"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.
Eales FA.Saffan was injected intravenously on 41 occasions in 11 horses and ponies to investigate its possible use in clinical equine anaesthesia. The optimum dose for induction was 1-90 mg per kg. This dose was divided into two halves, the first half given in five seconds and the second half, containing suxamethonium chloride 0.1 mg per kg, in the next 10 seconds. Induction was associated with excitement for up to 30 secs after the assumption of recumbency. At this dose rate anaesthesia lasted five to eight minutes. Muscle relaxation was poor. Recovery was associated with marked tactile and audible hy...
Cartoni GP, Montanaro M.The results and the improvement of the analytical procedures adopted for the control of doping in horses will be reported. This control has been systematically carried out in Italy for about 10 years in the laboratories of Italian Federation of Sport and Medicine in which the biological samples for the control of doping in various sport activities (football, cycling, athletics etc.) are also examined. In this way it is possible to use the same instruments for all these similar problems and compare the results. The analytical procedure is based on the following steps: 1) Extraction of the sampl...
Robinson NE, Scott JB, Dabney JM, Jones GA.Digital vascular pressures, blood flow, and vascular resistances were measured in 11 control ponies and in 8 animals (7 ponies and 1 horse) affected with laminitis created by feeding a high starch ration. Animals with laminitis had increased digital blood flow, increased arterial, small vein, and large vein pressures, and decreased vascular resistances. Comparison of digital lymph flow rates and protein concentrations in animals with laminitis and control animals revealed no differences. Digital vascular responses of the 2 groups to acetylcholine, epinephrine, histamine, or serotonin also did ...
Thompson DB, Spradborw PB, Studdert M.Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.
Hillidge CJ.The effects of the analeptic agent, Dopram (doxapram hydrochloride) were investigated in 2 ponies during Immobilon - induced neuroleptanalgesia. Although Dopram was demonstrated to exert a degree of respiratory stimulation, this was concluded to provide no overall advantage. The etorphine-induced hypoxic hypoxia was only partially reversed, and there was additional cardiovascular stimulation, in contrast to the previously reported tendency for arterial blood pressure to return towards conscious control values during the course of action of Immobilon.
Speirs VC, Reynolds WT.The diagnosis and successful surgical treatment of a diaphragmatic hernia in a 12 weeks old standardbred foal are described. The clinical syndrome in horses generally is contrasted with that seen in the foal described in this paper. Some of the factors contributing to the clinical signs are discussed.
Snow DH, Guy PS.The use of the technique of percutaneous needle biopsy in obtaining skeletal muscle samples in the horse is described. The biochemical, ultrastructural and histochemical investigations that can be carried out on this biopsy specimen are outlined. Analyses performed on the specimen may be used to obtain information on racing potential and state of fitness. These studies on normal horses will provide information for future investigations into the structural and biochemical alterations in muscle disorders in the equine.
Falco MJ, Whitwell K, Palmer AC.Sixty-seven TB horses in Britain suffering from clinical wobbler disease were divided into 5 groups, based on the presence or absence of pathological lesions and their nature. These groups were compared genetically with a control group of 67 TBs known not to exhibit signs of wobbling. Though analysed for both simple and complex modes of inheritance no evidence of a genetic basis was found in any group. The high breed incidence in TBs may be real or apparent. Considerably more male than female wobblers are reported. Other forms of possibly inherited ataxia in equidae are reviewed and reference ...
Smith HJ.Five of seven ponies whose strongyle worm burdens had previously been removed or markedly reduced by repeated thiabendazole treatments were reinfected with doses ranging from 100,000 to 500,000 small strongyle infective larvae. Reinfection of ponies resulted in the development of clinical signs characterized by abnormal feces, marked loss of weight and delayed shedding of winter hair coats. An abrupt increase in circulating eosinophils occurred during the first three weeks following reinfection. Patent infections developed in all ponies with worm eggs appearing in the feces from 12 to 15 weeks...
Jones DM.A short account of the natural history of the wild Equidae is given as a background to their management in captivity. In general the approach to their husbandry and veterinary care is similar to that for the domestic horse. A mixture of etorphine and acepromazine has been found to be the most effective for handling and conventional methods of anaesthesia can be safely superimposed on these if required. The data collected at Whipsnade on the haematology and biochemistry of these species is summarised in tabular form and an analysis is included of the post-mortem examinations of 105 equine carca...
Morales GA, Wells EA, Angel D.Discovery of two ill horses and three dogs naturally infected with Trypanosoma evansi near an experimental station in the Eastern Plains of Colombia led to a search for reservoir hosts of the parasite. Infection was detected in 8/33 healthy capybaras (Hydrochoerus hydrochaeris), none of the remaining 14 horses, and none of 32 Zebu cattle (Bos indicus), 18 paca (Cuniculus paca) and 20 spiny rats (Proechimys sp.). Contrary to common opinion, the results indicated a carrier state in the capybara. Diagnosis was based on morphology, behaviour in albino rats, and pathogenicity and host range in dome...
Smith HJ.A group of seven ponies naturally infected with large numbers of small strongyles and raised under conditions to minimize reinfection were treated periodically over a three year span with thiabendazole at the rate of 44 mg/kg body weight. Based on the absence of worm eggs in the feces following each treatment, thiabendazole removed the adult strongyles present with a new population subsequently developing by maturation of inhibited larvae. It took as many as four or five treatments to eliminate or reduce significantly the worm burdens present in the ponies under the conditions of this study. S...
Delbeke FT, Debackere M.It is well known that nikethamide (N,N-diethylnicotinamide, CoramineR) is metabolized very rapidly to nicotinamide. Hence, there is difficulty in proving that nikethamide has been used as a doping substance because nicotinamide is a normal physiological metabolite in the organism as well as a vitamin preparation. However, an intermediate metabolite (N-ethylnicotinamide) was found by us in the urine of horses treated with CoramineR. This was characterized by gas chromatography/mass spectrometry, and synthesized and identified as being N-ethylnicotinamide. The excretion and metabolism of niketha...
McIlwraith CW, Owen RA, Basrur PK.Cytogenetic and histological studies were carried out on an intersex horse which was diagnosed clinically as a cryptorchid. Surgery confirmed the horse to be a bilateral abdominal cryptorchid and histological examination revealed ovarian tissue associated with the left epididymis. Chromosome analysis of cultured cells from testicular tissue, ovarian tissue and skin revealed 64-XX and 64-XY make-up, the left gonad containing a greater preponderance of XX cells over XY cells. The external characteristics and behaviour of the horse were indistinguishable from that of a "routine" cryptorchid. Othe...
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...
Courtot D.At the request of the Service des Haras, our laboratory works on the toxicological problems of the sport-horse. These studies have resulted in the setting up of an anti-doping control for equestrian competitions of various types, not only flat racing. During events, horses, must be calm and docile to the riders' order. Frequently, the latter use tranquillizers to try and win events. The analytical method for the research and identification of these compounds is described. The technique involves successively: 1. alkalinisation of the sample - saliva, blood or urine after enzymatic hydrolysis. 2...
Moore JN, Kintner LD.Squamous cell carcinoma involving the pars esophagea of the stomach caused recurrent esophageal obstruction in an 11 year old Pinto gelding. The tumor encircled the esophagus and was attached to the diaphragm, spleen, aorta, left adrenal gland and kidney. Definitive diagnosis was provided by biopsy of the mass via standing left flank laparotomy.
Tobin T, Blake JW.Since procaine has both local anaesthetic and central stimulant actions its presence in the blood or urine of racing horses is forbidden. After rapid intravenous injection of procaine HC1 (2.5 mg/Kg) in thoroughbred mares plasma levels of this drug fell rapidly (t 1/2 alpha = 5 min) and then more slowly (t 1/2 beta = 50.2 min). These kinetics were well fitted by a two compartment open model (Model I). This model gave an apparent Vdbeta for procaine in the horse of about 3,500 litres. Since procaine was about 45% bound to equine plasma protein this gives a true Vdbeta for procaine of about 6,50...
Chvátal O, Hanák J.Surface electric potentials of the heart of four horses were measured by use of unipolar leak with the so called central Wilson's clip; the measurements were performed on 95 precisely fixed places of the equine body. Potentials found out in this way were re-measured with bipolar leaks: the negative electrode was fixed in the place of the highest negative potentials, the positive electrode was gradually attached to places with the highest values of positive potentials. The largest potential differences when the negative electrode was placed in the region of the heart were obtained from the regi...
Oikawa M, Ueno T, Yoshikawa H.This report describes the mesenteric arteriolar lesions in a Thoroughbred racehorse with endotoxaemia due to colic. The vascular lesions consisted of a striking loss of medial smooth muscle cells, associated with granular cell debris derived from necrosed muscle cells, plasma insudation, erythrocyte infiltration and the deposition of a fibrinoid substance (fibrinoid degeneration) in the entire arterial wall, possibly produced by the infiltration of blood components through endothelial cell junctions into the arterial wall. The morphology of the mesenteric arteriolar necrosis closely resembled ...
Espino-Solis GP, Osuna-Quintero J, Possani LD.This work reports the cloning and sequence determination of the horse alpha subunit of the integrin CD11c/CD18, a marker of dendritic cells. A cDNA clone of 4582 base pairs was obtained. It encodes a protein segment of 1086 amino acid residues of the extracellular domain with 10 potential sites of glycosylation, a transmembrane domain of 32 residues and a C-terminal cytoplasmic tail of 24 residues. A phylogenetic analysis of this integrin shows close similarity (83%) with that of Canis familiaris.
Goldstein MA, Schwark WS, Short CE, White KK.Depression of the cardiopulmonary system of the horse during anesthesia is not an uncommon event. In many situations simple approaches for improving the function of the horse are necessary to avoid loss of life. This study has been completed utilizing an anesthetic approach frequently used in horses and a cardioresuscitative technique which can be utilized by the practicing veterinarian. Severe depression to arrest were produced experimentally and each animal was resuscitated through support of ventilation and circulation.
Adachi M, Aoi S, Kamimura T, Tsuchiya K, Matsuno F.Quadrupedal mammals have fore-aft asymmetry in their body structure, which affects their walking and running dynamics. However, the effects of asymmetry, particularly in the transverse plane, remain largely unclear. In this study, we examined the effects of fore-aft asymmetry on quadrupedal trotting in the transverse plane from a dynamic viewpoint using a simple model, which consists of two rigid bodies connected by a torsional joint with a torsional spring and four spring legs. Specifically, we introduced fore-aft asymmetry into the model by changing the physical parameters between the fore a...
Fubini SL, Cummings JF, Todhunter RJ.As a prelude to studies on retrograde axonal transport of neurotoxin (ie, so-called suicide transport) as a means to prevent post neurectomy neuroma formation, preliminary studies were conducted with an innocuous enzymatic marker, horseradish peroxidase (HRP). The proximal stumps of resected medial and lateral palmar digital nerves in six ponies were injected via a tuberculin syringe and needle with 50 micron 1 of a 30 per cent solution of HRP in order to assess long distance retrograde axonal transport. The dorsal root ganglion of the cervical spinal enlargement (ie, C6, C7, C8, T1, T2) were ...
Cohen ND, Chu KK, Stanley SD, Wang N.To estimate the probability for exceeding a threshold concentration of furosemide commonly used for regulatory purposes after IV administration of furosemide in horses. Methods: 12 mature healthy horses (6 Thoroughbreds and 6 Quarter Horses). Methods: Venous blood was collected from each horse prior to and 0.25, 0.5, 0.75, 1, 2, 3, 4, 4.5, 5, and 6 hours after administration of 250 or 500 mg of furosemide. Concentrations of furosemide were determined, using an ELISA. Concentration of furosemide was modeled as a function of time, accounting for inter- and intrahorse variabilities. On the basis ...
Graves KT, Eberth JE, Bailey E.Homozygous and compound heterozygous Miniature horses for ACAN alleles D1, D2, D3* and D4 exhibit chondrodysplastic dwarfism (OMIA 001271-9796). In a previous study, the carrier rate for these four alleles, combined, was 26.2%. The purpose of this study was to investigate whether carriers of these dwarfism-causing alleles had a shorter withers height than non-carriers. A total of 245 Miniature horses were tested for these four ACAN alleles and also were measured for withers height. Of these horses, 98 were carriers and 147 were non-carriers. A statistically significant difference of 1.43 inche...
Satué K, Fazio E, Cravana C, Medica P.The evidence that androgens regulate the folliculogenesis supports the hypothesis that intrafollicular testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA) could be modified along follicular growth. The objective of this study was to evaluate the changes and related relationships between systemic and intrafollicular T, A and DHEA in post-deviation and impending ovulation follicles. Sixty ovaries were taken after the slaughter of 30 clinically healthy mares. In according to the sizes, the follicles were classified in 3 different categories, as small (20-30 mm), medium (31-40 ...
Lumsden JM, Stick JA, Caron JP, Nickels FA.Medical records of 51 horses with epiglottic entrapment were reviewed, and the outcome after surgical treatment was evaluated by use of results from a survey of owners and from race records. Horses with epiglottic entrapment and no additional problem (uncomplicated) of the nares, nasal passages, pharynx, or larynx (upper airway) that were treated by transoral axial division (group 1) or resection via laryngotomy (group 2), and horses with epiglottic entrapment complicated by an additional upper airway abnormality (group 3) were compared. The cost of treatment, duration of hospitalization, time...
Albu I, Georgia R, Georoceanu M.The Haversian canal system in the diaphysial compacta of the femur in 4 mammalian species (dog, pig, bovine, horse) was studied on the decalcified bone using a method developed by the authors. In the microscopic studies we found that in all species the network aspects vary with the depth of the compacta layer. In all layers, there is a background of longitudinal canals with more or less regular trajectories describing large curves. The anastomoses linking them are main elements that define the variety of the network aspects both from layer to layer and from species to species. The canal densit...
Borgsteede FH, Bruin G, Smolders EA.In 1983 and 1984 the effect of a deworming scheme, in which horses were treated at turn out and 4 and 8 weeks later, on the egg output, larval differentiation, weight gain, herbage infestation and in 1984, the percentages of some serum proteins were tested. In 1983 the experiment was done with 42 mares, 54 two year old male horses and 42 male yearlings, kept in groups with permanent or rotational grazing. In 1984 only 90 male yearlings were investigated. In 1983 albendazole and ivermectin were used, 1984 ivermectin. The results of the faecal examinations showed that after ivermectin treatment ...