"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.
Beetson SA, Hilbert BJ, Mills JN.The effectiveness of the glutaraldehyde coagulation test (GCT) in detecting failure to acquire colostral immunoglobulin in neonatal foals was investigated. This was achieved by comparing and correlating results from the GCT with those obtained by single radial immunodiffusion (SRID) of equine IgG. The GCT was found to be a practical, inexpensive, semiquantitative test with a high specificity and sensitivity at critical IgG levels.
Slocombe JO.This review summarizes information on the clinical signs, gross and microscopic lesions associated with nematode and cestode infections and discusses the development of these conditions in the equine host.
Brown CM.This article reviews the etiology, clinical findings, and significance of diseases of the heart valves, myocardium, pericardium, and great vessels of the horse. Each valve is considered separately from the point of view of murmur production. In addition, the role of the cardiovascular system in the etiology of sudden and unexpected death is considered.
Koblik PD, Hornof WJ.Survey thoracic radiography, although limited by physical considerations in the adult horse, can supply clinically useful information about changes in cardiac size and function. The radiographic features of cardiomegaly, altered pulmonary circulation, pulmonary edema, and pleural effusion as manifested in the horse are discussed. Nuclear cardiology can be performed in the standing horse. The initial transit of a radioactive tracer through the central circulation provides information about cardiac chamber size, efficiency of ventricular contraction, valvular competence, and presence of intracar...
Bonagura JD.The clinician must appreciate unique aspects of equine cardiovascular physiology in order to distinguish normal variation from a pathophysiologic state. Cardiovascular problems in the horse include auscultation of cardiac murmurs, identification of cardiac arrhythmias, and recognition of congestive heart failure. A cardiac data base including history, general and cardiovascular examination, and resting and postexercise electrocardiogram are necessary to evaluate most horses for significant heart disease. Additional studies, such as echocardiography and cardiac catheterization, are useful in se...
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...
Sweeney CR, Sweeney RW, Raker CW, Freeman DE.A 3-year-old Thoroughbred filly had a pharyngeal abscess causing obstruction of the upper respiratory tract. Diagnosis was made by a combination of endoscopy, biopsy, cytology, and radiography. Treatment with antimicrobials and analgesics resulted in successful resolution of the abscess.
Physick-Sheard PW.The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is ofte...
Muir WW, McGuirk SM.The rational therapy of cardiovascular disease in horses requires a thorough knowledge of the pharmacology and pharmacokinetics of several specific drugs (digitalis, digoxin). Calcium solutions, dopamine, and dobutamine are frequently used to treat congestive heart failure in horses. Quinidine, procainamide, lidocaine, and propranolol are used to treat a variety of supraventricular and ventricular arrhythmias. Furosemide, a highly potent loop diuretic, is used to eliminate edema and promote diuresis. A thorough understanding of the applied pharmacology, dosage recommendations, toxicity, and pr...
Ross MW, Martin BB, Donawick WJ.The case records of 23 horses with cecal perforation (CP) were reviewed. The horses averaged 4.5 years of age (6 weeks to 13 years) and included 9 intact males, 12 mares, and 2 geldings. Twelve of the horses were Standardbreds, 9 were Thoroughbreds, and 1 each, a Belgian and Morgan. The horses were allotted to 2 groups: group I-13 hospitalized horses in which CP occurred unexpectedly, and group II-10 horses with CP at the time of admission. The horses characteristically had been sick or affected with disease unrelated to the cecum. Sixteen horses had been given nonsteroidal anti-inflammatory d...
von Fellenberg R, Zweifel HR, Grünig G, Pellegrini A.Horse seminal plasma does not possess a proteinase inhibitor corresponding to human HUSI-I (human seminal plasma inhibitor). Instead a protein complex of high relative molecular mass (Mr) containing proteinase inhibitory activity was detected, which was called horse seminal plasma protein complex or HSPC. The compound had a broad enzyme-inhibiting spectrum. Its Mr was estimated to be 800 000 and it was composed of 7 different polypeptides with Mr values ranging from 11 000 to 30 000. Its carbohydrate content was between 3.5% and 5%. Despite the high molecular mass, the complex was soluble in d...
McGuirk SM, Muir WW.Cardiac arrhythmias are probably more common in horses than in any other domestic animal species. The most frequent clinical complaint associated with cardiac arrhythmias is exercise intolerance. Physical examination is characterized by auscultation abnormalities such as fast or slow heart rate, irregular rhythm, extra sounds, long pauses, or abnormal heart sounds. The electrocardiogram is used to make a definitive diagnosis of the dysrhythmia. Other laboratory and cardiac function tests are employed to determine the etiology and to assess the significance of the arrhythmia. Antiarrhythmic the...
Markel MD, Meagher DM, Ford TS.A 3-month-old Quarter Horse filly stepped on a fence staple and developed navicular bone osteomyelitis of the right hindfoot. A 1.5-cm spherical portion of medullary cavity containing purulent material was debrided and flushed with 0.9% NaCl solution. Cancellous bone was collected from a caudal sternebra and placed into the defect. The solar defect had filled with granulation tissue and was epithelialized 6 weeks after surgery. At 6-month follow-up evaluation, the navicular bone defect had healed and the foal was sound on the limb. Cancellous bone grafting may have merit for the treatment of n...
Reef VB.A thorough examination of the cardiovascular system is an integral part of a physical examination in the horse. The normal equine cardiovascular parameters are discussed, with an emphasis on auscultatory findings. The availability and application of other diagnostic techniques are discussed based upon findings of the physical examination.
Thomas DE, Beadle RE.The pharmacokinetics of 3-methylindole (3MI) given orally in 2 doses (10 mg/kg and 20 mg/kg) to horses were determined. The pharmacokinetic plasma-concentration profiles for 3MI (10- and 20-mg/kg dosages) in horses were represented by a 2-compartment open model with first-order absorption, as determined by nonlinear least-squares regression analysis. Absorption of 3MI at both dosages was rapid. Comparisons of the peak plasma concentrations, the postdistribution half lives, total clearances, and areas under the curve of the plasma-concentration profiles between the 10- and the 20-mg/kg dosages ...
Dubey JP.Thirteen 6-month- to 13-year-old equids were each inoculated orally with 10,000 infective Toxoplasma gondii oocysts. The equids remained clinically normal. Equids were euthanatized on postinoculation days 33, 45, 90, 104, 120, 140, 162, 183, 197, 204, 211, 294, and 476. Their tissues were bioassayed for viable oocysts by feeding muscles to Toxoplasma-free cats and by inoculation of pepsin digests of 13 organs into mice. Using mouse inoculation, T gondii was recovered from tissues of the 9 equids euthanatized on each of postinoculation days 33, 45, 120, 140, 183, 197, 211, 294, and 476. Toxopla...
Pellegrini A, von Fellenberg R.Pre-alpha 2-elastase inhibitor of horse plasma has recently been isolated in our laboratory. In this article we demonstrate that the inhibitor is a composite structure built of alpha 1-proteinase inhibitor and alpha 1-beta 1-glycoprotein. The compound inhibitor is biologically active, although it has previously been shown that its enzyme specificity is different from that of free alpha 1-proteinase inhibitor. Our observations are based on immunochemical cross-reactions between pre-alpha 1-elastase inhibitor and antibodies to alpha 2-beta 1-glycoprotein as well as antibodies to alpha 1-proteina...
Kirkpatrick CE, Skand DL.Giardia infection was believed responsible for chronic diarrhea, weight loss, lethargy, inappetence, and dermatitis in a 4-year-old Thoroughbred horse. Fecal cysts were detected by the zinc sulfate centrifugal flotation method. All clinical signs resolved upon treatment with metronidazole suspension (5 mg/kg body weight per os, TID for 10 days).
Bertone AL, Park RD, Turner AS.Radiographs of 23 foals (35 forelimbs) with carpal region angular limb deformities, which later were corrected by hemicircumferential transection of the periosteum and periosteal stripping, were evaluated as to geometric and morphologic abnormalities. Geometric evaluation included deviation angle and deviation pivot point. Morphologic abnormalities were categorized as: asymmetric width of the distal radial physis; asymmetric width of the distal radial epiphysis; carpal bone collapse or fracture; carpal bone hypoplasia; carpal bone displacement; and metacarpal bone displacement. Fifty-seven per...
Bertone AL, Turner AS, Park RD.Correction was attempted in 27 foals (41 limbs) with angular deformities at the carpal region (35 limbs), metatarsophalangeal region (5 limbs) and distal end of the tibia (1 limb) by hemicircumferential transection of the periosteum (HCTP) and periosteal stripping (PS). Successful outcome was determined by straight limbs and soundness, which was achieved in 81.5% of the cases, with 60% of the horses in performance training. Follow-up evaluation for all foals was completed at various times after physiologic closure of the physes. In none of the limbs was the deformity overcorrected. Owners of f...
Spier S.A 3-day-old foal was examined because of forelimb lameness. Brachial artery occlusion was diagnosed. The foal was euthanatized. Necropsy revealed brachial artery thrombosis and an atrial septal defect.
Bruce V, Turek RJ.The gluteus medius of two killed Thoroughbred horses were sampled along the muscle and across the muscle at four different depths. The distribution of fibre types in these two horses was assessed by staining cross sections of the muscle sample for ATPase. A non-uniform distribution of fibre types was found within the gluteus medius in both horses and there was a significant increase in percentage of slow twitch (ST) fibres from the surface to the deeper regions of the muscle. The rate of increase, however, depended on the individual site along the muscle. Averages ranges from a low of 2.4 per ...
Ratzlaff MH, Shindell RM, DeBowes RM.Blood pressures from the catheterized lateral digital vein of the fore-limbs of 6 clinically normal horses were measured at rest, at the walk, and at the trot. Digital venous pressures were compared with the phases of the stride and weight-bearing forces, using electrogoniometry and a force platform. Rapid increases in digital venous pressures to maximal values were observed immediately before maximal forces during the support period of the stride. At the trot, increases in peak vertical forces were paralleled by increases in peak digital venous pressures. Seemingly, the hydrodynamics of the d...
Bertone AL, Sullins KE, Stashak TS, Norrdin RW.Preformed collagen gel was topically applied to cutaneous wounds of the equine dorsal fetlock (thoracic limb) and metatarsal regions to evaluate the effect on exuberant granulation tissue production and wound healing. In 6 horses and 3 ponies (less than 140 cm high at the withers and less than 365 kg), 36 standardized cutaneous limb wounds were surgically induced (4 wounds/animal); 18 wounds were treated topically with collagen gel, and 18 wounds were not treated (controls). Collagen gel was initially applied to the wound at 0, 2, or 7 days after wound formation (groups 1, 2, and 3, respective...
Timoney JF, Eggers D.An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to...
Nollet H, Van Loon G, Deprez P, Sustronck B, Muylle E.To establish reference values for right ventricular maximal rate of increase in pressure (dP/dt(max)) in horses and determine the usefulness of this variable to evaluate cardiac contractility. Methods: 15 crossbred horses, 3 to 20 years old. Methods: Cardiac catheterization was performed, using a high-fidelity catheter tip micromanometer, to determine right ventricular dP/dt(max). The following mathematic corrections were made: for preload, (dP/dt(max))/instantaneous total pressure, (dP/dt(max))/instantaneous developed pressure, and (dP/dt(max))/end diastolic pressure; for afterload, (dP/dtCPI...
Hardeman LC, van der Meij BR, Back W, van der Kolk JH, Wijnberg ID.In cases of laminitis, an increased muscle force or contracture of the deep digital flexor muscle (DDFM) is suggested, but evidence-based research is lacking. Objective: To test if the DDFM of laminitic equines shows an increased muscle force detectable by needle-EMG including Interference Pattern Analysis (IPA). Methods: Cross-sectional study. Methods: Three groups consisted of Group 0 (control): 6 Royal Dutch Sport horses, 3 Shetland ponies and one Welsh pony (healthy, sound adults, mean ± s.d. weight 411 ± 217 kg). Group 1: 3 Royal Dutch Sport horses, one Friesian, one Haflinger...
Guarda F, Rattazzi C.The authors describe pathologic and histopathologic findings of three cardiac aneurysms in horses, two of which in the left ventricle and one in the right ventricle. The aneurysms were always associated with multiple foci of myocardiac fibrosis. A hypothesis concerning histogenesis of the lesion is formulated.
Ramadan MM, Dailey D.This is the first account of fatal toxicity in horses resulting from grazing on the pasture plant creeping indigo, , on the island of Oahu, in the Hawaiian Islands. A survey in the town of Waialua on the north shore of Oahu island indicated that creeping indigo is common and abundant on grazing lands during the rainy season and requires intensive chemical and physical control measures. Four pastures were surveyed where ranchers reported mortality of more than 17 horses since 2020. We document these incidents to alert state animal and livestock support officials, groups monitoring invasive spec...
Science (New York, N.Y.)March 4, 1966
Volume 151, Issue 3714 1085-1086 doi: 10.1126/science.151.3714.1085
Kennington GS, Ching CF.Hair samples from the horse, elk, deer, moose, and antelope; subcutaneous tissue from the moose and antelope; and cast and living skin of the rattlesnake were activated by exposure to a neutron flux. The resulting products were studied by pulse-height analysis. Differences in type and proportion of trace elements appear to be consistent within the species studied.
Hofing GL, Bennett DG.Patent infections with Strongylus vulgaris were established in 6 of 8 helminth-free ponies given 41 to 101 adult worms via nasogastric tube. The parasites were removed from the cecum and ventral colon and transferred within 1 to 2 hours of the death of the donor horses. Eggs were found in the feces of the recipients in 2 or 3 days; egg counts reached maximum, 28 eggs per gram of feces, at 4 weeks after ponies were inoculated. In 6 ponies euthanatized 3 to 7 weeks after parasitic transfers were done, 28% of the inoculated worms were found alive at necropsy. A 7th pony was maintained as a donor ...
Machová K, Juríčková V, Kasparová A, Petrová K, Sládková B, Svobodová I.Equine Facilitated Psychiatry and Psychology (EFPP) is a supportive non-pharmacological treatment program used in the treatment of patients with substance use disorder. The aim of this study was to evaluate a possible change in patient's health and health-related quality of life between the first and fourth session of the EFPP program using the Assessment of Quality of Life (AQoL) and the Health of the Nation Outcome Scales (HoNOS). The Human-Animal Interaction Scale (HAIS) and a 5-point Likert-type scale was used for an assessment of patient's mood in the experimental group. The study sample ...
Hallebeek JM, van Doorn DA, Beynen AC.In horses that exercise intensively (for example, event horses in training) the intake and energy requirements were compared on the basis of a diet record and estimates of energy required for exercise. Daily net energy intake over a 7 days period was on average 30% (n = 15) higher than the net energy requirement. Since the horses had a constant body weight, and thus were in energy balance, the energy intake was overestimated and/or the energy requirement was underestimated. The intake of digestible protein was 92% higher than the protein requirement. This study illustrates the problems concern...
O'Neill HD, Bladon BM.There is limited information on the treatment of lateral malleolus (LM) fractures in the horse, with no previously published case series for the outcome following arthroscopic removal of such fractures. This report reviews and evaluates findings of a retrospective study of 13 horses admitted to a private equine referral hospital over a 10 year period (1999-2009) that underwent arthroscopic removal of fractures of the LM. Hospital records were reviewed and details including patient history, aetiology of the fracture and limb affected, results of all diagnostic tests and surgical reports were do...
Tobin T, Swerczek TW, Blake JW.This report concerns the detection and acute toxicity of pine oil (a commercially available disinfectant) after intravenous administration in horses. alpha Terpineol was identified as a major constituent of pine oil. alpha Terpineol was recovered from equine tissues by extraction into heptane and detected by gas chromatography, using either flame ionization detection or pentafluoropropionic anhydride derivatization and electron capture detection. After intravenous injection of 0.1 ml/kg, death due to massive pulmonary edema occurred within minutes. In this animal blood and tissue levels of alp...
Smith RD.In this article, I have discussed the principles and methods of outbreak investigation, reinforcing important concepts with examples from the veterinary literature. The approach presented is applicable to outbreaks caused by any agent whether it is infectious versus noninfectious or contagious versus noncontagious. The solutions vary. The experience of others presented with similar situations may be especially helpful. Because of their nature, outbreaks are difficult to prepare for. When faced with a potential outbreak, the best strategy is to approach it scientifically, systematically, and wi...
Erkert RS, MacAllister CG, Higbee R, Moll HD, Reiners S, Crowson C, Bahr R, Bartels KE.Use of a neodymium:yttrium-aluminum-garnet laser to remove exuberant granulation tissue from the esophagus of a horse A 4-year-old Quarter Horse mare was evaluated because of recurrent esophageal obstruction. Endoscopic examination revealed a proliferative mass in the esophagus approximately 55 cm aborad to the nares. Histologic examination of biopsy specimens revealed diffuse suppurative esophagitis and granulation tissue with no evidence of neoplasia. The mass was excisedand ablated transendoscopically with a neodymium:yttrium-aluminum-garnet laser. During a follow-up examination 2 weeks aft...
Peter V, Marr C, Foote A, Auer H, Head M.This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations...