"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.
Slocombe JO, McCraw BM.Sixteen pony foals were reared worm-free and inoculated with Strongylus vulgaris. On day 7 after inoculation, 12 ponies were given a fenbendazole 10% suspension at dose rate of 50 mg/kg of body weight by stomach tube. On day 8 after inoculation, 8 of these ponies were given the 2nd treatment of the anthelmintic and on day 9, 4 of these ponies were given the 3rd treatment. (The other 4 of the 16 ponies were given only tap water, as controls.) The ponies were necropsied at death or on day 28 after inoculation. Fenbendazole was effective in minimizing the appearance of clinical signs associated w...
Vitums A, Bayly WM.Three Arabian males foals were presented with cyanosis, heart murmur, and exercise intolerance, Results of clinical evaluation suggested a tentative diagnosis of ventricular septal defect in conjunction with malformations of the great arteries. Each foal had a poor prognosis and was killed at the owners' requests. At necropsy, the malformed hearts of the three foals were virtually identical. Each heart had a large defect in the upper interventricular septum. The aorta originated from the hypertrophied right ventricle and partially overrode the ventricular septal defect. The aortic ostium was g...
Gibbs PG, Potter GD, Blake RW, McMullan WC.Milk production was measured in fourteen Quarter Horse mares at seven stages of a 150-d lactation period. Mares were divided into two groups of seven and fed diets containing either soybean meal or soybean meal and urea as nitrogen supplements. Rations were isocaloric, contained approximately 12.5% crude protein and were fortified with vitamins and minerals. Daily milk yield was estimated by the weigh-suckle-weigh method and milk composition was determined from samples taken by hand milking. Average daily milk yield ranged from 11.8 kg in early lactation to 9.8 kg in late lactation. Difference...
Frauenfelder HC, Fessler JF, Moore AB, Bottoms GD, Boon GD.The effects of dexamethasone (1 mg/kg of body weight) on hematologic, blood gas, and blood coagulation values in anesthetized ponies during endotoxin-induced shock were evaluated. Fifteen ponies were assigned to 3 groups of 5 ponies each: group 1, anesthetized nontreated and dexamethasone-treated controls; group 2, endotoxin, nontreated; group 3, endotoxin, dexamethasone treated. The hematologic changes in this endotoxin shock model included leukopenia and hemoconcentration. Significant hematologic effects were not seen in ponies after administration of dexamethasone. However, dexamethasone tr...
Nugent TE, Combie JD, Weld JM, Burns P, Tobin T.The enkephalins are small, pentapeptide neurotransmitter molecules which have reportedly been used in racing horses. In our experiments, D-Ala2-Metenkephalinamide and leucine enkephalin were administered to horses intravenously (IV) and intracisternally (IC). Leucine enkephalin had little effect on locomotor activity by either route at doses of 0.01 mg/Kg or less. Methionine enkephalinamide, an enzyme resistant enkephalin analog, had no significant effect when given IV (0.002 and 0.008 mg/kg). Other experiments involving intracisternal dosing with this long acting form at higher levels (0.005-...
Udén P, Van Soest PJ.1. The abilities of cattle, sheep, goats, equines and rabbits to digest mature timothy (Phleum pratense) hay were compared. Apparent digestibilities were partitioned into true digestibility, metabolic faecal output (MFO) and fibre digestibility. The aid of the study was to determine the relative effects of fermentation site (among groups) and of body-weight (within groups) on the efficiency of digestion. 2. The ruminants were superior to equines, which were in turn superior to rabbits, in digesting fibre-components of the hay. A large individual variation in digestibility was noted only for th...
Wilson MG, Nicholson WE, Holscher MA, Sherrell BJ, Mount CD, Orth DN.Using RIAs for six regions within proopiolipomelanocortin (proOLMC), gel filtration, and electrophoresis, we studied pituitary peptides in a normal horse and one with Cushing's disease caused by a pars intermedia adenoma. Almost all immunoreactive (IR) ACTH (78%) was 4,500 mol wt (4.5K) ACTH in normal pars distalis, but it was almost 100% corticotropin-like intermediate lobe peptide (CLIP) in normal pars intermedia. alpha MSH and beta MSH were found mainly in pars intermedia: equal concentrations of the beta MSH precursors, beta-lipotropin (beta LPH) and gamma LPH, were found in pars distalis....
Studdert MJ, Blackney MH.Adenovirus was isolated in equine fetal kidney cell cultures from the feces of 2 foals with diarrhea that also had large numbers (greater than 10(6)/g) of rotavirus particles in their feces. Unlike equine adenovirus type 1 (EAdV1), the fecal EAdV did not hemagglutinate human O, rhesus macaque, or equine RBC. By serum neutralization, the fecal viruses were identical with each other, but showed no relationship to EAdV1. Antiserum prepared against the fecal viruses did not contain hemagglutination-inhibiting antibody to EAdV1. It is proposed that the fecal viruses be considered prototypic of EAdV...
Steiss JE, Yuill GT, White NA, Bowen JM.A force plate system for measurement of the vertical component of the force applied by a horse's limb on ground contact was modified. The modifications included use of steel supporting posts for improved durability and an additional strain gauge on each arm of the Wheatstone bridge for increased sensitivity and temperature compensation. Data from clinically normal horses are provided to indicate the performance obtained with these modifications of the force plate system.
Sellers AF, Lowe JE, Drost CJ, Rendano VT, Georgi JR, Roberts MC.The circular and longitudinal muscle coats of equine "midcolon" were found to be directly electrically coupled. They appear to act in concert, in healthy animals, as a pacemaker in the area of the large colon pelvic flexure, for retropulsive-propulsive myoelectrical events. The retropulsive events keep the cecum and right ventral and left ventral divisions of the colon filled, imposing a delay time for fermentation of cellulose and for bacterial protein synthesis. Point-to-point involvement of adjacent colon sections was slowed by cooling the intestinal contents with no adverse clinical signs....
Houghton E.The methylated xanthines caffeine and/or theobromine are commonly encountered in drug-positive samples from racehorses and their metabolism and excretion in the horse and their analysis in urinary extracts has been of particular interest in this laboratory. Due to their polar nature the dimethylxanthines theobromine, theophylline and paraxanthine give unsatisfactory gas chromatographic performance and require derivatization prior to analysis by gas chromatography mass spectrometry. The present paper describes a simple deuteromethylation procedure to render the compounds amenable to analysis by...
Andersson L, Sandberg K.The equine coat color genes chestnut (e) and roan (Rn) have been tested for linkage to 15 protein and blood group loci. Data showing close or fairly close linkage to the serum albumin locus (Al) and loose linkage to the serum esterase locus (Es) for both e and Rn are presented. This means that three coat color genes (To, e and Rn) and three serum protein loci (Al, Gc, and Es) are linked in the same linkage group. The gene order can tentatively be written Al, Gc, Rn, To-e-Es. The implications of the results for studies on coat color inheritance in horses are discussed. The possibility of using ...
Ballard S, Shults T, Kownacki AA, Blake JW, Tobin T.After intravenous (i.v.) injection, acepromazine was distributed widely in the horse (Vd = 6.6 litres/kg) and bound extensively (greater than 99%) plasma proteins. Plasma levels of drug declined with an alpha half-life of 4.2 min, while the beta phase or elimination half-life was 184.8 min. At a dosage level of 0.3 mg/kg acepromazine was detectable in the plasma for 8 h post dosing. The whole blood partitioning of acepromazine was 46% in the plasma phase and 54% in the erythrocyte phase. Penile prolapse was clearly evident at doses from 0.01 mg/kg to 0.4 mg/kg i.v., and the duration and extent...
Sklan D, Donoghue S.1. Serum and intracellular distribution of retinol was determined in equines maintained on four levels of vitamin A intake. 2. The form of retinol transported in serum was determined by gel filtration and chromatography to be a complex of retinol bound to a protein of molecular weight (MW) of approximately 20000, which was in turn complexed probably with prealbumin to yield a complex with a MW of 75000 to 80000. 3. Increasing dietary vitamin A levels enhanced the concentration of lipoprotein-bound retinyl esters in the plasma. 4. Vitamin A in the liver cytosol was found predominantly as retiny...
Rose RJ, Sampson D.Total and individual non-esterified fatty acids (NEFA), pyruvate, lactate, alpha ketoglutarate, acetoacetate, beta hydroxybutyrate, glucose and insulin were measured in horses during an 80 km endurance ride and during four days of food deprivation. In the latter group venous blood-gas and acid-base parameters, and plasma cortisol concentrations were also measured. During exercise and food deprivation the NEFA became considerably elevated, the predominant of which were oleic (35 per cent), palmitic (24 per cent), linoleic (19 per cent) and linolenic (10 per cent). By one hour after feeding tota...
Rose RJ.Blood counts and noradrenaline estimations were performed in 14 horses competing in a 160 km endurance ride. Samples were collected before the ride, immediately after the ride. 30 minutes after the ride and the day after the ride. For statistical analysis, a group of seven horses that completed the ride at a mean speed of 234 m/minute (fast group) was compared with seven horses that completed the ride at a mean speed of 144 m/minute (slow group). Immediately after the ride the fast group of horses had higher packed cell volume, haemoglobin, neutrophils and lower lymphocyte counts than the slow...
Jörg A, Pasquier JM, Klebanoff SJ.Eosinophil peroxidase (donor: hydrogen-peroxidase oxidoreductase, EC 1.11.1.7) was isolated in a highly purified form (415/280 nm ratio, 1.05) from horse peripheral blood eosinophil. Eosinophil peroxidase was extracted from intact eosinophils (98-100% purity) or isolated eosinophil granules with 0.05 M acetate buffer (pH 4.7)/0.18 M NaCl and purified by chromatography on Sephadex G-200 and carboxymethylcellulose. Final elution was with 0.05 M acetate buffer (pH 4.7)/ 1 M NaCl. Horse eosinophil peroxidase is a strongly basic protein with bacterial properties when combined with H2O2 and iodide, ...
Power HT, McEvoy EO, Manning TO.A 4-month-old foal was examined because of generalized exfoliative dermatitis, with thick scales, extensive crusting, and oozing of serum. A diagnosis of pemphigus foliaceus was made by histologic and immunopathologic examinations of skin biopsy specimens. The foal was treated with a gold compound, aurothioglucose (1 mg/kg once weekly for 14 weeks). For the initial 5 weeks, high-dose glucocorticoid treatments also was used. The skin disorder resolved entirely after 12 weeks of treatment.
McKinnon AO, Lacham-Kaplan O, Trounson AO.The use of intracytoplasmic sperm injection (ICSI) for in vitro fertilization of equine oocytes and the developmental potential of these oocytes after transfer to the Fallopian tubes of synchronized mares were examined. Oocytes were aspirated from mature follicles 39 h after injection of a GnRH analogue and transported 190 km at 39 degrees C. Semen from a fertile and an infertile stallion was frozen and prepared for injection. Successfully injected oocytes were transferred surgically into the ampulla of the Fallopian tube either: (i) 4-8 h after semen injection; or (ii) after 24-48 h culture b...
Moeller RB, Crossley B, Pipkin A, Li Y, Balasuriya UBR.A 2-y-old female Grant's zebra ( Equus quagga [ burchellii] boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear ...
Schumacher J, Brink P, Easley J, Pollock P.To describe surgical techniques used for correction of congenital nasal deviation (wry nose) in horses (wry nose) and to report outcome. Methods: Retrospective study. Methods: Horses (n=4), 5-17 months old with wry nose. Methods: Nasal deviation was corrected by transecting the premaxillae/maxillae and nasal bones at their site of maximum curvature and realigning and stabilizing the bones in a more normal alignment using internal fixation. The nasal septum was removed during the same anesthetic period. Results: For each horse, physical appearance was improved and respiratory stridor eliminated...
Mack JK, Remler HP, Senckenberg E, Kienzle E.This study investigated the energy requirements of Warmblood foals with a change of the stud at weaning. Methods: Nine colts purchased at weaning participated in the study aged approximately 6 months to 1 year. They were transported to the stud by their breeders either having been separated from their dams in their home stable or upon arrival at the stud. The foals were offered a late first cut of haylage, oats and foal starter feed. To ensure individual feeding of concentrates, the foals were tethered twice daily. The total combined haylage intake of all foals per day was recorded. Individu...
Crawford WH, Ingle JE.A yearling horse was treated for a chronic wound with a 4 cm deficit in the deep digital tendon. The gap in the tendon was bridged with paired polypropylene braided implants designed for use as a ligament augmentation device. Uncomplicated healing and return to function occurred.
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Christensen JM, Blythe LL, Craig AM.Phenylbutazone was administered to six Thoroughbred horses in a cross-over study in which the horses received cimetidine pretreatment or no cimetidine pretreatment. Blood samples were collected at various times for 48 h after phenylbutazone administration and the plasma was analysed for phenylbutazone. Cimetidine pretreatment elevated phenylbutazone plasma concentrations during the first 8 h after phenylbutazone administration. The absorption rate, maximum phenylbutazone plasma concentrations and AUC were significantly greater with cimetidine pretreatment. The half-life of phenylbutazone did n...
Christensen LS.Borna disease virus has long been recognized as a cause of sporadic cases and epidemics of meningoencephalomyelitis in horses and sheep in southern parts of Germany. however, sero-epidemiological surveillances indicate that Borna disease virus has a global distribution in horses, without the recognition of clinical manifestations associated with the infection, in other parts of the world. During the past five years evidence has been presented suggesting that humans also can become infected with this virus or a closely related virus. A significantly increased sero-prevalence is seen in patient ...
Meyer S, Ptok M.The term 'laryngeal neuropathy' (LN) has first been used in veterinary medicine to describe an idiopathic and typically exercise induced inspiratory noise in horses.Nowadays, the term is often used in relation with intermittent vocal cord pareses in humans. Some authors use the term 'irritable larynx syndrome' (ILS) in a similar context. This article reviews the state of knowledge regarding LN and ILS and discusses the somewhat confusing terminology.For this systematic review a selective literature research in PubMed has been carried out.35 articles were found, which report on LN in animals an...
Delbeke FT, Landuyt J, Debackere M.A high-performance liquid chromatographic method to measure plasma and urinary alclofenac levels in equine biofluids is described. Isolation of the drug from plasma is achieved using liquid-liquid extraction with diethyl ether. Reversed-phase C18 solid phase extraction is used for the extraction of free and conjugated alclofenac from urine. The reproducibility and accuracy of the method were well within acceptable limits over the concentration ranges 0-10 and 0-20 micrograms/ml, respectively, for plasma and urine. Starting with 2 ml of plasma, a concentration of 0.1 microgram/ml could easily b...
Ledwozyw A, Jabłonka S, Tusińska E, Herbut M.Factor VIII level in horse, cattle, sheep and pig plasma was estimated by the use of synthetic chromogenic substrate S-2222 (benzoyl-isoleucyl-glutamyl-glycyl-arginyl-p-nitronilide). The highest level of this factor was stated in pig, the lowest one in sheep plasma.
The Journal of heredityNovember 25, 2009
Volume 101, Issue 2 246-250 doi: 10.1093/jhered/esp091
Mittmann EH, Lampe V, Mömke S, Zeitz A, Distl O.The availability of a high-quality draft sequence of the horse makes known the physical location of microsatellites. The aim of the present study was to establish a highly polymorphic minimal screening set of microsatellite markers for horses (MSSH) annotated on the horse genome assembly EquCab2.0. We have used the previously reported linkage and radiation hybrid maps and have extended these marker sets by filling in gaps as noted from annotation on the horse sequence. This MSSH covers all autosomes and the X chromosome with 322 evenly spaced microsatellites whose positions were determined on ...
Kotzé SH, Soley JT.The ileocaecal junction mucosal surface morphology of 5 horses and 1 donkey was examined using scanning electron microscopy and light microscopy. Based on differences in surface morphology, the junction could be divided into 4 distinct regions. The distal extremity of the ileum was characterized by the presence of typical finger-like villi followed by a narrow zone displaying short, stubby villi which gradually merged into a 3rd region representing the true transitional zone between the small and large intestine. In this region the villi fused, forming low ridges arranged in circular, semi-cir...
Feige K, Ehrat FB, Kästner SB, Schwarzwald CC.The purpose of this study was to evaluate plasmapheresis as a method for plasma extraction in comparison with centrifugation or gravity sedimentation. The study was designed as a cross over trial with six Freiberger horses undergoing plasma donation by plasmapheresis followed by whole-blood donation and subsequent plasma production 4 weeks later. Automated plasmapheresis and whole-blood donation were well tolerated in all horses. The plasmapheresis method achieved an almost complete removal of erythrocytes and leucocytes from plasma at all flow rates. After blood bag centrifugation, significan...
Pascoe DR, Stover SM.Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicor...
Archer DC, Cotton JC, Boswell JC.Gamma scintigraphy is an established imaging modality in the horse and is principally utilised to investigate skeletal disease using bone-seeking radiopharmaceuticals. However, depending on the radiopharmaceutical and imaging sequence, scintigraphy can be used to investigate disease in virtually any organ system. In this article the indications and validity of scintigraphy as a clinical diagnostic tool to investigate non-skeletal disease in the horse are reviewed. These indications include: investigation of dental disease, identification of inflammatory foci, vascular lesions, muscle and tendo...
Ekstrand C, Nostell K, Gehring R, Bondesson U, Bröjer J.Septicaemia in the neonatal foal is caused by both Gram positive and Gram negative bacteria. The life-threatening nature of this condition requires treatment to be initiated with broad spectrum antimicrobial drugs pending antimicrobial susceptibility testing. Potentiated sulphonamides, for example, trimethoprim combined with sulfadiazine, could be clinically relevant options but their pharmacokinetics in the neonatal foal are unknown. To describe the plasma disposition of trimethoprim and sulfadiazine in neonatal foals and to relate the results to patterns in the minimum inhibitory concentrati...