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.
Martin CJ, Chihara S, Chang DB.Alveolar wall from the lung of aging humans shows a progressive decrease in maximal extensibility, which should follow an increase in resting tissue length rather than a reduction in maximal length. An increase in resting tissue length is compatible with the change in lung volumes and reduction in elastic recoil that occurs with time. A model of the lung was used to compare the effects of a change in resting tissue length in diminishing elastic recoil with that of a reduction in the volume density of the elastic elements (emphysema). Such differentiation is important in selecting an animal tha...
McGuire TC, Crawford TB, Hallowell AL, Macomber LE.Failure in colostral immunoglobulin G (IgG) transfer was found in 9 of 87 Thoroughbred foals. Seven (78%) of these 9 foals acquired infections requiring therapy. Twelve of the foals had partial failure in colostral IgG transfer, and 3 of these had infections requiring therapy. The remaining 66 foals had normal transfer of colostral IgG, and only 2 had detectable infections. The failure of colostral IgG transfer was attributable to nursing problems in only one case. When presuckle postpartum colostrum was collected, 2 of 4 failures of colostral IgG transfer and 4 of 6 partial failures of colost...
Garner HE, Hahn AW, Salem C, Coffman JR, Hutcheson DP, Johnson JH.Acute laminitis-hypertension was produced experimentally by carbohydrate overloading of the gastrointestinal tract in 8 horses, and the resulting hemodynamic changes were measured. Statistically significant (P less than 0.01) increases in cardiac output, left ventricular ejection rate, heart rate, and arterial pressure were related to statistically nonsignificant changes in peripheral resistance and a delayed (Obel grade 3 plus 24 hours) decrease in plasma volume. When compared with control values, the doubling of cardiac output and left ventricular ejection rate simultaneous with little or no...
Hughes JP, Trommershausen-Smith A.Reproductive failure was studied in 12 phenotypically normal mares (9 Arabian, 3 Quarter horses, 1 Appaloosa and 1 pony). Karyotyping was performed using lymphocytes isolated from peripheral blood by density gradient procedures, followed by standard culture methods for karyotyping. Nine mares had karyotypes of 63,XO; 1 had 63,XO/64,XX; 1 had 63,XO/64,XY and 1 had 64,XY. All mares had small, firm ovaries that when removed and examined from 4 mares, lacked germ cells and consisted of undifferentiated ovarian stroma.
Burrows R, Spooner PR, Goodridge D.Ponies held in isolation for 40 months were vaccinated and revaccinated with four commercial equine influenza vaccines. Little or no HI antibody was detected after the first inoculation; second and subsequent annual revaccinations produced peak HI antibody titres between 7 and 14 days. Titres fell quickly between 14 and 28 days and less quickly thereafter. The decline of HI antibody appeared to be related more to the initial titre attained and to the period after vaccination than to the composition of the vaccine. The response to a first annual revaccination was superior to that produced by a ...
Lyons ET, Drudge JH, Tolliver SC.In 1 experiment, a prepatent period of 8 or 9 days was recorded for Strongyloides westeri in 4 pony foals raised worm-free but infected with parasitic 3rd stage larvae in the postpartum milk of a mare via gastric intubation. This is about 2 to 6 days less than the usual age that eggs of S westeri appear in the feces of naturally infected suckling foals, in central Kentucky.
In other studies, mares were treated with cambendazole or thiabendazole at 0 to 2 days after parturition and continued for 7 to 16 days. Appearance of S westeri eggs in feces of foals nursing treated mares was prevented ...
Jackson TA, Osburn BI, Cordy DR, Kendrick JW.Experimental infection with equine herpesvirus 1 (rhinopneumonitis) resulted in neurologic disease in 8 of 15 inoculated horses. Nonpregnant animals did not develop clinical disease, and microscopic examination of tissues revealed no changes. In all mares between 3 and 9 months of gestation, a neurologic syndrome appeared 6 to 8 days after inoculation. Mares inoculated when 10 months pregnant did not develop neurologic disorders, but several aborted. The histopathologic change common to both sequelae was vasculitis, involving smaller arteries and veins. Although blood vessel changes were detec...
Dubey JP, Streitel RH, Stromberg PC, Toussant MJ.Hearts, diaphragms, esophagi, and spinal cords from 266 horses were obtained at slaughter in Creston, Ohio. Tissues were examined microscopically for Sarcocystis in sections, digested in trypsin to obtain bradyzoites, and fed to 10 dogs and 10 cats. Intramuscular cysts were found in selections of two hearts from 57 horses and four esophagi from 107 horses. The cysts were up to 900 micron long and up to 70 micron wide. The cyst wall was 1 to 2 micron thick and cross-striated. The enclosed bradyzoites were banana-shaped, 15 to 20 by 20 to 3 micron, and contained several PAS-positive granules. Br...
Lyons ET, Drudge JH, Tolliver SC.Thirteen critical tests were conducted in horses naturally infected with helminths and bots. Single doses of thiabendazole (44 mg/kg of body weight) and trichlorfon (40 mg/kg of body weight) powder formulations were administered as suspensions sequentially given via stomach tube to evaluate the efficacy of the combination against the large parasites of horses. Parasite removal efficacies were 100% against 2nd instar Gasterophilus intestinalis and 2nd and 3rd instar Gasterophilus nasalis and 82 to 100% against 3rd instar G intestinals. There were complete removals of mature and immature Parasca...
Lee CG, Ross AD.Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.
Powell DG, Burrows R, Spooner P, Mumford J, Thomson G.The observations reported in this paper were obtained as part of a long term surveillance programme designed to monitor the efficacy of influenza vaccines and study the prevalence of influenza and other respiratory viruses among horses in Britain. Inactivated influenza vaccines were found to be effective in protecting horses from disease caused by influenza A/equine-1 but were less successful in protecting horses against influenza A/equine-2. The paper presents the clinical, epidemiological virological and serological findings obtained between 1971 and 1976.
Teruya JM, Santa Rosa CA, Giorgi W, Yanaguita RM.A serological examination was carried out for L. monocytogenes antibodies on 9,318 domestic animal--7,809 bovine, 838 horses and 671 swine--in São Paulo, Brazil. Serum agglutination in tubes was the method used. Only somatic antigens from serotypes 1, 2, 3, 4a and 4b were employed. It was considered reagent all sera reacting in a titer 1/20 while as positive only sera with 1/320 or above. According this criteria the results showed showed that in cattle 17.8% were reagent but only 8 sera were positive for types 1, 2 and 4b. Only type 1 was found in horses in a rate of 22.7% reagent, and 11 pos...
Chapman DI, Whiteside J.A radioimmunoassay method has been developed that enables the administration of therapeutic doses of synthetic corticosteroids to be detected in horse urine. Fourteen proprietary preparations of these steroids have been given by intramuscular injection to ponies and thoroughbreds. The administration of some preperations could still be detected six days after a single intramuscular injection of a therapeutic dose. The route of injection of dexamethasone-21-sodium phosphate, whether intramuscular, intravenous or intra-articular, did not appear to alter the length of time over which the steroid o...
Walker D.Rectal examination is a reliable method of diagnosing pregnancy in the mare. Also, test kits are available for the simple quick detection of pregnant mare serum gonadotrophin. Nevertheless there is a considerable demand by practitioners for an independent laboratory service in equine pregnancy diagnosis, particularly during the gestational phase when placental gonadotrophin is concentrated in the blood. An initial attempt to provide a service by means of the agar gel diffusion test was disappointing and alternatives were sought. The primary requirements for an ideal alternative technique were ...
Lapin DR, Ginther OJ.A crude equine pituitary ethanol extract (EE) was used to induce single and miltiple ovulations in seasonally anovulatory pony mares 3-15 years of age. 12 mares were injected daily for 14 days with EE; 6 of the EE-treated mares were also treated with human chorionic gonadotropin (HCG), and 6 control mares received saline vehicle only. In a 2nd experiment designed to determine if EE treatment could induce multiple ovulations in seasonally ovulatory mares, 7 mares were treated during diestrus, 7 mares were treated beginning on Day 1 of estrus, and 7 remained untreated. The results of experiment ...
Shahrabadi MS, Marusyk RG, Crawford TB.Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining...
McGuire TC.Isolated equine immunoglobulin (Ig)G(T) antibodies to equine infectious anemia virus P26 antigen did not precipitate with antigen when the ratio of antibody to antigen was high. However, at lower ratios of antibody to antigen precipitation occurred. In addition, complement-fixation by IgG and P26 antigen was inhibited by high concentrations of IgG(T). The unusual reaction pattern noted with IgG(T) antibodies was still detectable by the immunodiffusion test for equine infectious anemia virus. In situations of nonprecipitability by IgG(T), the adjacent positive control line was inhibited, and th...
Rau J, Tiedemann D, Sielhorst J, Tönissen A, Burger D, Martinsson G, Rohn K, Oldenhof H, Sieme H.Transvaginal ultrasound-guided aspiration (TUA) is a procedure which can be used for the reduction of twins post-fixation in the mare. The aim of this study was to evaluate the effect of the age of mares and the day of gestation on the outcome of TUA treatment. Methods: In 88 mares, diagnosed pregnant with twins, TUA of the yolk sac or allantoic fluid was performed between day 30 and 62 of gestation. Mares were aged 3-22 years. Ultrasonographic examination for a viable singleton pregnancy was performed by referring veterinarians 5-7 days and 4 weeks after TUA. Based on reported findings, effec...
Pomorska-Zniszczyńska A, Szczepanik M, Adamczyk N, Tarach M.Videodermoscopy is a method that enables the examination of many parameters of the skin and its structures. The aim of this study was to assess specific dermoscopic parameters in purebred Arabian horses during the summer. The study involved 21 clinically healthy purebred Arabian horses (18 mares and three stallions) that had not been used for breeding and were 1 to 25 years old. The videoderoscopic evaluation was performed on seven selected areas of the body: forehead, mane, neck, chest, flank, rump, and tail. The tests were carried out with Vidix and Olympus cellSens specialised software. Vid...
Steward SK, McKee HM, Watson AM, Salman MD, Hassel DM.Colic remains the number one cause of mortality in horses, and large colon displacement including colonic volvulus is one of the leading causes for equine hospitalization and surgery. Currently, there is not an adequate model to study the pathophysiology of this condition. The objective of this proof-of-concept study was to determine if subserosal implantation of bioinert microchips in the large intestine would be detectable by a RFID (radio-frequency identification) receiver when the implanted microchips were adjacent to the body wall, thus identifying the location of the colon within the abd...
Magnuson NS, Perryman LE, Suttle DP, Robinson JL, Mason PH, Marta KM.In an attempt to determine the metabolic defect causing severe combined immunodeficiency (SCID) in horses in which altered purine metabolism has been observed, various parameters of purine and pyrimidine metabolism were evaluated. The activities of nine purine enzymes (adenosine kinase, purine nucleoside phosphorylase, deoxyadenosine kinase, deoxycytidine kinase, 5'-nucleotidase, AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase, and adenine phosphoribosyl transferase were measured in fibroblasts. All activities determined for SCID horses were normal. Uptake of 10 microM adenosine...
Watson ED.The ability of equine endometrium to release prostaglandin (PG) F, PGE2, and leukotriene (LT) B4 was studied in vitro, using endometrial tissue from diestrous mares. Because of the high cross-reactivity of the PGF antiserum with PGF1 alpha and with PGF2 alpha, results were quoted as total immunoreactive PGF. Significant concentrations of these arachidonate metabolites were released into tissue culture medium between 1 and 24 hours of incubation. Significantly higher concentrations of PGE, but not of PGE2 or LTB4, were released from endometria of mares with chronic endometritis than from genita...
Van Der Vekens N, Hunter I, Timm A, Decloedt A, De Clercq D, Deprez P, Goetze JP, van Loon G.Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stab...
Fritsch R, Hausmann R.In 26 horses measurings of blood pressure, using the Dinamap 1255 research monitor, were performed and compared for accuracy with blood pressure values obtained by direct measurement in the arteria carotis. It was found that oscillometrically ascertained initial blood values in standing horses have a sufficient correlation to initial blood pressure values obtained by direct measurement. But every blood pressure change is registered too late, when using the oscillometric blood pressure apparatus. This temporal delay becomes unacceptable, when a considerable increase in blood pressure occurs. A ...
Plotka ED, Vevea DN, Eagle TC, Tester JR, Siniff DB.Homogeneous Silastic rods containing ethinylestradiol (EE) (1.5 or 4 g), estradiol-17 beta (E) (4 g) or progesterone (P) (6 g) were implanted into feral mares (Equus caballus) between 4- and 10-yr-old. Six treatment groups (greater than or equal to 10 mares/group) of non-pregnant mares received 36 g P and 12 g E (P+E), 36 g P and 8 g EE (P+HEE), 1.5 g EE (LEE), 3 g EE (MEE, 8 g EE (HEE) or control-implanted mares (CI). CI received implants containing no steroid. Two groups of pregnant mares received P+HEE or HEE. Stallions were placed with the mares 15 to 26 mo after implanting. Blood was coll...
May-Davis S, Doveren A, Sweere R, Smak J, Vermeulen Z.Hereditary multiple exostoses (HME) is a condition rarely diagnosed in horses, which has not been previously reported in Dutch Warmblood horses. Its presentation resembles that diagnosed in humans, and it is predominantly active during periods of skeletal maturation. This case study reports a link between a granddam with no obvious HME lesions and its first and second generations presenting with HME, albeit with different sires. The severity in affected horses (n = 5) varied from one foreleg to the other with extensive multiple lesions of 123 of 205 bones in a half sibling in the first genera...
Hisey EA, Ross PJ, Meyers S.As standard in vitro fertilization is not a viable technique in horses yet, many different techniques have been used to create equine embryos for research purposes. One such method is parthenogenesis in which an oocyte is induced to mature into an embryo-like state without the introduction of a spermatozoon, and thus they are not considered true embryos. Another method is somatic cell nuclear transfer (SCNT), in which a somatic cell nucleus from an extant horse is inserted into an enucleated oocyte, creating a genetic clone of the donor horse. Due to limited availability of equine oocytes in t...
King N, Suleiman MS.Exercise induces significant changes in the free intracellular amino acid pool in skeletal muscle but little is known of whether such changes also occur in cardiac muscle. In this study the effect of regular exercise on the size and the constituents of the free amino acid pool in the hearts and in the plasma of thoroughbred horses was investigated. The total free intracellular amino acid pool in the hearts of control horses was 30.9 +/- 1.2 mumol/g wet weight (n = 6). Glutamine but not taurine was present at the highest concentration (13.5 +/- 0.9 and 7.7 +/- 0.69 mumol/g wet weight for glutam...
van den Hoven R, Meijer AE, Wensing T, Breukink HJ.Gluteal muscle specimens were taken from 4 horses. From 1 of the 4 gluteal muscles, serial sections were prepared. Individual muscle fibers were identified and studied, using photomicrographs of sections stained by different enzyme histochemical methods. In specimens in which cytoplasmic soluble enzymes were studied, use was made of the semi-permeable membrane technique to hamper enzyme diffusion into reaction fluids. Enzymes involved in glycogenolysis, glycolysis, the tricarboxylic acid cycle, synthesis of reduced nicotinamide adenine dinucleotide phosphate, the pentose phosphate cycle, the a...
Cavasin JP, Miller AD, Duhamel GE.An 8-year-old Anglo-European gelding with progressive neurological signs was humanely destroyed and submitted for necropsy examination. The right parietal cortex was disrupted by a well-demarcated, intraparenchymal, 1.5 cm diameter, tan, homogeneous, dense mass. Microscopical examination was consistent with an astrocytoma, which was confirmed on the basis of strong immunohistochemical labelling for glial fibrillary acidic protein. The neoplastic population lacked immunolabelling for oligodendrocyte transcription factor 2. Labelling for ionized calcium binding adaptor molecule 1 highlighted la...
Hauspie S, Martens A, Declercq J, Busoni V, Vanderperren K, van Bree H, Saunders JH.To describe the radiographic appearance of the dorsoproximal aspect of the sagittal ridge of the third metacarpal/metatarsal bone in Warmblood horses. Methods: The lateromedial radiographic projections of the metacarpo-/metatarsophalangeal joints performed on horses as a part of stallion selection were used. The dorsal aspect of the distal third metacarpal/metatarsal bone was divided in two areas. The appearance of the bone surface in area I was classified as normal, irregular, notch, indentation and lucency. For area II, the categories were normal, irregular, depression or lucency and flatten...
Smith RF, Jackson LS, Moore A.An 125I radioimmunoassay to determine the pattern of urinary excretion of etorphine (a semisynthetic opiate agonist) after its administration to horses is described. Three thoroughbred horses were each given 5, 15, 30 and 100 micrograms of etorphine intramuscularly. Urine was collected for up to 72 after administration. The maximum etorphine concentration after administration of a dose of 5 micrograms was 711 pg ml-1 (concentrations were greater than 100 pg ml-1 after 23 h in all three horses); a 15 micrograms gave 2661 pg ml-1 (levels remained above 100 pg ml-1 for more than 44 h in each hors...
da Silva TRO, Gonçalves PNC, Marcus VB, Mucellini CI, Dos Santos IR, Kommers G, Driemeier D, Flores EF, Cargnelutti JF, Flores MM.For approximately one decade, a novel papillomavirus termed Equus caballus papillomavirus-2 (EcPV-2) has been associated with equine penile/preputial papillomas and squamous cell carcinomas (SCCs). It is currently believed that the virus has a carcinogenic activity, being able to induce such neoplastic lesions. After being first described, EcPV-2 has been detected in many countries from North America, Europe, and Asia; however, to date, it has not been reported in Brazil. The aim of this research was to investigate the presence of EcPV-2 in penile/preputial papillomas and SCCs of Brazilian hor...
