"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.
Clarke KW, Paton BS.The effects of administration of one of four opiates (pethidine 1 mg/kg bodyweight (bwt), morphine 0.1 mg/kg bwt, methadone 0.1 mg/kg bwt, and butorphanol 0.05 mg/kg bwt) given intravenously to horses and ponies already sedated with detomidine (10 micrograms/kg bwt) were investigated. Behavioural, cardiovascular and respiratory effects of the combinations were compared with those occurring with detomidine alone. Addition of the opiate increased the apparent sedation and decreased the response of the animal to external stimuli. At doses used, butorphanol produced the most reliable response. Sid...
Meyer H, Hübert PH.The production and differentiation of monoclonal antibodies (mabs) against the Rac-H strain of EHV-1 used as an attenuated live vaccine to prevent rhinopneumonitis and abortion is described. Seven different antigenic sites were detected by the 15 mabs produced. EHV-1 specific mabs as well as EHV-1 and -4 common mabs could be established, allowing easy typing of EHV isolates. One mab recognized the vaccine strain only. This reaction was used to investigate a possible involvement of the vaccine strain in cases of abortion. Common antigenic determinants with EHV-1,-3,-4 and BHV-1 could also be de...
Schneider RK, Bramlage LR, Gabel AA, Barone LM, Kantrowitz BM.The medical records and radiographs of all horses with a third carpal bone fracture admitted to The Ohio State University Veterinary Hospital from 1979 to 1987 were reviewed. Three hundred and seventy-one fractures were found in 313 horses; 57 percent were Standardbreds, 41 per cent were Thoroughbreds, and only 1.6 per cent were Quarterhorses. All were young racehorses (average age = 3.1 years). Third carpal fractures occurred more frequently in the right limb (60 percent) than the left limb (40 percent); Thoroughbreds had a greater right-left disparity (67.5 percent R, 27.1 per cent L). Fract...
Hanson RR, Nixon AJ, Calderwood-Mays M, Gronwall R.In an attempt to determine the best method for surgical removal of devitalized small colon lesions, 12 horses underwent a double small colon resection and end-to-end anastomosis. In 4 horses (study 1), an appositional single-layer (APP-1) suture pattern was compared with an inverting 2-layer (INV-2) suture pattern. In 8 horses (study 2), an appositional 2-layer (APP-2) suture pattern was compared with the INV-2 suture technique. Polydioxanone suture (size 1-0), was used. Horses were evaluated at necropsy 3, 10, 14, 28, or 56 days after surgery. Postoperative complications (peritonitis, impacti...
Whitwell KE, Harris P, Farrington PG.Four out of 12 horses grazing a field in Berkshire, England, suffered a prostrating illness and died within 12 to 72 h. Serum biochemical abnormalities, including markedly elevated muscle enzymes, were demonstrated and at post mortem widespread myodegeneration was found in both skeletal muscle and myocardium. Urine analysis revealed myoglobinuria, and renal changes were seen histologically. Although similar pathologically, the clinical syndrome and circumstances of the outbreak were not typical of equine exertional rhabdomyolysis (EER). The outbreak bore a striking resemblance to other reporte...
Kotzé SH.The veins draining the ileocaecal junctions of horses (n = 19), donkeys (n = 3) and a plains zebra, (Equus burchelli antiquorum) were injected with latex via the ileocolic vein, and dissected. In all specimens the ileocaecal papilla was drained by 2 major papillary veins: one cranial and one caudal to the papilla. A smaller dorsal vein drained either into the cranial or into the caudal vein. The submucosal veins seemed to increase in number in the ileocaeacal junction to form a venous plexus. This plexus, together with veins from the caecum and the distal ileum immediately bordering the ileoca...
Merkens HW, Schamhardt HC.Force plate and high-speed film data from a group of six walking horses were used to study the distribution of the ground reaction forces (GRF) of the concurrently loaded limbs. Three different degrees of supporting lameness were induced in a forelimb or a hindlimb using modified horse shoes. In all experiments the alterations in the distribution in the transverse horizontal GRF (Fx) were small. During unilateral forelimb lameness, the decreased longitudinal horizontal GRF (Fy) was compensated by an increase of the Fy forces of the contralateral forelimb and the ipsilateral hindlimb. The decre...
Wood T, Weckman T, Woods WE, Tobin T, Dougherty J.Variable interval (VI) reinforcement scheduling is a specific type of operant conditioning that is sensitive to drug effects even when overt clinical signs of the drug have diminished. Six horses were conditioned to break a light beam with a head-bobbing movement and this behaviour was reinforced with a reward of clean oats (approximately 30 mg/reinforcement). Initial training procedures included familiarisation with the behavioural equipment and fixed-ratio reinforced scheduling. To establish baseline rates of behaviour, the horses were converted to a variable interval (60 secs) reinforcement...
Alves RM, van Rensburg LJ, van Wyk JA.The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9,500 metacercariae. No clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and 28-34 weeks post-infestation with F. gigantica, respectively. The results...
Colahan P, Piotrowski G, Poulos P.A kinematic analysis of the instant centers of rotation analysis was performed on 21 metacarpophalangeal joints from 11 horses. Manual and computerized methods were used to locate the instant center of rotation on photocopies of transparent composite tracings of a series of radiographs of each joint. The instant centers of rotation of the proximal phalanx about the distal portion of the third metacarpal bone were located consistently on or near the eminence for attachment of the collateral ligaments. The instant centers of rotation of the sesamoids about the distal portion of the third metacar...
Lloyd KC, Kelly AB, Dunlop CI.A foal born 3 weeks prematurely was treated for respiratory distress, using a combination of oxygen therapy and mechanical ventilatory assistance. Clinical response and arterial blood gas tensions were monitored regularly. Continuous positive-airway pressure and intermittent positive-pressure ventilation administered via a nasotracheal tube were effective in improving arterial oxygenation and ventilatory function.
Anderson GS, Belton P, Kleider N.Culicoides hypersensitivity is a chronic, recurrent, seasonal dermatitis of horses that has a worldwide distribution, but has only recently been reported in Canada. It is characterized by intense pruritus resulting in lesions associated with self-induced trauma.A survey of veterinarians and horse-owners in British Columbia showed no differences in susceptibility due to the sex, color, breed, or height of the horses. The prevalence of the disease in the 209 horses surveyed was 26%. Horses sharing the same pasture could be unaffected. The disease was reported primarily from southwestern British ...
Britt DP, Clarkson MJ.The presence of benzimidazole-resistant strains of equine small strongyles was confirmed in horses at two properties in north west England by a series of faecal egg counts and larval cultures after treatment with mebendazole. A trail formulation of mebendazole in combination with piperazine citrate gave greater reductions in faecal egg counts than mebendazole alone but was much less effective than pyrantel embonate or dichlorvos.
Gopal D, Wilson GS, Earl RA, Cusanovich MA.The ion binding properties of horse, bovine, and tuna cytochrome c (both oxidized and reduced) have been measured using a combination of ultrafiltration, neutron activation, and ion chromatography. The ions investigated were chloride, phosphate, and Tris-cacodylate. Ion chromatography and neutron activation analysis techniques were employed to determine the concentration of free anions. Binding constants are obtained from modified Scatchard plots (in the range of 10-2000 M-1). The redox potentials for cytochrome c at different ionic strengths, pH 7.0, have been determined. In this paper we rep...
Pycock JF, Allen WE.Streptococcal endometritis was induced experimentally in pony mares during oestrus. Uterine fluid was collected 30, 60, 120 or 240 minutes later and tested for its effect on the in vitro morphology and chemotaxis of equine neutrophils by two independent methods. The maximal response occurred between 30 and 60 minutes after infection and persisted until 240 minutes. The chemo-attractant contained both heat labile and heat stable components and the latter appeared to be active at low concentrations.
Green P, Tong JM.Although wood chewing by horses is recognised as a common vice, there are few reports of specific disease associated with the habit. Two cases of acute obstruction of the small intestine by solid aggregations of wood splinters are described in horses which were both habitual wood chewers. Details are presented of the clinical findings in these cases, including the surgical treatment of acute colic. Both horses returned to full working fitness. The authors review the syndrome of enterolithiasis in horses, and discuss the causes and significance of wood chewing as a stable vice.
de Kok PM, Beijer NA, Buck HM, Sluyterman LA, Meijer EM.The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified only in their nicotinamide group, have been studied using AMBER molecular mechanics energy-minimization procedures. Starting geometries were taken from X-ray crystallographic data for NAD+/Me2SO/LADH reported by Eklund and co-workers. In this study the NAD+ analogues were encaged by the constituent amino acids of the enzyme within a range of 0.6 nm from the initial NAD+/Me2SO/Zn2+ complex. The calculational method used is able to rationalize individual substituent effects and to evaluate the essenti...
Schultze AE, Sonea I, Bell TG.Although primary malignant pulmonary neoplasia of horses is rarely encountered, this diagnosis was confirmed in 2 horses on the basis of necropsy and histopathologic findings. One horse, with cystic mucinous adenocarcinoma, had respiratory tract and neurologic signs directly attributable to the neoplasm, and a tentative antemortem diagnosis of pulmonary neoplasia was made. The other horse, with anaplastic bronchogenic carcinoma, did not have clinical signs of pulmonary neoplasia.
Orsini JA, Sepesy L, Donawick WJ, McDevitt D.A mare was examined for episodic choking and an abscess in the perilaryngeal region. One month before referral, the mass progressively enlarged, causing esophageal choking. An extraluminal compression of the esophagus 90 cm from the external nares was found on endoscopy and contrast radiography. Serosanguinous fluid aspirated from the mass contained keratinized squamous cells and neutrophils, compatible with an esophageal cyst. Surgical exploration was performed, with incomplete surgical excision. The remaining portion of the cyst was marsupialized and treated locally with a 2% inorganic iodin...
Stefani M, Berti A, Camici G, Manao G, Degl'Innocenti D, Prakash G, Marzocchini R, Ramponi G.Two structurally different acylphosphatases found in horse brain were purified; they were not immunologically related. The molecular masses were almost identical and the kinetic parameters were rather similar. The data reported indicate that one of the purified brain acylphosphatases and an enzyme, previously isolated from horse muscle, are the same protein. The presence of this acylphosphatase form in the brain has not been reported before. The other acylphosphatase seemed to be the same as the enzyme which had been purified from calf brain and partially characterized by Diederich and Grisoli...
Ralston SL, Nockels CF, Squires EL.Hematologic data and results of diagnostic tests were compared between aged (greater than or equal to 20 years old) and young (less than or equal to 5 years old) horses to identify hematologic and metabolic changes associated with aging. Initial data were obtained from 8 aged and 6 young mares (group 1). Similar data were collected from a second group of aged (3 mares and 3 geldings) and young (1 mare and 5 geldings) horses (group 2). Dexamethasone suppression tests (DST) and necropsies were performed on 6 additional mares and mare 8 from group 1 (group 3). Complete blood counts and serum bioc...
Wichtel JJ, Reinertson EL, Clark TL.Nonsurgical correction of uterine torsion was performed in 7 mares, and 6 foals were subsequently born alive. Uterine rupture necessitated euthanasia in 1 mare. Correction was achieved by rolling of the mares after general anesthesia had been induced. Previously, this technique was believed to be associated with a high prevalence of fetal and maternal mortality. Nonsurgical correction may be a satisfactory alternative to abdominal surgery in treating uterine torsion in mares.
Van Camp SD.The endometrial biopsy is a safe and effective means of predicting a mare's prognosis for foaling. A thorough understanding of the normal cyclic and seasonal pattern displayed by the normal endometrium is necessary before interpreting pathologic changes. Several systems for prognostic classification have been proposed, including a recent one that combines many of the criteria used in the other systems.
Goodson J, Tyznik WJ, Cline JH, Dehority BA.Microbial numbers, pH, fluid volume, and turnover rate in the pony cecum were measured during an abrupt change from an all-forage to an all-concentrate diet, both fed at maintenance energy levels. Concentrate feeding resulted in increased (P less than 0.01) numbers of total viable anaerobic bacteria. The numbers of organisms growing on selective starch medium increased (P less than 0.01) when concentrate was fed, while numbers on xylan and pectin media decreased (P less than 0.025). Seven days after the diet change to concentrate, the number of bacteria growing on lactate medium increased (P l...
Perryman LE, O'Rourke KI, McGuire TC.Six normal and four immunodeficient horses were injected with a cloned variant of equine infectious anemia virus (EIAV). The six normal horses had detectable EIAV in their plasma by 7 days postinjection. During their primary viremic episode, which was accompanied by fever and anemia, maximum titers of EIAV in plasma ranged from 10(3.8) to 10(4.8) 50% tissue culture infective doses per ml. All six normal horses cleared detectable virus from their plasma by 21 to 35 days after injection. Horses with combined immunodeficiency became viremic by 9 days postinjection and also developed anemia. In co...
Blakley BR, Skelley KW.Normal cholinesterase activity in brain tissue was measured in various mammalian and avain species. The cholinesterase activity in the cerebrum of cattle, swine, sheep and horses was approximately 2-3 umoles/min/g of tissue in each instance. The whole brain cholinesterase activity of small feral mammals was approximately 2 to 5 fold greater than the domestic animals. Considerable interspecies variability was present in the feral mammals. Similar variability was also observed in the avian brain cholinesterase determinations. The avian whole brain cholinesterase activities ranged from 9.78 to 21...
Blackburn NK, Swanepoel R.During the nine years from October 1972 to September 1981 African horse sickness (AHS) virus was isolated from 23 suspected cases of the disease in Zimbabwe and complement fixation antibody titres indicative of recent infection were detected in a further 49 horses. The 23 isolations belonged to seven of the nine known serotypes of AHS virus. In response to a questionnaire in 1980 the owners of 20% (1,654/8,000) of the horses in Zimbabwe indicated that they had recorded 207 cases of clinically diagnosed AHS with 107 deaths from 1975 to 1980. Fifty-six cases with 50 deaths had occurred in foals ...
The Journal of traumaAugust 1, 1988
Volume 28, Issue 8 1255-1259 doi: 10.1097/00005373-198808000-00020
Landercasper J, Cogbill TH, Strutt PJ, Landercasper BO.A survey of all American Veterinary Medical Association members in Minnesota and Wisconsin was conducted by questionnaire to document injuries resulting from animal treatment. Of 995 respondents, 64.6% had sustained a major animal-related injury. Seventeen per cent were hospitalized within the last year. Of those hospitalized, 25.3% required a surgical procedure. Hand injuries were most common in a veterinarian's career (52.6% of respondents), followed by trauma to the arms (27.6%), and the head (20.8%). The thorax (8.3%), genitalia (3.9%), and intra-abdominal viscera (2.8%) were injured less ...
Sturgeon BP, Milne EM, Smith KC.A 20 x 10 cm, lobulated mass was present in the perianal region of a 4-year-old Dales pony. Histopathology revealed an unencapsulated, loose arrangement of sheets and whorls of narrow mesenchymal cells, situated in the deep dermis. Intervening areas had a myxomatous appearance. The whorls were often arranged around a central structure resembling an axon or a vascular structure. Immunohistochemistry revealed that the elongated mesenchymal cells and central axon-like structures expressed vimentin, S-100, and neuron-specific enolase, but not pancytokeratin, glial fibrillary acid protein, and the ...
Labelle AL, Metzler AG, Wilkie DA.Neoplasia, for which surgical excision is a frequent treatment, is the most common disease of the equine nictitating membrane. There is little long-term follow-up information available to the practitioner regarding the long-term effects of nictitating membrane excision on ocular health. No information is available to compare recurrence of primary neoplasia of the nictitating membrane after excision with local or general anaesthesia. Objective: To evaluate the long-term complications of nictitating membrane resection in horses; recurrence of neoplasia of the nictitating membrane when nictitatin...
Nottle BF, Tatarniuk DM, Caldwell FJ, Bell CD, Caston SS, Merkatoris PT, Gillen AM, Katzman SA.To describe the presentation, diagnosis, treatment, and outcome for horses with fibro-osseous lesions of the craniofacial complex. Methods: Retrospective multicenter case series. Methods: Thirty horses evaluated for fibro-osseous lesions of the skull from January 1, 2001 through December 31, 2019 in four centers. Methods: Medical records were reviewed for signalment, clinical presentation, histological and diagnostic imaging findings, treatment instituted, and outcome. Long-term outcome information was obtained by owner questionnaire or the medical record. Results: Diagnoses included ossifying...
Dart AJ, Pascoe JR, Snyder JR.Segmental ischemic necrosis of the descending colon associated with discrete tears of the mesocolon were diagnosed in 2 mares following foaling. After foaling, both mares had a slow onset of signs of abdominal pain and gradual deterioration of clinical status. Increases in peritoneal fluid total protein concentration and WBC count and a palpable impaction of the descending colon on examination per rectum were useful diagnostic aids. Surgical intervention was successful in one mare, but not in the other.
Coffman JR, Hammond LS, Garner HE, Thawley DG, Selby LA.A COMMON progression of chronic laminitis is ischaemic
necrosis with secondary infection a frequent complication.
For 6 years we have performed a complete blood count
(CBC) on all hospitalised horses (at the University of Missouri
Veterinary Hospital) every Monday, Wednesday and Friday.
Preliminary scrutiny of the results indicated that persistent
elevation of the total white blood cell count (WBC) and
neutrophilia was consistent with poor prognosis in horses
affected with laminitis. Because of these considerations we
decided to perform a retrospective examination of the blood
cell d...
Swor TM, Watkins JR, Bahr A, Epstein KL, Honnas CM.Previous olecranon fracture reports contain a small proportion of type 5 fractures, mostly treated with conservative therapy. Objective: To evaluate the clinical details and outcome of type 5 olecranon fractures in a large group of horses treated by tension band plate fixation and to compare results with other treatment methods. Methods: Medical records of 97 cases, including 32 (33%) classified as type 5, were reviewed. Subject details, history, radiographic findings, treatment and follow-up results (2-146 months post operatively) were recorded. Results: Treatment included open reduction and ...
Hughes KJ.Ocular manifestations may develop in many systemic diseases of horses; however, signs may not be observed unless ophthalmological examination is specifically undertaken. Recognition and assessment of ocular lesions in horses with systemic disease is desirable to facilitate diagnosis and determination of treatment options and diagnosis for both the underlying systemic disease and ocular manifestations. The purpose of this article is to review systemic diseases of horses that may have ocular signs as part of the disease process. Systemic diseases are discussed in categories of pathways for devel...
Lyons ET, Drudge JH, Tolliver SC.Critical tests were conducted in 14 naturally infected equids (13 horses and 1 pony) to evaluate the antiparasitic activity of haloxon. Single doses were administered by stomach tube to 3 horses and 1 pony (60 mg/kg of body weight), by addition to the feed of 3 horses (60 mg/kg), and intraorally by powder gun to 7 horses (65 mg/kg). Haloxon was efficacious (99% to 100%) against infections of Parascaris equorum, Oxyuris equi (mature and immature), and Strongylus vulgaris at both dosage levels. Probstmayria vivipara parasites were removed in 1 horse treated at 60 mg/kg by stomach tube and S equi...
Sasaki N, Hobo S, Yoshihara T.This study concerns the establishment of a simple testing method for breath concentration of hydrogen and methane in horses. Twenty-eight healthy thoroughbreds and 24 Arabians were used. Breath samples were collected using one-minute closed circulatory respiration through an aluminum bag filled with 10 liters of pure oxygen, which was mounted on the subjects by means of a face mask. Breath samples obtained, were analyzed by gas chromatography. A significant correlation in both hydrogen and methane levels was observed for samples collected at separate times. These findings confirmed the usefuln...
Mendoza P, d'Anjou MA, Carmel EN, Fournier E, Mai W, Alexander K, Winter MD, Zwingenberger AL, Thrall DE, Theoret C.Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse....
Lang A, Brucker P, Ludwig M, Wrede T, Theunert J, Gasse H.The topographical correlations between certain extracranial and intracranial osseous points of interest (POIs), and their age-related changes, are indispensable to know for a diagnostical or surgical access to intracranial structures; however, they are difficult to assess with conventional devices. In this pilot study, the 3-dimensional coordinates of extra-/intracranial POIs were determined, thus avoiding perspective distortions that used to be intrinsic problems in 2-dimensional morphometry. The data sets were then analysed by creating virtual triangles. The sizes, shapes, and positions of t...
ALEXANDER F.No abstract available1. The magnitude of the rhythmic contractions of the perfused ileum varied with the supply of oxygen.
2. Isotonic sodium chloride solution was as good as Tyrode's solution for suspension of the red cells in the perfusion fluid.
3. Variation of the potassium and calcium content of the perfusion fluid had little effect on motility. Sodium ions had a specific function in maintaining motility.
4. The chloride ions in the perfusion fluid were replaced by bromide, phosphate and sulphate ions without affecting motility. Iodide ions were toxic.
5. The ileum perfused wi...
Puppione DL, Della Donna L, Bassilian S, Souda P, MacDonald MH, Whitelegge JP.As a continuation of our proteogenomic studies of equine apolipoproteins, we have obtained molecular masses for several of the apolipoproteins associated with the HDL in horse cerebrospinal fluid (CSF). Using electrospray-ionization mass spectrometry (ESI-MS), we report on values for apolipoproteins, A-I and A-II, as well as acylated apoA-I. In comparison with our previously published data on equine plasma apolipoproteins, there appears to be a higher percentage of acylated apoA-I in the CSF than in plasma. As was the case in plasma, apoA-II circulates as a homodimer. These studies also reveal...
Doležal P, Doležalová J, Morávková T, Stupka R.In 2018, more than 50 cases of horse death by equine atypical myopathy (AM) were reported in the Czech Republic. This disease is often associated with the toxin hypoglycine A (HGA), which is found in several maple plant materials. To monitor this toxin in products of these trees that grow in or around horse pastures, a rapid and inexpensive analytical method that can provide the required accuracy is needed. Until now, maple samples have been prepared for gas chromatography using time-consuming methods, with preparation processes taking longer than 1 h. In this work, a shorter method (25 mi...
Garner C, Stephen C, Pant SD, Ghorashi SA.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the causative agents of equine endometritis. In this study, a panel of different bacterial species, and colonies derived from bacteriological cultures of 38 clinical samples, were subjected to Loop-Mediated Isothermal Amplification (LAMP) assay and PCR, followed by high-resolution melt (HRM) curve analysis. All clinical samples were genotyped into three distinct groups based on HRM curve analysis. Differences in melting curve profiles were a reflection of DNA variation in sorD gene which was confirmed by DNA sequencing. A mat...
Roumen MP, Borgsteede FH, Vos JH.In autumn 2002 and 2003, the Animal Health Service received several young horses for post mortem investigation that had died or had been euthanised. It was found that severe cyathostominosis was the cause of death. The aetiology, pathology and diagnosis of this infection is discussed. Advice is given for preventative measures and usage of anthelmintics.