"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.
Vengust M, Wen X, Bienzle D.A 4-year-old donkey was evaluated for progressive neurological abnormalities consisting of depression, stupor, weakness, and recumbency. Diagnostic evaluation for viral involvement identified an asinine herpesvirus in DNA extracted from deep pharyngeal swabs. Specific primers were designed based on comparison with equine herpesviral DNA polymerase sequences and yielded an 875-base pair product from the donkey. This sequence had complete identity with short sequences of asinine herpesvirus previously identified in donkeys with interstitial pneumonia. Amino acid analysis of the entire sequence i...
Simhofer H, Stoian C, Zetner K.The aim of this study was to evaluate the long-term results of apicoectomy and retrograde endodontic treatment in 12 horses with apical cheek teeth infections. The affected apices were removed using a diamond bur mounted on a dental drill, and after pulp removal the root canals were filed with Hedstrøm files and then alternately flushed with sodium hypochlorite, hydrogen peroxide and alcohol. The pulp canals were dried and filled with endodontic cement and gutta-percha points. An undercut was made in the apical aspect of the root canals that were then sealed with self-curing glass ionomer cem...
Rubio-Martínez LM, Cruz AM, Gordon K, Hurtig MB.To characterize the mechanical properties of subchondral bone (SCB) of the distopalmar aspect of the condyles of the third metacarpal bone (MC3) and their correlations with structural aspects of MC3s in Thoroughbred racehorses. Methods: 12 pairs of MC3s from Thoroughbred racehorses euthanized for various reasons. Methods: MC3s were collected from horses with mild (n = 6) and with severe (6) SCB changes, as determined by micro-computed tomography (CT). Specimens of SCB plate and trabecular bone were cut from the distopalmar aspect of condyles and sagittal ridge and examined with 3-dimensional m...
Sanchez LC, Giguère S, Lester GD.To identify factors associated with short-term survival in bacteremic neonatal foals, evaluate the racing performance of Thoroughbred survivors, and evaluate changes in causative organisms and their antimicrobial susceptibility. Methods: Retrospective case series. Methods: 423 bacteremic foals. Methods: Medical records of foals that were hospitalized in 1982 through 2007 were reviewed, and those with bacteremia were included in the study. Data retrieved included signalment, physical examination and clinicopathologic findings at admission, localized infections, concurrent illnesses, duration of...
Westermann CM, Dorland B, de Sain-van der Velden MG, Wijnberg ID, Van Breda E, De Graaf-Roelfsema E, Keizer HA, Van der Kolk JH.To evaluate alterations in skeletal muscle carnitine metabolism during exercise and training by measuring changes in plasma acylcarnitine concentrations in Standardbreds. Methods: 10 Standardbred geldings with a mean +/- SD age of 20 +/- 2 months and weight of 384 +/- 42 kg. Methods: In a 32-week longitudinal study, training on a treadmill was divided into 4 phases as follows: phase 1, acclimatization for 4 weeks; phase 2, 18 weeks with alternating endurance and high-intensity exercise training; phase 3, increased training volume and intensity for another 6 weeks; and phase 4, deconditioning f...
Rubio-Martínez LM, Cruz AM, Gordon K, Hurtig MB.To characterize the microstructure of subchondral bone (SCB) plate and trabecular bone (TBB) of the distopalmar aspect of the condyles of third metacarpal bones (MC3s) from Thoroughbred racehorses at 2 different stages of SCB disease via micro-computed tomography (CT). Methods: 12 pairs of MC3s from Thoroughbred racehorses euthanized for various reasons. Methods: MC3s were collected from horses with mild (n = 6) or severe (6) SCB disease, as determined via micro-CT. Cubic (6 x 6 x 6-cm) specimens of SCB plate and TBB were cut from the palmar aspect of condyles and sagittal ridges and examined ...
Levine JM, Ngheim PP, Levine GJ, Cohen ND.To determine sex, breed, and age distributions in a population of horses with cervical vertebral compressive myelopathy (CVCM), compared with contemporaneous control horses. Methods: Retrospective case-control study. Methods: 811 horses with CVCM and 805 control horses. Methods: The Veterinary Medical Database was searched to identify horses with CVCM and contemporaneous control horses registered between July 1974 and August 2007. Admission date, admitting institution, sex, breed, age at the time of registration in the database, weight, and discharge status (alive, died, or euthanized) were re...
Choi SK, Cho CY, Yeon SH, Cho BW, Cho GJ.Genetic characterization of the Jeju horse (JH) was performed to construct a correct pedigree of the JH family. A total of 111 horses including 79 JH were genotyped using 20 microsatellite loci. The number of alleles varied from 5 to 11 (mean 7.45) in the JH. The observed heterozygosity and expected heterozygosity ranged from 0.293 to 0.891 and from 0.357 to 0.841, respectively. The polymorphic information contents (PIC) ranged from 0.335 to 0.816. AHT4, ASB2, ASB17, ASB23, CA425, HMS2, HMS3, HTG10, LEX3 and VHL20 loci had relatively high PIC values (> 0.7). The total exclusion probability ...
Jischa S, Walter I, Nowotny N, Palm F, Budik S, Kolodziejek J, Aurich C.To determine endometrial regeneration in postpartum mares by analysis of histologic features, apoptosis and cell proliferation markers, lectin binding, cytokines, and progesterone and estrogen receptors in endometrial biopsy specimens. Methods: 9 postpartum mares. Methods: Mares were examined on postpartum days 1, 9, and 16, and uterine biopsy specimens were obtained for histologic examination. Lectin binding was analyzed histochemically, and expressions of Ki-67 antigen (proliferation marker), lysozyme, and caspase 3 (apoptosis marker) were studied immunohistochemically. Gene expressions for ...
Sugiyama A, Takeuchi T, Morita T, Matsuu A, Kanda T, Shimada A, Amaya T, Hikasa Y.A 15-year-old, neutered-male pony presented with a history of weight loss during 4 months. Clinical evaluation revealed severe bradycardia and complete atrioventricular block. At necropsy, a lobulated mass in the anterior mediastinum and moderate enlargement of the superficial cervical lymph nodes were observed. The vagus nerve and the brachiocephalic trunk were embedded in this anterior mediastinal tumor. Histologically, the mass was composed of sheets of neoplastic lymphoid cells expressing CD3, with a low mitotic rate. To the best of our knowledge, this is the first reported case of mediast...
Letendre LT, Tessman RK, McClure SR, Kvaternick VJ, Fischer JB, Hanson PD.To determine pharmacokinetic parameters and variables, firocoxib concentrations in urine and plasma, urine-to-plasma ratios, and the urine depletion profile of firocoxib and to evaluate whether the pharmacokinetic behavior of firocoxib was governed by linear processes after multiple doses of firocoxib were administered IV and orally. Methods: 6 healthy female horses (5 Paint horses and 1 Quarter Horse) in experiment 1 and 12 healthy male and female horses in experiment 2. Methods: In experiment 1, 6 horses were orally administered firocoxib paste once daily for 12 consecutive days, and plasma ...
McConnico RS, Morgan TW, Williams CC, Hubert JD, Moore RM.To determine pathophysiologic effects of phenylbutazone on the equine right dorsal colon (RDC). Methods: 12 healthy adult horses. Methods: A controlled crossover observational study was conducted. Clinical and serum variables, colonic inflammation (histologic grading), and measurement of myeloperoxidase (MPO) activity, malondialdehyde (MDA) and prostaglandin E(2) (PGE(2)) concentrations, ingesta volatile fatty acid (VFA) content, and arterial blood flow in the RDC were evaluated for a 21-day period in horses administered phenylbutazone (8.8 mg/kg, PO, q 24 h) or a control substance. Results: D...
Fielding CL, Magdesian KG, Carlson GP, Rhodes DM, Ruby RE.To apply the principle of sodium dilution to calculate the changes in the extracellular fluid (ECF) volume (ECFV) and intracellular fluid volume (ICFV) that occur during dehydration and rehydration in horses. Methods: 8 healthy horses of various breeds. Methods: Horses were dehydrated over 4 hours by withholding water and administering furosemide. Saline (0.9% NaCl) solution was administered IV during the next 2 hours (20 mL/kg/h; total 40 mL/kg). Horses were monitored for an additional hour following IV fluid administration. Initial ECFV was determined by use of multifrequency bioelectrical i...
Olafsdóttir G, Svansson V, Ingvarsson S, Marti E, Torsteinsdóttir S.One of the prerequisite for developing DNA vaccines for horses are vectors that are efficiently expressed in horse cells. We have analysed the ectopic expression of the human serum albumin gene in primary horse cells from different tissues. The vectors used are of pcDNA and pUC origin and include the cytomegalovirus (CMV) promoter. The pUC vectors contain CMV intron A whereas the pcDNA vectors do not. Insertion of intron A diminished the expression from the pcDNA vectors whereas insertion of a Kozak sequence upstream of the gene in two types of pUC vectors increased significantly the in vitro ...
Sinclair EA.A pharyngeal cyst was diagnosed in a 5-year-old Dutch Warmblood mare, after presentation for coughing, dyspnea, and abnormal respiratory noise. Complete surgical excision was performed and the mare returned to normal function and performance. Histopathology found no evidence of thyroglossal duct remnants. Kyste pharyngien chez un Warmblood hollandais âgé de 5 ans. Un kyste pharyngien a été diagnostiqué chez une jument Warmblood hollandaise âgée de 5 ans qui avait été présentée pour un problème de toux, dyspnée et bruit respiratoire anormal. Une excision chirurgicale complète a é...
Burton S, Reid-Smith R, McClure JT, Weese JS.Methicillin-resistant Staphylococcus aureus (MRSA) colonization was not identified in any of 497 horses from Atlantic Canada. Methicillin-susceptible S. aureus (MSSA) was isolated from a subsample of 19/242 (7.9%) horses. Colonization with MSSA is relatively common in healthy horses in Atlantic Canada, but MRSA is currently rare or absent. Colonisation par Staphylococus aureus de chevaux en santé sur la côte atlantique du Canada. La colonisation par Staphylococus aureus résistant à la méthicilline (SARM) n’a été identifiée sur aucun des 497 chevaux testés provenant de la côte atlan...
de Raat IJ, van den Boom R, van Poppel M, van Oldruitenborgh-Oosterbaan MM.Insect bite hypersensitivity (IBH) in horses is most likely caused by Culicoides species, although other insects may also play a role. Until now no effective cure has been found for this condition, although numerous therapeutic and preventive measures have been used to control insect hypersensitivity. One such method is to apply a topical insecticide to horses. In this study, the effect of a topical insecticide containing permethrin (3.6%) was examined in seven pairs of horses. The horses were placed inside a tent trap to collect Culicoides spp. and other insects attracted to the horses on two...
Witonsky SG, Ellison S, Yang J, Gogal RM, Lawler H, Suzuki Y, Sriranganathan N, Andrews F, Ward D, Lindsay DS.Equine protozoal myeloencephalitis (EPM) due to Sarcocystis neurona infection is 1 of the most common neurologic diseases in horses in the United States. The mechanisms by which most horses resist disease, as well as the possible mechanisms by which the immune system may be suppressed in horses that develop EPM, are not known. Therefore, the objectives of this study were to determine whether horses experimentally infected with S. neurona developed suppressed immune responses. Thirteen horses that were negative for S. neurona antibodies in serum and cerebrospinal fluid (CSF) were randomly assig...
Dacre IT, Shaw DJ, Dixon PM.Histological measurements of dimensions of primary, regular secondary and irregular secondary dentine, pulp diameter and assessment of the levels of predentine, resting lines and enlarged areas of intertubular dentine were performed in apically infected mandibular and maxillary cheek teeth (CT). These examinations showed significantly reduced regular and irregular secondary dentine thickness in diseased as compared to control CT, with 21/26 infected maxillary CT and 15/18 infected mandibular CT having reduced regular secondary dentine (varying between 27.4% and 89.1% reduced secondary dentine ...
Collins J, Hanlon A, More S, Duggan V.The equine industries in Ireland are vibrant and growing. They are broadly classified into two sectors: Thoroughbred racing, and sports and leisure. This paper describes these sectors in terms of governance, education and training in equine welfare, and available data concerning horse numbers, identification, traceability and disposal. Animal welfare, and specifically equine welfare, has received increasing attention internationally. There is general acceptance of concepts such as animal needs and persons' responsibilities toward animals in their care, as expressed in the 'Five Freedoms'. As y...
Cernanská D, Paoletti B, Králová-Hromadová I, Iorio R, Cudeková P, Milillo P, Traversa D.Five horse farms located in eastern Slovakia were investigated for the presence of benzimidazole-resistant strongyles by faecal egg count reduction test and egg hatch assay. Coprocultures were prepared for each farm from faecal samples taken pre- and post-treatment and harvested larvae were molecularly examined with a Reverse Line Blot assay. Faecal egg count reduction values ranged from 0 to 52.5% and all farms were positive for benzimidazole-resistant cyathostomins. Seven benzimidazole-resistant cyathostomin species were molecularly identified on farms before and also after treatment. These ...
Wells AE, Blache D.In many equestrian pursuits such as dressage and show-jumping, it is important that the horse exhibits the same level of balance when ridden to the left as when ridden to the right in canter - that is, to show no motor bias. It is a long-held belief within such disciplines that to reduce bias that exists in horses and thus to enhance symmetry of performance to the left and right, the horse needs to be worked equally in both directions, although there is a lack of scientific evidence of this influencing bias. There also is little compelling evidence for either the existence or absence of motor ...
Tsitsimpikou C, Spyridaki MH, Georgoulakis I, Kouretas D, Konstantinidou M, Georgakopoulos CG.Flurbiprofen and its main acidic metabolites were detected in equine urine after a single-dose administration of 500 mg flurbiprofen to two 2.5-3.5-years-old mares, in order to be used in equine doping control routine analysis. The urine levels of the parent drug were determined using GC/MS. Five acidic metabolites were found in the urine. The structure of the proposed metabolites was confirmed by HRMS accurate mass measurements. The highest flurbiprofen concentration was 204 mug ml(-1) at 1-3 h post administration. Flurbiprofen could be detected for 24-37 h in urine using the standard screeni...
Adams AA, Katepalli MP, Kohler K, Reedy SE, Stilz JP, Vick MM, Fitzgerald BP, Lawrence LM, Horohov DW.Advanced age is associated with a low-grade, systemic inflammatory response characterized by increased inflammatory cytokine production both in vitro and in vivo, termed inflamm-aging. It is also known that increased white adipose tissue, associated with obesity, leads to increased production of inflammatory cytokines. To date, it is unknown whether increased adiposity contributes to the age-related increased inflammatory status. Here we show that peripheral blood mononuclear cells (PBMC) from old horses compared to young horses have increased inflammatory cytokine production; moreover, fat ol...
Parlevliet JM, Paccamonti DL, Barker SA.This study was conducted to measure the concentration of cefquinome in the endometrium of mares after intrauterine treatment and to evaluate associated inflammation. Mares (n = 14) were randomly assigned to one of the following groups: (i) control (n = 4) were either not treated (n = 2) or received (n = 2) lactated Ringer's intrauterine for 1 or 3 days; (ii) treated mares (n = 10) received intrauterine cefquinome for 1 or 3 days. After at least 10 days had passed following the last treatment and ovulation, mares were given Prostaglandin F2alpha (PGF2alpha) and were randomly assigned to an alte...
Pusterla N, Mapes S, Rejmanek D, Gebhart C.The objective of this study was to determine whether Lawsonia intracellularis was present in the feces of free-living animals collected on two equine premises with documented occurrence of equine proliferative enteropathy (EPE). Fresh feces from black-tailed jackrabbits (Lepus californicus, n=100), striped skunks (Mephitis mephitis, n=22), feral cats (Felis catus, n=14), Brewer's Blackbirds (Euphagus cyanocephalus, n=10), Virginian opossums (Didelphis virginiana, n=9), raccoons (Procyon lotor, n=4), California ground squirrels (Spermophilus beecheyi, n=3), and coyotes (Canis latrans, n=2) were...
Carstanjen B, Schönert S, Heblinski N, Gruber AD.Fibroleiomyomas of the ovary are rare. This smooth muscle tumour may develop and increase in size during pregnancy. Diagnosis is based on histological and immunohistochemical analyses. Histologically, the ovarian fibroleiomyoma consists of non-invasive bundles of smooth muscle cells that synthesize collagen-like extracellular matrix. This case report describes an ovarian fibroleiomyoma in a pregnant multiparous broodmare with a history of intermittent signs of colic.
Fairbairn SM, Lees P, Page CP, Cunningham FM.Antigen-induced airway hyperresponsiveness in allergic horses has previously been demonstrated when clinical signs of acute airway obstruction were apparent, as a consequence of exposure of animals to hay and straw for variable periods of time, and repeat measurements of hyperresponsiveness have been made no earlier than 1 week after challenge. In the present study airway responsiveness to methacholine has been measured in normal horses and allergic horses in clinical remission before and 24, 48 and 72 h after a hay and straw challenge of fixed, short, duration (7 h). Correlations between earl...
Springer A, Ehrmann C, Lembcke M, Roscher K, Strube C.Equine piroplasmosis, caused by the protozoan pathogens or , is endemic in many (sub-)tropical regions worldwide, including Southern Europe. In Germany, it mainly plays a role as an imported parasitosis. Nevetherless, tick species with known vector potential for equine piroplasms occur in Germany. Thus, a long-term establishment of autochthonous cycles after introduction via infected equids or ticks cannot be excluded. In the present case, 2 horses developed clinical infection after returning from a trail riding trip to southern France. During treatment, a feeding tick was discovered on one ...
Mizukami T, Abe Y, Maki K.In this study, the equivalence of the kinetic mechanisms of the formation of urea-induced kinetic folding intermediates and non-native equilibrium states was investigated in apomyoglobin. Despite having similar structural properties, equilibrium and kinetic intermediates accumulate under different conditions and via different mechanisms, and it remains unknown whether their formation involves shared or distinct kinetic mechanisms. To investigate the potential mechanisms of formation, the refolding and unfolding kinetics of horse apomyoglobin were measured by continuous- and stopped-flow fluore...
Greco-Otto P, Massie S, Shields E, Roy MF, Pajor E, Léguillette R.The Heavy Horse Pull is a competition where teams of two horses pull an increasingly heavy sled for a short distance. Similar to human wrestlers, some horses may undergo rapid weight change in order to enter a lower weight category. The objectives were to study the physiological effects of this practice as well as of the pulling competition in draft horses. Results: Fifty horses were divided into light-, middle- and heavyweight categories based on their arrival weights and competed 1-3 days after. Body weight was measured upon arrival and pre-competition. Blood was sampled for chemistry and h...
McDowell KJ, Webb BA, Williams NM, Donahue JM, Newman KE, Lindemann MD, Horohov DW.A new abortigenic disease, now known as mare reproductive loss syndrome (MRLS), significantly affected the horse industry in the Ohio River Valley of the United States in late April and early May of 2001 and 2002. In 2001, approximately 25% of all pregnant mares aborted within several weeks (over 3,000 mares lost pregnancies), and abortion rates exceeded 60% on some farms. Mare reproductive loss syndrome struck hard and without warning, it was caused by something in the environment, it was not transmitted between animals, and it was not associated with any known abortigenic agent or disease. T...
Lepage OM, Doumbia A, Perron-Lepage MF, Gangl M.Maggot debridement therapy is a long-established tool to promote wound healing. Objective: To describe and assess the results of this technique in equids with various lesions. Methods: Retrospective analysis performed on cases in which, depending on clinical case, type, size and location of the wound, maggots were applied either in direct or indirect contact with the wound. Results: Treated cases (n = 41) included horses with foot pathology (n = 9), laceration of the limbs (n = 15), other soft tissue abscesses or wounds (n = 6), fistulous withers (n = 5), other musculoskeletal infection (n = 2...
Carrieri ML, Peixoto ZM, Paciencia ML, Kotait I, Germano PM.Laboratory diagnosis is essential to confirm suspected cases of equine rabies and to determine the medical care needed for human postexposure antirabies prophylaxis. Equine rabies transmitted by the vampire bat, Desmodus rotundus, has increased gradually in the State of São Paulo. The present study has several objectives, the most important being the evaluation of fluorescent antibody test (FAT) and virus-isolation laboratory tests performed with different equine nervous system tissues (cortical, hippocampus, cerebellar, brainstem and cervical medullar) to determine the tissue for which the t...
Borges AS, Watanabe MJ.The close relationship between guttural pouches, cranial nerves, and sympathetic structures make neurologic abnormalities due to diseases of the guttural pouches (especially mycosis) possible. Recognition of epistaxis or mucopurulent nasal discharge, together with signs of dysfunction of the cranial nerves in contact with the guttural pouches, are important key points in order to consider a comprehensive evaluation of these structures and further definitive diagnosis. Diseases of the guttural pouches can also cause signs such as dysphagia, abnormal soft palate positioning, laryngeal paralysis,...
Rouse BT, Ditchfield WJ.Nasal secretions and serum were collected from ponies in order to determine the types of immunoglobulins responsible for antibody activity against Myxovirus influenzae A-equi 2. Using specific antisera to remove each immunoglobulin, the antiviral activity of serum was shown to be a property of IgG globulin, whereas in nasal secretions activity was found in both IgG and IgG(T) globulins. However in secretions the predominant activity was attributed to IgG(T) globulin. Because of its sensitivity to 2 mercaptoethanol, early serum antibody was assumed to belong to the IgM class of immunoglobulins....
Kümmerle JM, Kummer MR.To describe the arthroscopically accessible anatomy of the tarsal collateral ligaments in the horse. Methods: Descriptive study. Methods: Cadaveric equine hind limbs (n = 24) obtained from horses without tarsal disease. Methods: Two pairs of tarsal joints were used to obtain silicone models of the tarsocrural joint and dissect the tarsal collateral ligaments (CLs). Ten pairs of tarsocrural joints had arthroscopic exploration and the accessible parts of the tarsal CLs were marked with an arthroscopic hook knife. Subsequently, the limbs were dissected and the marked positions were allocated to t...
Aarnes TK, Lerche P, Bednarski RM, Hubbell JAE.This study evaluated use of midazolam, ketamine, and xylazine (MKX) for total intravenous (IV) anesthesia (TIVA) in horses. Medical records of 46 horses undergoing a clinical procedure using MKX for TIVA were reviewed. Age, breed, procedure, heart rate (HR), respiratory rate (RR), pre-anesthetic drugs, induction drugs, and total volume of MKX were recorded. Duration of anesthesia, time to standing, number of attempts to stand, and recovery score were also recorded. All horses were premedicated with an alpha-2 adrenoceptor agonist and anesthesia was induced with ketamine and midazolam. Duration...
Kent MG, Shoffner RN, Hunter A, Elliston KO, Schroder W, Tolley E, Wachtel SS.An inherited genetic disorder causes XY embryos of the horse to develop as mares. On the basis of our study of 38 such mares, we have identified four grades or classes of XY sex reversal according to this scheme: class I, nearly normal female, of which some are fertile; class II, female with gonadal dysgenesis, normal mullerian development; class III, intersex mare with gonadal dysgenesis, abnormal mullerian development, enlarged clitoris; class IV, virilized intersex characterized by high levels of testosterone. In general, class I and class II mares were typed H-Y antigen-negative whereas cl...
Medina-Torres CE, Underwood C, Pollitt CC, Castro-Olivera EM, Hodson MP, Richardson DW, van Eps AW.Lamellar perfusion is thought to be affected by weightbearing and limb load cycling; this may be critical in the development of supporting limb laminitis. Objective: To document the effects of unilateral weightbearing and altered limb load cycling on lamellar energy metabolism and perfusion. Methods: Randomised, controlled (within subject), experimental trial. Methods: Nine Standardbred horses were instrumented with microdialysis probes in the foot lamellar tissue and skin (over the tail base). Urea (20 mmol/l) was added to the perfusate. Samples were collected every 15 min for a 1 h con...
Radtke A, Fortier LA, Regan S, Kraus S, Delco ML.Equine diagnostic anaesthesia can be a useful tool in challenging lameness examinations. However, anaesthetics diffuse over time leading to nonspecific desensitisation of periarticular structures. Nerves that convey sensation from the distal limb to the central nervous system pass in close proximity to the caudal stifle joint capsule. Therefore, diffusion of intra-articular (IA) anaesthetics could cause inadvertent desensitisation of the distal limb resulting in a false diagnosis of stifle lameness. Objective: To determine if IA stifle anaesthesia can alleviate lameness originating in the dist...
Théon AP.This article covers the principles and applications of radiation therapy in horses. The goal in treating tumors by irradiation is tumor control with minimum treatment complications. Various treatment techniques are available to achieve this goal. The prognosis depends on many factors such as the extent and location of the tumor, tumor type and tumor cell proliferation. Radiation therapy is a very effective treatment modality for equine tumors but logistical reasons limit its impact in equine oncology.
Green SL, Specht TE, Dowling SC, Nixon AJ, Wilson JH, Carrick JB.A neonatal foal was examined because of apparent abdominal pain and distention, anemia, and hemoperitoneum. Exploratory laparotomy was performed, and a large spherical mass, which had ruptured, was found in the area of the left ovary. Left salpingo-oophorectomy was performed. The mass was determined to be a juvenile granulosa cell tumor.
O'Leary SA, White JL, Hu JC, Athanasiou KA.The equine cervical facet joint is a site of significant pathology. Located bilaterally on the dorsal spine, these diarthrodial joints work in conjunction with the intervertebral disc to facilitate appropriate spinal motion. Despite the high prevalence of pathology in this joint, the facet joint is understudied and thus lacking in viable treatment options. Objective: The goal of this study was to characterise equine facet joint cartilage and provide a comprehensive database describing the morphological, histological, biochemical and biomechanical properties of this tissue. Methods: Descriptive...
Duncan JL, Reid JF.In a controlled trial in naturally-infected young ponies, oxfendazole administered orally at dose-rates of 10 mg per kg and 50 mg per kg resulted in complete elimination of Trichostrongylus axei, Parascaris equorum, Oxyuris equi and adult Strongylus vulgaris. Also, all migrating Strongylus edentatus larvae recovered from the subperitoneal tissues of the flank were found to be dead. Minimum efficiencies of 99.8 per cent and 99.1 per cent were obtained against adult small strongyles (Trichonema spp) and 97.6 per cent and 100 per cent of developing small strongyle larvae at dose-rates of 10 mg pe...
Munson L.A 17-year-old Quarter Horse mare developed rapidly progressive, bilateral, firm enlargements of both mammary glands, ventral abdominal edema, dyspnea, and neurologic signs. The horse was euthanatized, and a carcinoma of the mammary gland was diagnosed at necropsy. Microscopically, normal glandular parenchyma was replaced by neoplastic nodules, and the tumor had metastasized to most visceral organs and throughout the musculoskeletal and central nervous systems. The tumor had a solid pattern, with microglandular differentiation, and numerous syncytial sheets.
Martin BW, Terry MK, Bridges CH, Bailey EM.Three Shetland ponies were given a single oral dose of ground Cassia occidentalis seeds in aqueous suspension. The clinical signs observed resembled those seen in naturally occurring and experimental cases in cattle. The syndrome was characterized by an afebrile course, incoordination, recumbency and death. Elevations of blood alkaline phosphatase, CPK, LDH, and SGOT were observed. Although muscle lesions were not seen grossly, microscopic lesions included segmental necrosis of skeletal muscle fibers. The findings were regarded as sufficiently characteristic of C. occidentalis poisoning to be ...
Lallemand E, Trencart P, Tahier C, Dron F, Paulin A, Tessier C.To evaluate pharmacokinetic-pharmacodynamic variables and local tolerance at injection-site of marbofloxacin administered via regional intravenous limb perfusion (RIVLP) in standing horses. Methods: Adult horses (n = 6). Methods: RIVLP were performed with rubber tourniquets applied to the forelimbs of standing sedated horses. Marbofloxacin (0.67 mg/kg) was randomly injected in 1 forelimb, with the contralateral limb serving as a control (0.9% NaCl solution). Samples of jugular blood and synovial fluid from the radiocarpal joint of the marbofloxacin-perfused limb were collected before and...
Fujiyama M, Jones T, Duke-Novakovski T.To evaluate perioperative stress-related hormones in isoflurane-anesthetized horses administered infusions of dexmedetomidine alone or with butorphanol or remifentanil, compared with ketamine-morphine. Methods: Randomized, prospective, nonblinded clinical study. Methods: A total of 51 horses undergoing elective surgical procedures. Methods: Horses were premedicated with xylazine, anesthesia induced with ketamine-diazepam and maintained with isoflurane and one of four intravenous infusions. Partial intravenous anesthesia (PIVA) was achieved with dexmedetomidine (1.0 μg kg hour; group D; 12 hor...
Davis MS, Royer CM, McKenzie EC, Williamson KK, Payton M, Marlin D.Inspired air is warmed to body temperature and fully humidified by the upper airway mucosa under normal resting conditions. This conditioning process may not be completed by the upper airways during conditions of increased minute ventilation or when the inspired air is unusually cold, resulting in cooling and desiccation of lower respiratory surfaces. Excess heat and water loss from intrapulmonary airways is believed to be the provocative stimulus for exercise-induced bronchoconstriction (occurring immediately after exercise) and associated late phase airway obstruction (occurring a few hours ...
Davis JL, Stewart T, Brazik E, Gilger BC.The purpose of this study was to determine the influence of age, breed and gender on vertical pupil diameter (VPD) following a single dose of 1% atropine sulfate ophthalmic solution in the normal equine eye. Methods: Thirty-two horses of various ages, breeds and genders were included. The horses had no history or clinical signs of ophthalmic disease. All horses studied had darkly pigmented irides. Methods: Two milligrams of 1% atropine sulfate ophthalmic solution was topically administered as a single dose in the right eye of each horse on Day 0. The VPD (mm) was measured in both eyes using di...
Monzón CM, Jara A, Nantulya VM.The sensitivity of an antigen detection enzyme immunoassay (Ag-ELISA) based on a Trypanosoma brucei group-specific monoclonal antibody was evaluated to detect circulating Trypanosoma evansi antigen in horse sera. Three horses and 2 mules were experimentally infected with T. evansi. Circulating antigens were detected on 7 and 21 days postinfection. Antigen levels increased during the course of the illness and remained high even when parasitemia was low or when parasites could not be detected. Antigens were cleared from serum when drug treatment was effective but persisted when it was not. In 6 ...
Specht TE, Breuhaus BA, Manning TO, Miller RT, Cochrane RB.A 12-year-old Arabian stallion was evaluated for a refractory skin problem of 2 years' duration. Skin nodules and pustules, which would rupture, had developed over the right lumbar muscles. Anaerobic culturing from the pustules yielded Actinomyces viscosus, and histologic examination of biopsy specimens revealed globular eosinophilic structures. Concomitant treatment with isoniazid (8 mg/kg of body weight, q 24 h for 8 weeks), trimethoprim-sulfadiazine (30 mg/kg, q 24 h for 8 weeks), and sodium iodide solution (66 mg/kg, every 1, 2, or 4 weeks, for 32 weeks) resolved the condition.
Cogley TP.Lesions were formed in the mouth of the horse by first- and second-stage Gasterophilus intestinalis larvae. The lesions resulted as larvae burrowed through the top millimeter of the tongue and then became embedded in the interdental gingiva. Appearance of the lesion was dependent on the degree of larval burrowing activity and healing that had taken place. Active tunneling production occurred at the posterior end of the lesion. Extensive change in configuration and color was apparent along the longer lesions with active larvae. Virtually all tissue in the path of the larvae was removed while fo...
Gehlen H, Inerle K, Bartel A, Stöckle SD, Ulrich S, Briese B, Straubinger RK.There are limited data on Lyme borreliosis (LB), a tick-borne disease caused by the Borrelia burgdorferi sensu lato complex, in horses. Seropositivity is not necessarily associated with clinical disease. Data on seropositivity against Borrelia burgdorferi and Anaplasma phagocytophilum in German horses are sparse. Therefore, serum samples from horses (n = 123) suspected of having Lyme borreliosis and clinically healthy horses (n = 113) from the same stables were tested for specific antibodies against Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum. The samples were screened for an...
Easley J, Dixon PM, Reardon RJ.There are limited reports on the efficacy of functional orthodontic correction of overjet or overbite in foals. Objective: To report the outcome of using orthodontic tension bands in combination with an inclined plane biteplate in the treatment of overjet, with or without concurrent overbite, rates of correction of these 2 malocclusions and associated complications. And to examine factors associated with outcomes. Methods: Retrospective case series. Methods: Clinical records for 73 foals treated at a single clinic, by the same surgeon were analysed. Overall change and rates of change in overje...
