
Tanaka T, Aramaki S, Momose A.A thin-layer chromatographic screening procedure for some basic, neutral and acidic drugs was developed using 3 ml of horse plasma. Chloroform-2-propanol (95:5, v/v) was used as the extraction solvent. The drugs were identified by a high-performance thin-layer chromatographic plate and spraying successively with some detection reagents. In this study, the extraction recovery rates and the detection limits were determined at the same time.
Turgut K, Sasse HH.The mucociliary tracheal transport rate and clearance index were measured in 16 healthy horses and 16 horses suffering from chronic obstructive pulmonary disease. A marker, Indian ink in syrup, was placed in the mucus layer of the interior wall of the trachea, just in front of the carina, and its displacement was measured after 30 and 60 minutes. The same procedure was repeated 30 minutes after the intravenous administration of 0.8 microgram clenbuterol/kg bodyweight. In the diseased horses the mucociliary transport rate was significantly lower than in the healthy horses. After clenbuterol adm...
van Haeringen H.Investigations for the presence of antibodies to red blood cell antigens were carried out in equine colostrum and serum. Material from 181 mares without clinical disease was tested. The object was to obtain information on the number of mares producing antibodies capable of inducing haemolytic disease in newborn foals. Of the mares 2.8% was positive for haemolysins. These mares are expected to be a risk for haemolytic disease. In addition agglutinating antibodies were identified in 39.2 per cent of the mares examined. It is not known whether or not these antibodies constitute a hazard for the f...
Shappell KK, Caron JP, Stick JA, Parks AJ.Dorsal displacement of the soft palate associated with dysphagia and aspiration pneumonia was diagnosed in 2 young foals. The displacement appeared to be congenital. Clinical signs associated with the condition were resolved after staphylectomy. Dorsal displacement of the soft palate is usually recognized in adult animals as an upper respiratory tract disease, but may be a contributing factor to dysphagia and lower respiratory tract disease in young animals.
Shahriar F, Moore J.Thymic malignancy is rare in horses. Thymic epithelial tumor was diagnosed in an 18-year-old mare with invasion and metastasis to the pericardium and heart. At necropsy, the cranial thoracic cavity was obliterated by a large mass located in the thymic region and the right atrium was also expanded and effaced by a similar mass. Histologically, the neoplasm was composed of sheets of spindle cells with intraparenchymal Hassall's corpuscles and formation of pseudorosettes around blood vessels compatible with type A thymic epithelial tumor according to World Health Organization classification. The ...
Rigg DL, Ramey DW, Reinertson EL.Respiratory distress and laryngeal paralysis were found to be caused by a Streptococcus equi abscess of cranial mediastinal lymph nodes, putting pressure on the trachea at the thoracic inlet. Surgical drainage was required to relieve the compression, and long-term antibiotic therapy was used to treat the bacterial infection. The trachea returned to normal diameter but left laryngeal hemiplegia persisted. Peritracheal abscesses should be considered in the differential diagnosis of inspiratory dyspnea of the horse.
Pickett BW, Voss JL.Experimental and clinical observations were made to treat abnormal sexual behaviour. The most common cause of abnormality was mismanagement of the animal; over-use and rough treatment at service and too-frequent ejaculation during winter had a detrimental effect on the behaviour of young stallions. Pain due to injury incurred at copulation or when associated with mounting attempts was also a common cause of impotence. Most impotent stallions responded well to re-training and recovery can be achieved without pharmacological treatment in most cases.
Bertone AL, Powers BE, Turner AS.An aged Thoroughbred stallion was examined because of progressive lameness, carpal swelling, and weight loss. Radiography revealed a destructive lesion in the caudomedial, distal portion of the radius. Chondrosarcoma was diagnosed by tumor-core biopsy. Gross and histologic evaluation of the neoplasm after necropsy revealed a locally invasive chondrosarcoma at the distal end of the radius that infiltrated the radiocarpal joint capsule and invaded the carpal bones. The malignant nature of this tumor was evident by its invasiveness and histologic features of cell pleomorphism and presence of mito...
Schönherr W.Francis CLATER presumably was born in 1754 near Nottingham. He became farrier after years of apprenticeships at Newark and Retford. In 1783 the first edition of his book "Every man his own farrier" was published. Within 50 years at least 30 editions were printed. This book was translated by PRETOT into French (1822), by S. von TENNECKER (1823) and by LENTIN (1834) into German and by TURNE (1838) into Russian language. Contents of some editions are compared and valued.
May CJ, Greenwood RE.A thoroughbred foal had a convulsive attack 12 hours after birth followed by further convulsions on the 10th, 11th and 12th days after birth. It was treated successfully by medication with primidone, feeding by stomach tube and careful nursing.
Santschi EM, Juzwiak JS, Honnas C, Walker WT, Hunter B, Whitman JL, Prichard MA, Morehead JP.The objective of this study is to describe the management and outcomes of eight horses with subchondral lucencies (SCLs) of the medial aspect of the antebrachiocarpal (ABC) joint. The medical records and radiographs of the carpi of 8 horses with SCLs of the medial aspect of the ABC joint were reviewed. Follow-up clinical information was obtained for 6-60 months (the median duration of 14 months). Treatment was successful if radiographic healing was apparent or lameness was reduced or eliminated. Four horses had SCLs in the distomedial radius (DMR) and four in the proximal aspect of the radio...
Orsini JA, Orsini PG, Sepesy L, Acland H, Gillette D.Intestinal carcinoid, or argentaffinoma, should be an etiologic consideration for horses with chronic colic. A mare was referred with a history of chronic colic. Previously, the signs of colic had subsided in response to impiric treatment, but recent episodes of colic did not. Clinical signs and results of physical examination supported the finding of strangulating obstruction of the small intestine. Exploratory celiotomy revealed internal herniation with simultaneous volvulus of the jejunum and accompanying carcinoid.
Trevorrow P.In this sensational case, it was alleged that after jinking unexpectedly and throwing its rider, racehorse Ile de Chypre, had been nobbled by an ultrasonic emitter concealed within a pair of binoculars. Ile de Chypre was 4-1 favourite at the King George V Handicap at Ascot on June 16, 1988 and a good distance away from the pack, a clear winner albeit for this alleged act of sensational intervention.
Loy RG, Evans MJ, Pemstein R, Taylor TB.Treatment of foaling mares with 150 mg progesterone and 10 mg oestradiol daily beginning within 12 h of parturition resulted in a delay of ovulation (15.6 +/- 2.6 days compared with 10.3 +/- 2.4 days in untreated mares). When mares were mated after this 5.3-day delay there was no advantage in reproductive performance over that of mares mated according to a conventional management system. Gonadotrophin secretion was inhibited during treatment but the following secretory patterns were similar to those of normal oestrous periods.
McGorum BC, Railton DI, Clarke CJ, Dixon PM, Woodman MP, Long KJ.Hydatid cysts (metacestode of Echinococcus grunulosus) are a
common incidental post-mortem finding in horses in the United
Kingdom (Cranley 1982), being found most frequently in the liver
and the lungs (Schwabe 1986). However, hydatid cysts are well
tolerated by horses and clinical hydatidosis is rare, even in
heavily infected animals (Thompson and Smyth 1975; Thompson
and Allsopp 1988). Clinical disease has been attributed to hydatid
cysts in the equine retrobulbar region (Bamett et ul. 1988), brain
(Gordon 1974, quoted by Thompson 1977) and liver (Barvaux
and Derzelle 1947). This is...
Elze K, Schulz J, Rob O.Necrosis of the skin on both lateral aspects of the hind limbs following the caudal branch of the lateral saphenous vein in 22 suckling foals is described. The first clinical signs were observed on days 2-5 post natum. S. aureus was isolated from the wounds. Decubitus in the region of the malleolus lateralis tibiae was considered the starting point of an ascending infection. This type of dermonecrosis was only observed in boxes with hard floors where the straw bedding was pushed aside by the lying foals regularly, never, however, in boxes with deep and permanent sawdust or straw bedding. Thera...
Geor R, Hope E, Lauper L, Piela S, Klassen J, King V, Murphy M.The effects of dexamethasone (0.2 mg/kg of body weight; IV, IM, and PO) and methylprednisolone acetate (120 mg given intra-articularly) on serum osteocalcin and cortisol concentrations were studied in 6 horses. Serum osteocalcin and cortisol concentrations were serially monitored after each treatment. A significant (P < 0.05) decrease in serum osteocalcin and cortisol concentrations was observed from 12 to 24 and 2 to 48 hours, respectively, after IV and IM administrations of dexamethasone. Serum osteocalcin and cortisol concentrations were significantly decreased from 6 to 48 and 3 to 72 h...
Paccamonti DL, Buiten AV, Parlevliet JM, Colenbrander B.Breeding soundness evaluation (BSE) of stallions is a routine component of stud farm practice. Guidelines for assessing satisfactory breeding potential have been developed using data derived from stallions of full-size breeds. In view of the increasing popularity of miniature stallions, knowledge of normal semen parameters of these stallions is important. Therefore, testicular measurements and semen parameters from 216 sexually rested miniature stallions were obtained. Semen was collected twice, 1.5 to 3 h apart, using an artificial vagina. Values were averaged over the 2 collections because o...
Barnett AL, Steel JD, Stewart GA.Free erythrocyte protoporphyrin was estimated in 166 Thoroughbred horses and the mean value was found to be 4o vg.Poo ml. packed cells. Signifi-cantly lower haemoglobin concentrations were found in 21 horses whose erythrocyte protoporphyrin concentration was 7o p.g.lioo ml. packed cells or greater.
Manohar M, Goetz TE, Hassan AS.Recently, it was reported that acute hypervolemia improves arterial oxygen tension in human athletes known to experience exercise-induced arterial hypoxemia. Since exercise-induced arterial hypoxemia is routinely observed in racehorses and is known to limit performance, we examined whether pre-exercise induction of acute hypervolemia would similarly benefit arterial oxygenation in maximally exercising thoroughbred horses. Two sets of experiments, namely, placebo [intravenous (IV) physiological saline] and acute hypervolemia (IV 7.2% NaCl, causing an 18.2% expansion of plasma volume) studies we...
Hacker DV, Buyukmihci NC, Franti CE, Bellhorn RW.The mydriatic effect of 10% phenylephrine was evaluated in 9 horses. Base-line pupillary size in mesopic conditions and during light stimulation was ascertained before application of pharmacologic agents. In study 1, 10% phenylephrine was applied to each eye (n = 5 horses). After 15 minutes, the pupillary size was determined in both lighting conditions. Phenylephrine was again applied to each eye, and after an additional 15 minutes, the pupillary size was determined. In study 2, 1% tropicamide was applied to each eye (n = 4 horses), and after 30 minutes, the pupillary size was determined in bo...
Sardari K, Kazemi H.To evaluation of clinical examination for differential diagnosis of navicular region pain from other forms of palmar heel pain in the forelimb in horses the present study was undertaken. Thirty four horses with lameness referable to the palmar aspect of the hoof based on their response to the palmar digital nerves analgesia were divided into 2 groups based on their response to both distal interphalangeal joint and navicular bursa analgesia. Horses that were profoundly improved by both analgesic blocks (distal interphalangeal joint and navicular bursa) were considered to have navicular region p...