"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.
Clayton HM, White AD, Kaiser LJ, Nauwelaerts S, Lavagnino M, Stubbs NC.A lightweight bracelet that provides tactile stimulation to the horse's pastern and coronet induces a higher flight arc of the hoof. This study addresses the pattern of habituation to these devices. Objective: To evaluate short-term habituation to tactile stimulation of the pastern and coronet in trotting horses. Methods: Tactile stimulation was provided by a lightweight (55 g) device consisting of a strap with seven chains that was attached loosely around the pastern. Reflective markers were fixed to the dorsal hoof wall, the forehead and over the tenth thoracic vertebra of eight sound horses...
Raudsepp T, Chowdhary BP.The pseudoautosomal region (PAR) is a genomic segment on mammalian sex chromosomes where sequence homology mimics that seen between autosomal homologues. The region is essential for pairing and proper segregation of sex chromosomes during male meiosis. As yet, only human/chimp and mouse PARs have been characterized. The two groups of species differ dramatically in gene content and size of the PAR and therefore do not provide clues about the likely evolution and constitution of PAR among mammals. Here we characterize the equine PAR by i) isolating and arranging 71 BACs containing 129 markers (1...
Moyaert H, Haesebrouck F, Dewulf J, Ducatelle R, Pasmans F.Faecal samples of sixty-six 3-day- to 6-month-old foals were screened for Helicobacter equorum DNA by means of a PCR amplifying a 1074 bp fragment of the 23S rRNA gene with primers specific for this enterohepatic Helicobacter species. H. equorum DNA was demonstrated in faeces from 28.6% of the less than 1-month-old foals, while 67.8% of foals from 1 to 6 months of age tested positive. In a previous study, H. equorum was demonstrated in faeces of 0.8-7.9% of adult horses. These results indicate that the prevalence of H. equorum in horses differs with the age of the investigated horse population...
Stokol T, Gold J, Johnson A, Ainsworth D.A 3-day-old filly was presented to the Cornell University Hospital for Animals with an umbilical hematoma and mild aspiration pneumonia. The foal underwent abdominal surgery for resection of the hematoma. Recovery was uneventful, but 3 days after surgery, the foal became progressively tachypneic. Imaging studies revealed bilateral pleural effusion and pleuropneumonia. Cytologic evaluation and bacterial culture of the pleural fluid from both sides of the chest revealed sterile exudates, consisting mostly of neutrophils, with fewer macrophages and lymphocytes. Pleural fluid macrophages contained...
Pratt SM, Christian JA, Paige Jackson L, Hawkins JF, Sojka JE.A 16-year-old castrated male Arabian horse was presented to the Purdue University Veterinary Teaching Hospital with a 4-hour history of colic. Initial examinations provided strong evidence for small intestinal obstruction. Abdominal surgery revealed a strangulating lipoma, and 25 feet of small intestine were resected. Postoperatively, the horse developed obstructive ileus due to adhesion formation, which required a second laparotomy. During and after surgery, the abdomen was lavaged with sodium carboxymethylcellulose (CMC). One week after the second surgery, evaluation of peritoneal fluid reve...
Bauer N, Moritz A.Besides flow cytometric detection of cellular hemoglobin (HGB) concentration, the ADVIA 2120 uses a novel cyanide-free colorimetric method to determine extracellular total HGB concentration. In human samples, the results are equivalent to those of the cyanmethemoglobin method on the ADVIA 120. Cyanide-free HGB measurement has not been evaluated in animal samples. Objective: The aim of this prospective study was to compare the 3 methods of HGB analysis on the ADVIA 2120 and ADVIA 120 in blood samples from dogs, cats, and horses. Methods: Consecutive fresh K(3)EDTA blood samples from 119 dogs, 1...
Traversa D, Kuzmina T, Kharchenko VA, Iorio R, Klei TR, Otranto D.This study investigated the genetic variability within Cylicocyclus nassatus (Nematoda, Strongylida, Cyathostominae) collected from different domestic and wild hosts (i.e. horse, donkey, Przewalskii horse, tarpan and Turkmen kulan) and localities in Europe and/or USA. The ribosomal Internal Transcribed Spacer 2 (ITS2) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were PCR-amplified and sequences characterized from seventy individual parasitic specimens. While ITS2 displayed 0-0.6% variation rate among all individual adult specimens of C. nassatus examined, 22 different seque...
Vandekerckhove A, Glorieux S, Broeck WV, Gryspeerdt A, van der Meulen KM, Nauwynck HJ.An in vitro model of the upper respiratory tract of the horse was developed to investigate mechanisms of respiratory diseases. Four tissues of the upper respiratory tract of three horses were collected. Explants were maintained in culture at an air-liquid interface for 96h. At 0, 24, 48, 72 and 96h of cultivation, a morphometric analysis was performed using light microscopy, scanning electron microscopy and transmission electron microscopy. The explants were judged on morphometric changes of epithelium, basement membrane and connective tissue. Viability was evaluated using a fluorescent Termin...
Rakesh V, Datta AK, Ducharme NG, Pease AP.Computational model for airflow through the upper airway of a horse was developed. Previous flow models for human airway do not hold true for horses due to significant differences in anatomy and the high Reynolds number of flow in the equine airway. Moreover, models that simulate the entire respiratory cycle and emphasize on pressures inside the airway in relation to various anatomical diseases are lacking. The geometry of the airway was created by reconstructing images obtained from computed tomography scans of a thoroughbred racehorse. Different geometries for inhalation and exhalation were ...
Haritou SJ, Zylstra R, Ralli C, Turner S, Tortonese DJ.Equine pituitary pars intermedia dysfunction (PPID) is a common and serious condition that gives rise to Cushing's disease. In the older horse, it results in hyperadrenocorticism and disrupted energy metabolism, the severity of which varies with the time of year. To gain insight into the mechanism of its pathogenesis, 24-h profiles for peripheral plasma melatonin, serotonin, dopamine and cortisol concentrations were determined at the winter and summer solstices, and the autumn and spring equinoxes in six horses diagnosed with Cushing's disease and six matched controls. The nocturnal rises in p...
Coutinho da Silva MA.The use of assisted reproductive techniques (ART) has helped owners to produce offspring from valuable mares that were considered infertile using standard breeding techniques. Before referring a mare for an ART, the practitioner should be able to identify the underlying cause of subfertility of the mare. The objective of this review is to provide information regarding embryo transfer, oocyte transfer and intracytoplasmic sperm injection, the three most common ART used in equine practice. Knowing the complexity as well as the risks of these techniques, enables practitioners to refer a subfertil...
Figueiredo MD, Moore JN, Vandenplas ML, Sun WC, Murray TF.To evaluate proinflammatory effects of the second-generation synthetic lipid A analogue E5564 on equine whole blood and isolated monocytes and to determine the ability of E5564 to prevent LPS (lipopolysaccharide)-induced procoagulant activity (PCA); tumor necrosis factor (TNF)-alpha production; and mRNA expression of TNF-alpha, interleukin (IL)-1beta, IL-6, and IL-10 by equine monocytes. Methods: Venous blood samples obtained from 19 healthy horses. Methods: Whole blood and monocytes were incubated with Escherichia coli O111:B4 LPS, E5564, or E5564 plus E coli O111:B4 LPS. Whole blood and cell...
Brosnan RJ, Esteller-Vico A, Steffey EP, LeCouteur RA, Liu IK, Vaughan B.To test the hypothesis that head-down positioning in anesthetized horses increases intracranial pressure (ICP) and decreases cerebral and spinal cord blood flows. Methods: 6 adult horses. Methods: For each horse, anesthesia was induced with ketamine hydrochloride and xylazine hydrochloride and maintained with 1.57% isoflurane in oxygen. Once in right lateral recumbency, horses were ventilated to maintain normocapnia. An ICP transducer was placed in the subarachnoid space, and catheters were placed in the left cardiac ventricle and in multiple vessels. Blood flow measurements were made by use o...
Anderson JD, Galuppo LD, Barr BC, Puchalski SM, Macdonald MM, Whitcomb MB, Magdesian KG, Stover SM.To describe clinical and scintigraphic abnormalities in horses with a bone fragility disorder. Methods: Retrospective case series. Methods: 16 horses with scintigraphic evidence of multiple sites of increased radiopharmaceutical uptake (IRU). Procedures-Medical records were reviewed for information on signalment; history; clinical, clinicopathologic, and diagnostic imaging findings; and treatment. Follow-up information was obtained through telephone interviews with owners. Results: Horses ranged from 4 to 22 years old; there were 8 castrated males and 8 females. Foci of IRU most commonly invol...
Firshman AM, Valberg SJ, Baird JD, Hunt L, DiMauro S.To determine insulin sensitivity, proportions of muscle fiber types, and activities of glycogenolytic and glycolytic enzymes in Belgians with and without polysaccharide storage myopathy (PSSM). Methods: 10 Quarter Horses (QHs) and 103 Belgians in which PSSM status had been determined. Methods: To determine insulin sensitivity, a hyperinsulinemic euglycemic clamp (HEC) technique was used in 5 Belgians with PSSM and 5 Belgians without PSSM. Insulin was infused i.v. at 3 mU/min/kg for 3 hours, and concentrations of blood glucose and plasma insulin were determined throughout. An i.v. infusion of g...
Koenig JB, Martin CE, Nykamp SG, Mintchev MP.To evaluate whether changes in myoelectrical activity in the cecum and large colon of horses can be detected via multichannel electrointestinography (EIG). Methods: 6 healthy mature horses. Methods: Each horse underwent 3 EIG procedures. Intestinal myoelectrical activity (cecum and large colon) was recorded during a 20-minute period following i.v. administration of physiologic saline (0.9% NaCl) solution (20 mL; baseline), erythromycin lactobionate (0.5 mg/kg), or detomidine (0.015 mg/kg); intestinal contractions were concurrently viewed via B-mode ultrasonography. By use of computer software,...
Higgins JK, Puschner B, Kass PH, Pusterla N.To determine concentrations of alpha-tocopherol in serum and CSF of healthy horses following administration of supplemental vitamin E in feed. Methods: 10 healthy adult horses. Methods: Horses were allocated to receive supplemental d-alpha-tocopherol (1,000 U/d [group A; n=5] or 10,000 U/d [group B; 5]) in feed for 10 days. Blood samples were collected before (baseline), during, and at intervals for 10 days after discontinuation of vitamin E administration for assessment of serum alpha-tocopherol concentration. Cerebrospinal fluid samples were collected prior to and 24 hours after cessation of...
le Jeune SS, Nieto JE, Dechant JE, Snyder JR.Gastroscopic examinations were performed in 62 Thoroughbred broodmares (33 pregnant, 29 non-pregnant) at one breeding farm to investigate the prevalence of gastric ulceration. Age, pregnancy status, race earnings, last race start, herd size, medical history, number of live foals, breeding years, feed type and number of feedings were recorded, plus coat condition and body condition score were determined. Twenty-one mares were re-evaluated after foaling, and the foaling date, foal weight at birth and placenta weight were recorded. The overall prevalence of gastric ulcers was 70.9%, with a median...
Wild TF.Paramyxoviruses have been implicated in both animal and human infections. Some viruses, such as Morbilliviruses are responsible for large-scale epidemics. However, there are limited observations of these viruses crossing the host species barrier in nature. In 1994, in Australia a fatal infection in horses and humans was identified to be caused by a new Paramyxovirus, Hendra virus (HeV), and in 1998 in Malaysia, a closely related virus, Nipah virus (NiV) was responsible for fatal infections in pigs and humans. These two viruses were sufficiently different from previously described Paramyxovirus...
Ramzan PH, Marr CM, Meehan J, Thompson A.A novel radiographic projection is described for assessing part of the temporomandibular articulation of horses. It minimises the superimposition of osseous structures of the cranium that limit the usefulness of conventional projections and permits improved imaging in cases of suspected disease.
Arroyo LG, Vengust M, Dobson H, Viel L.A 10-day-old quarter horse colt was presented for signs of disorientation and inability to nurse. Hydronephrosis/hydroureters, with concomitant pyelonephritis and a severe electrolytes disturbance, were diagnosed. The clinical findings closely resembled those described for a syndrome of transient pseudohypoaldosteronism in human neonates. Un poulain Quarter horse âgé de 10 jours a été présenté pour des signes de désorientation et d’incapacité à se nourrir. Une hydronéphrose/hydrouretères avec pyélonéphrite concomitante et débalancement électrolytique sévère ont été diagno...
Leblanc MM.Most equine infertility cases can be solved with a methodical, thorough physical and reproductive examination and appropriate diagnostic laboratory aids. Repeated examinations may be needed in some cases to identify subtle anatomical abnormalities or irregularities between hormonal and physiological relationships of the reproductive tract. For pregnancy to occur, hormonal signaling must be exquisitely synchronized with physical changes of the reproductive tract and deposition of fertile semen in the uterus. Asynchrony of these events, infection, inflammation, previous trauma to the reproductiv...
Laha R, Sasmal NK.Diagnosis of Trypanosoma evansi infection in a horse stable of Eastern Region of India on the basis of examination of Giemsa stained blood smears have been done. A high percentage (12.74%) of horses of this stable was found suffering from T evansi infection. This high prevalence of T evansi in horses, in this area could be considered as an alarming situation which has never been explored previously in horses of Eastern Region of India. After a period of 2 months and 18 days of treatment with quinapyramine sulphate and quinapyramine chloride, reinfection with T evansi in treated horses of this ...
Merritt JS, Davies HM, Burvill C, Pandy MG.The equine distal forelimb is a common location of injuries related to mechanical overload. In this study, a two-dimensional model of the musculoskeletal system of the region was developed and applied to kinematic and kinetic data from walking and trotting horses. The forces in major tendons and joint reaction forces were calculated. The components of the joint reaction forces caused by wrapping of tendons around sesamoid bones were found to be of similar magnitude to the reaction forces between the long bones at each joint. This finding highlighted the importance of taking into account muscle...
Probst A, Macher R, Hinterhofer C, Polsterer E, Guarda IH, König HE.This study aims to elucidate the topographical anatomy of the carpal flexor retinaculum or palmar anular carpal ligament (PACL) in the horse. Ten specimen of the carpus of five healthy horses were studied by dissection in layers. Slices of 5 mm in thickness facilitated observation of the soft tissues. The superficial layer of the PACL subdivides into five compartments: one for the palmar nerve and the arterial and venous branches, one for only the radial artery, one for the radial vein, and one for the tendon of the radial carpal flexor muscle, and finally for the deep layer that supports all ...
Araújo JA, Curcio B, Alda J, Medeiros RM, Riet-Correa F.Two outbreaks of Hypochaeris radicata-induced Australian stringhalt involving two farms and seven horses from southern Brazil are reported here. Subsequently, the disease was experimentally reproduced in a feeding trial with one colt fed H. radicata from the suspect paddocks. Fresh H. radicata was fed to the experimental animal for 50 days at an average daily dosage of 9.8 kg. Initially, the plant was collected from the paddock where the clinical disease occurred and was fed for 19 consecutive days producing mild clinical signs. However, on days 20-23 fresh plant was collected from a neighbori...
Liu IK, Troedsson MH.Diagnosis and treatment of endometritis in the mare has been controversial and mostly empirical. The lack or inability of researchers to establish or develop a model that can serve as a standard or control makes this area of equine reproduction difficult to address scientifically. However, major advances have been made, particularly with the demonstration of the importance of uterine contractility in the elimination of bacteria, fluid, and inflammatory products from the uterus after breeding. This review provides a historical perspective of what has been done, and where we are now, in the appr...
Gálvez N, Fernández B, Sánchez P, Cuesta R, Ceolín M, Clemente-León M, Trasobares S, López-Haro M, Calvino JJ, Stéphan O, Domínguez-Vera JM.Transmission Electron Microscopy (TEM), X-ray Absorption Near Edge Spectroscopy (XANES), Electron Energy-Loss Spectroscopy (EELS), Small-Angle X-ray Scattering (SAXS), and SQUID magnetic studies were performed in a batch of horse spleen ferritins from which iron had been gradually removed, yielding samples containing 2200, 1200, 500, and 200 iron atoms. Taken together, findings obtained demonstrate that the ferritin iron core consists of a polyphasic structure (ferrihydrite, magnetite, hematite) and that the proportion of phases is modified by iron removal. Thus, the relative amount of magneti...
Hughes JP, Trommershausen-Smith A.Reproductive failure was studied in 12 phenotypically normal mares (9 Arabian, 3 Quarter horses, 1 Appaloosa and 1 pony). Karyotyping was performed using lymphocytes isolated from peripheral blood by density gradient procedures, followed by standard culture methods for karyotyping. Nine mares had karyotypes of 63,XO; 1 had 63,XO/64,XX; 1 had 63,XO/64,XY and 1 had 64,XY. All mares had small, firm ovaries that when removed and examined from 4 mares, lacked germ cells and consisted of undifferentiated ovarian stroma.
Sullins KE, Messer NT, Nelson L.Twenty-one adult horses were randomly assigned into 7 groups of 3 and were treated for 5 days with procaine penicillin G, benzathine penicillin , or phenylbutazone in various combinations and dosage schedules. Serum concentration of penicillin was measured serially over a 7-day period. The highest mean peak serum concentration was 2.06 micrograms/ml. Comparable peak values were seen 2 to 4 hours after administration of 22,000 IU of procaine penicillin G/kg of body weight given once or twice daily. A minimum serum concentration of 0.25 micrograms/ml was selected as adequate for efficacy against...
Enck KM, Lee KW, McKinney BH, Blankenship KD, Montesano C.It has been demonstrated that immunoglobulin (Ig)E specific for cross-reactive carbohydrate determinants (CCD) is present in the serum of sensitized humans, dogs and cats, and that these CCD-specific antibodies might confound serological testing. Objective: The objective was to determine whether or not CCD-reactive antibodies occur in horses and to investigate the prevalence of CCD-reactive IgE antibodies in equine sera using a monoclonal cocktail-based enzyme-linked immunosorbent assay designed to detect allergen-specific IgE in horses, and to evaluate a means for successful inhibition of the...
Carstens A, Kirberger RM, Dahlberg LE, Prozesky L, Fletcher L, Lammentausta E.The purpose of this study was to determine whether delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping are accurate techniques for measuring cartilage thickness in the metacarpus3/metatarsus3 (Mc3/Mt3) of Thoroughbred racehorses. Twenty-four Mc3/Mt3 cadaver specimens were acquired from six healthy racehorses. Cartilage thickness was measured from postintra-articular Gd-DTPA(2-) images acquired using short tau inversion recovery (STIR), and proton density weighted (PDw) sequences, and compared with cartilage thickness measured from corresponding histolog...
McDonnell SM, Garcia MC, Kenney RM, Van Arsdalen KN.Imipramine hydrochloride was administered to five male horses (400-500 kg b.wt.): one experienced young stallion, two mature normal breeding stallions, one 5-year-old stallion with erection and ejaculatory dysfunction, and one long-term castrated male horse. Oral imipramine treatment (100 to 600 mg, twice daily) led to frequent erection and masturbation while at rest in the stall in a nonsexual context. Intravenous imipramine treatment over a range of doses (50 to 1000 mg) similarly induced erection and masturbation in all animals. Erection typically occurred within 10 minutes after injection,...
Péters F, Franck T, Pequito M, de la Rebière G, Grulke S, Salccicia A, Verwilghen D, Chiavaccini L, Deby-Dupont G, Serteyn D.The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro. In this study the inhibition of the production of reactive oxygen species (ROS) by neutrophils was studied in two groups of horses, which received a dose of 0.1 mg/kg of either acepromazine or promethazine intravenously. Blood samples were collected before (T0) and 0.5, 1, 3 and 5 h after drug administration. The chemiluminescence (CML) response of neutrophils was measured ex vivo in the presence of luminol for a period of 10 min and the maximum CML value (peak value) record...
Williams MM, Davis EG, KuKanich B.The objective of the study was to assess the pharmacokinetics of terbinafine administered orally to horses and Greyhound dogs. A secondary objective was to assess terbinafine metabolites. Six healthy horses and six healthy Greyhound dogs were included in the pharmacokinetic data. The targeted dose of terbinafine was 20 and 30 mg/kg for horses and dogs, respectively. Blood was collected at predetermined intervals for the quantification of terbinafine concentrations with liquid chromatography and mass spectrometry. The half-life (geometric mean) was 8.1 and 8.6 h for horses and Greyhounds, respe...
Bustos CP, Dominguez JE, Garda D, Moroni M, Pallarols Molinari N, Herrera M, Chacana PA, Mesplet M.Salmonella spp. causes digestive clinical signs in horses. Foals and hospitalized animals are more susceptible to the disease. Nowadays, the report of multidrug-resistant Salmonella spp. producer of extended-spectrum β-lactamases, is more frequent. The aim of this work was to study the clonal relationship and antimicrobial susceptibility profiles among Salmonella ser. Typhimurium isolates, obtained during a salmonellosis outbreak in an Argentinian equine hospital. Thus, in 2017, we studied the genotypic profiles and the susceptibility to antimicrobials of the strains isolated from three anima...
Pitel MO, McKenzie EC, Johns JL, Stuart RL.Selenium or alpha-tocopherol deficiency can cause neuromuscular disease. Beta-carotene has limited documentation in horses. Objective: To evaluate the effect of owner practices on plasma beta-carotene concentration and risk of selenium and alpha-tocopherol deficiencies. Methods: Three-hundred and forty-nine adult (≥1 year), university and privately owned horses and mules. Methods: Cross-sectional study. Whole blood selenium, plasma alpha-tocopherol, and plasma beta-carotene concentrations were measured once. Estimates of daily selenium and vitamin E intake, pasture access, and exercise loa...
Hanche-Olsen S, Kielland C, Ihler CF, Hultin Jäderlund K.Acquired equine polyneuropathy (AEP), a neurological disease clinically characterised by knuckling of metatarsophalangeal joints, has been described in numerous Nordic horses during the last 20 years. Although clinical recovery has been reported, large-scale data on long-term follow-up of survivors have been lacking. Objective: To describe long-term survival of AEP affected horses registered in Norway, with a focus on athletic performance and possible residual clinical signs connected to the disease. Methods: A retrospective cohort study. Methods: The study includes 143 horses recorded with A...
Byrne CA, Marshall JF, Voute LC.Investigation of image quality in clinical equine magnetic resonance (MR) imaging may optimise diagnostic value. Objective: To assess the influence of field strength and anaesthesia on image quality in MR imaging of the equine foot in a clinical context. Methods: Analytical clinical study. Methods: Fifteen equine foot studies (five studies per system) were randomly selected from the clinical databases of three MR imaging systems: low-field standing (LF St), low-field anaesthetised (LF GA) and high-field anaesthetised (HF GA). Ten experienced observers graded image quality for entire studies an...
Gronqvist G, Rogers C, Gee E, Bolwell C, Gordon S.Students enrolled in veterinary degrees often come from an urban background with little previous experience in handling horses and other large animals. Many veterinary degree programmes place importance on the teaching of appropriate equine handling skills, yet within the literature it is commonly reported that time allocated for practical classes often suffers due to time constraint pressure from other elements of the curriculum. The effect of this pressure on animal handling teaching time is reflected in the self-reported low level of animal handling competency, particularly equine, in stude...
Baker D, Kreeger J.An expansile, yellow, soft mass was observed in the free wall of the right ventricle of a 3-year-old, male, Morgan, horse at necropsy. The mass was composed of well differentiated adipocytes in solid sheets or infiltrating between muscle fibers with associated myofiber degeneration. The mass was interpreted to be an infiltrative lipoma of the heart.
Beech J.The cytology of cerebrospinal fluid samples from horses is described. The samples were obtained from 24 normal horses, 35 horses with axonal degeneration and/or spinal cord compression, 29 horses with encephalomyelitis, 14 horses with other lesions of the nervous system, and eight horses with signs of neurologic dysfunction of undetermined origin. (Three of the latter were suspected botulinum intoxications.) Fluid was aspirated from the atlanto-occipital space following general anesthesia or immediately after a lethal dose of barbiturate. In two horses, fluid also was aspirated from the lumbos...
Beech J, Fletcher JE, Lizzo F, Johnston J.In vitro twitch characteristics of the semimembranosus muscle were evaluated in 9 clinically normal horses, in 15 horses with chronic intermittent rhabdomyolysis (CIR) and in 2 horses with myotonia. Effects of phenytoin on in vitro muscle twitch and clinical signs of CIR and myotonia were evaluated in these same horses. Times to 90% relaxation were prolonged in the horses with CIR (mean +/- SEM, 186 +/- 5.9 ms) and in 2 horses with myotonia (197 and 177 ms) compared with those in clinically normal horses (mean +/- SEM, 146 +/- 2.1 ms). Horses with CIR also had significantly (P less than 0.05) ...
Palmer E.The use of photoperiod, progestagen, prostaglandin and hCG treatments was investigated to obtain mating of mares at predetermined times. The objectives were: (1) synchronization of oestrus at an early time of the year, (2) simplification of treatment schedules by use of vaginal sponges, and (3) use of several controlled cycles by successive synchronization. The following conclusions were reached. First, after a 16 h photoperiod was applied beginning on 25 November, hormonal synchronization of oestrus and ovulation followed by cyclicity were obtained on 1 February; i.e. 2 months of light are es...
Wolff C, Egenvall A, Hanche-Olsen S, Gröndahl G.Acquired equine polyneuropathy (AEP) is an emerging disease in horses in Sweden, Norway and Finland since 1995. Affected horses show bilateral pelvic limb knuckling and weakness, sometimes progressing to recumbency and euthanasia. The aetiology is unknown but is thought to be non-infectious and non-genetic, though possibly toxic or toxico-infectious. The objectives of this study were to describe the spatial, temporal and spatio-temporal features of AEP in Norway and Sweden for the period of 1995 to 2012. Data from all documented case farms (n = 136) were used. Space-time interaction cluste...
Williams D, Siock P, Stenn K.A major challenge to the study of hair follicle growth is an appropriate assay system. Because equine mane follicles are large and noncurved, enabling easy dissection; are readily accessible from a single defined source; and possess a long anagen growth phase, we initiated a study of them in culture. As in our previous studies of human and sheep follicles (Dev Biol 165:469, 1994), we found in this system that transection level dictates the pattern of follicle growth in vitro: follicles transected below the sebaceous gland show a type 1 growth pattern (the shaft grows out with an adherent sheat...
Rosenkrantz W.Pemphigus foliaceus is the most common autoimmune skin disease in horses and is associated with the production of autoantibodies directed against surface proteins of the keratinocyte. Pemphigus vulgaris is a rare autoimmune skin disease in horses. Systemic lupus erythematosus and cutaneous lupus erythematosus are recognized in horses and both are rare. Bullous pemphigoid is a rare autoimmune disease in horses caused by immunologic attack of the basement membrane zone by autoantibodies. Erythema muliforme is an immunologic reaction in the skin in which keratinocyte cell death is the prominent c...
Lindsay DS, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in the Americas. The apicomplexan protozoan most commonly associated with EPM is Sarcocystis neurona. A direct agglutination test (SAT) was developed to detect antibodies to S. neurona in experimentally infected animals. Merozoites of the SN6 strain of S. neurona collected from cell culture were used as antigen and 2-mercaptoethanol was added to the antigen suspension to destroy IgM antibodies when mixed with test sera. Mice fed sporocysts of S. speeri or S. falcatula-like sporocysts from opossums did not sero...
Radcliffe CH, Woodie JB, Hackett RP, Ainsworth DM, Erb HN, Mitchell LM, Soderholm LV, Ducharme NG.To compare upper airway mechanics, arterial blood gases, and tracheal contamination in horses with induced left laryngeal hemiplegia (recurrent laryngeal neuropathy [RLN]) treated by laryngoplasty/vocal cordectomy (LPVC) or modified partial arytenoidectomy (MPA). Methods: Repeated measures under the following conditions: Control, RLN, LPVC, and MPA. Methods: Six horses. Methods: Two trials were conducted under all conditions at 80% and 100% of maximal heart rate (HR(max)). In Trial 1, arterial blood gases, tracheal and pharyngeal pressures, and laryngeal videoendoscopy were recorded. In Trial ...
Andrade DGA, Cerri FM, Barbosa GVM, Basso RM, Takahira RK, Pantoja JCF, Oliveira-Filho JP, Borges AS.Analysis of the cerebrospinal fluid (CSF) is important as a complementary test in horses with neurologic diseases, and sequential analysis may provide information about the treatment response or evolution and quantitative measures of the CSF drug concentration during treatment. The aim of this study was to compare erythrocyte and nucleated cell counts and protein concentration in multiple CSF samples obtained sequentially from two different puncture sites in clinically healthy horses. Eight and 12 horses, with no evidence of neurologic disease, were subjected to CSF collection from the atlanto...
Fries M, Montavon S, Spadavecchia C, Levionnois OL.Methods of evaluating locomotor activity can be useful in efforts to quantify behavioural activity in horses objectively. Objective: To evaluate whether an accelerometric device would be adequate to quantify locomotor activity and step frequency in horses, and to distinguish between different levels of activity and different gaits. Methods: Observational study in an experimental setting. Methods: Dual-mode (activity and step count) piezo-electric accelerometric devices were placed at each of 4 locations (head, withers, forelimb and hindlimb) in each of 6 horses performing different controlled ...
Herd RP, Donham JC.Thirty-one horses with naturally occurring summer sores were given a single IM injection of 0.2 mg of ivermectin (22,23-dihydroavermectin B1)/kg during the summer of 1980. Larvae of Draschia and/or Habronema spp were recovered from biopsy samples taken from 21 of 25 horses (84%) on the day of anthelmintic treatment. There was a marked clinical improvement in 26 horses (84%) 7 days after ivermectin was given. The typical summer sore was replaced by healthy pink granulation tissue at 7 days and this healed after 1 to 5 weeks. Biopsy samples were taken from 21 of these horses 1 to 6 weeks after t...
Juśkiewicz J, Fotschki B, Jaworska J, Siemieniuch M.Gastrointestinal microbiota play a key role in the nutrients digestion and hence maintaining animal health and welfare. The diet offered to the animals in captivity may differ considerably from that on natural pastures. In a stabled maintenance system, horses have a limited choice of habitat and feed. Time spend for feeding is relevant for equine welfare because the reduction of the time devoted for foraging may be responsible for inducing gastric inflammation and ulceration. Therefore, in the present study, it was hypothesized that fecal bacterial fermentative processes differ between free-ro...
Galuppo LD, Stover SM, Willits NH.To compare the biomechanical properties, in full limb preparations, of intact second phalanx and a simulated comminuted second phalangeal fracture stabilized with either two bone plates or a custom Y-plate. Methods: In vitro biomechanical assessment of intact limbs and of paired limbs with a simulated second phalangeal fracture stabilized by one of two fixation methods. Animal Population-Thirteen pairs of equine cadaveric forelimbs. Methods: A comminuted second phalangeal fracture was created in six paired cadaveric limbs. For each limb pair, the fracture was stabilized with two plates in one ...
Bianco AW, Constable PD, Cooper BR, Taylor SD.Nonsteroidal anti-inflammatory drugs (NSAIDs) are an integral component of equine analgesia, yet currently available NSAIDs are both limited in their analgesic efficacy and have adverse effects. The NSAID ketorolac tromethamine (KT) is widely used in humans as a potent morphine-sparing analgesic drug but has not been fully evaluated in horses. The purpose of this study was to determine the pharmacokinetic profile of KT in horses after intravenous (i.v.), intramuscular (i.m.), and oral (p.o.) administration. Nine healthy adult horses received a single 0.5-mg/kg dose of KT via each route of admi...
