"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.
Dabareiner RM, White NA.Medical records from all horses with large colon impaction admitted between 1985 and 1991 were examined. Large colon impaction was diagnosed in 147 of 1,100 (13.4%) horses with colic. One hundred thirty horses were admitted for further evaluation of acute onset of abdominal pain after having been examined and treated by referring veterinarians, and 17 horses that were hospitalized for unrelated medical problems developed large colon impaction. Female horses (92/147; 62.6%) were more commonly affected than males. The age ranged from 1 to 29 years (median, 7.1 years). Mean duration of clinical s...
Furr MO, Lessard P, White NA.Thirty-two physical examination and laboratory variables were recorded during examination of 165 horses admitted for acute abdominal disease. Univariate analyses were performed to determine which of the variables were significantly different between horses that lived or died. Stepwise logistic regression was performed to identify variables with the best predictive value. Four variables (heart rate, peritoneal fluid total protein concentration, blood lactate concentration, and abnormal mucous membrane) remained significant when entered into the model. Histograms for each significant variable we...
Moslemi S, Silberzahn P, Gaillard JL.Explants of equine full-term placenta have been shown to synthesize 19-norandrogens from labelled androgens. Steroid metabolites were purified by silica-gel column chromatography then analysed and quantified by c18-reverse-phase HPLC coupled to a radioactive flow detector. 19-Norandrostenedione was subsequently recrystallized to constant specific activity, providing unequivocal evidence of its synthesis by the equine placenta. 19-Norandrostenedione synthesis appeared to be localized in the microsomal fraction. Regardless of the substrate used, formation of 19-norandrogens was far weaker than t...
van Rensburg IB, Jardine JE, Carstens JH, van der Walt ML.Specimens from the ileum, colon and rectum were aseptically collected from 50 consecutive horse carcases submitted for necropsy to the Department of Pathology, Faculty of Veterinary Science, University of Pretoria. These were bacteriologically examined for the presence of Salmonella. Seventeen of these were positive for Salmonella at one or more sites. Serotyping of the isolates revealed a dominance of Salmonella Hayindogo in these horses.
Wright IM, Montesso F, Kidd LJ.This paper describes the clinical and radiological features, surgical techniques used and results obtained in 6 horses with fractures of the tibial tuberosity. The horses were presented between 24 h and 8 weeks following injury. In all 6 cases, the fragments were displaced proximocranially and in 2 of these, there was comminution. Four were treated by open reduction and internal fixation using an AO/ASIF narrow dynamic compression plate and in 2 cases the fragments were removed. All horses returned to full athletic function and remained sound in follow-up times of 17-36 months. Implant removal...
Théon AP, Pascoe JR.One hundred and fifteen horses with periocular tumours were treated with iridium-192 interstitial brachytherapy. Tumours included squamous cell carcinomas (n = 52) and sarcoids (n = 63). All horses were scheduled to receive 60 Gy (minimal tumour dose) given at a low dose rate (0.034 +/- 0.010 Gy/h). The mean and median follow-up times to last contact or death were 24 and 16 months, respectively. Chronic radiation reactions included palpebral fibrosis (10.4%), cataract (7.8%), keratitis and corneal ulceration (6.9%). Cosmetic changes included permanent epilation (21.7%) and hair dyspigmentation...
Wang ZW, Yu MF, Robinson NE, Derksen FJ.The present study was conducted to determine if acetylcholine (ACh) release from airway cholinergic nerves is increased and if modulation of ACh release by prejunctional receptors is altered in horses with heaves, an obstructive airway disease characterized by airway inflammation and bronchospasm. Trachealis strips and bronchial segments of normal horses and horses affected with heaves were suspended in 2-ml tissue baths. ACh release was induced by electrical field stimulation and the bath ACh content was measured by high performance liquid chromatography (HPLC) with electrochemical detection....
Wattle O, Ekfalck A, Funkquist B, Obel N.The authors postulated that a period of forced recumbency during an acute attack of laminitis may counteract the disabling effects on the secondary epidermal laminae. On the basis of this concept a study was made of the behavior of three healthy Shetland ponies when placed in a box in which the ceiling was too low for a standing position but allowed comfortable sternal recumbency. When the height of the box was about 125% of the vertical distance between the withers and the sternum, the ponies lay calmly during most of the experimental period and the rare attempts at rising did not seem to put...
Kannegieter NJ, Dore ML.Endoscopy of the upper respiratory tract was performed in 100 horses during high speed treadmill exercise. Reasons for endoscopy were a history of an abnormal noise during exercise in 75 horses, poor performance in 17 horses and to evaluate the results of upper respiratory tract surgery in 8 horses. Of the 75 horses with a history of an abnormal noise during exercise the cause was determined in 67 (89%). Endoscopic abnormalities were detected at rest in 40 of these 75 horses (53%). In these 40 horses, a similar diagnosis as to the cause of the abnormal noise was made at rest and during exercis...
Osborne AC, Carter SD, May SA, Bennett D.An investigation was made into the possible contribution of autoimmune mechanisms to equine arthropathies. Serum and synovial fluid (SF) immune complexes and anti-collagen Type II antibodies were measured, by ELISA, in groups of horses with naturally occurring osteoarthritis (OA), osteochondritis dissecans (OCD), bone fracture, traumatised joints, synovitis, infected joints and non-diseased (control) joints. Significantly raised anti-collagen Type II antibodies were found in osteoarthritic (P < 0.02) and traumatised joint synovial fluids (P < 0.01) compared with the control, where ten of...
Campbell AJ, Gasser RB, Chilton NB.In the current study, molecular techniques were evaluated for the species identification of individual strongyle eggs. Adult worms of Strongylus edentatus, S. equinus and S. vulgaris were collected at necropsy from horses from Australia and the U.S.A. Genomic DNA was isolated and a ribosomal transcribed spacer (ITS-2) amplified and sequenced using polymerase chain reaction (PCR) techniques. The length of the ITS-2 sequence of S. edentatus, S. equinus and S. vulgaris ranged between 217 and 235 nucleotides. Extensive sequence analysis demonstrated a low degree (0-0.9%) of intraspecific variation...
Mueller PO, Hunt RJ, Allen D, Parks AH, Hay WP.The effect of intraperitoneal sodium carboxymethylcellulose (SCMC) administration on clinical outcome and survival was evaluated in horses undergoing exploratory celiotomy for acute gastrointestinal disease. Comparison of variables was made retrospectively between 44 horses that had SCMC and 92 horses (controls) not treated with SCMC. Mean age, body weight, heart rate, packed cell volume and plasma total protein of horses at admission, and convalescent period were not significantly different between control and SCMC groups. No significant differences were noted between control horses and SCMC ...
Soraci A, Benoit E, Jaussaud P, Lees P, Delatour P.Carprofen (CPF) enantiomers and their glucuronide conjugates (GLUC) were measured in plasma and bile of horses after IV administration of the racemic compound (0.7 mg/kg of body weight). The CPF was detectable in plasma for up to 72 hours after dosing, whereas GLUC appeared early (time for maximal plasma concentration, 1 hour) and was measurable transiently at low concentration (maximal plasma concentration, 0.5 microgram/ml). The enantiospecific plasma profiles indicated a clear predominance of R-CPF, whereas the stereoselectivity of the glucuronides favored S-GLUC. At 1, 2, and 12 hours afte...
Johansson KE, Pettersson B, Uhlén M, Gunnarsson A, Malmqvist M, Olsson E.Seven Swedish isolates of Ehrlichia species from the blood of four dogs and three horses with clinical granulocytic ehrlichiosis, were identified by direct solid phase DNA sequencing of polymerase chain reaction (PCR) products from the 16S rRNA gene. The amplified DNA fragments were produced with primers complementary to the universal regions, U1, U2, U5 and U8 of the 16S rRNA molecule. Identical sequences were obtained from all seven isolates. This nucleotide sequence was similar to the sequences deposited in GenBank for Ehrlichia phagocytophila and E equi. The sequence of the Swedish ehrlich...
The Journal of heredityMarch 1, 1995
Volume 86, Issue 2 129-135 doi: 10.1093/oxfordjournals.jhered.a111542
Woolf CM.One method of assessing the influence of stochastic events on phenotypic variation is to study morphological differences in paired limbs of the same individual. These limbs have identical genotypes and similar intra-uterine environments and are analogous to monozygotic twins. Common white leg markings have a multifactorial mode of inheritance in the Arabian horse. Asymmetry occurs frequently for these markings. Using computerized registration records obtained from the Arabian Horse Registry of America, Inc., the types of markings were quantified in the left foreleg and left hind leg of bay and...
Causey RC, Paccamonti DL, Todd WJ.A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew, the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates gre...
Kelley LC, Hill JE, Hafner S, Wortham KJ.Spontaneous equine pulmonary granular cell tumors were diagnosed in six mature horses at slaughter. These tumors were grossly recognized as multiple (5/6) or single (1/6) creamy white, firm nodules. The tumors, located adjacent to bronchi and bronchioles, often invaded airways, resulting in partial to complete occlusion of the lumina. Neoplastic cells were rounded to polyhedral with numerous eosinophilic cytoplasmic granules that reacted uniformly positive with S-100 and neuron-specific enolase antibodies and multifocally with glial fibrillary acidic protein antibodies. These cells were negati...
The Journal of physiologyFebruary 15, 1995
Volume 483 ( Pt 1), Issue Pt 1 201-209 doi: 10.1113/jphysiol.1995.sp020578
Hartmann J, Scepek S, Lindau M.1. We have investigated the granule size distributions in human and horse eosinophils by time-resolved patch-clamp capacitance measurements. 2. During exocytosis of single granules the electrical capacitance of the plasma membrane increases in discrete steps. The steps in horse cells are about six times larger than those in human cells in accordance with the difference in granule size. 3. In both species a multimodal capacitance step size distribution is observed with a first peak at 6-7 fF corresponding to granules with a diameter of about 450-500 nm and a surface area of about 0.7 microns2, ...
Breukink HJ, Eysker M.Now and then cases have been reported where horses died suddenly after intravenous application of Ivomec. Lethal anaphylactic reactions in horses are known to occur incidentially after intravenous application of drug dissolved in propyleneglycol or glycerolformol. Since Ivomec is registered for use in cattle, sheep and pig, its use in horses has to be regarded as 'off label use'. It is concluded that in the treatment of inhibited stages of cyathostomes ivermectin has no effect whether or not it is applied intravenously or orally. Since lethal anaphylactic reactions can occur, intravenous appli...
Hildebrand DP, Burk DL, Maurus R, Ferrer JC, Brayer GD, Mauk AG.The spectroscopic and structural properties of the His93Tyr variant of horse heart myoglobin have been studied to assess the effects of replacing the proximal His residue of this protein with a tyrosyl residue as occurs in catalases from various sources. The variant in the ferric form exhibits electronic spectra that are independent of pH between pH 7 and 10, and it exhibits changes in absorption maxima and intensity that are consistent with a five-coordinate heme iron center at the active site. The EPR spectrum of the variant is that of a high-spin, rhombic system similar to that reported for...
Raidal SL, Love DN, Bailey GD.Confinement of horses with their heads elevated for periods up to 24 hours was used to evaluate the extent and the effects of bacterial contamination of the equine lower respiratory tract. Significant (P < 0.05) increases in bacterial numbers (up to 10(9) colony forming units/mL in transtracheal aspirate derived samples) occurred within 6 or 12 hours in most horses. Pasteurella/Actinobacillus spp and Streptococcus spp were most commonly isolated. Lowering of the head for 30 minutes every 6 hours to facilitate postural drainage did not prevent multiplication of organisms to levels equivalent...
Ladefoged O, Stürup S.A case of copper deficiency or molybdenum toxicosis in cattle, sheep and horses after heavy pollution of a pasture with fly ash is described. If the pastures had not been grazed by cattle and sheep as well as the horses, it would have been difficult to identify the reason for the intoxication in the horses. It is argued that molybdenum intoxication, although seldom seen in non-ruminants, was the cause of the deaths of the horses. It is suggested that the bioavailability of molybdenum in fly ash is high and therefore can cause equine intoxication.
Wassall DA, Gregory RJ, Phipps LP.The detection of antibodies against Trypanosoma equiperdum in 689 equid sera was compared by enzyme-linked immunosorbent assay (ELISA), the complement fixation test (CFT) and an indirect immunofluorescent test (IIF). CFT was the least sensitive technique, susceptible to anti-complementary factors and the most technically demanding. IIF was more sensitive, but was only suitable for testing limited numbers of samples. In this study, ELISA was the most sensitive test, the least labour intensive and lends itself to a considerable degree of automation. It is suggested that ELISA would be relatively...
Rahman AZA, Adzahan NM, Zakaria Z, Mayaki AM.Horse wounds can be easily infected with bacteria depending on the nature of its cause such as laceration, abrasion, or puncture as well as the nature of its environment. Various treatments are available in managing open wounds, including the usage of topical antibiotics and antiseptics. However, antibiotic resistance has been a major concern attributed with chronic wound infection. The aim of this study was to test the efficacy of ionized water at different pH against the growth of common bacteria from horse wounds. Methods: Ten swab samples from equine infected wounds were collected and bact...
Nielsen BD.Much research has been conducted in an attempt to decrease skeletal injuries in athletic horses. The objective of this literature review is to compile the findings of over three decades of research in this area, make practical recommendations, and describe how research can develop over the years. An initial study investigating the role of bioavailable silicon in the diets of horses in race training produced the unexpected finding of decreased bone mineral content of the third metacarpus subsequent to the onset of training. Further studies revealed this decrease to be associated with stall hous...
de Souto EPF, Kommers GD, Souza AP, Miranda Neto EG, Assis DM, Riet-Correa F, Galiza GJN, Dantas AFM.Pythiosis is an endemic disease in northeastern Brazil and we now report the epidemiological, clinical and pathological findings in a retrospective study of naturally occurring cases in domestic animals. From January 1985 to December 2020, the Laboratory of Animal Pathology of the Federal University of Campina Grande examined 13,542 tissue samples from necropsies and biopsies. Among these samples, 306 were diagnosed as pythiosis: 195 cases in horses, 75 in sheep, 19 in dogs, six in mules, four in cattle, three in cats, two in goats, one in a donkey and one in an ostrich. Affected equids had le...
Ishak GM, Dutra GA, Gastal GDA, Elcombe ME, Gastal MO, Park SB, Feugang JM, Gastal EL.This study aimed to gain insight on the effect of different seasons of the year on the expression pattern of growth factor and hormone receptors involved in follicle development. A novel follicle wall biopsy technique was used to collect in vivo follicle wall layers (ie, granulosa, theca interna, and theca externa) and follicular fluid samples from growing dominant follicles, simultaneously and repeatedly, using the same mares during the spring anovulatory (SAN), spring ovulatory (SOV), summer (SU), and fall ovulatory (FOV) seasons. The immunofluorescent expression patterns of epidermal growt...
Freeman KP, Roszel JF, McClure JM, Mannsman R, Patton PE, Naile S.Thirty-six transtracheal washing (TTW) and 12 bronchoalveolar lavage (BAL) specimens collected in clinical practice from horses with and without respiratory disease were reviewed. Cytological features were considered in accordance with the presenting complaint, clinical signs, clinical diagnoses, microbiological, radiographic and/or endoscopic findings, therapy, and response to therapy. The trichrome-stained TTW and BAL specimens were useful in interpreting the results of concurrent microbiological cultures, and determining whether a condition was present based on occurrence of typical cytolog...
Mathisen SR, Wu HD, Sauvage LR, Walker MW.Because repeat sternotomies are becoming much more prevalent with repeat coronary bypass operations, prevention of direct adhesions of the heart and grafts to the back of the sternum by use of synthetic or xenograft material to close the pericardiotomy has become a matter for investigation. In this study bovine and equine glutaraldehyde-processed xenografts were implanted bilaterally in dogs for implant intervals of 6 weeks and 3, 6, 9, and 12 months. The bovine and equine xenografts both performed well in resisting the adhesion of the heart to their inner surfaces and less well in resisting a...
Seco Diaz O, Desrochers A, Hoffmann V, Reef VB.An 8-day-old Arabian-Morgan cross colt underwent cardiac evaluation. The foal was tachycardic, tachypneic, exercise intolerant and had a loud right-sided heart murmur and cyanotic mucous membranes. Total anomalous pulmonary venous connection was diagnosed with echocardiography and confirmed at postmortem examination. Total anomalous pulmonary venous connection is a very rare congenital cardiac abnormality that has not been reported before in the horse.
Fransson BA.This article reviews the etiology, diagnosis, and treatment of rectal perforation and rectocutaneous fistula in small animals. In addition, the literature regarding use of enterostomy in small animals is reviewed and comparative aspects of this procedure in humans and horses are presented. A case report of rectal perforation leading to rectocutaneous fistula formation and the use of colostomy in the management of the case is presented.
Spurlock SL, Spurlock GH, Donaldson LL.A 3-year-old Thoroughbred mare with signs of acute abdominal pain and chronic pneumonia was found to have pneumothorax. A single application of suction was successful in resolving the pneumothorax. The underlying pneumonia was treated with long-term antibiotic administration selected on the basis of results of bacteriologic culture and antimicrobial susceptibility testing of a transtracheal aspirate. The pneumonia resolved, and the mare returned to competition as a show hunter.
King SS, Douglas BL, Roser JF, Silvia WJ, Jones KL.There is a well-documented increase in luteolytic failure, resulting in spontaneously prolonged corpus luteum (SPCL) function, during estrous cycles of horses in autumn. The cause of this phenomenon may be due to seasonal alterations in PGF(2alpha) and/or in prolactin (PRL) secretion around luteolysis. To investigate this, progesterone (P4), 13, 14-dihydro, 15-keto PGF(2alpha) (PGFM) and PRL concentrations were compared between summer and autumn estrous cycles during natural luteolysis and luteolysis induced by benign uterine stimulation. A single estrous cycle from mares in June-July (n=12) w...
MacAllister CG, Mosier D, Qualls CW, Cowell RL.The primary hematologic abnormalities in 2 adult horses with chronic weight loss were hypoalbuminemia and hyperglobulinemia. One horse was anemic, had subclinical disseminated intravascular coagulation, and prolonged plasma sulfobromophthalein half-life. Small-intestinal dysfunction with malabsorption was indicated by abnormal D-xylose absorption test results. Clinicopathologic and pathologic findings were consistent with a diagnosis of malabsorption and protein-losing enteropathy, attributable to lymphocytic and plasmacytic infiltration of the intestine.
Lopes MAF, Hardy J, Farnsworth K, Labens R, Lam WYE, Noschka E, Afonso T, Cruz Villagrán C, Santos LCP, Saulez M, Kelmer G.Standing flank laparotomy can be an alternative to ventral midline laparotomy in horses with colic. Standing flank laparotomy avoids general anaesthesia, provides excellent access to some regions of the abdominopelvic cavity and costs less than ventral midline laparotomy. Objective: To report a series of cases of peritoneal and intestinal diseases other than SC diseases managed with standing flank laparotomy. Methods: Retrospective case series. Methods: Records from equids with colic subjected to standing flank laparotomy at five hospitals (2003-2020) were reviewed. Descriptive data analysis w...
Revold T, Ihler CF, Karlström K, Larsen S, Essén-Gustavsson B.The trotting speed of Norwegian-Swedish Coldblooded Trotters (NSCTs) is, although inferior to Standardbred speeds, gradually increasing. This development is mainly attributed to breeding progresses. Characteristics of the middle gluteal muscle have recently been described in a small number of these horses but the actual spread in muscle parameters within the population is unknown. Objective: To describe the characteristics of the middle gluteal muscle and their naturally occurring variability in young NSCT horses and investigate possible association with body size, individual breeding index an...
Blanke A, Fischer ML, Fuchs M, Schusser GF.Since there is a lack of information about the normal appearance or pathological findings of the equine external ear canal (EEEC) and tympanic membrane (TM), we aimed to find a practical way to perform the otoscopic examination in standing, sedated horses. Therefore, we worked with common veterinary video endoscopes, which are normally used for gastroscopy or bronchoscopy. Both ears each of 38 randomly selected, chemically restrained horses were otoscopically examined. 33 of those horses had no history or signs of potentially ear-associated diseases. However, two horses with vestibular disease...
Rumpler MJ, Kandala B, Vickroy TW, Hochhaus G, Sams RA.Glycopyrrolate (GLY) is an antimuscarinic agent that is used in humans and domestic animals primarily to reduce respiratory tract secretions during anesthesia and to reverse intra-operative bradycardia. Although GLY is used routinely in veterinary patients, there is limited information regarding its pharmacokinetic (PK) and pharmacodynamic (PD) properties in domestic animals, and an improved understanding of the plasma concentration-effect relationship in racehorses is warranted. To accomplish this, we characterize the pharmacokinetic-pharmacodynamic (PK-PD) actions of GLY during and after a 2...
Boorman S, Hanson RR, Velloso Alvarez A, Zhong K, Hofmeister E, Boone LH.To determine the effect of concurrent versus delayed treatment with corticosteroid on equine articular tissues also treated with local anesthetic in vitro in the presence of inflammatory mediators. Methods: Controlled laboratory study. Methods: Five geldings, one mare (aged 3-18 years). Methods: From each horse, 24 synovial and 12 osteochondral explants were cultured in a 12-well plate (2 wells/group, 2 synovial and 1 osteochondral explant/well, total 216 explants in the study). Explants were stimulated in culture medium with 10 μg/ml recombinant equine interleukin-1β and 10 μg/ml tumor...
Kalhoro AB, Rex MA.Twenty-one horses undergoing clinical surgery and diagnostic procedures received 15% glyceryl guaiacolate followed by a rapid intravenous injection of a thiobarbiturate for induction of anaesthesia. Premedication was with atropine and acepromazine. Induction was smooth and free from problems apart from transient apnoea in some horses. Maintenance of anaesthesia was with oxygen and halothane administered by means of a closed circle system with soda-lime absorber and with the vaporiser out of circuit. During the period immediately following induction, the heart rate increased and the respiratory...