"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.
Parry BW, McCarthy MA, Anderson GA.Resting coccygeal blood pressure values were measured, indirectly, on 296 horses (97 Thoroughbreds, 97 Standardbreds and 102 hacks). Blood pressure was found to vary with the class of horse examined; on average Thoroughbreds had significantly higher values than Standardbreds and hacks, whereas blood pressures of the last two groups were not significantly different. There was no demonstrable effect of sex, height or heart rate on blood pressure, but temperature and age did influence the value recorded. Mean (+/- sd) (n = 296) coccygeal uncorrected values (systolic pressure/diastolic pressure) w...
Drudge JH, Lyons ET, Tolliver SC.Critical tests were completed on six horses to evaluate the antiparasitic activity of a paste formulation mixture of morantel citrate and trichlorfon, administered intraorally at the dose rate of 6 mg morantel base kg-1 and trichlorfon at 30 mg kg-1. Aggregate average removals were: 78% for two horses infected with 2nd instar Gasterophilus intestinalis; 100% for one infected with 2nd instar G. nasalis; 96% for six infected with 3rd instar G. intestinalis; 100% for four infected with 3rd instar G. nasalis; 100% for five infected with Parascaris equorum; 100% for one infected with mature Oxyuris...
Kleider N, Lees MJ.The investigation of a chronic, seasonal dermatitis of horses in southwestern British Columbia is described. Typically the history indicated an insidious onset, followed by a gradual progression in the severity of the signs each year. Lesions appeared during the warmer months of the year and tended to regress during the winter. The clinical signs consisted of areas of pruritus and excoriation, affecting predominantly the ventral midline, mane and tailhead. In all cases corticosteroid therapy relieved the pruritus and allowed the lesions to heal.The salient pathological findings were hyperkerat...
Lucke VM, Lane JG.The clinical and pathological aspects of two cases of C-cell (parafollicular cell) tumours of the thyroid are described. Both the horse and the pony presented with a paralaryngeal mass and a history of constant gulping. Ultrastructural examination of the tumours demonstrated that they were composed of C-cells containing typical, membrane-bound secretory granules. The pony is alive and well three years after surgery and the horse has raced successfully following removal of the tumour.
Flieger S, Sławomirski J, Boratyński Z, Jastrzebski M.Two medullae oblongatae of horses were cut into 15 microns cross-sections and stained according to the modified method of Nissel. The lateral motor nucleus lies in the lateral and median part of the ventral column of spinal cord grey matter. It adjoins medially nucleus motorius medialis of the spinal ventral column. Cells of this nucleus occur both along the whole lumbar and sacral segment of the spinal cord. In the lateral motor nucleus three cell groups are distinguished-median, basal and lateral. The latter is divided in some segments into subgroups-dorsal and ventral. Along the nucleus qui...
Meyer H.Skin diseases of the horse can be produced or enhanced through nutrient deficiency, intestinal formation of detrimental substances, photosensitizing compounds and by intake of allergenes. An exact case history regarding feeding is useful for evaluation of every skin abnormality.
Holler AC.A farrier is a specialist in the shoeing of horses. It has been estimated that in the United States over 8 million horses are ridden for show and pleasure. These horses need hoof and leg care. The farrier does give this care and in so doing is subject to occupational hazards. These hazards cover a wide range and include bites from horses and farmer's dogs, ergonomic problems, noise and exposure to metal and welding fumes. Many of the hazards he encounters are unique to his profession.
Carlsten J, Kvart C, Jeffcott LB.A practical and safe method of angiocardiography for the horse is described. The technique involved the rapid injection of 50 to 150 ml contrast agent via catheters in the right and left heart, pulmonary artery and aorta. The examination was carried out with the horse in the standing position or under general anaesthesia. Angiocardiograms were performed on 10 normal horses and satisfactory pictures of the right and left ventricles, pulmonary arteries, aorta and coronary circulation were obtained. The technique was also used in a foal with severe congenital heart disease. The most practical met...
McIlwraith CW.This paper reviews the current status of diagnostic and surgical arthroscopy in the horse. Arthroscopy has been used as a diagnostic aid since 1974 and is useful for evaluation of abnormalities in synovial membrane and articular cartilage. Surgical arthroscopy is a more recent advance that has replaced conventional arthrotomy in 90 per cent of the author's cases. Clinical conditions currently being treated using arthroscopic techniques rather than arthrotomy include all chip fractures in the carpus, chip fractures of the first phalanx, chronic proliferative synovitis in the fetlock and osteoch...
Badoux DM.The ratio between the length of the anterior and posterior cruciate ligaments and the distance between their femoral and tibial attachments in the canine and equine knee joint reveals that these structures form a Tchebychev mechanism for parallel motion.
Obi TU, Taylor WP.Serum samples collected from 1,197 goats, 586 sheep, 254, cattle, 55 dogs and 44 horses were examined for antibodies to adenovirus by the agar-gel precipitation test. Results show that 17.7% of the goats, 18.4% of the sheep, 4.3% of the cattle, and 4.5% of the horses had precipitating antibodies. None of the dog sera examined was positive. The results seem to indicate a moderate level of previous exposure to adenovirus infection especially among goats and sheep in Nigeria.
Sławomirski J, Flieger S, Jastrzebski M, Boratyński Z.The studies carried out on 2 spinal cords of horses showed that cells of the medial motor nucleus (nucleus motorius medialis) are present in all neuromers of the lumbar and sacral segment of the spinal cord. It lies in the medial part of grey matter of the ventral column, neighbouring laterally and ventrally with cells of the lateral motor nucleus, whereas dorsally with cells of the nucleus of the ventral commissural horn. Along the nucleus numerous constrictions and intervals are found, which are connected with various numbers of nerve cells in particular cross-sections.
Acland HM, Mann PC, Robertson JL, Divers TJ, Lichtensteiger CA, Whitlock RH.Six foals of three different breeds, born to healthy mares, appeared normal at birth, and died at two to five days of age with icterus, ataxia, head pressing, and terminal hepatic coma. Their livers were less than one-half normal weight. Most of the liver was dark red-brown and slightly rubbery. Histologically, these areas were characterized by severe bile ductule proliferation, mild portal tract fibrosis, and massive hepatocellular necrosis and lobular collapse. A small proportion of the liver, usually on the peripheral part of the lobes, was grossly light brown and slightly raised. Histologi...
Yovich JV, Horney FD, Hardee GE.Ten cases of pheochromocytoma in horses were obtained from the literature and a computer search of medical records. The clinical, laboratory and pathological features of pheochromocytoma in horses were reviewed. Pheochromocytoma is a catecholamine secreting tumor which tends to occur in older horses without breed or sex predisposition. It is usually unilateral adrenal medullary in location and benign. Malignancy was present in one horse. The most common clinical signs were sweating, tachycardia, tachypnea, muscle tremor and anxiety; however the tumor may be asymptomatic. Clinical signs were no...
Holt PE, Pearson H.The presenting signs, treatment and postoperative progress of 13 horses with vesical and urethral calculi are reviewed. Single, discrete stones were present in 10 animals in which the results of treatment were generally good. In three horses with sabulous cystic deposits, urolithiasis was associated with bladder paralysis and the response to treatment was poor.
Hopfer SM, Van Kruiningen HJ, Daniels WH.Twelve horses were divided into three groups and given various doses of a mixed species strongyle inoculum, representing light, moderate, and heavy infections. Three weeks after the larval inoculations, three animals from each group were given larvicidal doses of thiabendazole (TBZ) (440 mg kg-1 on two consecutive days); one animal from each group served as a non-medicated control. Treatment was repeated three weeks later. One treated animal from each group was designated for long-term study; others were necropsied to study adult and larval parasite loads. Six of the twelve animals with strong...
Perryman LE, Wyatt CR.Equine lymphocytes incubated with Con A and isolated on discontinuous BSA density gradients suppressed mixed lymphocyte reactions in a cell dose- and Con A dose-dependent manner. Suppressor lymphocytes were radiosensitive, even after the initial Con A incubation phase was completed. Suppressor activity was consistently demonstrated using peripheral blood mononuclear leukocytes from normal horses, but was absent in thymus cells and variably present in lymph node cells. Suppressor lymphocytes were present in horses with selective IgM deficiency, and within neoplastic lymph nodes from a horse wit...
Marolt J, Naglić T, Hajsig D.A case of a spontaneous mycokeratitis of a previously injured cornea in a horse is described. The infection was caused by Aspergillus oryzae. After application of Chloramphenicol ophthalmic ointment a corneal clouding was found in the centre which was circularly sharply defined and which - after dispensing Dexamethason-Neomycin eye drops - expanded all over to a purulent keratitis. The demarcated and initially non purulent mycotic lesions largely improved after the application of tincture of iodine, whereas the purulent keratitis could be completely cured only by a lasting treatment with Lugol...
Pfeil L, Zetner K.A mare with rectal prolaps was operated at Vienna University. The prolaps was corrected by mucosal resection only. The remaining vital layers of the corresponding intestinal section were saved. The advantage of a special tissue saving operating technique in the rectal area is seen in avoiding postoperative complications.
Thomson JR, McPherson EA.The effects of environmental control on horses affected with chronic obstructive pulmonary disease was assessed by clinical examination and pulmonary function tests, ie, maximum change in intrathoracic pressure, tidal volume, minute volume, non-elastic work of breathing, dynamic compliance, inspiratory and expiratory flow rates and arterial blood gas analysis. A controlled environment (ie, bedding horses on shredded paper and feeding a complete cubed diet) caused symptomatic COPD affected horses to become asymptomatic within four to 24 days (mean +/- sd 8.4 +/- 4.8 days). When asymptomatic, th...
Clemente CH.A synthetic fixed dressing for great animals is described, which is worked up in such a manner that it is possible to fix on its soles a non-abrasive rubber plate.
Parks CM, Manohar M.Blood-gas tensions and acid-base status were examined in 8 healthy grade ponies at rest (heart rate = 55 +/- 3 beats/min) and during moderate (fast trot; heart rate = 155 +/- 3 beats/min) and severe (gallop; heart rate = 218 +/- 7 beats/min) exercise performed on a treadmill. Arterial oxygen tension and hemoglobin-oxygen saturation of exercising ponies did not change from the resting values. Arterial oxygen content increased markedly during exercise, as a consequence of increased hemoglobin concentration. The total oxygen content, as well as the saturation of hemoglobin with oxygen in the mixe...
Piché CA.An outbreak of strangles, which occurred during the spring, summer and fall of 1980 on a Standardbred stud farm in eastern Alberta is described. The infective organism, Streptococcus equi, may have been introduced by an outside mare that was brought to the stud for breeding. All of the groups of horses on the farm were affected. For the most part, the disease was allowed to run its natural course. Only severely affected individuals were treated. During the outbreak, the foals were prophylactically treated with penicillin to prevent them from contracting the disease. Ten horses died of complica...
Evans KS, Carpenter SL, Sevoian M.The enzyme-linked immunosorbent assay (ELISA) antigen-positive and agar-gel immunodiffusion test (AGID)-negative horses do not have infective equine infectious anemia (EIA) virus. The ELISA testing of horse leukocyte culture (HLC) supernatants did detect EIA virus in a HLC that was infected with the Wyoming strain of EIA virus and in HLC derived from horses in febrile, acute, or subacute stages of EIA infection. In supernatants of HLC derived from chronic and inapparent carrier horses, EIA virus was not detected with ELISA. Direct fluorescent antibody tests detected EIA virus in HLC infected w...
Hilbert BJ, Rowley G, Antonas KN.A method previously described was used to determine the hyaluronic acid concentration in synovia from normal and arthritic horse joints. The concentration of hyaluronic acid in the synovia from arthritic joints was found to be significantly lower than the concentration in fluid from normal joints.
Westermarck E, Lindberg LA, Sandholm M.A sensitive gel-diffusion assay for determination of phospholipase A was developed. PLA standards, serum, faecal and pancreas homogenate samples with PLA-activity were allowed to diffuse from wells into agar-gels containing lecithin-membranes. The turbidity cleared radially upon PLA-activity. The diameters of the cleared zones showed a linear relationship with the log of the enzyme concentration. Serum samples resulted in some turbidity within the cleared zones. This interference originating from serum lipoproteins could be abolished by hydrophobic absorption. The gel-diffusion method was comp...
Dipeolu OO, Adeyefa CA.Ticks of the species Amblyomma variegatum (Fabr.), Boophilus decoloratus (Koch), Boophilus geigyi Aeschl. et Morel, and Hyalomma rufipes Koch were detached from cattle, sheep and horses and the influence of these various hosts on the biology of ticks was investigated. No A. variegatum was found in horses. The parameters studied were preoviposition and oviposition periods, ovipositional capacity, eclosion period, hatching patterns, egg sizes and temperature effect. Although the preoviposition and eclosion periods were similar in each tick species irrespective of the host from which the adults w...
Rapp HJ, Weiss R, Bockisch FJ, Becker M, Stechele M.Using the direct sedimentation method, the air pollution with fungal spores was measured in indoor riding arenas and compared to horse stables, outside riding arenas and covered sport courts. Depending on the location of indoor arenas and stables, the presence of "dust-nests", the number of horses ridden, and the moisture of the tread layer, an air pollution was measured which was equivalent to that in stables except at times of feeding and straw-giving. Outside and in sport arenas a low air pollution was found. Recommendations are given, regarding optimum air hygiene especially for horses wit...
Wijnberg ID, Back W, van der Kolk JH.This paper describes a case of unilateral stringhalt present for 18 months in the right hind limb of a 4-year-old Warmblood gelding. The only abnormalities detected by electromyography (EMG) were a prolonged insertion activity, fibrillation potentials, and positive waves at rest and enhanced EMG activity in the right lateral digital extensor muscle on muscle contraction. This was interpreted as denervation and hyperirritability of this muscle. Both similarities and differences with Australian stringhalt could be found. As described for horses suffering from Australian stringhalt, phenytoin sod...
Arndt S, Kilcoyne I, Vaughan B, Dechant JE.To identify etiology, clinical findings, diagnostic results, treatment, and short- and long-term survival and to report factors associated with nonsurvival and survival in horses with peritonitis. Methods: Retrospective study. Methods: Horses (n = 72). Methods: Medical records at William R. Pritchard Veterinary Medical Teaching Hospital from 2007-2017 were reviewed for horses diagnosed with peritonitis. The essential inclusion criterion was a peritoneal nucleated cell count of ≥25 000 cells/μL. Gastrointestinal rupture and cases in which peritonitis occurred after abdominal surgery or cas...
Kirschvink N, Art T, Lekeux P, Roberts C, Gustin P.8-Epi-PGF2alpha, a prostaglandin-like compound generated by oxidative stress, has been shown to be an in vitro bronchoconstrictor in airways from healthy laboratory animals and healthy humans, but it has never been studied in diseased airways. Here, the bronchoconstrictive capacity of 8-epi-PGF2alpha on isolated bronchial rings (BR) of healthy and heaves-affected horses was evaluated by comparing the maximal effect and the potency of 8-epi-PGF2alpha to those of (1) acetylcholine (ACh), (2) its stereoisomer PGF2alpha and (3) its synthetic receptor agonist, U46619. Furthermore, the potential cap...
Weston MC, Collins ME, Cunningham FM.Inappropriately activated eosinophils can contribute to disease pathogenesis and intracellular signalling pathways that regulate functional responses may represent a therapeutic target. Little is known about intracellular signalling in equine eosinophils and this study examined the role of phospholipase C (PLC) and a range of protein kinases on responses to histamine and CCL11. Histamine (10(-4) M) or CCL11 (5.6 x 10(-9) M)-induced actin polymerization, migration and superoxide production by eosinophils from healthy horses were compared in the presence and absence of selective kinase inhibitor...
Stecco R, Paccamonti D, Gutjahr S, Pinto CR, Eilts B.Oxytocin is released in response to teasing during both estrus and diestrus in mares, and at least during estrus, teasing results in an increase in electromyographic activity in the uterus. Exogenous oxytocin causes an increase in intrauterine pressure and prior studies have shown that this response is correlated to the day of the estrous cycle. To determine if teasing causes an increase in intrauterine pressure and if this response varies by day of the cycle, intrauterine pressure was measured while mares were teased with a stallion 2 days before ovulation, on the day ovulation was detected a...
Pellegrini MG, Corda EM, Manca L, Olianas A, Sanna MT, Fais A, Masala B.A study was made of the Hb phenotype of the Sardinian dwarfhorse (Equus caballus jara), one of the last surviving wild horse species in Europe. Hb haplotypes and their frequencies were found to be similar to those described in the Arabian horse (BI = 0.551, BII = 0.389, A = 0.036, V = 0.015), which suggests possible introduction onto the island from North Africa. The oxygen binding properties of the whole hemolysates and of the four different horse Hbs, separated by ion-exchange chromatography, were considered with regard to the effect of chloride, 2,3-bisphosphoglycerate and lactate. Results ...
Pratt SM, Stacy BA, Whitcomb MB, Vidal JD, De Cock HE, Wilson WD.A 13-year-old Morgan gelding was evaluated because of a mass in the caudal region of the abdomen. The horse had been presumed to be a gelding, but necropsy findings revealed a retained testis in the right retroperitoneal space. Histologically, the retained testis contained neoplastic cells; metastases were identified in the liver, spleen, lungs, and sublumbar lymph nodes. Immunohistochemical examination of the testis and metastatic tissues confirmed the diagnosis of malignant Sertoli cell tumor. Testicular neoplasms are infrequently reported in stallions. Seminomas are most commonly reported, ...
Trotter GW.Although many wounds in horses heal successfully by second-intention healing or delayed closure, some wounds can be sutured primarily, with reasonably high expectations of first-intention healing. To expect to achieve these results, one needs to have a rational treatment plan. Such a plan should be based on a working knowledge of the biology of tissue repair and tissue infection. Treatment decisions should be based more on results of experimental and clinical trials rather than on testimonials of other practitioners.
Oikawa M, Ohishi H, Katayama Y, Kushiro A, Yoshikawa H, Yoshikawa T.A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with...
Reef VB, Roby KA, Richardson DW, Vaala WE, Johnston JK.Two dimensional ultrasonographic evaluation of the iliac arteries and terminal portion of the aorta was utilized in 18 horses with histories of exercise intolerance or hindlimb lameness. A plaque or thrombus was imaged in one or more of these vessels in 5 horses. In 2 horses, the initial rectal examination findings were normal and the thrombus may have been missed without the use of diagnostic ultrasonography.
A method of inhalation anaesthesia using diethyl ether, following induction with thiopentone, is described in ponies. The high concentrations of ether needed to maintain anaesthesia were obtained by using a Marrett head in circle vaporizer. This methods would only be used in ponies, since the diameter of the tubing is too small for use on larger horses.
Jones DM, Fielden ED, Carr DH.Two intact and 2 ovariectomized mares aged 3-16 years had bipolar electrodes implanted in the myometrium to measure electromyographic (emg) activity during normal and exogenously simulated (with oestrogen and progesterone) cyclical activity (anoestrus, transition, oestrus and dioestrus). Oxytocin, cloprostenol, propantheline bromide and clenbuterol were administered during each cycle stage. In 1 mare, emg activity was recorded during natural breeding (4 times) and through the first 20 days of pregnancy. Simultaneous intrauterine pressure recordings (IUP) using an open tipped catheter system we...
Mariën T, Adriaenssen A, Segers L.A modified colon tray to perform large colon evacuations in horses was designed. A funnel-shaped accessory was constructed to create a mechanical separation between the sterile and nonsterile part of the tray. Sterile hooks were used to make a temporary and stabile colostomy. Thirty horses with surgical correction of nonstrangulating large colon obstruction underwent a large colon evacuation with this modified tray. The surgical procedure was uncomplicated and resulted in a positive outcome in 29 horses. This less labour-intensive way to evacuate the large colon results in minor contamination ...