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.
Lu Z, Timoney PJ, White J, Balasuriya UB.Equine rhinitis viruses A and B (ERAV and ERBV) are common equine respiratory viruses belonging to the family Picornaviridae. Sero-surveillance studies have shown that these two viral infections are prevalent in many countries. Currently, the diagnosis of ERAV and ERBV infections in horses is mainly based on virus isolation (VI). However, the sensitivity of VI testing varies between laboratories due to inefficient viral growth in cell culture and lack of cytopathic effect. Therefore, the objective of this study was to develop molecular diagnostic assays (real-time RT-PCR [rRT-PCR] and conventi...
Rodrigues MA, Figueiredo L, Padrela L, Cadete A, Tiago J, Matos HA, Gomes de Azevedo E, Florindo HF, Gonçalves LM, Almeida AJ.Strangles is an extremely contagious and sometimes deadly disease of the Equidae. The development of an effective vaccine should constitute an important asset to eradicate this worldwide infectious disease. In this work, we address the development of a mucosal vaccine by using a Supercritical Enhanced Atomization (SEA) spray-drying technique. Aqueous solutions containing the Streptococcus equi extracts and chitosan were converted into nanospheres with no use of organic solvents. The immune response in a mouse model showed that the nanospheres induced a well-balanced Th1 and Th2 response charac...
Hartig W, Houe H, Andersen PH.At present Denmark has no central database holding records of equine health and disease. Nor have attitudes to the establishment of a national database, and the concerns it raises, been investigated in a systematic way. The objective of the present study was to assess the attitudes and concerns of potential database stakeholders. Attitudes to participation, and the location, financing and management of the proposed database, together with any concerns it raises, were investigated in a questionnaire study of 13 potential stakeholder groups in Denmark (in total, 1581 questionnaire recipients and...
Nielsen MK, Olsen SN, Lyons ET, Monrad J, Thamsborg SM.Strongyle parasites are ubiquitous in grazing horses, and the large strongyle Strongylus vulgaris is considered the most pathogenic helminth parasite of horses. Recent investigations have suggested an association between occurrence of this parasite and usage of selective therapy based on regular fecal egg counts. The established diagnostic method for S. vulgaris involves larval culture and subsequent morphological identification of third stage larvae under the microscope. Recently, a real-time PCR assay was developed and validated for the detection and semi-quantification of S. vulgaris eggs i...
Leise BS, Watts M, Tanhoff E, Johnson PJ, Black SJ, Belknap JK.STAT1 and STAT3 are important signaling molecules in disorders of systemic inflammation and are likely to be involved in laminitis, as laminar and systemic inflammation have been well documented in experimental models of laminitis. Objective: The STAT1 and STAT3 activation (via phosphorylation of tyrosine and serine moieties) is occurring in the laminar tissue during the developmental and onset of lameness time points in both the black walnut extract (BWE) and carbohydrate overload (CHO) models of laminitis. Methods: Archived laminar tissue from horses. Methods: Experimental studies of induced...
Gambini A, Jarazo J, Olivera R, Salamone DF.The production of cloned equine embryos remains highly inefficient. Embryo aggregation has not yet been tested in the equine, and it might represent an interesting strategy to improve embryo development. This study evaluated the effect of cloned embryo aggregation on in vitro and in vivo equine embryo development. Zona-free reconstructed embryos were individually cultured in microwells (nonaggregated group) or as 2- or 3-embryo aggregates (aggregated groups). For in vitro development, they were cultured until blastocyst stage and then either fixed for Oct-4 immunocytochemical staining or maint...
Eliashar E.Shoes were originally applied to horses' feet to protect against excessive wear. Over the years, countless types of shoes and farriery techniques have been developed not only as a therapeutic aid to treat lameness but also to maintain or enhance functionality. The past 3 decades have provided equine veterinarians and farriers with new information relating to limb biomechanics and the effects of various farriery methods. This article describes the principles of foot biomechanics and how they are affected by some of the more common farriery and shoeing techniques.
O'Grady SE.Sheared heels develop as an adaptation-distortion of the hoof capsule as a result of an abnormal strike and loading pattern of the foot, which is generally a consequence of limb conformation. The growth rate around the circumference of the hoof should be approximately uniform, but regional disturbances in growth rate can occur to either increase or decrease growth. The primary conformational trait that is observed in horses that develop sheared heels is a rotational deformity of the distal limb and a narrow chest. Farriery is directed toward improving the hoof capsule distortion and decreasing...
Eggleston RB.Radiographic evaluation of a horse's foot gives tremendous insight into the relationship between the structures within the foot and between the foot and distal limb. The information gained from a radiographic study is highly dependent on the quality of the radiographs. A systematic approach should be taken when planning a radiographic study of the foot. Taking the time to examine the foot and prepare it properly will avoid the need, risk, and expense of repeating images and will improve the quality and therefore the interpretation of your radiographic images. When evaluating the foot for podia...
Dong JB, Zhu W, Cook FR, Goto Y, Horii Y, Haga T.Equine infectious anemia (EIA) has posed a major challenge and caused significant losses to the equine industry worldwide. PCR detection methods have considerable potential as an adjunct to conventional serological diagnostic techniques. However, most published PCR methods, including that recommended by the OIE, were designed using laboratory-adapted virus strains and do not function with field isolates of EIA virus (EIAV). In the present study, a nested PCR assay for detection of EIAV proviral DNA in peripheral blood cells of naturally infected horses was developed. Primer sets were designed ...
Murata D, Misumi K, Fujiki M.We hypothesized that semi-quantitative determinations of changeable blood flows in granulation and scar tissues during tendon healing could be helpful for differentiation between the acute phase rich in blood vessels and the remodeling phase with fewer vessels. Ten Thoroughbreds with injured superficial digital flexor tendon (SDFT) in a forelimb were used for evaluation of blood flows in the injured tendons of racehorses using color Doppler (CD) ultrasonography. Using longitudinal CD images, features of maximum color activities were defined. These were rhythmically blinking, tiny to small sign...
Dzierzęcka M, Charuta A.Proximal phalanges in horses are among bones that are most prone to injuries. So far, the detailed analysis of densitometric and geometric parameters of both front legs proximal phalanges in horses has not been investigated. The aim of this study was to compare the densitometric and geometric parameters between proximal phalanges in equine both front legs with the use of peripheral quantitative computed tomography (pQCT). Methods: The study material comprised isolated both front legs proximal phalanges derived from 22 horses. The structure analysis of the proximal phalanges was conducted with ...
Tee SY, Horadagoda N, Mogg TD.Flaviviruses, including Kunjin virus, are arboviruses that cause encephalomyelitis in humans and horses. This case report describes an Arabian gelding exhibiting neurological signs of flavivirus encephalomyelitis, the diagnostic investigation and confirmation of an unreported case of Kunjin virus equine encephalomyelitis in Australia.
Zauscher JM, Estrada R, Edinger J, Lischer CJ.To evaluate intra- and interobserver variability in ultrasonographic measurements of the proximal aspect of the suspensory ligament (PSL) in the horse. Objective: A minimum difference of ≥20% is required to differentiate reliably between physiological and pathological alterations related to dimensions. Methods: Two operators examined the PSL in all 4 limbs of 14 horses twice using different techniques and different probes with and without standoff pads. Measurements were taken from the longitudinal and transverse images. Inter- and intraoperator variability was evaluated using agreement indi...
Kol A, Walker NJ, Galuppo LD, Clark KC, Buerchler S, Bernanke A, Borjesson DL.Autologous cellular therapy products including adipose-derived stromal vascular fraction (SVF), bone marrow mononuclear cells (BMMNs), cord blood mononuclear cells (CBMNs) and platelet rich plasma are options for treatment of acute orthopaedic lesions while mesenchymal stem cells (MSCs) are culture expanded. These products may contribute to healing by secreting matrix proteins or growth factors, but they may also act on endogenous MSCs to facilitate healing. Objective: To determine the effects of cell therapy products on MSCs function in vitro. The hypothesis was that cell therapy products pro...
Cordes V, Lüpke M, Gardemin M, Seifert H, Staszyk C.In equine dentistry periodontal diseases, especially periapical inflammation, are frequently occurring problems. Anachoresis is believed to be the most common cause for the development of such disorders. Nevertheless, there is still no substantiated explanation why settlement of pathogen microorganisms occurs in equine periodontal tissues. It is expected that excessive strains and stresses occurring in the periodontal ligament (PDL) during the horse's chewing cycle might be a predisposing factor. In this study this assumption was examined by finite element (FE) analyses on virtual 3-D models o...
Patterson-Kane JC, Becker DL, Rich T.The equine superficial digital flexor tendon (SDFT) is a frequently injured structure that is functionally and clinically equivalent to the human Achilles tendon (AT). Both act as critical energy-storage systems during high-speed locomotion and can accumulate exercise- and age-related microdamage that predisposes to rupture during normal activity. Significant advances in understanding of the biology and pathology of exercise-induced tendon injury have occurred through comparative studies of equine digital tendons with varying functions and injury susceptibilities. Due to the limitations of in-...
Ball BA, Almeida J, Conley AJ.Endocrinological assays are important for evaluation of mares with granulosa-cell tumours (GCTs), and our research in mares indicates that anti-Müllerian hormone (AMH) may be a good biomarker for this type of ovarian tumour. Objective: To evaluate the use of serum AMH concentrations for endocrine diagnosis of GCTs in mares. Methods: Archived serum samples (n = 403) previously assayed for determination of serum inhibin, testosterone and progesterone concentrations (GCT panel) were assayed for serum AMH concentrations using a heterologous enzyme-linked immunosorbent assay previously validated b...
Suontama M, van der Werf JH, Juga J, Ojala M.Heritability and repeatability and genetic and phenotypic correlations were estimated for trotting race records with linear and generalized linear models using 510,519 records on 17,792 Finnhorses and 513,161 records on 25,536 Standardbred trotters. Heritability and repeatability were estimated for single racing time and earnings traits with linear models, and logarithmic scale was used for racing time and fourth-root scale for earnings to correct for nonnormality. Generalized linear models with a gamma distribution were applied for single racing time and with a multinomial distribution for si...
Brophy PM, MacKintosh N, Morphew RM.Anthelmintics are the cornerstone of parasitic helminth control. Surprisingly, understanding of the biochemical pathways used by parasitic helminths to detoxify anthelmintics is fragmented, despite the increasing global threat of anthelmintic resistance within the ruminant and equine industries. Reductionist biochemistry has likely over-estimated the enzymatic role of glutathione transferases in anthelmintic metabolism and neglected the potential role of the cytochrome P-450 superfamily (CYPs). Proteomic technologies offers the opportunity to support genomics, reverse genetics and pharmacokine...
de Vries A, Taylor PM, Troughton G, Liu B, Fowden AL, Sear JW.This study examined the pharmacokinetics of propofol by infusion in ponies using an analyser for the rapid measurement of propofol concentrations. The analyser (Pelorus 1000; Sphere Medical Ltd., Cambridge, UK) has a measurement cycle of approximately five minutes. Ten Welsh-cross ponies (weighing 135-300 kg) undergoing minor procedures were studied after premedication with acepromazine 0.03 mg/kg and detomidine 0.015 mg/kg. Anaesthesia was induced with ketamine 2 mg/kg and diazepam 0.03 mg/kg, and maintained with an infusion of propofol at an initial rate of 0.16 mg/kg/min for the first thirt...
Salas Y, Márquez A, Canelón J, Perazzo Y, Colmenárez V, López JA.Pythium insidiosum is a pathogenic oomycete known since 1890 that causes pythiosis in mammals. In this report, seven P. insidiosum isolates were recovered from Venezuelan horses and were characterized. The strains were recovered from biopsied tissues and kunkers collected from granulomatous masses located on the hind limb and from a nodular lesion in the left upper eyelid, which decrease the ability of the horses to be used for working purposes. The methods used to identify P. insidiosum isolates were based on the production of sporangia and zoospores, histopathology and PCR assay. To further ...
Ranera B, Remacha AR, Álvarez-Arguedas S, Castiella T, Vázquez FJ, Romero A, Zaragoza P, Martín-Burriel I, Rodellar C.Bone marrow-derived mesenchymal stem cells (BM-MSCs) are widely used in regenerative medicine in horses. Most of the molecular characterisations of BM-MSCs have been made at 20% O(2), a higher oxygen level than the one surrounding the cells inside the bone marrow. The present work compares the lifespan and the tri-lineage potential of equine BM-MSCs expanded in normoxia (20% O(2)) and hypoxia (5% O(2)). No significant differences were found in long-term cultures for osteogenesis and adipogenesis between normoxic and hypoxic expanded BM-MSCs. An up-regulation of the chondrogenesis-related genes...
Muranaka M, Yamanaka T, Katayama Y, Niwa H, Oku K, Matsumura T, Oyamada T.To investigate the pathology of equine influenza, necropsy of 7 horses experimentally infected with equine influenza A virus (EIV) subtype H3N8 was conducted on post-infection days (PID) 2, 3, 7, and 14. Histopathologically, rhinitis or tracheitis including epithelial degeneration or necrosis with loss of ciliated epithelia and a reduction in goblet cell numbers, was observed in the respiratory tracts on PIDs 2 and 3. Epithelial hyperplasia or squamous metaplasia and suppurative bronchopneumonia with proliferation of type II pneumocytes were observed on PIDs 7 and 14. Viral antigen was detecte...
Sharp DC.This paper will discuss development of the equine conceptus, especially from the perspective of the maternal environment in which it develops and to which it has considerable influence.
Duncan ID, Baker GJ, Heffron CJ, Griffiths IR.The larynges of 6 horses were examined endoscopically and the findings correlated with the gross and histological appearance of the intrinsic laryngeal muscles and their nerve supply. In all cases it appeared that the balance between abductor and adductor muscle groups had been lost due to preferential atrophy of individual muscles or groups of muscles. The laryngeal abnormalities recorded were asymmetry of the larynx with asynchronous left sided abduction and fluttering or trembling of the left vocal cord and arytenoid cartilage. It is suggested that these changes represent the early signs of...
Frazier K, Liggett A, Hines M, Styer E.We describe a fatal case of mushroom intoxication in an 18-y-o horse presumably due to Amanita verna. Horses are normally regarded as too fastidious to eat the ill-flavored toadstools. In this case, the horse had a rare benign brain tumor, meningioangiomatosis, which may have altered the horse's normal eating behavior resulting in consumption of the mushrooms.
Bolton JR, Merritt AM, Cimprich RE, Ramberg CF, Streett W.The D-xylose absorption test was applied to clinically normal horses and to horses with signs of gastrointestinal disease. A dosage of 0.5 grams of xylose per kilogram of bodyweight was useful in detecting horses that absorbed the pentose abnormally. The clinical findings were correlated with gross and microscopic findings by biopsy and at necropsy. Gastrointestinal lesions associated with abnormal xylose absorption were classified as: 1) villous atrophy; 2) edema of the lamina propria or 3) necrosis of the lamina propria.
Yovich JV, McIlwraith CW, Stashak TS.Osteochondritis dissecans of the sagittal ridge of the third metacarpal and metatarsal bones was diagnosed in 8 horses during an 18-month period. Seven of the horses were less than or equal to 2 1/2 years old. Synovial distention of the affected fetlock joints and a pain response to fetlock flexion were typical findings. Lameness predominated in 1 limb at a trot, although fetlock flexion frequently elicited lameness in other affected limbs. Radiography revealed bony lesions (flattening, erosion, or fragmentation) of the sagittal ridge in at least 2 fetlock joints in all horses. The onset of si...
Cvitas I, Galichet A, Ling SC, Müller EJ, Marti E.Thymic stromal lymphopoietin (TSLP) plays a key role in the development of allergic inflammation. Little is known about possible triggers of equine TSLP expression. Objective: To investigate TSLP expression in equine insect bite hypersensitivity (IBH) skin lesions. The capacity of TLR 1-8 ligands (L) and of atopic cytokine milieu as potential triggers of TSLP and of interleukin (IL)-6 as a downstream effector molecule of TLR signalling, were examined in primary equine keratinocyte cultures. Methods: Lesional skin from IBH-affected and healthy skin from control-horses (n = 9 each group) was s...
Nemery E, Gabriel A, Grulke S, Piret J, Toppets V, Antoine N.Lameness due to stifle and especially meniscal lesions is frequent in equine species. In humans, mechanoreceptors involved in proprioceptive function are well studied. Given the high incidence of meniscal injuries in horses, and the lack of information concerning them in equine menisci, our objective was to study these corpuscles in six healthy anterior horns of the equine medial meniscus, which is the most common localisation reported for equine meniscal injuries. Immunohistochemical stainings were performed using antibodies against high molecular weight neurofilaments and glial fibrillary ac...
Singh K, Holbrook TC, Gilliam LL, Cruz RJ, Duffy J, Confer AW.Multisystemic eosinophilic epitheliotropic disease was diagnosed histologically in a 17-year-old Quarter Horse intact mare that was presented with a chronic history of respiratory distress. At necropsy, the lungs were poorly collapsed and the pulmonary parenchyma contained innumerable, discrete, spherical nodules in a miliary pattern. A few similar nodules were scattered in the liver and the renal lymph nodes. Histologically, these nodules consisted of fibrosing eosinophilic granulomas. Based on histologic findings and the absence of an etiologic agent, a diagnosis of multisystemic eosinophili...
Jackson CA, deLahunta A, Dykes NL, Divers TJ.Cholesterinic granulomas have been previously reported as an incidental post mortem in horses. Three adult horses with diencephalic dysfunction due to cholesterinic granulomas are described. All the horses exhibited profound depression, somnolence and reluctance to move. One horse experienced generalised seizures. Cerebrosinal fluid was xanthochromic with an elevated total protein in two of the cases evaluated. The large cholesterinic granulomas caused expansion of the lateral ventricle and secondary hydrocephalus due to the build up of cerebrospinal fluid behind the mass. Cholesterinic granul...
Yu K, Pfeiffer C, Burden C, Krekeler N, Marth C.Increased ambient temperatures has been identified to contribute to reproductive outcomes for several domesticated species, but its impact on equine reproduction has not been previously investigated. Therefore, this study aimed to examine the relationship between ambient climatic conditions, as measured by temperature-humidity index (THI) between day 7 and day 14 of gestation, and early embryonic loss (EEL) in recipient mares undergoing embryo transfer. The study examined records from 834 embryo transfers at an equine breeding facility in Victoria, Australia. Early embryonic loss was defined a...
Almadhidi J, Moslemi S, Drosdowsky MA, Séralini GE.Aromatase (estrogen synthetase) is a steroidogenic enzyme complex which catalyzes the conversion of androgens to estrogens (termed aromatization). This enzyme was purified from adult equine testis to homogeneity by five chromatographic steps. The ability of purified and reconstituted equine aromatase to exhibit an estrogen 2-hydroxylase activity was tested and compared to testosterone aromatization. Enzymatic activities were assessed by tritiated water release from labelled estradiol and testosterone. Kinetic analysis of estradiol 2-hydroxylation showed an apparent K(m) of 23 microM and a V(ma...
Martin LM, Johnson PJ, Amorim JR, DeClue AE.Resveratrol, a phytophenol, is a commonly used equine nutraceutical supplement touted to exert anti-inflammatory effects. The effect of orally administered resveratrol on tumor necrosis factor (TNF), interleukin-1β (IL-1β), leukocyte phagocytic activity or oxidative burst function have not been reported in horses. The objective of this study was to determine the effects of a commercially available, orally administered resveratrol product on innate immune functions in healthy adult horses. Whole blood was collected from 12 horses prior to and following 3 weeks of treatment with either the man...
Slater J.Josh Slater looks back at the past 125 years of developments in equine infectious disease, including landmark discoveries in microbiology and genomics, and considers what the future may hold.
Tennent-Brown B.Although a range of plasma-based products (e.g., cryoprecipitate, albumin, platelet-rich plasma, individual coagulation factors) are available to human physicians, equine veterinarians are largely restricted to using whole blood, frozen plasma, and fresh frozen plasma for transfusions. The indications for frozen or fresh frozen plasma in human medicine are relatively limited, and there is little evidence supporting the efficacy of these products in many cases. Furthermore, many human physicians have concerns regarding disease transmission and anaphylactic reactions after administration of any ...
Maylin G, Fenger C, Machin J, Kudrimoti S, Eisenberg R, Green J, Tobin T.Aminorex, (RS)-5- Phenyl-4,5-dihydro-1,3-oxazol-2-amine, is an amphetamine-like anorectic and in the United States a Drug Enforcement Administration [DEA] Schedule 1 controlled substance. Aminorex in horse urine is usually present as a metabolite of Levamisole, an equine anthelmintic and immune stimulant. Recently, Aminorex identifications have been reported in horse urine with no history or evidence of Levamisole administration. Analysis of the urine samples suggested a botanical source, directing attention to the Brassicaceae plant family, with their contained GlucoBarbarin and Barbarin as p...
Urie NJ, Lombard JE, Marshall KL, Digianantonio R, Pelzel-McCluskey AM, McCluskey BJ, Traub-Dargatz JL, Kopral CA, Swenson SL, Schiltz JJ.Vesicular stomatitis (VS) is caused by a contagious rhabdovirus that affects horses, cattle, and swine. Clinical signs of vesicular stomatitis virus (VSV) infection in pigs and cattle are indistinguishable from foot-and-mouth disease (FMD), a foreign animal disease and reportable disease in the United States (Rodriguez et al., 2000). A VS epidemic occurred in the Rocky Mountain region in 2014-15. A study was conducted in Colorado to evaluate horse- and management-level factors associated with VS. For a horse to be considered a clinical VS horse, there were two requirements. First, clinical VS ...
Rose PL, Seeherman H, O'Callaghan M.Comminuted fractures of the middle phalanx have been well described in the horse. Choice of treatment, surgical planning and prognosis have traditionally been based upon evaluation of radiographs. However, the complex nature of comminuted fractures makes radiographic interpretation difficult. Computed tomography (CT) allows the production of cross-sectional images with spatial separation of structures which are superimposed on survey radiographs. This allows accurate assessment of the number and direction of fracture lines within the bone. In this paper we report the use of CT in the evaluatio...
Messer NT, Johnson PJ.The evidence-based literature pertaining to thyroid dysfunction and Cushing's syndrome is discussed in this article. Summaries of and recommendations for the treatment of these conditions are made. There is a need for reliable diagnostic tests for these conditions in horses.
Casagrande Proietti P, Bietta A, Coppola G, Felicetti M, Cook RF, Coletti M, Marenzoni ML, Passamonti F.The objective of this manuscript was to validate published PCR-based methods for detection of β-haemolytic Streptococci by comparison with established bacteriological techniques using 85 clinical isolates recovered from uterine swabs of mares with clinical signs of endometritis and to determine the distribution of SeeL/SeeM and SzeL/SzeM superantigens in isolates of Streptococcus equi subsp. equi (S. equi) and S. equi subsp. zooepidemicus (S. zooepidemicus). The conventional bacteriological techniques showed the vast majority of these isolates (78) were S. zooepidemicus with just 5 Streptococ...
Lew AM, Thomas LM, Huntington PJ.Sera of sixteen horses with clinical signs of EIA from six different outbreaks and sera of 100 uninfected horses were used to validate an ELISA for EIA diagnosis. The antigen used was a recombinant protein derived from the amino-terminal portion of the transmembrane envelope protein of EIA (gp45). Reactivity between positive and negative sera could be clearly distinguished. Comparison with the traditional agar gel immunodiffusion test (commonly called the Coggins test) showed that the ELISA was superior in sensitivity. Comparison of this ELISA with the FAST-ELISA system showed that the latter ...