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.
Allen BV.Results of blood counts have been analysed in three-year-old racehorses in training comprising 77 colt stayers, 27 colt sprinters, 61 filly stayers and 35 filly sprinters. The distributions of haemoglobin, erythrocyte count and haematocrit were significantly higher in colt stayers compared to the other three groups. In fillies these values were also significantly higher in stayers compared to sprinters. The erythrocyte count was significantly higher in filly stayers compared to colt sprinters but there were no significant differences between haemoglobin or haematocrit values in these groups. N...
Palmer SE.The prevalence of carpal fractures was determined for 211 thoroughbred and 75 standardbred racehorses. Statistically significant differences were found in the location of fractures between the 2 breeds. In the thoroughbred and standardbred groups, total fractures (460) were distributed nearly equally between the left (224) and right (236) carpi. The most common site of fracture in the thoroughbred group was the distal aspect of the radiocarpal bone (112), whereas the most common site of fracture in standardbred horses was the proximal surface of the third carpal bone (61). Slab fractures were ...
Strambini GB, Gonnelli M.The inactivation of equine liver alcohol dehydrogenase by guanidine hydrochloride and urea has been studied by monitoring the intrinsic tryptophan fluorescence and phosphorescence emission. The use of triplet-state lifetimes to probe the flexibility of protein structure at the site of tryptophan-314 reveals a distinct behavior between the two denaturants. At predenaturational concentrations, the loss of enzyme activity in guanidine hydrochloride is associated with a loosening of intramolecular interactions resulting in a greater fluidity of the interior region of the macromolecule. In contrast...
Jeffcott LB, McCartney RN, Speirs VC.A safe, non-invasive method for the accurate measurement of bone mineral content in the third metacarpal bone of the horse is described. The technique involves scanning the bone with a single photon beam from an Americium-241 source. Data were obtained from the excised metacarpal bones from both forelimbs of 50 normal and seven lame horses. Measurements were made in vivo on eight normal and seven lame horses and on one experimental horse with osteopenia induced by partial weightlessness in a flotation tank. In the normal horses bone mineral content altered with age, particularly in the first s...
Snyder JR, Pascoe JR, Hietala SK, Holland M, Baggot DJ.Gentamicin sulfate (2.2 mg/kg of body weight, IV) was given to anesthetized horses. Jejunal and large colon tissue samples (1 g), serum, and urine were collected over a 4-hour period. Maximum gentamicin concentrations in serum (10.06 +/- 2.85 micrograms/ml) occurred at 0.25 hours after injection. Maximum gentamicin concentrations in the large colon (4.13 +/- 1.80 micrograms/ml) and jejunum (2.26 +/- 1.35 micrograms/ml) occurred in horses at 0.5 and 0.33 hours, respectively. Tissue concentrations decreased in parallel with serum concentrations and were still detectable at the end of the 4-hour ...
Merkens HW, Schamhardt HC, Hartman W, Kersjes AW.The ground reaction force patterns from 20 clinically sound Dutch Warmblood horses (Group A) were recorded at the normal walk. The data from four to 10 stance phases of each limb were computer averaged after normalisation to the animal's body mass and to the stance time. This analysis method allowed comparison of data from left and right fore- and hindlimbs within and between horses. The left-to-right symmetry in the reaction force peaks of contralateral limbs of one horse exceeded 90 per cent. The time in the stance phase at which the peaks occur were even more symmetrically distributed. A ch...
Trotter GW, Miller D, Parks A, Arden W.Persistent, severe metabolic acidosis complicated the operative and postoperative period in a 4-year-old mare with colic. On the basis of clinical and laboratory findings, a renal tubular disorder was diagnosed. Renal tubular acidosis is rare in horses. In the only report found on the subject, type I renal tubular acidosis was described in 2 horses. Bicarbonate titration studies in our case helped document type II renal tubular acidosis in this mare.
Ishiyama T, Shinagawa M, Sato G, Fujinaga K, Padmanabhan R.Equine adenovirus (EAd) DNA prepared from infected bovine kidney (MDBK) cells contained additional sequences of about 100 to 700 bp at the left-hand end of the genome. These aberrant viral genomes were produced even after the first passage of the wild type EAd in MDBK cells and their relative amounts did not change significantly during serial passage. The left terminal fragments of two defective viral DNAs were cloned into the plasmid vector pBR322 and the nucleotide sequences of their terminal regions were analyzed. The data indicate that one viral DNA contained a duplication of the inverted ...
Mair TS, Osborn RS.X-ray diffraction crystallography was used to determine the crystalline composition of 18 equine urinary calculi, including stones originating in the kidney, bladder and urethra. Calcium carbonate in the form of calcite was found to be the major component in all calculi examined. Other components commonly found included weddellite and substituted vaterite. Urine deposits from a number of normal horses were also examined. The significance of these findings, as well as those from a number of previous reports, are discussed in relation to the possible aetiology of urolithiasis in the horse.
Mendoza L, Alfaro AA.Thirty-nine pythiosis equine cases, were studied at the Veterinary Medicine School of the National University of Costa Rica, between 1981 and 1984. Lesions were located in different parts of their anatomy: anterior and posterior extremities, abdomen, thorax, breast and mammary gland, and were characterized by their tumoral appearance with necrotic tissue in which yellow-white coral-like necrotic masses, called kunker or leeches were shown. Splendore-Hoeppli like phenomenon and eosinophilic inflammatory reaction around the hyphae, was microscopically observed. Pythium sp. (Hyphomyces destruens)...
Autefage A, Alvinerie M, Toutain PL.Synovial fluid and plasma kinetics of methylprednisolone acetate (MPA) and methylprednisolone (MP) after a single intra-articular administration of MPA at a therapeutic dose (111 mg in toto) was measured in five horses. MPA was detected in synovial fluid for two to six days post injection and MP, which results from synovial MPA hydrolysis, was present in pharmacologically significant concentrations for 4.8 to 39 days, depending on the horse. MPA synovial concentration was maximal (289 +/- 284 micrograms/ml) at the first sampling time (2 h after administration) and MP synovial concentration was...
Manohar M.Eight healthy adult grade ponies were studied at rest as well as during maximal exertion carried out with and without adenosine infusion (3 microM X kg-1 X min-1 into the pulmonary artery) on a treadmill to compare levels of blood flow in respiratory muscles with those in other vigorously working muscles and to ascertain whether there remained any unutilized vasodilator reserve in respiratory muscles of maximally exercising ponies. Radionuclide-labeled 15-micron-diam microspheres, injected into the left ventricle, were used to study tissue blood flows. During maximal exertion, there were incre...
Allen WE.THE accumulation of a gross excess of fluid in the amniotic or
allantoic cavities is not uncommon in bovidae, although the
latter occurs most frequently. The resulting pathological
conditions are usually referred to as hydrops amnii and
hydroallantois, respectively. They are often associated with
abnormalities of the foetus in cattle (Vandeplassche el ul1965;
Roberts 1971) and hydro-allantois is quite common in twin
pregnancies (Roberts 1971).
This article describes two cases of excess foetal fluid in the
mare, both of which were associated with abnormal
pregnancies.
Burrell MH, Mackintosh ME, Taylor CE.Streptococcus pneumoniae was isolated from nasopharyngeal swabs and tracheal washings taken from Thoroughbred horses in training at three of four separate stables that were sampled during investigations into respiratory disease. The growth of Strep pneumoniae in culture was enhanced by an environment enriched with carbon dioxide. In one stable, five of 15 horses that were sampled repeatedly were found to carry the organism for at least four months. There was an apparent association between lower respiratory tract inflammatory disease and heavy growths (10(6) to 10(8) colony forming units/ml) p...
Woods WE, Weckman T, Wood T, Chang SL, Blake JW, Tobin T.A commercially available radioimmunoassay kit was used to screen for the presence of etorphine in post-race urines from horses racing in Kentucky. Most horse urines contained small amounts of materials which reacted positively in this immunoassay. These materials are apparently endogenous to the horse and were called apparent etorphine equivalents. The levels of these apparent etorphine equivalents in post-race urines from 70 horses were estimated. Their modal level averaged 0.1 ng/ml, the population distribution was log normal, and individual horses showed levels of up to 0.8 ng/ml.
MacGregor CM.Radiographic examination of the navicular bones of 258 horses was carried out. Of these 258 horses, 83 were sound (Group A), 151 had been diagnosed clinically as having navicular disease (Group B), and 24 had a forefoot lameness of unknown aetiology (Group C). Seven basic shapes of distal nutrient foramina were identified from these radiographs. A scoring system was then developed based on these different types of distal nutrient foramina. When this scoring system was applied to the radiographs of the 258 horses examined significant differences were found between the mean navicular scores of t...
Amin TM, Sirs JA, Allen BV, Colles CM.A preliminary investigation has been undertaken of blood rheology in horses and ponies, its variation in navicular disease and the changes following treatment with warfarin. Erythrocyte flexibility, measured by a centrifuge packing technique, is higher in horses (30 per cent min-1) than in ponies (23.8 per cent min-1). There are corresponding differences in blood viscosity. The high erythrocyte flexibility in horses is caused by an unknown factor present in plasma. The erythrocyte flexibility in horses with navicular disease is even higher, at 38.5 per cent min-1. Treatment with warfarin reduc...
Mendoza L, Kaufman L, Standard PG.A practical, sensitive, and specific immunodiffusion test was developed for diagnosing and monitoring pythiosis in horses. Culture filtrates, a soluble cell mass, and trypsinized Pythium sp. antigens were evaluated against prepared rabbit anti-Pythium sp. serum and pythiosis horse case sera. The culture filtrate antigens demonstrated the greatest capacity for detecting precipitins and the greatest stability during storage. In contrast, the trypsinized antigens had the weakest capability for detecting multiple precipitins and the poorest stability. The 13 sera from horses with proven active pyt...
Hodgson DS, Steffey EP, Grandy JL, Woliner MJ.Cardiopulmonary effects of spontaneous, assisted, and controlled ventilatory modes were determined with 6 young, healthy geldings anesthetized with halothane at a constant dose (1.3 minimum alveolar concentration). All horses were in lateral recumbency, and all modes of ventilation were studied at least once during each anesthetic exposure. Cardiac output did not differ between spontaneous and assisted ventilation modes, but both modes were associated with significantly (P less than 0.05) higher cardiac output than that with controlled ventilation. The PaCO2 differed significantly (P less than...
Walker M, Geiser D.Heart rate, blood velocity, volumetric blood flow, and arterial diameter for 10 horses given acetylpromazine were determined from measurements of the dorsal metatarsal artery 3 (the great metatarsal artery), using 2-dimensional real-time and gated pulsed Doppler ultrasonography. Acetylpromazine induced significant increases in arterial diameter (P less than 0.01) and volumetric flow rate (P less than 0.05)--all compatible with adrenergic blockade. There was a trend indicating that there was increased blood velocity. Heart rate was unchanged.
Takai S, Kawazu S, Tsubaki S.Humoral immune response to intestinal Rhodococcus (Corynebacterium) equi in horses was studied by enzyme-linked immunosorbent assay. Anti-R. equi immunoglobulin M (IgM), IgG, and IgA antibodies were demonstrated in the healthy horse population. Adult horse levels of anti-R. equi IgM and IgG antibodies were reached by 5 to 9 weeks of age in two healthy newborn foals. R. equi was recovered from the foals in the range of 10(3) to 10(4) per g of intestinal contents. A 1-week-old foal was infected with R. equi by mouth daily for 9 weeks. The foal did not show any clinical signs of illness. Anti-R. ...
Stadler P, Deegen E.Dynamic compliance, airway resistance, viscous work and respiratory frequency were measured at intervals in horses over 12 h periods. Variation, daily averages and circadian patterns were recorded. Examinations were performed on 24 horses. They were divided into three groups: Normal horses, horses with chronic latent bronchitis and horses with manifest chronic obstructive pulmonary disease (COPD). Significant differences were found between the daily averages and the fluctuations when the normal group and the COPD group were compared. In most cases differences between all three groups were sign...
de Camargo MM, Kuribayashi JS, Bombardieri CR, Hoge A.Studies focusing on the equine humoral response are scarce, with a bias towards the pre- and post-parturition mare and its foal. The present study attempted to expand current knowledge by establishing normal ranges for adult horse serum isotypes. Immunoglobulin (Ig) concentrations were obtained by screening 47 horses of various breeds and in different training regimes. Radial immunodiffusion values (mg/dL) were 196+/-73 for IgA, 2704+/-1424 for IgG, 419+/-220 for IgG(T) and 70+/-30 for IgM. All values passed the Kolmogorov-Smirnov normality test. The results will be of use to the field veterin...
Kasper DT, Gandy RF.The 2016 Equibase data set of American Quarter Horse starts in North America was analyzed, with the purpose of ranking the sires of the racehorses. A speed z-score derived from the race times and distances was used as a racing performance measure. Mixed effects models were used on various subsets of the data based on race distance and sire offspring number. The sire categorical variable was considered as a random effect. Various statistical criteria were used to optimize the model. The constructed models were then varied in terms of the random and fixed effects included, and the conditional mo...
Donadeu FX, Ginther OJ.The role of estradiol and inhibin in suppression of FSH and LH during the initiation of follicle deviation was examined in mares. In Experiment 1, the two largest follicles (F1, F2) were retained during a wave and the rest were ablated as they reached > or =10 mm. The largest follicle was left intact (control, n=12) or was ablated when it reached > or =20.0 mm (Day 0; expected beginning of deviation). The second largest follicle continued growing (n=9) or regressed (n=4) after F1 ablation. Circulating estradiol and total inhibin decreased after Day 0 in the F2-regressing group, whereas e...
Major MD, Grant BD, White KK, Ratzlaff MH, Gallina AM, Crawley GR.Mechanical properties of equine suspensory apparatus preparations and three braided synthetic prostheses were evaluated in vitro. Force versus displacement plots and failure modes were recorded from single load-to-failure testing in 18 cadaver limbs before and after replacement of each suspensory apparatus with a prosthesis. Mean load at failure, energy to failure, and stiffness values of polytetrafluoroethylene (PTFE) prostheses were lower than those of the suspensory apparatus and aramid prosthesis. The PTFE prosthesis failed by elongation or rupture of the prosthesis. Mechanical properties ...
Hillman RB, Olar TT, Squires EL, Pickett BW.Stallion semen was collected, using artificial vaginas at 44 to 46, 48 to 50, and 52 to 54 C, to study the effects of temperature on seminal quality and sexual behavior. The temperature of the artificial vagina had no significant effect on motility, gel volume, gel-free seminal volume, total seminal volume, pH, number of mounts per ejaculate, total time to ejaculation, or seminal temperature. Spermatozoa were collected, then exposed to water-bath temperatures of 38, 45, 49, or 53 C for 1 minute. Mean motility was similar after exposure to temperatures of 38 or 45 C, but exposure to temperature...
Seddighi R, Knych HK, Cox SK, Sun X, Moorhead KA, Doherty TJ.To determine the sedative effects and pharmacokinetic profile of detomidine when administered intravaginally as a gel formulation to horses. Methods: Randomized, crossover, masked experimental design. Methods: A group of six healthy adult mares (494 ± 56 kg). Methods: Mares were studied on two occasions and were administered either detomidine hydrochloride (10 μg kg) intravenously (treatment IV) or detomidine gel (40 μg kg) intravaginally (treatment IVG), separated by 1 week. Sedation, ataxia, muzzle-floor distance and heart rate (HR) were evaluated every 15 minutes for 240 minutes. Venous ...
van den Bogaard AE, Thijssen HH, Hemker HC.The anticoagulant, warfarin, has been reported to be effective as treatment for navicular disease in horses. Since other forms of treatment for this disease are palliative, this new anticoagulant therapy has become widely employed. Despite the fact that initiation of anticoagulant therapy is relatively simple, attending veterinary practitioners should be aware that careful monitoring of this therapy is required for both safety and efficacy. Navicular disease is an example of equine thrombotic disease, and the goal of warfarin therapy is the prevention of new thrombus formation, while at the sa...
Chvala S, Nowotny N, Kotzab E, Cain M, van den Hoven R.To evaluate use of the acupuncture meridian test for detection of recent or recently reactivated equine herpesvirus type 1 (EHV-1) infection in horses with decreased performance. Methods: Case-control study. Methods: 40 horses. Methods: Physical and neurologic examinations were performed, and acupuncture points on the bladder meridian were tested for sensitivity reactions in case and control horses. Polymerase chain reaction assays were performed to determine whether EHV-1 or equine herpesvirus type 4 (EHV-4) DNA could be detected in peripheral blood mononuclear cells. Complement fixation (CF)...
Bryant B, Meehan LJ, Roberts V.Standing computed tomographic (CT) examination of the equine guttural pouch frequently reveals deviation of the midline septum. The significance of deviation is currently unknown. The aims of this retrospective, single-centre study were to determine the prevalence of deviation of the midline septum of the guttural pouch and determine whether there was an association between the presence and degree of deviation of the septum, and guttural pouch disease. Case records were reviewed, identifying 95 horses that had undergone a standing, sedated, head CT and guttural pouch endoscopy. The presence, l...
Zierz J, Wintzer HJ.To judge acute processes of pain objectively the results are told of a determination of adrenaline and noradrenaline in the plasma of 30 horses suffering from pain. Besides a scheme basing on an awarding of points is developed to ascertain changes of physiological and ethological parameters caused by pain. These results in changes of behaviour are compared to results determined by laboratory experiments. Concerning pain of medium and high level a relation to the concentration of catecholamines is noticed. Therefore the total of certain clinical observations is suitable for graduating acute pai...
Pusterla N, Mapes S, Leutenegger CM.A questionnaire was developed to document the knowledge base of large-animal diplomates of the American College of Veterinary Internal Medicine (ACVIM) regarding polymerase chain reaction (PCR) technology and to identify the common use of this technology in equine practice. Ninety-three of the 278 mailed questionnaires were returned, for an overall response rate of 33.4%. Ninety respondents (99%) reported being familiar with the general principles of nucleic acid probe technology; however, only 52 (57%) knew the difference between conventional (traditional) and real-time (second-generation) PC...
Carlson KL, Chaffin MK, Corapi WV, Snowden KF, Schmitz DG.The starry sky hepatic pattern is an unusual ultrasonographic appearance of equine liver characterized by numerous small, hyperechoic foci, some of which cast an acoustic shadow, distributed randomly throughout the hepatic parenchyma. Our objectives were to describe the signalment, clinical signs, clinicopathological findings, primary disease process, and ultrasonographic findings of horses with this ultrasonographic pattern, as well as determine the associated gross and histologic changes. The starry sky pattern was identified in 18 adult horses of mixed gender and breed. The horses had vario...
Pinaffi FL, Khan FA, Silva LA, Beg MA, Ginther OJ.The effects of a PRL-stimulating substance (sulpiride) on PRL and PGF2α secretion and on luteal and ovarian follicular dynamics were studied during the estrous cycle in mares. A control group (n = 9) and a sulpiride group (Sp; n = 10) were used. Sulpiride (25 mg) was given every 8 h from Day 13 postovulation to the next ovulation. Repeated sulpiride treatment did not appear to maintain PRL concentrations at 12-h intervals beyond Day 14. Therefore, the hypothesis that a long-term increase in PRL altered luteal and follicular end points was not testable. Hourly samples were collected from the h...
Raidal SL, Wright JD.Records of 220 thoroughbred horses presented to the Randwick Equine Centre or the University of Queensland Veterinary Teaching Hospital for surgical management of carpal injury were reviewed. Details of racing performance were obtained, enabling evaluation of racing success following surgery. Age and sex matched control horses not known to have suffered carpal injury were selected from the Australian Stud Book and the Australian Racehorse Register. Control and treated populations were compared in terms of overall career racing success. Radiographs or xeroradiographs from 198 horses were availa...
Johnson BJ.Immediately record the findings. A tape recorder would be excellent for this. If none is available, findings should be written down as soon as possible before memory of the examination fades. It is important to record comments on every organ that you examined. Three years from now in a court deposition, it may be difficult for the practitioner to remember if he looked at the adrenal glands or if there was no gross evidence of hyperplasia. When writing a report, it is a good idea to describe the tissue changes rather than just to give an interpretation. An example of the latter would be, "The h...
Ralston SL, Molnar A.In 1999, the Young Horse Teaching and Research Program (YHTRP) was initiated at Rutgers University. The unique aspect of the program was using horses generally considered "at risk" and in need of rescue, but of relatively low value. The risks of using horses from pregnant mare urine (PMU) ranches and Bureau of Land Management (BLM) mustangs were high, but, ultimately, unrealized. No students or staff members were seriously injured over the course of the next 12 yr, and the horses were sold annually as highly desirable potential athletes or pleasure horses, usually at a profit. The use of "at r...
Easley KJ.Infertility in the mare associated with VVR must be managed as a complex problem. A complete reproductive evaluation of the mare is required to establish the cause of VVR in order for proper therapy to be recommended. Establishing a prognosis for the mare's future breeding soundness is important to the horse owner and breeding manager. VVR is almost always associated with other reproductive problems and must be dealt with in view of this.
Baird AN, Scruggs DW, Watkins JP, Taylor TS.Sixteen horses were allotted to 4 groups of 4 horses each to evaluate the effect of tendon sheath lavage with 4 solutions (balanced electrolyte solution, 0.1% povidone-iodine, 0.5% povidone-iodine, and 0.5% chlorhexidine). The synovitis caused by 0.1% povidone-iodine lavage was not appreciably worse than that caused by balanced electrolyte solution lavage, but the 0.5% povidone-iodine and chlorhexidine lavages caused severe synovitis, and, therefore, should not be used for tendon sheath lavage.