"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.
Merritt AM, Kohn CW, Ramberg CF, Cimprich RE, Reid CF, Bolton JR.Five clinically normal, mature horses and 11 with chronic diarrhea were given 51Cr-tagged Cohn fraction V equine albumin intravenously. All urine and feces were collected separately, and blood for plasma analysis was taken periodically for 5 to 8 days after injection of the isotope. Plasma clearance of albumin into the intestinal tract of normal horses was calculated as 0.67 +/- 0.23 (SD) ml/kg of body weight/day, with 1.33 +/- 0.69% of the 51Cr dose appearing in the feces in 5 days. Of the 11 diarrheal horses, 8 had a plasma clearance of 0.49 +/- 0.21 ml/kg/day with 1.12 +/- 0.68% of the dose...
Webel SK, Franklin V, Harland B, Dziuk PJ.Pony mares were observed from January to August for incidence of oestrus, duration of oestrus, length of the oestrous cycle and for ovulation and fertility after injection of HCG. From January to 15 May most mares showed oestrus but the duration of oestrus was quite variable and few mares ovulated in response to HCG. From 15 May to 17 August oestrous cycles were more regular and ovulation was induced within 40-50 h by an intramuscular injection of 1500-5000 i.u. HCG. Pregnancy was established by one mating at a fixed time after HCG in 20 of 69 mares. Degenerate eggs were recovered from the ovi...
Sasse HH, Hajer R.The manufacturers state that NAB 365 is a beta2-receptor-stimulating sympathicomimetic agent. According to the medical literature it combines a bronchial antispasmodic effect with certain bronchia secretolytic properties and has few untoward side-effects on, for instance, the heart and intestine. The effectiveness of administration of NAB 365 in horses with chronic or acute respiratory disease was tested in the Department of Veterinary Internal medicine in Utrecht. NAB 365 administered at a dosage of 0.8 gamma/kg, of body weight was found to have a marked bronchodilative effect in horses. Ther...
Tarr MJ, Olsen RG, Krakowka GS, Cockerell GL, Gabel AA.Erythrocyte rosette (ER) formation of equine peripheral blood lymphocytes (PBL) was characterized. Guinea pig and, to a lesser extent, human erythrocytes formed ER; cat, cow, dog, hamster, mouse, rat, and sheep erythrocytes showed negligible rosetting properties. Conditions of the assay were varied to determine which procedure allowed the largest percentage of rosette formation. The PBL from 20 normal horses were then assayed, averaging 38 +/- 2% ER. To characterize the erythrocyte receptor as being on T or B cells, equine thymocytes from 6 foals were assayed; the thymocytes formed an average ...
Main AR, McKnelly SC, Burgess-Miller SK.A butyrylcholinesterase of mol.wt. approx. 83000 was observed in pooled rabbit serum. The enzyme was named monomeric butyrylcholinesterase to distinguish it from the larger oligomeric butyrylcholinesterase of horse and human serum whose subunits are the same size as the monomeric enzyme. The active-site concentration of monomeric butyrylcholinesterase in the pooled serum was 0.18mum, which is five times the concentration of butyrylcholinesterase in pooled horse serum. This was surprising, since the horse serum is regarded as a rich source of butyrylcholinesterase, whereas rabbit serum is not g...
Rose RJ, Davis PE.A 4-year-old thoroughbred stallion with a history of loss of racing form was studied over a period of approximately 7 months. At the initial examination he showed positive T waves in 1 chest lead and wandering of the pacemaker. This was followed by an episode of paroxysmal atrial fibrillation which disappeared spontaneously and was replaced by significant T wave changes in all the chest leads. During a period when these changes persisted, there was progressive lengthening of the P wave and the P-R interval. Because the last ECG showed evidence of intra-atrial block, first degree A-V block and ...
Anderson BG, Anderson WD.Methyl methacrylic casts were prepared and tissue was freshly collected for histologic examination to compare the vascular supply and the structure of the vessels of the iris in the adult horse with those of the dog. In the horse, ciliary blood vessels divided in the iris and formed a complete major arterial circle of the iris. In the dog, the ciliary blood vessels divided in the ciliary body and, by means of recurrent branches, formed a complete arterial circle. From this circle, radial arteries extended toward the pupillary margin. The radial vessels in the horse were nearly straight and joi...
O'Driscoll JG, Troy PT, Geoghegan FJ.The clinical pattern, bacteriological investigation and subsequent treatment of a serious outbreak of venereal disease in stud farms on both sides of the Irish Sea is described. The consistency with which Bacillus proteus was isolated from infected mares and stallions was remarkable. Prompt treatment with ampicillin, to which the organism was sensitive in vitro, eradicated the disease. No local treatment was applied.
Jirgensons B, de Haas GH.Conformation of porcine, bovine, and equine pancreatic phospholipases A2 (EC 3.1.1.4) and their zymogens was studied by the circular dichroism (CD) probe in the far and near ultraviolet spectral zones.
All these phospholipases and their zymogens displayed CD curves suggesting the presence of moderate amounts of α-helical conformation. However, on the basis of known primary structure and recent X-ray structural analysis of prophospholipase A2 crystals (Drenth, J., Enzing, C.M., Kalk, K.H. and Vessies, J.C.A. (1976) Nature 264, 373–377), it has to be concluded that the positive CD band cen...
Franken P, Schotman JH.The activities and concentrations of a number of erythrocytic enzymes and intermediate products of erythrocyte metabolism were determined in twenty-one normal standard-bred horses which were studied clinically and biochemically. These studies showed that equine anaerobic glycolysis is characterized by a biochemical pattern similar to that observed in human PK deficiency. The greater sensitivity of equine haemoglobin to oxidants is attributable either to low stability of GSH, which may be due either to the low activity of GR or that of 6PGD as observed in the studies. In addition, the saturatio...
Mills JH, Fretz PB, Clark EG, Ganjam VK.An ovarian neoplasm measuring 10 by 8 by 6 cm was surgically removed from a 14-year-old Appaloosa mare. For 2 years prior to surgery, the mare had manifested marked behavioral changes, becoming aggressive toward other broodmares. Histologically, the tumor was found to be an arrhenoblastoma. Preoperative endocrinologic findings (high serum testosterone and low serum estradiol concentrations) supported the diagnosis.
Klug E, Brinkhoff D, Flüge A, Scherbarth R, Essich G, Kienzler M.Practical experiences of the phantom method for collection of genital secretions from stallions are reported. Taking a phantom used in the Richard-Götze-Haus Tierärztliche Hochschule Hannover as a prototype two further models slightly modified have been constructed, baring a flat hollow in the right side of the caudal phantom body for manual inserting of the Artificial Vagina. These three models fulfill four important conditions for routine use: (1) sufficient sexual attractivity for the stallions; 80-85% successful collections of presecretions out of a total of 1050 using the dummy and 70% ...
Pohlmeyer K, Hertsch B.The arterial blood vessels in 24 humeri of equine fetusses and foals are described. The relation between the age and the distribution of these arteries are explained and completely discussed.
Gay CC, Carter J, McCarthy M, Mason TA, Christie BA, Reynolds WT, Smyth B.Indirect arterial blood pressure was determined on 33 horses prior to surgical intervention for the diagnosis and/or correction of acute abdominal disorders and a relationship between low systolic blood pressure and non-survival was established. It is suggested that blood pressure determination should be used to augment other methods of clinical and laboratory examination in cases of equine colic.
O'Callaghan MW.The problem of transitory cardiac arrhythmias in equidae is discussed particularly with regard to the referral of suspect cases to specialist institutions for second opinion. Recently developed electro-stimulation techniques designed to uncover problem arrythmias, are briefly described and their potential in the analysis of cardiac electrical function under varying conditions is reviewed. The author cautions on the too rapid evaluation of the techniques for this purpose while remaining optimistic of the potential of electro-stimulation in the objective analysis of cardiac electric parameters.
Scott EA, Snoy P, Prasse KW, Hoffman PE, Thrall DE.A yearling Quarter Horse colt was examined because of intermittent esophageal obstruction. A soft tissue mass was palpated in the cervical portion of the esophagus. Plain and contrast radiography and esophagoscopy were utilized to confirm the location of the lesion in the esophageal wall. Surgical exploration and removal of the mass was performed through a ventral midline cervical incision. Histologically, the mass was a keratinizing squamous epithelial inclusion cyst.
McQueary CA, Worley DE, Catlin JE.Of 22 foals from 4 localities in southwestern Montana, 59% were found to be infected with Eimeria leuckarti. Oocysts collected from feces of 4 positive horses were sporulated and subsequently administered to a 5- to 6-month-old foal. The prepatent period was 31 days and the patent period was between 5 and 10 days.
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Grelck H, Hörchner F, Wöhrl H.Ten pony foals were infected with Fasciola hepatica; five animals received up to 1000 metacercariae orally, the remaining animals received up to 80 specimens of 24 hours old adulescariae intraperitoneally. The rate of development of the parasites varied in a wide range between 0,2 and 41%. Most of the liverflukes were found in animals severely infected with strongyles in the same time. Only 22 weeks after oral infection, the flukes had reached a length of 20 mm and sexual maturity. Fasciola-eggs could not be detected in the feces.
Jann HW, Cook WR.Monopolar electrosurgical cutting was used to correct epiglottal entrapment in 5 horses. The operations were carried out in the conscious animal, using topical anesthesia. The procedure required the use of a coagulation electrode designed specifically for electrosurgery, introduced through the instrument channel of a fiberoptic endoscope. The results were satisfactory and serious complications were not encountered. In 2 horses, excessive submucosal swelling developed at the site of the surgical wound, and the tumefaction took several weeks to subside in one of these horses. In both horses, the...
Charnock LN, Davidson MG, Keys DA, Gilger BC, McMullen RJ.To evaluate the normal refractive state in horses in NCSU and ECMR and determine the prevalence of naturally occurring refractive errors and their association with breed, age, coat color, iris color, sex, and geographic location. Methods: Horses from NCSU (January 2009-November 2012) and ECMR (January 2013-September 2016) underwent ophthalmic examination and streak retinoscopy. Location, color, breed, sex, and iris color were recorded. Gross and net refractive values for each meridian (horizontal and vertical), spherical refraction, astigmatism for both eyes, and anisometry were recorded, and ...
Harris WF.Three horses exhibited nervous and cardiopulmonary signs after ingestins small amounts of metaldehyde, and 2 died in 3 to 5 hours. A colt given 0.1 mg/kg was similarly affected and died.
Fielding CL, Magdesian KG.To evaluate changes in electrolyte concentrations and hydration status that take place in endurance horses prior to the start of a competition and determine whether these changes would be associated with elimination. Methods: 19 horses entered in the 2016 Tevis Cup 100-Miles (160 km) One-Day Western States Trail Ride. Methods: Heparinized blood samples were collected at 5 time points: prior to transport to the ride (T0), during check-in the day before the ride (T1), 1 to 2 hours before the start of the ride (T2), at the 15-km mark (T3), and at the 55-km mark (T4). Packed cell volume and plasma...
Kalmykov NP.The first data on polymorphism and preadaptation of the Pleistocene horses in the mountains surrounding Lake Baikal are presented. It has been shown that disregard of intraspecific polymorphism leads to unreasonable ignoring of their diversity, phylogenetically false constructions, and incorrect interpretation of natural environment.
Stadtbäumer G.Pleural effusion in the horse can be caused by diseases such as pneumonia, trauma, pulmonary abscesses and thoracic neoplasms. Besides clinical (auscultation, percussion) and radiographic diagnostic procedures, the ultrasonic examination represents a method that supplies detailed information on quantity and location of fluid in the pleural space. By means of ultrasonic examination the most favourable position for a thoracentesis can be determined. Control of thoracentesis' efficiency as well as exact supervision of the disease's course are made feasible by repeated sonographic examinations.
Lalatta Costerbosa G, Barazzoni AM, Clavenzani P, Callegari E.In this study the histochemical fiber type analysis of the articularis humeri muscle of the horse was performed. This muscle is composed of type I and type IIA fibers. A large number of spindles has been observed and the presence of these receptors could help to understand the role played by this muscle.
Schofield WL, Mulville JP.The modified Forssell's procedure was performed on 10 horses in an attempt to cure oral stereotypies. Three horses were cured completely, two horses were considerably improved, and five horses continued to perform the stereotypy after periods of remission ranging from two weeks to six months. This rate of success for the modified Forssell's procedure, as in other published reports, was lower than for the original Forssell's procedure. Surgery to eliminate a stereotypical behaviour pattern may exacerbate the stress for an animal and the modified Forssell's procedure can no longer be recommended...
Kneller SK, Losonsky JM.Bilateral metacarpophalangeal radiographs of 100 Thoroughbreds were examined for visualization and location of the major nutrient foramen of the proximal phalanx. The foramina were located on the dorsal or palmar aspects of the cortex or were not visible radiographically. Of the 100 horses, 60 had the same pattern in both forefeet. In the remaining 40 horses, the left and right proximal phalangeal foramina were asymmetric. Of the 200 proximal phalangeal foramina (100 horses), 53 were on the dorsal aspect of the cortex and 101 were on the palmar aspect of the cortex; 46 were not visible radiogr...
Schneider RK, Mayhew IG, Clarke GL.The duration of anesthetic effect and the histopathologic changes resulting from a controlled freeze of the palmar and plantar digital nerves in the horse were evaluated. Two techniques were compared: (i) nerves were frozen by direct application of the cryoprobe after surgical exposure and (ii) nerves were frozen by percutaneous application of the cryoprobe to the overlying skin. Return of skin sensation and ability to detect a stimulus were used to determine return of nerve function. The duration of anesthetic effect was significantly (P less than 0.005) longer for nerves frozen after surgica...