Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Smith LJ, Mellor DJ, Marr CM, Mair TS.Septic digital tenosynovitis is a serious problem in the horse, with a poor prognosis being reported for recovery. Objective: The occurrence of septic digital tenosynovitis would significantly reduce the likelihood of a horse returning to its previous level of athletic function. Methods: Medical records of 90 horses treated for septic digital tenosynovitis were reviewed. Data retrieved included age, sex, location of inciting cause of sepsis, time from onset of clinical signs to presentation for treatment, and whether the horse survived to be discharged. Long-term outcome was determined through...
Burn JF, Franklin SH.The presence of abnormal respiratory sounds is commonly associated with obstructions of the upper respiratory tract. In order to establish their clinical significance measurements are required of both normal and abnormal respiratory sounds produced by horses exercising over-ground. Objective: To determine whether high quality recordings of respiratory sound can be made during over-ground exercise, and to develop a convenient measurement system that can be used to obtain respiratory sounds from horses exercising in field conditions. Methods: A range of prototypes was evaluated against the requi...
de Grauw JC, van de Lest CH, van Weeren R, Brommer H, Brama PA.Joint pain is one of the most common causes of lameness in the horse but its pathogenesis is poorly understood. Objective: To investigate which synovial fluid markers may be related to the presence of clinically detectable joint pain in the horse. Methods: Concentrations of structural (CPII, C2C, GAG) and inflammatory markers (PGE2, LTB4, CysLTs, bradykinin and substance P) were measured in fetlock joint fluid from 22 horses in which lameness was localised to the fetlock region by perineural anaesthesia. Levels of these markers were then compared in horses that responded (n = 15) to those that...
Changoor A, Hurtig MB, Runciman RJ, Quesnel AJ, Dickey JP, Lowerison M.To improve osteochondral graft reconstruction of subchondral cystic lesions in the medial and lateral femoral condyles by matching the material properties of donor and recipient sites. Objective: To measure biomechanical and biochemical parameters that influence the function and healing of osteochondral grafts used to reconstruct subchondral cystic lesions. Objective: Suitable donor sites are available within the stifle joint for reconstructing the femoral condyles, despite considerable regional property variation. Methods: Fifty-six osteochondral cores were harvested from 6 distal femurs for ...
Bergin BJ, Pierce SW, Bramlage LR, Stromberg A.Hyaluronan (HA) has been used to treat joint disease via intra-articular, i.v. and oral administration. The efficacy of intra-articular and i.v. use has been evaluated but the oral route has yet to be examined. Objective: To determine the effect of oral hyaluronan gel on joint effusion following arthroscopic surgery for osteochondritis dissecans (OCD) of the tarsocrural joint of yearling Thoroughbreds. Methods: Forty-eight yearlings diagnosed with unilateral or bilateral osteochondritis dessicans (OCD) of the tarsus were arbitrarily chosen prior to arthroscopic surgery. The yearlings were incl...
Wilmink JM, van den Boom R, van Weeren PR, Barneveld A.The acceptance of skin grafts in horses is unpredictable and the final cosmetic result can be disappointing. Besides movement and infection, graft failure is often caused by chronic inflammation, inherently present during second intention healing of limb wounds in horses. In human burns affected by infection and inflammation, the acceptance of the island skin grafts of the modified Meek technique appeared to be better than meshed sheet skin grafts. Objective: The percentage take of Meek micrografts is higher than of other techniques; and rates of both wound contraction and epithelialisation ar...
Weekes JS, Murray RC, Dyson SJ.In recent years, pain arising from the proximal metacarpal and metatarsal regions has become well recognized as a cause of lameness and various disease entities have been identified. However, our knowledge of normal patterns of radiopharmaceutical uptake is limited, making interpretation of images problematic. It is therefore important to characterize normal patterns of radiopharmaceutical uptake at specific sites to ensure valid interpretation of images in clinical cases with subtle lesions. The purpose of this study was to describe the pattern of radiopharmaceutical uptake in the proximal me...
Engeli E, Yeager AE, Erb HN, Haussler KK.The purpose of this study was to establish the normal percutaneous ultrasonographic appearance of anatomic structures within the equine sacroiliac region. Percutaneous ultrasonography was performed in a cranial-to-caudal direction in 10 normal adult live horses. The following structures were examined in detail: supraspinous ligament, lumbar and sacral spinous processes, thoracolumbar fascia and its caudal extension, tubera sacralia, ilial wings, dorsal and lateral portions of the dorsal sacroiliac ligaments, lateral part of the sacrum, and the lateral sacral crest. After ultrasonography, all a...
Kornas S, Nowosad B, Skalska M, Bołoz T.The studies were carried out in 2001 and 2002 on horses from riding clubs in Krakow area. On the basis of McMaster method EPG (eggs per gram) and prevalence of infection (%) was evaluated. The most common parasites were strongyles (Strongylidae). In the first year of study in dynamics of strongyles eggs output of horses kept on paddocks two peaks were observed: in May (450 EPG) and January (427 EPG), in comparison with horses under pasture system where the highest level of strongyles eggs output were in May (832 EPG), from August (420 EPG) to October (385 EPG) and in March (482 EPG). In the se...
Kuzmina TA, Kuzmin YI, Kharchenko VA.Experimental studies on the survival of infective stage larvae of horse strongyles and their ability to overwinter on pasture were carried out in central Ukraine (Poltavska oblast). Faecal pats (1.5 kg each) of naturally infected horses were placed on pasture, and samples of faeces and surrounding vegetation (10 g each) were collected each month, excluding the winter months, from November 2002 until April 2004. The number of infective third stage larvae was calculated in each sample and compared with that from the control faecal samples cultivated in the laboratory. In the control samples, the...
Niedermaier G, Wollanke B, Hoffmann R, Matiasek K, Gerhards H.Neither the ultrastructure of the vitreous body from horses without ocular diseases, nor the pathomorphological changes in the vitreous body associated with equine recurrent uveitis (ERU) have been described. However, the vitreous body plays an important role in the pathogenesis of ERU. Ten vitreous body samples obtained from 5 horses without ocular disease, and 38 vitreous body samples from horses with ERU (collected during vitrectomy) were examined by transmission electron microscopy. The vitreous body samples of horses without ocular diseases were characterized by a loose network of unbranc...
Stokes AM, Venugopal CS, Hosgood G, Eades SC, Moore RM.The goals of this study were to determine the concentration-response (C-R) relationship of endothelin-1 (ET-1), compare 2 ET-receptor antagonists and determine the antagonist concentrations that block the vasomotor effects of ET-1, and compare the effectiveness of ET-1 and previously studied vasoconstrictors in equine palmar digital arterial and venous rings in vitro. Vessel rings from 8 nonlaminitic horses were placed in Tyrode's solution, 1 side fixed to the floor of an organ bath and the other side fixed to a force-displacement transducer. Two separate studies were conducted: (I) incubation...
Dubuc V, Lepault E, Theoret CL.Wound repair in horse limbs is often complicated by excessive fibroplasia and scarring. Occlusion of the microvessels populating the granulation tissue appears to be involved in the excessive accumulation of extracellular matrix during the repair of limb wounds. This study aimed to determine whether endothelial cell hypertrophy or hyperplasia, or both, contribute to microvascular occlusion and whether the pericyte is involved in this anomaly. We created 5 wounds, each 2.5 x 2.5 cm, on both forelimbs and on the body of 6 horses. One limb was bandaged to stimulate excessive wound fibroplasia. We...
Saito S, Sawai K, Minamihashi A, Ugai H, Murata T, Yokoyama KK.We describe here the isolation and maintenance of pluripotent embryonic stem (ES) cells from equine blastocysts that have been frozen and thawed. Equine ES cells appear to maintain a normal diploid karyotype in culture. These cells express markers that are characteristic of mouse ES cells, namely, alkaline phosphatase, stage-specific-embryonic antigen 1, STAT3, and Oct4. We also describe protocols for the induction of differentiation in vitro to neural precursor cells in the presence of basic fibroblast growth factor (bFGF), epidermal growth factor, and platelet-derived growth factor and to he...
Brandon CI, Vandenplas M, Dookwah H, Linden J, Murray TF.The aim of the current study was to clone the equine adenosine A(2A) receptor gene and to establish a heterologous expression system to ascertain its pharmacologic profile via radioligand binding and functional assays. An eA(2A)-R expression construct was generated by ligation of the eA(2A) cDNA into the pcDNA3.1 expression vector, and stably transfected into human embryonic kidney cells (HEK). Binding assays identified those clones expressing the eA(2A)-R, and equilibrium saturation isotherm experiments were utilized to determine dissociation constants (K(D)), and receptor densities (B(max)) ...
Brandon CI, Vandenplas M, Dookwah H, Murray TF.The aim of this study was to establish a heterologous expression system for the equine adenosine A(3) receptor (eA(3)-R) in an effort to ascertain its pharmacologic profile. Initially, radioligand binding assays identified clones expressing the eA(3)-R in human embryonic kidney cells (HEK) based on the specific binding of [(125)I]AB-MECA. Subsequently, adenylate cyclase assays were utilized to demonstrate functional coupling of the eA(3)-R to the G-protein/adenylate cyclase system. Equilibrium competition binding assays were then performed using selective and non-selective A(3) agonists and an...
Sledge DG, Miller DL, Styer EL, Hydrick HA, Baldwin CA.Granulomatous dermatitis in horses has been linked to many etiologies, including various parasites, fungi, and bacteria. Idiopathic forms of granulomatous inflammation-producing diseases, some of which are localized to the skin, also have been reported in horses. Herein we describe a case of recurrent equine granulomatous skin disease characterized by intranuclear viral inclusions within macrophages and giant cells. The histologic changes were primarily noted in the deep dermis and included multifocal to coalescing areas of necrosis marked by histiocytic cell infiltration and presence of giant...
Hornyák A, Bakonyi T, Kulik M, Kecskeméti S, Rusvai M.The occurrence of two important pathogens, equine herpesvirus 1 (EHV1) and equine arteritis virus (EAV) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (PCR) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in Hungary. We found 26 EHV1- and 4 EAV-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccination, EHV1 is a far more important cause of abortions in the studs than EAV. We compared the virus co...
Popot MA, Donval A, Bonnaire Y, Huau J.Feces are a possible medium to be used for horse doping control. Efficient methods for detecting drugs in feces collected from various animals are routinely applied in institutes of food safety in Belgium. We have already tested whether they are applicable to horse feces. In this report, accelerated solvent extraction (ASE), an efficient method for extracting compounds from solid material, has been tested. ASE has been used to replace the diethyl ether liquid-liquid extraction step present in the method initially set up. This technique has been optimized for detecting several non-steroidal ant...
Rezaian M.Histology of the tongue, including apex, root and body, in four adult Caspian miniature horses was examined. Serial sections with 6 mum thickness were stained with haematoxylin-eosin and Masson trichrome and studied under light microscope. The tongue was covered by stratified squamous epithelium. It was thick and keratinized bearing numerous lingual papillae on the dorsum, mostly filiform with a very fine keratinized thread projecting above the surface and bending backward. The fungiform papillae were sparsely scattered among the filiform papillae and covered with keratinized squamous epitheli...
Nielsen MK, Kaplan RM, Thamsborg SM, Monrad J, Olsen SN.Development of resistance to anthelmintic drugs by horse strongyles constitutes a growing threat to equine health because it is unknown when new drug classes can be expected on the market. Consequently, parasite control strategies should attempt to maintain drug efficacy for as long as possible. The proportion of a parasite population that is not exposed to anthelmintic treatment is described as being "in refugia" and although many factors affect the rate at which resistance develops, levels of refugia are considered the most important as these parasites are not selected by treatment and so pr...
Valentine BA, Taylor GH, Stone JK, Halse RR.Forty-four nodular and noninvasive cutaneous fungal granulomas were identified in 34 horses over a 14.5-year period. Cutaneous fungal granulomas were most common in young horses (mean age 6.1 +/- 4.2 years; range 1-19 years). There was no apparent breed or sex bias. Granulomas were either single or multiple, and most often occurred in the skin of the head and neck. The characteristic histological finding was a nodular dermal mass with a mean diameter of 7.3 mm (range 2.5-20 mm) and an intact overlying epithelium. Lesions most often exhibited intense lymphocytic inflammation, with admixed pyogr...
Nogueira SA, Torres SM, Malone ED, Diaz SF, Jessen C, Gilbert S.Imiquimod is an immune response modifier with potent antiviral and antitumour activity. The objective of this pilot study was to evaluate the efficacy of an imiquimod 5% cream (Aldaratrade mark: 3M, Saint Paul, MN, USA) as a topical treatment for equine sarcoids. Fifteen horses with a total of 19 tumours were enrolled, including mixed (7), fibroblastic (5), flat (3), verrucous (2), and nodular (2) types. Baseline data included history, physical examination, tumour location, measurement and digital photography. Imiquimod was applied by the owners three times a week until complete resolution of ...
Butcher MT, Bertram JE, Benzuidenhout AJ.The distal forelimb of the horse has a complex array of ligaments that play a critical role in determining function of the digit and are often associated with the initiation of foot pathologies. The collateral ligaments of the distal sesamoid bone (CLDS) play an important role in digit stabilization near the end of foot contact and there is also limited evidence to suggest that the CLDS stabilize the proximal interphalangeal joint (PIPJ) during weight bearing. By virtue of their anatomical attachments where the ligaments pass dorsal to the axis of rotation of the PIPJ, it is reasonable to assu...
Sherman RA, Morrison S, Ng D.Hoof disease and injuries are common and serious problems for equines. Maggot debridement therapy (MDT) has been used to treat problematic wounds in humans, but has been used only rarely in other animals. US veterinarians who had employed MDT were surveyed to investigate their reasons for the choice of this treatment and their clinical experiences with it. Between 1997 and 2003, 13 horses were treated by eight veterinarians who used MDT to control infection or debride wounds, which could not easily be reached surgically or were not responding to conventional therapy. Seven animals were lame, a...
Hurtgen JP.Inflammatory conditions of the uterus, collectively known as endometritis, can be classified as acute, chronic, active, or subclinical. This condition causes substantial reductions in mare fertility. To diagnose and treat mares with endometrial inflammation, it is imperative to identify predisposing factors and challenges to the reproductive tract of the mare in a chronological order; these factors change from those of the young maiden filly to the older, multiparous broodmare. This paper addresses predisposing factors, diagnostic procedures and therapy strategies for different mare groups.
Songsermsakul P, Sontag G, Cichna-Markl M, Zentek J, Razzazi-Fazeli E.The paper describes a method for the sensitive and selective determination of zearalenone and its metabolites in urine, plasma and faeces of horses by high performance liquid chromatography and atmospheric pressure chemical ionisation (APCI) mass spectrometry (MS). While only one step sample clean-up by an immunoaffinity column (IAC) was sufficient for plasma samples, urine and faeces samples had to be prepared by a combination of a solid-phase extraction (SPE) and an immunoaffinity column. The method allows the simultaneous determination of zearalenone and all of its metabolites; alpha-zearal...
Raulo SM, Sorsa T, Maisi P.To evaluate inhibitory effects of synthetic matrix metalloproteinase (MMP) inhibitors in vitro on gelatinolytic and collagenolytic activities in tracheal epithelial lining fluid (TELF) of horses with recurrent airway obstruction (RAO). Methods: 10 horses with RAO and 5 healthy control horses. Methods: Substrate-based functional assays, collagen I and gelatin degradation, were used to measure endogenous collagenolytic and gelatinolytic activities in TELF. In vitro inhibition of MMP activity in TELF with 2 chemically modified tetracyclines (CMTs; CMT-3 and CMT-8) and 2 bisphosphonates (BPs; zole...
Eades SC, Stokes AM, Moore RM.To evaluate changes in digital vascular function in horses with carbohydrate overload (CHO)-induced laminitis and determine the effects of an endothelin (ET) receptor antagonist and nitroglycerin on laminitis-associated vascular dysfunction. Methods: 20 adult horses without abnormalities of the digit. Methods: Hemodynamic variables were recorded before (baseline) and hourly after all horses were administered a CHO ration via nasogastric tube. In 4 groups of 5 horses each, saline (0.9% NaCl) solution or ET receptor antagonist (10(5)M in digital blood) was administered into the digital arterial ...
Held JP, Oliver JW.A study was designed to assess the secretory response of thyroid glands in horses to an economically feasible dose (5 IU) of thyrotropin injected IV, and to establish valid blood sampling periods in cases in which thyroxine concentrations were different from base-line values. Significant (P less than 0.001) response (doubling or near-doubling of base line) occurred as early as 3 hours after thyrotropin administration, with peak response at 4 to 5 hours. It was concluded that administration of 5 IU of thyrotropin is economical and effective in the horse, with collection of a second blood sample...
East IJ.In 2007, an epizootic of equine influenza (EI) occurred in Australia, involving parts of the states of Queensland and New South Wales. Following an extensive control program, the disease was eradicated within 4 months, after infecting more than 75,000 horses on over 10,000 properties. In Queensland, examination of land use patterns revealed that the majority of infected premises (89.5%) were located in one of three land use classes viz. rural residential, residential-unspecified or grazing natural vegetation. All nine clusters of infection in Queensland were surrounded to some degree by parcel...
Sebastian M, Gantz MG, Tobin T, Harkins JD, Bosken JM, Hughes C, Harrison LR, Bernard WV, Richter DL, Fitzgerald TD.During 2001, central Kentucky experienced acute transient epidemics of early and late fetal losses, pericarditis, and unilateral endophthalmitis, collectively referred to as mare reproductive loss syndrome (MRLS). A toxicokinetic/statistical analysis of experimental and field MRLS data was conducted using accelerated failure time (AFT) analysis of abortions following administration of Eastern tent caterpillars (ETCs; 100 or 50 g/day or 100 g of irradiated caterpillars/day) to late-term pregnant mares. In addition, 2001 late-term fetal loss field data were used in the analysis. Experimental dat...
Doxey DL, Milne EM, Harter A.The outcome for 35 horses with chronic dysautonomia which were kept in the hospital at the Royal (Dick) School of Veterinary Studies and subsequently returned to their owners is recorded. They constituted 42.7 per cent of the 82 chronic cases seen between 1991 and 1994; the other 47 horses were euthanased while in hospital. Of the 35 animals returned to their owners four died and 27 were available for follow up; of these 27, 12 were working competitively and six were being trained for future competitive work. It takes at least a year before it is clear whether a horse can compete successfully ...
Johnson DJ, Ostlund EN, Palmer TJ, Fett KL, Schmitt BJ.Semen from an apparently healthy 4-year-old American Quarter Horse was submitted to the National Veterinary Services Laboratories for Equine arteritis virus isolation. Visual inspection of the semen sample upon arrival noted it was unusually yellow in color. The semen sample was inoculated onto cell monolayers, and cytopathic effect was observed 5 days postinoculation. The resultant isolate tested negative for Equine arteritis virus, and was subsequently identified as Equine rhinitis A virus. Equine rhinitis A virus has been isolated from horse urine, but has not been described in stallion sem...
Rodríguez A, Peña L, Flores JM, González M, Castaño M.This study was undertaken to investigate the presence of neuroendocrine cells (N.E.C.) by immunocytochemical means in equine lungs during three distinct evolutionary periods: fetal, neonatal and adult. The authors identified bombesin, somatostatin and calcitonin secretory cells. In the fetal lungs the N.E.C. were located in the interstitial tissue and exhibited greater immunoreactivity to bombesin than to the other two neuropeptides studied. A large number of calcitonin-producing cells and a smaller number of bombesin-positive cells were seen in the bronchial and bronchiolar epithelium of newb...
Bostedt H.A clinical study about the effects of a beta 2-mimetic agent (Clenbuterol) in mares with pregnancy disorders or disorders during the periparturient period (n = 34) is reported. In general, a single dose of 0.3 mg Clenbuterol given i.v. induces sufficient tocolysis. Subsequent doses or follow-up treatment depend upon individual development during dystocia, indication of treatment and clinical preparturient status (dorsoflexio uteri ante partum, abortus imminens, preparturient labor pains).
Bistner SI, Riis RC.Several manifestations of equine corenal ulcers caused by mycotic agents are discussed. Antifungal therapy is reviewed. Mycotic keratitis should be suspected when routine corneal ulcer therapy is nonproductive.