"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
McGuire TC, Crawford TB.Equine fibroblasts persistently infected with equine infectious anemia virus acquire a new cell membrane antigen demonstrable by indirect radioimmunoassay, using infected horse serum as an antibody source.
Ferguson JA, Reeves WC, Milby MM, Hardy JL.Of 359 horses vaccinated with attenuated Venezuelan equine encephalomyelitis (VEE) vaccine (strain TC-83), 87% developed hemagglutination-inhibition (HI) antibodies to VEE virus within 1 month. Blood from a subsample of 101 of the 359 horses was obtained over a 1-year period. Within 1 month after vaccination, 84% of the 101 horses had developed VEE HI antibodies, 87% had developed VEE-neutralizing (Nt) antibodies, and 78% had developed VEE complement-fixing (CF) antibodies. One year after vaccination, 58% of the horses had VEE HI antibodies and 73% had VEE Nt antibodies. The percentage of hors...
Komárek J, Matousek V, Jadrný L.Blood parameters were studied in two groups of horses in the "Velká Pardubická" steeple-chase in 1974, 1975 and 1976. After the race, the levels of lactate showed a manifold increase; an increase was also ascertained in the levels of glucose, sodium, potassium, haemoglobin, in the haematocrit value and in the number of erythrocytes. The following parameters significantly dropped: the levels of acid-base balance - pH, base excess, bicarbonate levels. It was proved that the values of the same parameters in horses during training were incomparably lower. It is advisable to examine horses thorou...
Dixon RJ, Hartley WJ, Hutchins DR, Lepherd EE, Feilen C, Jones RF, Love DN, Sabine M, Wells AL.An outbreak of perinatal foal mortality associated with a herpesvirus is described. Twenty two foals either were still-born, or died soon after birth, or were weak and soon developed severe respiratory signs, or were normal at birth and developed respiratory symptoms 18 to 24 hours later. Elevated temperatures, heart and respiratory rates were constant features. The animals were severely leucopaenic, and showed an absolute neutropaenia. At autopsy the lungs were enlarged, and showed varying degrees of aeration and moderate to severe oedema and congestion. Histopathology showed an acute focal n...
Stros K, Krivanec K, Komárek J, Malinský B.There is a description of equine dermatophytosis enzootic, caused by the microscopic fungus Trichophyton equinum. The disease affected 32 horses, mostly young, all in the same herd (74.4%). The diseased horses were successfully treated with the preparation Fenoform forte, applied superficially at the concentration of 0.5% of the active substance. The authors made an attempt to determine the criteria for clinical differentiation of fully developed trichophytosis and microsporosis of horses. Trichophytosis (T. equinum) is characterized as typical numerous small and round patches, covered by smal...
Dietz WH, Alvarez O, Martin DH, Walton TE, Ackerman LJ, Johnson KM.Forty-five horses were infected peripherally or intrathecally with enzootic or epizootic strains of Venezuelan equine encephalomyelitis (VEE) virus. Low titers of virus appeared in cerebrospinal fluid (CSF) after peripheral inoculation of enzootic or epizootic VEE virus strains. Intrathecal infection with either epizootic or enzootic VEE virus produced higher titers of virus in CSF than did peripheral infection. In contrast to peripheral infections with enzootic strains, intrathecal infections with these strains caused death. The animals that died had widespread histopathologic changes and lar...
Kingsbury HB, Quddus MA, Rooney JR, Geary JE.The distal portion of the forelimb of the horse is provided with a stay apparatus composed of tendons, ligaments, and fascia. This stay apparatus provides the major resistance to joint flexion during the support phase of the stride. The laboratory test system described was shown to be able to reproduce in vitro limb motions and hoof forces measured with a running horse. These results indicated the stay apparatus operates in a largely passive mode, active muscle contraction apparently serving to provide rigidity only early in the support phase of the stride. The testing system described was des...
Turner GV.Some aspects of the pathogenesis and comparative pathology of toxoplasmosis are described. The general pattern of infection, with or without necrosis, and tissue cyst formation as it occurs in all species is dealt with. The wide pathological manifestations of toxoplasmosis as seen in sheep, cattle, pigs, horses, dogs, cats, chinchillas and man are reviewed.
Hardy JL, Apperson G, Asman SM, Reeves WC.After prolonged selection, two hybrid strains of Culex tarsalis were evolved that were highly resistant to infection following ingestion of western equine encephalomyelitis virus. These strains were greater than 25,000-fold more resistant than the most susceptible parental strain when fed on viremic chicks. Resistance was associated with a mesenteronal barrier since both refractory and parental strains were equally susceptible to infection by intrathoracic inoculation. Susceptibility was dominant, possibly incompletely dominant, over resistance. Inheritance was probably polyfactorial but this ...
Rawlinson RJ, Jones RT.The history and clinical findings of 1 horses with guttural pouch mycosis referred to us are described. The salient features of the history and clinical signs common to both cases were profuse spontaneous nasal haemorrhage, partial pharyngeal paralysis; subsequently bilateral nasal discharge containing food material, inability to drink and parotid pain became evident. One case made a gradual recovery with conservative medical treatment while the second case was destroyed and submitted for post-mortem, histopathological and microbiological examination. This examination failed to establish the i...
Wentink GH.The movements of the right hind limb of horses with normal locomotion were studied using cinephotography and electromyography. A model of the cycle of a stride in the walk and the trot was constructed and the kinetic parameters of the segments of the limb were calculated. A good correlation was obtained between the kinetics and the periods of the cycle of a stride during which individual muscles display activity. The results of this study demonstrate that: at placing and lifting, i.e., when a change occurs in the direction of the movement of the limb; b) At the walk, the greatest forces operan...
Perryman LE, McGuire TC.Combined immunodeficiency in horses is a genetic disorder in which there is a defect in the production of committed B and T lymphocytes. In this study, peripheral blood mononuclear leukocytes from foals with combined immunodeficiency were examined for their capacity to stimulate and respond in one-way mixed lymphocyte cultures. Irradiated cells from combined immunodeficient foals were uniformly capable of stimulating cells from unrelated horses. However, none were able to respond to allogeneic stimulation. Examination of cells from known carrier horses revealed no difference in capacity to sti...
McIlwraith CW, Fessler JF.The usefulness of inferior check ligament desmotomy as a treatment for acquired tendon contracture in horses was evaluated in 13 cases of deep digital flexor (DDF) contracture and in 3 cases of combined superficial digital flexor (SDF) and DDF contracture. In 8 of 9 cases of DDF contracture in which the dorsal surface of the hoof had not passed beyond being vertical to the ground, the surgical procedure was successful in returning the limb to a normal position and function. Compared with DDF tenotomy, inferior check ligament desmotomy was a superior treatment technique because of decreased pos...
Johnson L, Amann RP, Pickett BW.Changes within the equine seminiferous tubules during the cycle of the seminiferous epithelium were studied light and scanning electron microscopy (SEM). Once observed with SEM, tubules were sectioned and staged using light microscopy. As viewed by SEM, the weblike, spongy cytoplasm of germ cells or Sertoli cells in stages I and II extended over the entire height of the germinal epithelium. The cytoplasm of the basal portion of the germinal epithelium in stages III to VIII was similar to that in stages I and II. However, the cytoplasm which occupied the luminal third of the epithelium in stage...
Gentry PA, Woodbury FR, Black WD.The clotting times obtained with different assay procedures for routine coagulation tests were examined for horse and pony samples. The whole blood clotting time test and the activated coagulation test seemed to give similar results when both tests were done at 22 C. The results obtained for the activated partial thromboplastin time assay varied, depending on the commercial reagent used for the test. Consistent results were obtained for the one-stage prothrombin time assay with each reagent used.
Meuten DJ, Butler DG, Thomson GW, Lumsden JH.Chronic granulomatous enteritis associated with weight loss and hypoproteinemia was identified in 2 horses. Both horses continued to have normally formed feces. Malabsorption of carbohydrate and lipid, with concomitant gastrointestinal protein loss was demonstrated in 1 case. One horse was treated symptomatically and gained 108 kg. In both cases, principal gastrointestinal lesions were partial to total villus atrophy and transmural mononuclear leukocytosis, with lymphocytes and histiocytes predominating. The cause of the condition was not identified in either case.
Rumbaugh GE, Smith BP, Carlson GP.internal abdominal abscesses in 25 horses, including 8 horses that died or were euthanatized, were found to be caused by Streptococcus equi, Streptococcus zooepidemicus, or Corynebacterium pseudotuberculosis. Breed or sex predilection was not found. Although horses of all ages were affected, those under 5 years of age were more commonly affected. Nearly all of the horses had a history of respiratory catarrh or lymphadenitis. Horses with internal abdominal abscesses also had intermittent, prolonged colic or chronic weight loss. Most horses had increased rectal temperature, increased heart and r...
Gandini M, Cerullo A, Gallo L, Iussich S, Minoli L, Giusto G.To describe a technique for a side-to-side jejunocecal anastomosis in horses using radiofrequency thermofusion (TF) of the intestines supported by a Cushing oversew and to compare this anastomosis to handsewn and stapled techniques. Methods: Ex vivo study. Methods: Intestinal tracts from 24 slaughtered horses. Methods: A radiofrequency device was used to perform a jejunocecal anastomosis (Group RFA). The construction time and bursting pressure of this construct were compared with those of a hand-sewn double layer (Group HS) and stapled anastomoses (Group ST) without oversew of the staple line....
Hole SL, Manfredi JM, Clayton HM.The equine first premolar ("wolf tooth," Triadan number 05) is frequently extracted, and although extracted teeth have been observed to vary greatly in size, published data describing tooth dimensions are limited. Total length, root length, crown height, and crown width were measured in 65 extracted wolf teeth. Dimensions, expressed as median (range) mm, were total length: 21 (12-34), root length: 13.2 (0-19.6), crown height: 7 (2-20), and crown width: 7 (2.6-16). Root length exceeded crown height in 61 of the 65 teeth. Crown height and crown width were either not correlated or poorly correlat...
Ozaydın T, Celik I, Sur E, Oznurlu Y, Uluısık D.We attempted to characterize the cytochemical staining patterns of leukocytes and to determine the percentages of alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACPase) positive lymphocytes in peripheral blood of thoroughbred foals at different ages. Blood samples were obtained from the jugular veins of 60 healthy thoroughbred foals, 1 day, 3 days and 1 year old. Each age group included 10 male and 10 female animals. Peroxidase (PO) activity was detected in neutrophils, eosinophils and monocytes. Lymphocytes were negative for PO staining. Periodic acid-Schiff (PAS) staining was o...
Pfaff G.In South Africa 2,41% of horses bleed in a race. If all raced until they were 7 years old probably another 2,12% would bleed. Many others bleed after the race or during exercise or at rest. The incidence of epistaxis is significantly greater in geldings than in females and uncastrated males (P less than 0,001). There is an age distribution of bleeding which is highest at 4 years and lowest at 2 years of age (P less than 0,001).
Ott EA, Brown MP, Roberts GD, Kivipelto J.Forty-four weanling horses were used in two experiments to evaluate the effect of starch intake on growth and skeletal development. In Exp. 1, the weanlings were fed either a grain-based, high-starch (31.1%, DM basis) concentrate or a by-product-based, low-starch (0.0%) concentrate with coastal bermudagrass (Cynodon dactylon) hay. Corn oil was used to equalize the energy concentration of the concentrates. The concentrate:hay ratio was 64:36 (as-fed basis), and intake was the same for both diets. Body weight gains were greater by the weanlings consuming the high-starch concentrate (0.81 vs. 0.6...
Schmidt P, Meyer H, Hübert P, Hafner A, Andiel E, Grabner A, Dahme E.The detection of equine herpesvirus type 1 (EHV-1) in infected cell cultures, and in tissues taken at necropsy, by the in-situ hybridization technique is described. A 4.9 kb Bam HI fragment of EHV-1 vaccine strain RacH was used as a probe after labelling with [alpha-32P] thymidine 5'-triphosphate ([32P]TTP) or digoxigenin-deoxyuridine 5'-triphosphate (dUTP). Both probes specifically detected EHV-1 DNA in either cytospin or paraffin wax-embedded preparations of infected cells. The digoxigenin-labelled probe was further used to examine tissue sections of equine fetuses which had been aborted due...
Art T, Tack S, Kirschvinck N, Busoni V, Votion D, Freeman K, Lekeux P.This study aimed at measuring the functional consequences and the pulmonary cytology changes following a simulation of pulmonary haemorrhage. Pulmonary function tests including lobeline-induced hyperventilation, cytology of tracheo-bronchial wash (TBW) and thoracic radiographs were performed before, as well as 1, 7, 14 and 28 days after, the instillation of 300 ml of blood into the lungs of 4 horses deemed free of exercise-induced pulmonary haemorrhage (Group 1). Control data (Group 2) were obtained by instilling the same volume of saline into the lungs of the same horses in a crossover design...
Grabner A.Using a fibreoptic endoscope ("small gastroscope" with outside diameter of 9.3 mm) a simple and sparing inspection of the guttural pouch is performed. The flap-type tube cover is opened by means of medial leverage with a guidance probe shifted through the work duct of the endoscope. The same procedure is used in diagnostic specimen collection and therapeutical measures such as irrigations. Guttural pouch topography and pathological disorders are illustrated by endoscopic photography. The different diseases such as follicular hyperplasia, ascending pharyngeal catarrh, perforating abscesses of t...
Hartley JW, Hahn AW, DeLorey M, Caldwell WM.We have developed and used a system for recording and analyzing the electrocardiogram (ECG) of the horse during exercise. The system consists of a commercial ECG transmitter telemetering a Z lead (base-apex) ECG from an exercising horse. The received data are then remodulated at an audio frequency and stored on a audio cassette recorder. Exercise protocols of up to 10 minutes are digitized using a Macintosh II computer. For rhythm analysis, a computer program to identify the various waves of the ECG uses a modification and refinement of the integrated-squared-derivative (ISD) technique. This t...
Heufelder B, Mettenleiter E, Tietje S, Traenckner CM.The clinical signs, diagnosis and pathology of an adult horse with a complex odontoma are described. Computer tomography was shown to be a new diagnostic technique with outstanding potential in the investigation of diseases of the equine head.
Waelchli RO, Winder NC.Endometrial biopsies were obtained from four mares during consecutive oestrous cycles on the first day of oestrus, on the day when ovulation was detected, and four and eight days after ovulation. Cycle stages were confirmed by means of rectal palpation, ultrasonography and plasma progesterone determination. Immunohistochemical evaluation of the formalin fixed biopsy specimens was performed using a peroxidase anti-peroxidase technique. Immunoglobulin (Ig)A-, IgM-, IgG(Fc)- and IgG(T)-containing cells were detected in all biopsies; with IgA- and IgG(Fc)-containing cells generally predominating. ...
Brück I, Lehn-Jensen H, Yde G.A Warmblood mare was observed to ovulate spontaneously 12 follicles within 2 days, none of which exceeded 22 mm in diameter. On Days 13 and 17 after ovulation, 6 embryonic vesicles were identified in the uterus by ultrasonography but by Day 26, 5 of the vesicles had disappeared. Development of the surviving conceptus was monitored until Day 42. Plasma progesterone concentrations rose to 14 ng/ml on Day 7, decreased over the next 8 days and then plateaued to around 4-6 ng/ml until Day 70. The occurrence of multiple spontaneous ovulations was diagnosed repeatedly in this mare. However, the devel...
Landry Z, Roloson MJ, Fraser D.The metapodials of extinct horses have long been regarded as one of the most useful skeletal elements to determine taxonomic identity. However, recent research on both extant and extinct horses has revealed the possibility for plasticity in metapodial morphology, leading to notable variability within taxa. This calls into question the reliability of metapodials in species identification, particularly for species identified from fragmentary remains. Here, we use ten measurements of metapodials from 203 specimens of four Pleistocene horse species from eastern Beringia to test whether there are s...