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.
Kirkpatrick CE, Saik JE.Ciliated protozoa of several morphological types were found in the colonic tissue of 8 horses, mostly immature Standardbreds. Most of the protozoa observed appeared similar to those normally found as commensals in the equine large intestinal lumen. In all cases, organisms were located in the lamina propria; organisms were also found in the submucosa of 2 horses. The association of colonic disease with the presence of intramural ciliates was unclear.
Dean PW, Robertson JT.A urachal remnant, causing pollakiuria and dysuria, was diagnosed by rectal palpation of a urinary bladder adhesion and endoscopic visualization of a urinary bladder diverticulum. Surgical excision of the remnant resulted in relief of abnormal micturition, but the filly was euthanatized 9 months after surgery because of a chronic ventral midline incisional infection. Pollakiuria and dysuria associated with urachal abscessation occur most commonly in calves. This report documents the syndrome in a horse.
Hayden DW, Johnson KH, Wolf CB, Westermark P.Systemic amyloidosis involving the digestive tract is described in an 11-year-old Morgan stallion. The disease was characterized clinically by weight loss, ptyalism, anaemia, persistent mature neutrophilia, hypoalbuminaemia and hypergammaglobulinaemia. The D-xylose absorption test indicated malabsorption. Necropsy revealed oral, oesophageal and gastric ulcers and reddened segments of small bowel mucosa with scant haemorrhages. Microscopically, amyloid deposits were found throughout all tissue layers of the digestive tract, except the serosa. Deposits of amyloid were most apparent in the small ...
Stover SM, Steffey EP, Dybdal NO, Franti CE.Five horses were anesthetized similarly by use of xylazine, guaifenesin, thiamylal sodium, and halothane in oxygen on 3 consecutive days, and minor surgical procedures were performed. For 1 to 10 days after the last anesthetic exposure, clinical, hematologic, and serum biochemical features were monitored, and after necropsy, histologic examination of major organ tissues was performed. Predominant hematologic changes from base-line values included leukocytosis (maximal at 27 hours, 10,500 +/- 1,750 cells/microliter), neutrophilia (maximal at 51 hours, 7,485 +/- 1,719 cells/microliter), and lymp...
McCarthy RN, Hutchins DR.A retrospective analysis of 74 cases that underwent surgery for colic was undertaken to determine short and long term survival rates and the incidence of post-operative complications. In 28 cases colic was related to small intestinal lesions and in 46 cases to large intestinal lesions. Pre-operative packed cell volume and heart rate were found to be inversely related to short-term survival. Twenty-five horses (34%) recovered from surgery and were discharged. Of 18 of these cases with available histories, 6 subsequently had one or more episodes of colic since surgery of which 5 eventually died ...
Songer JG, Beckenbach K, Marshall MM, Olson GB, Kelley L.Isolates (n = 94) of Corynebacterium pseudotuberculosis were obtained from sheep, goats, horses, and cattle from various parts of the world. The isolates were characterized biochemically and by restriction endonuclease analysis of DNA. We found near homogeneity in the ability of isolates to ferment carbohydrates and to produce urease. All isolates produced phospholipase D and catalase. The ability of isolates from horses to reduce nitrate, the inability of isolates from sheep and goats to do so, and the correlation of this characteristic with results of restriction endonuclease analyses confir...
Horvath CJ, Ames TR, Metz AL, Larson VL.Pituitary-dependent hyperadrenocorticism was diagnosed in a 14-year-old Arabian mare with chronic weight loss, hirsutism, polyuria, and polydipsia. The mare had a stress leukogram, glucosuria, and consistent hyperglycemia. Plasma glucose concentrations were resistant to suppression by insulin. Plasma cortisol concentrations were within normal limits, but did not respond to dexamethasone suppression and had an exaggerated response to ACTH stimulation. At necropsy, a chromophobe adenoma of the pars intermedia of the pituitary gland was found. The zona fasciculata of the adrenal cortex and the pa...
Firth EC, Schamhardt HC, Hartman W.Two to 7 days after birth, 9 foals were anesthetized, and strain gauges were applied to lateral and medial aspects of the third metacarpal bone of the left forelimb. In 5 of these foals, strain gauges also were applied to the radius of the left forelimb. Four to 6 days later, foals were walked (5 sets of 10 to 20 strides), and compressive and tensile strains in the bone beneath strain gauges were recorded on paper and diskette. After recording base-line data, a wedge was fitted to the hoof of the limb with the strain gauges, in such a way that the lateral bearing surface was raised, and strain...
Koblik PD, O'Brien TR, Coyne CP.The effect of dorsopalmar projection obliquity on calculation of distal phalangeal rotation (DPR) angle was determined in 8 feet obtained from 5 horses that had been euthanatized because of laminitis. A true lateromedial view of each foot served as a reference, with additional views taken at 5, 10, 15, and 20 degrees of x-ray tube head rotation in both a dorsal and in a palmar direction. Projection obliquity resulted in consistent underestimation of DPR angle. Where projection obliquity exceeded 10 degrees, there were significant (P less than 0.05) differences in DPR angle. The magnitude of un...
Wyatt CR, Davis WC, McGuire TC, Perryman LE.Six monoclonal antibodies reacting with equine T lymphocytes at different stages of maturation were selected from antibodies produced against lymphoid cell preparations. EqT12 and EqT13 antibodies identified subsets of cortical thymocytes with high terminal deoxynucleotidyltransferase (TdT) activity and no phytolectin responsiveness. EqT12+ thymocytes were scattered throughout the cortex while EqT13+ thymocytes were located in the subcapsular cortex. EqT12 bound to small numbers of bone marrow cells, splenocytes, and circulating lymphoid cells, but not to mature T lymphocytes. EqT13 bound to v...
Sundquist B, Lövgren K, Morein B.A monovalent experimental ISCOM vaccine has been prepared with the envelope glycoproteins haemagglutinin and neuraminidase of the equine virus strain A/Solvalla/79 (H3N8). In vaccination trials on BALB/c mice the ISCOM vaccine induced more than ten times higher serum antibody titres measured in ELISA than a corresponding experimental micelle vaccine. Similarly, in guinea-pigs the ISCOMs induced about tenfold higher haemagglutination inhibition (HI) and neuraminidase inhibition (NI) titres than a micelle vaccine or a conventional killed influenza whole virus vaccine. Horses vaccinated with a di...
Murray MJ, Ball MM, Parker GA.A 3-month-old foal with a history of persistent fever and leukocytosis was found to have pneumonia, ulceration of the squamous portion of the stomach, and dilatation of the distal portion of the esophagus. The foal was euthanatized and necropsied. The distal portion of the esophagus was severely dilated, and there was severe ulceration and mural thickening of the stomach at the cardia. Because of the severe gastric ulceration and mural thickening, the gastroesophageal junction was fixed in an open position, permitting gastroesophageal reflux. The megaesophagus and pneumonia were considered to ...
Gibbs PG, Potter GD, Schelling GT, Kreider JL, Boyd CL.Mature ponies fitted with permanent ileal cannulas were used in a 3 X 3 Latin square experiment to quantify prececal, postileal and total tract digestion of hay protein. Coastal Bermuda grass (CB), containing 11.7% crude protein, and two qualities of alfalfa, containing 15.0% (low-protein alfalfa; LA) and 18.1% (high-protein alfalfa; HA) crude protein, were fed in coarsely chopped form at 2% of body weight daily. Total tract apparent digestibility of the N in HA (73.8%) was higher than that in CB (57.0%; P less than .05) and was slightly higher than that in LA (66.1%; P less than .10). Nitroge...
Stull CL, Rodiek AV.Two experiments were conducted to determine the response of blood glucose, insulin and cortisol levels to four common equine diets. Experiment 1 was designed to determine the diurnal variation of glucose and two glucoregulatory hormones, insulin and cortisol, in four fasting geldings. No diurnal variation was observed in either glucose or insulin levels during the 24-h sampling period. However, cortisol levels did exhibit a circadian rhythm, with elevated values observed in the morning and low values in the evening. Experiment 2 investigated the response of glucose, insulin, cortisol and selec...
Bridges CG, Ledger N, Edington N.Ponies, without evidence of previous exposure to Equine herpes virus-1 (EHV-1), were experimentally infected with EHV-1 subtype 2 and investigated for lymphocyte transformation to virus-infected cell polypeptides, as shown by separation with gel electrophoresis. Animals made significant responses to Western blot fractions that corresponded to molecular weights of approximately 30,000, 40,000-45,000, 60,000-65,000, 80,000-95,000 and 100,000-140,000 MW. These molecular weight ranges correlated with the positions of major EHV-1 subtype 2 glycoproteins that were found at migration distances approx...
Kloppe LH, Varner DD, Elmore RG, Bretzlaff KN, Shull JW.A breeding trial was conducted to evaluate the effect of insemination timing on the fertility of mares bred with frozen/thawed equine semen. One stallion and 60 reproductively sound, estrous-synchronized mares were included in the study. Mares were assigned to one of three groups (n = 20): 1) insemination with fresh semen every other day during estrus from detection of a 35-mm follicle until ovulation, 2) insemination with frozen/thawed semen every day during estrus from detection of a 35-mm follicle until ovulation or 3) insemination with frozen/thawed semen once, within 6 h after ovulation. ...
Greenblatt DJ, Engelking LR.Adult female ponies (130-225 kg) with chronically implanted external biliary fistulas (T-tubes) participated in three-way cross-over studies using either i.v. lorazepam (10 mg) or acetaminophen (2 g), two model drugs biotransformed mainly by hepatic conjugative reactions. The objectives were to determine the systemic pharmacokinetics, urinary and biliary excretion and degree of enterohepatic circulation (EHC) of these compounds. Trial conditions were: A: EHC intact, with blood and urine, but not bile, collected after i.v. drug administration; B: EHC interrupted, with blood, urine and bile coll...
Platt H.A retrospective study was carried out on post-mortem and biopsy tissue samples from 26 horses with non-alimentary lymphoma. On the basis of their histopathology and cytology, the cases were grouped into several categories: (1) Lymphoblastic lymphomas (6 cases) and primary lymphoblastic leukaemia (2 cases). (2) Histiolymphocytic lymphomas involving the skin (6 cases) or lymph nodes (3 cases). (3) Lymphomas showing follicular development (4 cases). (4) Plasmacytic lymphomas (4 cases). (5) Lymphocytic lymphoma (1 case). Most affected horses were middle-aged or old but lymphoblastic neoplasms tend...
McKinnon AO, Squires EL, Harrison LA, Blach EL, Shideler RK.During breeding of mares, ultrasonographic detection of uterine fluid accumulations in the first postpartum ovulatory period was associated with significantly decreased pregnancy rates, when compared with rates in control mares (P less than 0.005). The previously gravid uterine horn was recognized as the larger horn, when assessed for size by ultrasonography, for a mean of 21 days (range, 15 to 25 days) after parturition. On the basis of similar measurements obtained during 3 ultrasonographic scans (5-day period), uterine involution was determined to be completed in a mean of 23 days (range, 1...
Livesey MA, Arighi M, Ducharme NG, Horney FD, Hurtig MB.Incarceration of the large colon by the suspensory ligament of the spleen was diagnosed and surgically corrected on exploratory celiotomy in 76 horses exhibiting abdominal pain. The condition was diagnosed most frequently during the winter months in mature males of mean age 4.7 years. Clinical signs progressed slowly and included mild to moderate abdominal pain and distension with moderate tachycardia. The mean duration of colic prior to surgical intervention was 20.7 hours. The mild nature of the colic, the findings on palpation per rectum, and the continued passage of feces in 40% of horses,...
Kasman LH, Hughes JP, Stabenfeldt GH, Starr MD, Lasley BL.Serum and urinary estrone sulfate concentrations were determined in 7 pregnant mares before and after prostaglandin-induced abortion (n = 4) or surgical removal of the fetus (n = 3) to determine the source of estrogen during early pregnancy (gestation days [GD] 44 to 89). Estrone sulfate concentrations also were determined in serum samples (stored frozen for 2 years) from 3 mares that had been ovariectomized between GD 51 and 58. Estrone sulfate concentrations decreased in serum and urine after expulsion or removal of the fetus (urinary patterns were more definitive than were patterns for seru...
Bostedt H.A clinical study about the effects of a beta 2-mimetic agent (Clenbuterol) in mares with pregnancy disorders or disorders during the periparturient period (n = 34) is reported. In general, a single dose of 0.3 mg Clenbuterol given i.v. induces sufficient tocolysis. Subsequent doses or follow-up treatment depend upon individual development during dystocia, indication of treatment and clinical preparturient status (dorsoflexio uteri ante partum, abortus imminens, preparturient labor pains).
Bowling AT, Clark RS.Data from 5934 matings of American Standardbred horses provided evidence for an excess of heterozygotes at the albumin locus, statistically significant (P less than 0.01) in one mating class (A1-AB stallions x Al-A dams), primarily attributed to an excess of heterozygotes among male offspring.
Silver M.THERE is no shortage of anatomical information on the equine foetus and its placenta, from the early work of Ruini in the 16th century to the recent studies of Steven and colleagues (Steven 1982); by contrast, knowledge of the physiology of the foal in utero is sparse. In other domestic animals there have been considerable ads ances in foetal and neonatal physiology and endocrinology in recent years due mainly to the develop-ment of the chronically catheterised foetal preparation in which sequential observations can he made in the conscious animal (Silver 1981). Some information about the deve...
of surveillance testing, April to June 2017International disease occurrence in the second quarter of 2017These are among matters discussed in the most recent quarterly equine disease surveillance report, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
Allen WE.Plasma concentrations of sodium benzylpenicillin were measured following intrauterine infusion at a dose rate of 22,000 u/kg (250,000 u/ml). The reproductive status of the mare at the time of infusion did not appear to influence plasma concentrations of penicillin, but preswabbing the endometrium for bacteriological culture resulted in peak plasma concentrations which were nearly twice those found in unswabbed mares.
Bittmar A, Kosiniak K.Experiments conducted on the freezability of 400 ejaculates collected from 64 stallions demonstrate the possibility of predicting the semen's ability to withstand the freezing/thawing process. If the sperm concentration, AspAT activity and total protein content in the seminal plasma of raw ejaculates are determined before freezing, the effects of freezing may be forecast in about 80% of the ejaculates.
Uchida-Fujii E, Niwa H, Kinoshita Y, Nukada T.Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese Thoroughbred racehorses putatively identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry as Actinobacillus were further identified by PCR of the A. equuli toxin gene, by CAMP test, and by 16S rRNA sequencing analysis. Actinobacillus equuli subsp. haemolyticus was isolated most frequently (16/27) and was related to respiratory infections. Actinobacillus equuli subsp. equuli (4/27) was isolated from...
Michalski G, Earman S, Dahman C, Hershey RL, Mihevc T.Multiple stable isotope analysis can be a powerful technique in forensic sciences. Oxygen and nitrogen isotopes were used to determine the source of nitrate that was responsible for the poisoning deaths of 71 wild horses in the Nevada desert. The nitrate was present in a water-filled hole known as 'the Main Lake depression.' Nitrate from the Main Lake depression had delta(18)O and delta(15)N values that were very positive (+32 per thousand, +37 per thousand), and Delta(17)O values of approximately +2 per thousand. The isotopic data suggested that the most probable source of the nitrate was nit...