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.
Puigdemont A, Arboix M, Gaspari F, Bortolotti A, Bonati M.The protein binding of propafenone in vitro was assessed in plasma of mouse, rat, rabbit, dog, sheep, man, cow, and horse at two concentration levels. In all species and at both concentrations propafenone was found highly bound (86-99%) to plasma proteins. No significant relationship was found between free propafenone and the plasma protein fractions. A concentration-dependency was seen in plasma of mouse, sheep, man, and horse, in which the free fraction of propafenone became larger on raising the concentration. Qualitative and quantitative differences were observed in the protein plasma prof...
Roberts MC, Clarke LL, Johnson CM.A reproducible, reversible model of colitis induced in ponies by administering castor oil (2.5 ml/kg bodyweight [bwt] per os) was characterised by abdominal pain, fever, watery diarrhoea, dehydration, hypovolaemia, toxaemia, leucopenia, decreased serum Cl, Na and K levels and metabolic acidosis. The signs were most severe between 24 and 48 h post induction, stabilisation was frequently observed after 72 h, although diarrhoea could persist beyond 96 h. Morphological and in vitro transport studies (right ventral colon) were conducted on tissues from animals destroyed at 24, 48 and 72 h. In the c...
Wilson DA, Badertscher RR, Boero MJ, Baker GJ, Foreman JH.Ultrasonography was used to evaluate the ventral midline incisions of 21 ponies following exploratory laparotomy. The incisions were evaluated before surgery and at weekly intervals from one to seven weeks after surgery. Both 5.0 and 7.5 MHz linear array and 7.5 MHz sector transducers were used for the evaluations. The incisional complications observed were drainage, oedema, suture sinus formation, suture abscess, superficial dehiscence and incisional hernia. Ultrasonographic imaging of the ventral midline incision was an easy, reliable and objective method for detecting and monitoring the pro...
Saudek V, Boyd J, Williams RJ, Stefani M, Ramponi G.A complete range of two-dimensional NMR experiments was used for the assignment of the 1H-NMR spectrum of horse muscle acylphosphatase. Firstly the spin systems of some easily identifiable amino acid side chains were assigned. These side chains involved all the aromatic residues and all the leucine, valine, isoleucine, threonine, alanine, proline as well as some of the glycine residues. Analysis of nuclear Overhauser enhancement spectra in our previous work had identified the sequential and long-range patterns characteristics for secondary structure elements. This result had also provided the ...
Archambault D, Wang ZM, Lacal JC, Gazit A, Yaniv A, Dahlberg JE, Tronick SR.To provide more sensitive and convenient methods for the detection of equine infectious anemia virus (EIAV), we developed an enzyme-linked immunosorbent assay (ELISA) employing the EIAV gag precursor (Pr55gag) produced by using recombinant DNA techniques. The antigenic reactivity of the recombinant EIAV Pr55gag was found to be equivalent to that of the virion p24gag and elicited high-titered antiserum in rabbits. When a large number of horse sera were analyzed for the presence of antibodies to EIAV by this ELISA, a radioimmunoassay for EIAV p15gag, or the standard agar gel immunodiffusion test...
Kirker-Head CA, Kerwin PJ, Steckel RR, Rubin CT.Liquid metal strain gauges (LMSG) were implanted surgically at three locations on the intact linea alba (LA) in eight horses. LA strain, strain rate, change in strain and stress were recorded during general anaesthesia, recovery from anaesthesia, standing, vocalisation, rectal palpation and at the walk, trot and canter. LA stress was quantitated using an in vitro tensiometric technique. Stress-strain responses differed significantly (P < 0.05) with location, but each described a characteristic relationship for viscoelastic tissues. Maximum peak stress, peak strain and change in strain occurred...
Althouse GC, Seager SW, Varner DD, Webb GW.An experiment was conducted to evaluate three commercially available test kits, the Azostix, Multistix and Uric-acid test, for the detection of urine in the equine ejaculate. Azostix, which tests for urea nitrogen, consistently detected urine in the equine ejaculate. Urine contamination was evident when a color change occurred in the reagent pad, going from yellow to green after 10 sec of exposure. The sensitivity of Azostix to urea nitrogen in contaminated samples was 39 mg/dl. The Multistix test kit also successfully detected urine in semen. In the Multistix nitrite pad the color changed fro...
Ingvast-Larsson C, Kallings P, Persson S, Appelgren LE, Wiese B.The pharmacokinetics of theophylline at rest and the effects on cardio-respiratory and blood lactate responses to exercise were investigated after repeated oral administrations in six healthy Standardbred horses. A dose of 5 mg/kg body weight was administered every 12 h. The binding of theophylline to plasma protein was also determined. There was good agreement between predicted and observed plasma concentrations of theophylline at steady state. The mean half-life of elimination was shown to be 17.0 +/- 2.5 h, the mean half life of absorption was 1.6 +/- 1.8 h, the apparent volume of distribut...
Jöchle W.In this uncontrolled clinical study 12 investigators cooperated to evaluate the analgesic and sedative effect of detomidine (DORMOSEDAN; Farmos Group Ltd; Finland) in 234 horses with abdominal pain caused by colic. The study was designed to use each animal as its own control and to evaluate its response to the drug over a 60 min period. Detomidine was given intravenously (i.v.) once in 169 cases (167 horses, 1 mule, 1 donkey) at a dose of 20 micrograms/kg bodyweight (bwt), and to 65 horses at 40 micrograms/kg bwt. The higher dose was used predominantly in horses with severe pain which were mor...
Gerring EL, King JN.Cisapride and domperidone were both effective in restoring electrical and mechanical activity, coordination between gastric and small intestinal activity cycles and the stomach to anus transit time in three ponies in which post operative ileus was induced experimentally. Cisapride (0.1 mg/kg bodyweight intramuscularly) for three to eight doses prevented idiopathic post operative ileus in 22 clinical cases requiring colic surgery. The only side effects after cisapride were increased bowel sounds and slight, transient sounds of discomfort. No adverse side effects were seen in 16 cases following ...
Lester GD, Bolton JR, Cambridge H, Thurgate S.The myoelectrical activity of the ileum, caecum and large colon was monitored from Ag-AgCl bipolar recording electrodes in four conscious 'parasite-naive' weanling foals. All foals were inoculated with 1000 infective 3rd-stage Strongylus vulgaris larvae and alterations to the myoelectrical activity observed. The frequencies of caecal and colonic spike bursts increased significantly in all post infection periods coinciding with assumed larval penetration into the intestinal mucosa and migration through the vasculature. Peaks in caecal and colonic activity occurred at Days 1 to 5 post infection....
Murray MJ, Grodinsky C, Anderson CW, Radue PF, Schmidt GR.Gastroendoscopic examinations were performed on 187 horses, ranging from one to 24 years. Eighty-seven horses had clinical problems including chronic, recurrent colic for seven or more days (25), one or more episodes of colic within the previous seven days (13), or acute colic (10), diminished appetite (53), poor bodily condition (40), and/or chronic diarrhoea (9). One hundred horses that had no signs of gastrointestinal problems were examined as part of a gastroendoscopic survey. Lesions observed in the squamous fundus, squamous mucosa adjacent to the margo plicatus along the greater curvatur...
Smyth GB, Young DW, Hammond LS.Gastrin is the only hormone known to stimulate secretion of hydrochloric acid. It also has trophic effects on specific parts of the mucosa of the gastrointestinal tract. Using radioimmunoassay techniques, postprandial serum gastrin and insulin concentrations were measured in six adult horses to establish effects of different diets on gastrin concentrations. Insulin concentrations were measured to provide support to the patterns of gastrin secretion because patterns of insulin secretion were already known. The horses were fed coastal bermuda hay, or twice daily 5 kg of a complete pelleted ratio...
Fessler JF, Bottoms GD, Coppoc GL, Gimarc S, Latshaw HS, Noble JK.Endotoxin (LPS) was quantitated in experimental subjects and in horses with naturally occurring gastrointestinal strangulation obstruction and/or septicaemic diseases to establish the fate of LPS and the clinical usefulness of the Limulus amoebocyte lysate (LAL) assay. The assay was validated for sensitivity (10 pg/ml), recovery (90 to 106 per cent), intra-assay precision (CV = 5.5 per cent) inter-assay precision (CV = 11 per cent), and stability of diluted, heat treated, frozen samples (at least 90 days). Plasma concentrations of LPS after sublethal (3 micrograms/kg) jugular or portal vein bo...
Trim CM, Moore JN, Clark ES.An ultrasonic flow probe was implanted around a branch of the left renal artery in five horses. The effects of dopamine were studied in the unsedated horses 10 days after surgery. Three experiments, separated by at least two days, were performed in random order on each horse. In two experiments, dopamine was infused intravenously for 60 mins at either 2.5 and 5.0 micrograms/kg bodyweight (bwt)/min. Saline was infused for 60 mins before and after each infusion, and for 180 mins in the third experiment as a control. Renal blood flow increased during administration of dopamine at both dose rates ...
Merritt AM, Campbell-Thompson ML, Lowrey S.Five 5 to 6 month old horses were surgically prepared with silver electrodes sutured to the serosa of gastric antrum, duodenum and proximal portions of the jejunum. Normal migrating motility complex (MMC) periodicity was determined during daytime hours in horses that were fed and horses from which food was withheld for 24 hours. Periodicity was defined as time span from the end of one period of regular spike activity (RSA) to the end of the next RSA in the MMC. The periodicity was 120.5 +/- 9.5 (SEM) minutes in horses from which food was withheld, and was 125.7 +/- 20.3 minutes in horses fed h...
Orsini JA, Benson CE, Spencer PA, Van Miller E.Resistance of gram-negative bacteria to gentamicin has become an increasingly common problem among clinical isolates from human beings. Susceptibility of isolates from horses to gentamicin and amikacin was evaluated for the period from July, 1983 to June, 1985. All isolates of Escherichia coli, and species of Enterobacter, Klebsiella, Proteus, and Pseudomonas examined were susceptible to amikacin, except 2 of the 46 Pseudomonas isolates. In contrast, 13 to 50% of isolates were resistant to gentamicin. Escherichia coli, and Klebsiella, Proteus, and Enterobacter species isolates were highly sign...
Trim CM, Adams JG, Cowgill LM, Ward SL.The purpose of this survey was to identify complications occurring in horses with colic during anaesthesia and recovery from anaesthesia; and to determine any relationships between these complications and drugs used for induction or maintenance of anaesthesia. Two hundred and thirty nine horses were anaesthetised on a total of 250 occasions for colic surgery between January 1985 and May 1987. Of these, 189 recovered from 200 anaesthetic episodes. Most horses received xylazine and guaifenesin with either thiobarbiturate (68 per cent) or ketamine (24 per cent) and anaesthesia was maintained with...
Orsini PG, Raker CW, Reid CF, Mann P.The normal radiographic anatomy of the equine larynx was determine by use of xeroradiography and dissection. The body and laminae of the thyroid cartilage, the muscular process of the arytenoid cartilages, and the dorsal lamina and arch of the cricoid cartilage had radiographic evidence of mineralization (calcification) and/or ossification in clinically normal horses. There was a significant (P less than 0.01) increase in the degree of mineralization of the thyroid and arytenoid cartilages with advancing age. Horses with diagnosis of arytenoid chondrosis (arytenoid chondral dysplasia, arytenoi...
Palmer JE, Benson CE, Lotz GW.Ten healthy, mature ponies were orally infected with Ehrlichia risticii using Ehrlichia-infected P388D1 mouse monocyte tissue culture cells. Seven developed signs of equine ehrlichial colitis including fever, depression, anorexia, reduced borborygmi, increased abdominal hyperresonance, and diarrhoea. Three remained clinically normal apart from early fever in one. Indirect fluorescent antibody titres were detected in the clinically affected ponies by Days 12 to 17 post infection and increased rapidly to high levels (1:640 to 1:5120) which were maintained until the end of the observation period ...
Young DR, Richardson DW, Markel MD.A randomised, blind prospective study was performed to evaluate effects of low dose heparin therapy on complication and survival rates in 33 horses following exploratory celiotomy. Four horses had non-strangulating lesions and seven had strangulating lesions of the small intestine, 19 had non-strangulating lesions of the large intestine, and three had duodenitis-proximal jejunitis. Eighteen required an enterotomy or intestinal resection and anastomosis. Sixteen received heparin subcutaneously (66 iu/kg every 12 h) post operatively and 17 received a saline placebo for a mean of 3.7 days. There ...
King JN, Gerring EL.Post operative ileus is a serious complication of abdominal surgery in horses and there is evidence that endotoxin plays a significant role in its pathogenesis. Pre-treatment with intravenous (i.v.) flunixin (1.1 mg/kg bodyweight [bwt]) or phenylbutazone (4.4 mg/kg bwt) significantly antagonised the acute disruption of gastric, small intestinal and large intestinal motility induced by 0.1 microgram/kg bwt i.v. endotoxin in ponies implanted with gastrointestinal strain gauges. Phenylbutazone was more effective than flunixin and this was significant (P < 0.01) for the stomach and left dorsal col...
Tokuriki M, Aoki O, Niki Y, Kurakawa Y, Hataya M, Kita T.Electromyographic (EMG) activity of 4 muscles of the cubital joint and the strain of forelimb hooves were recorded telemetrically in 4 Thoroughbreds (with and without a rider) standing, walking, trotting, and cantering. Bipolar fine wire electrodes were inserted into the muscles, and strain gauges were attached to the hoof wall. Motion pictures (16 mm), synchronized with EMG tracings, were taken to obtain kinematic data. When horses were standing, the biceps brachii had tonic activity, but the brachialis and the caput longum and the caput laterale of the triceps brachii had no EMG activity. Th...
Saudek V, Wormald MR, Williams RJ, Boyd J, Stefani M, Ramponi G.Nuclear magnetic resonance spectra of acylphosphatase were searched for signs of beta-structure, i.e. characteristic nuclear Overhauser enhancement patterns displayed in the two-dimensional spectra, typical chemical shifts, coupling constants and slow 2H-H exchange. The results provided identification of the main-chain resonances of amino acid residues involved in the beta-structure. The full sequential assignment of this region was gained by identification of some amino acid spin systems and their alignment with the primary sequence. The assignment of the side-chains was virtually completed s...
Uehara N, Momose A.The doping test method used in a horse race requires the accurate detection of a wide variety of drugs and metabolites as well as the rapidity in order to examine a large number of samples within a limited time. For this purpose, the routine method consists of a preliminary screening and a confirmatory test. In this paper, a historical review for the development of the doping test method in Japan is described. The metabolism and pharmacology of drugs in horses are also discussed.
HETRICK FM, YANCEY FS, HANSEN PA, BYRNE RJ. Four horses inoculated with EEE virus remained asymptomatic following injection but did develop measurable HI and neutralizing antibodies as a result of infection. HI antibodies were detectable earlier than neutralizing antibodies but the levels tended to drop more rapidly. 2. Of 14 horses and ponies having significant levels of neutralizing antibody, 5 to 9 had measurable HI antibody depending on number of units of antigen employed in the test. 3. Sera from 3 clinical cases of EEE were positive on the HI test while only one of these animals had a significant neutralizing antibody level.
McGivney CL, Sweeney J, Gough KF, Hill EW, Katz LM.Endoscopic tip placement in the pharynx and water flushing interval (FI) may affect exercising upper respiratory tract (URT) endoscopic results. Objective: To determine associations between the endoscopic tip position in the pharynx and automated FI with overground endoscopic (OGE) results. Methods: Randomised balanced 2X5 factorial design. Methods: A total of n = 200 horses undergoing OGE were randomly assigned into 10 groups (n = 20/group) of different automated endoscopic FIs (no flushing, 60, 120, 180, 240 s) with the endoscope tip positioned either rostrally (position A) or caudally ...
Wittek T, Sobiraj A.In the present study the concentrations of L-carnitine (total carnitine, free carnitine, and acyl carnitine) and several parameters of the lipid metabolism were measured during the estrus in 10 broodmares. The carnitine concentrations varied in a wide range between the mares. The differences of the mean carnitine concentrations during the estrus did not reach the level of significance (P < 0.05). There was no relationship between the concentrations of total and free carnitine to the follicle size; however, the concentration of acyl carnitine was significantly correlated (r = -0.42). Because...
Slocombe JO, Cote JF.The anthelmintic canbendazole (CBZ), adminis-
tered in several formulations to horses in critical
trials, has been shown to have high effcacy
against intestinal nematodes (3, 4, 6). There are
two reports of field trials with CBZ (2, 5), and
although a large number of horses were involved,
the efficacies reported were for a restricted
number of nematodes. Recently, CBZ paste was
administered to horses in another field trial and
the findings on rxdatability, safety and efficacy
against a wide range of nematodes are presented.
Dyke TM, Hubbell JA, Grosenbaugh DA, Beard W, Mitten L, Sams RA, Hinchcliff KW.The pharmacokinetics of furosemide were investigated in anaesthetized horses with bilateral ureteral ligation (BUL) with (n = 5) or without (n = 5) premedication with phenylbutazone. Horses were administered an intravenous (i.v.) bolus dose of furosemide (1 mg/kg) approximately 60-90 min after BUL. Plasma samples collected up to 3 h after drug administration were analysed by a validated high performance liquid chromatography method. Median plasma clearance (CLp) of furosemide in anaesthetized horses with BUL was 1.4 mL/min/kg. Apparent steady state volume of distribution (Vd(ss)) ranged from 1...
Watson ED, McDonnell AM, Cí·¯ord D.The characteristics of the cyclicity of 12 maiden thoroughbred mares kept in two groups were studied over a total of 58 cycles. On average, oestrus lasted 5.3 days and in 60 per cent of the cycles ovulation occurred in the last two days of oestrus. Oestrus and ovulation tended to be synchronised in each group of mares. The mean diameter of single-ovulating preovulatory follicles on the day before ovulation was 41.5 mm and during the seven days before ovulation they grew 2.5 mm/day. More than one follicle ovulated in 19 (33 per cent) of the cycles (seven double ovulations and 12 dioestrous ovul...
Karlström K, Essén-Gustavsson B.An assumed link between red cell hypervolaemia, an excessive amount of training and impaired performance of hypervolaemic horses has led to a theory that the muscle fibres could be affected. Myosin heavy chain (MHC)-based fibre type composition in gluteus medius muscle of red blood cell normo- (NV) and hypervolaemic (HV) Standardbred trotters was evaluated using immunohistochemistry. Muscle biopsies were obtained from 13 NV and 16 HV horses. Serial transverse sections were cut and reacted with antibodies against different isoforms of the myosin heavy chains MHCI, MHCIIA and MHCIIX. Sections we...
Eagle MT, Koch DB, Whalen JP, Hintz HF, Krook L.The left thoracic limb was immobilized in a plaster cast in 6 grade weanling ponies for 6 weeks. Two ponies were injected intramuscularly each day with 2.4 micrograms of 25-hydroxycholecalciferol [25(OH)D3] per kg bodyweight, two with 1.2 micrograms and two received no injections. Immobilization of 25(OH)D3 treatment had no significant effect on mineral metabolism. Immobilization resulted in significantly decreased weight and specific gravity of metacarpus III (MCIII). Histologic examination and triple fluorochrome incorporation showed that the osteopenia was caused by atrophy of osteoblasts w...
Dusek J, Munk Z.The study was based on the documentation of the Napajedla Stud Farm of the English Thoroughbred horse for 1888-1972. Evaluating the effect of the age of stallions on their fertility (leaving aside the variability of the age of their mothers), such an effect was found to be significant only in four out of the 26 studs evaluated. In 65% of the selected stallions, the correlation coefficients were found to be negative, but without statistical significance. However, the objective of the study was to evaluate stallions and mares parallelly as to their age variability and fertility. The relationship...
Rose PL, Auer JA, Hulse D, Hightower D, Schenk RK.beta-Tricalcium phosphate (TCP) was evaluated as a synthetic bone grafting material in horses. Sixteen horses were randomly assigned to 4 groups of 4 horses. In each horse, an 11-mm by 10-mm circular defect with a smooth margin was created surgically in the weight-bearing surface of both third metacarpal bones (McIII) and the left third metatarsal bone. The defect in the left McIII was filled with TCP, the defect in the right McIII was filled with a mixture of 50% autogenous cancellous bone (ACB) and 50% TCP, and the defect in the left third metatarsal bone was not filled to serve as a control...
Mariani LPR, Sampaio F, Silveira AB, Bastos LF, Weber SH, Michelotto PV.Diseases of the stifle joint remain a challenge for veterinarians. The objective of this study was to achieve a valuable acupuncture suggestive diagnosis to be considered for stifle joint diseases in horses. Thirty-nine nonlame horses involved in different activities were assessed. Acupuncture was independently performed by two evaluators. Reactions of the animal when pressurizing the point suggestive of stifle disease (PSSD), Bladder-20 and/or Bladder-21, were considered as the inclusion criteria for inclusion in the stifle group (SG, n = 31), and the animals with no reactions were assigne...
Hoff TK, Hood DM, Wagner IP.To evaluate the clinical efficacy of topically administered glyceryl trinitrate (GTN) for inducing digital submural vasodilation in clinically normal horses. Methods: 7 adult horses without foot abnormalities. Methods: A concurrent-control crossover design was used to determine whether topical application of GTN ointment for prevention or treatment of laminitis would result in a detectable increase in digital perfusion. Heat-acclimated horses instumented for detection of wall surface temperature (HWST), mean systemic pressure, and heart rate were used. Horses were exposed to cold to induce dig...
Meek DG, Dickinson EO.An illustrated approach to the medial aspect of the equine fetlock joint is described, whereby the collateral ligaments are transected. This approach is suggested as a possible technique for metatarsal or metacarpal bone fracture repair by retrograde pinning, arthrodesis of the fetlock joint and other joint and sesamoid bone surgery. The histological evidence of satisfactory healing is presented and the advantages and disadvantages are discussed.
Cornick JL, Carter GK, Bridges CH.Chronic hepatic disease was diagnosed in 6 horses with history of anorexia and weight loss. These horses consistently had abnormally high serum gamma-glutamyltransferase activities, total and direct bilirubin and blood ammonia values, and sulfobromophthalein clearance times, whereas serum iditol dehydrogenase, aspartate transaminase, and alkaline phosphatase activities were variable. In the 6 horses, histologic examination of the liver revealed lesions of chronic hepatitis with varying degrees of fibrosis. All 6 horses had ingested kleingrass (Panicum coloratum) for variable periods. Three hea...
Berndtson WE.Data from testes of 16, 2- to 3-yr-old stallions and 34 yearling beef bulls were utilized in a components of variance approach to calculate the number of observations required per testis and(or) the number of animals required per treatment group to provide experiments of known sensitivity and precision, where treatment was to be assessed by one of several endpoints. The latter included paired testes weight, seminiferous tubular diameter, the number of germ cells per seminiferous tubular cross-section, or the number of elongated spermatids per gram of testicular parenchyma or per testis. For al...
Apukhovska LI, Vendt VP, Ivashkevych SP.Sterols of the whole erythrocytes, hemoglobin, membranes and their protein fractions were studied. Erythrocytes and their components were established to contain, besides cholesterol, other substances of the sterol nature. Cholesterol, 7-dehydrocholesterol and other substances of the cholesterol series are practically completely linked with the lipoproteid fractions of the erythrocyte membrane whereas all sterols found in the native erythrocytes in negligible amounts are bound with hemoglobin.
Tremelling AM, Marley RA, Marley MB, Woofter CM, Docherty C, Salvator AE, Muakkassa FF.Many Americans sustain large animal-related injuries (LARIs) from blunt trauma. We compare the injuries and management of LARI in our region of the United States with those of motor vehicle crashes (MVCs). Methods: A 15-year retrospective study of trauma patients with LARI matched to MVC controls by Injury Severity Score (ISS), age, and sex was conducted. Values were statistically compared, and differences were considered statistically significant at P < .05. Results: There were 156 LARI cases, of which 87% were related to horses, 8% to bulls, and the remainder to deer, mules, bison, cows, ...