Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Netherwood T, Chanter N, Mumford JA.There have been several case reports of foal diarrhoea associated with Clostridium perfringens. However, there has been no epidemiological assessment of the strength of the association of these bacteria with foal diarrhoea or of their relative importance. To prepare methods for such a study, the success of different cultural techniques for the isolation of C perfringens was examined with respect to the various physiological states of the bacteria. The germination and growth of C perfringens NCTC 8239 endospores of differing maturity were favoured by different pre-treatments which failed to rec...
Curran JM, Sutherland RJ, Peet RL.To evaluate various biochemical tests as indicators of subclinical liver disease in horses exposed to pyrrolizidine alkaloid toxicosis. Methods: A clinical pathology field study. Methods: Twenty-two clinically normal horses from four properties in the Kimberley region of Western Australia. Methods: Serum samples from each horse were assayed for gamma glutamyltransferase, alkaline phosphatase and aspartate aminotransferase activities, and for serum bile acid concentration, albumin and total protein. Serum protein electrophoresis was performed and their amino acid profiles determined. Bromosulph...
Siles-Lucas M, Cuesta-Bandera C.A comparison was made, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), of excretory/secretory (ES)-crude and immunopurified (with the corresponding anti-host serum) hydatid fluids-and somatic (S)-protoscoleces-proteins, from several ovine, equine, swine, bovine and human Echinococcus granulosus Spanish isolates. Likewise, the host influence on parasitic ES protein expression was studied, comparing purified hydatid fluids from ovine and equine cysts obtained from natural hosts and in RNMI mice. Purified hydatid fluids patterns, under reducing conditions, yielded the mos...
Weaver SC, Salas R, Rico-Hesse R, Ludwig GV, Oberste MS, Boshell J, Tesh RB.Venezuelan equine encephalomyelitis (VEE) virus has caused periodic epidemics among human beings and equines in Latin America from the 1920s to the early 1970s. The first major outbreak since 1973 occurred in Venezuela and Colombia during 1995, and involved an estimated 75,000 to 100,000 people. We report an epidemiological and virological investigation of this epidemic. Methods: Virus isolates were made in cell culture from human serum, human throat swabs, and brain tissue from aborted and stillborn human fetuses, as well as from horse brain tissue and pooled mosquito collections. Human sera ...
Cohen ND, Honnas CM.To determine the incidence of the risk factors for developing diarrhea in horses after celiotomy for colic. Methods: Retrospective cohort study. Methods: 357 adult horses that had celiotomy for colic at the teaching hospital between Jan 1, 1990 and Sep 1, 1994. Methods: Medical records of horses that had celiotomy for colic were reviewed to abstract information regarding development of diarrhea, signalment, history, and treatment. Results: In horses that had celiotomy for colic, the incidence of diarrhea was 53.2% (190/357). Using multiple logistic regression, horses with a disorder of the lar...
Aleman M, Spier SJ, Wilson WD, Doherr M.To describe clinical manifestations of Corynebacterium pseudotuberculosis infection in horses and to evaluate diagnostic methods for identification of this disease. Methods: Retrospective case series. Methods: 538 horses with a diagnosis of C pseudotuberculosis infection. Results: Median age of horses with external abscesses was similar to that in horses with internal abscesses. Breed and sex did not appear to be associated with infection. Cases were detected during all 12 months; however, the disease was most common in the fall and early winter, with the highest incidence in September, Octobe...
Gerhards H, Wollanke B.In Germany very little is known about antibody titers against Borrelia burgdorferi in the horse. In the USA there exist some studies on the titer levels and symptoms due to borrelia infections. Beside lameness, fever, polyarthritis, pneumonia and dullness there is a study showing a connection between panuveitis and Borrelia infection in the horse. In human medicine the infection with Borrelia burgdorferi becomes more and more important. Uveitis and other eye diseases due to Borrelia burgdorferi are proved and documented. The goal of this study was to find a connection between antibodies to Bor...
Kane AJ, Stover SM, Gardner IA, Case JT, Johnson BJ, Read DH, Ardans AA.To evaluate selected shoe characteristics as risk factors for fatal musculoskeletal injury (FMI) and specifically for suspensory apparatus failure (SAF) and cannon bone condylar fracture (CDY) of Thoroughbred racehorses in California. Methods: Case-control study. Methods: Thoroughbred racehorses (n = 201) that died of were euthanatized at California racetracks between August 1992 and July 1994. Methods: Shoe characteristics were compared between case horses affected by FMI (155), SAF (79), and CDY (41) and control horses that died for reasons unrelated to the appendicular musculoskeletal syste...
Bowling AT, Byrns G, Spier S.The pedigree origin of a base pair substitution in the horse muscle sodium channel gene that confers susceptibility to the muscle disease hyperkalemic periodic paralysis (HYPP) was investigated with a set of 978 Quarter Horses. The horses were chosen at random, based on a collection of blood samples taken between 1989 and 1991 to meet parentage testing requirements, primarily but not exclusively from breeding stallions. The frequency of Quarter Horses positive for the base pair substitution, all heterozygotes, was 4.4%, which corresponds to an allelic frequency of 0.02. All horses positive for...
Uzal FA, Woodman MP, Giraudo CG, Robles CA, Doxey DL.'Mal seco' is an almost invariably fatal disease of horses in Argentina and Chile, which resembles grass sickness, a dysautonomia of horses in Europe. The aetiology of mal seco remains unknown. An attempt to reproduce the disease was made by feeding horses with Festuca argentina, a plant considered to be toxic to animals and which was consistently found in the diet of nine horses suffering from mal seco. Three horses were fed with F argentina ad libitum for 28 days. The plant was infected with an endophytic fungus, whose morphological characteristics were in agreement with descriptions of Acre...
Daugschies A.Drug resistance of parasites is a worldwide problem of increasing importance in animal production. Considerable information is available on the development of resistance in chicken coccidia and in strongyles of horses, sheep, goats and pigs. A review is given of the development, incidence, and management of drug resistance with emphasis on the situation in Germany.
Hyatt AD, Selleck PW.The ultrastructure of the equine morbillivirus (EMV) which was implicated in the death of one human and fourteen horses in Queensland, Australia during September 1994 and a 36 year old man from Queensland in October 1995 is described. The ultrastructure of the virus and the intracellular virus-specific structures are characteristic for the family Paramyxoviridae. Cytoplasmic nucleocapsids were observed within the infected cells monolayers, endothelial cells (lung) of infected horses and the neurons within the brain of the 36 year old Queensland man. Aggregates of smaller nucleocapsid-like stru...
Wilson DA, MacFadden KE, Green EM, Crabill M, Frankeny RL, Thorne JG.Trimethoprim-potentiated sulphonamides (TPS) are among the most frequently administered antimicrobials in equine medicine. Anecdotally, TPS has been implicated as a cause of mild to moderate diarrhea in horses. The purpose of this study was to document the prevalence of diarrhea in horses receiving TPS, to characterize the severity of the diarrhea, and to identify any other factors associated with the development of diarrhea. A 2-part study was designed to identify the prevalence of diarrhea associated with TPS in our clinic population. Part I was a case-control retrospective study of 135 reco...
Mair TS, Dyson SJ, Fraser JA, Edwards GB, Hillyer MH, Love S.The case records of 23 horses and one donkey affected by hypertrophic osteopathy (HO) (Marie's disease) were reviewed. All affected animals presented with limb swellings, which were bilaterally symmetrical and usually involved both fore- and hindlimbs. Associated signs included stiffness/lameness and weight loss. Radiological features included periosteal new bone formation over the diaphyses and metaphyses of affected bones. The metacarpal and metatarsal bones were most frequently affected. Articular surfaces remained free of disease. Seventeen animals were destroyed on humane grounds, 3 horse...
Nordengrahn A, Rusvai M, Merza M, Ekström J, Morein B, Belák S.Equine herpesvirus type 2 (EHV-2), a member of the Gammaherpesvirinae subfamily, was studied in a two-phase respiratory disease complex of young foals as a predisposing factor for the secondary bacterial invasion of lungs with Rhodococcus equi (R. equi). Foals were immunized against EHV-2 on a farm where R. equi pneumonia regularly occurred during the last years. The immunizations were performed by using a subunit vaccine which selectively presents envelope glycoproteins of EHV-2 in a multimeric form of immunostimulating complexes (iscoms). The etiological role of EHV-2 was estimated by observ...
Gould AR.The nucleotide sequence of the matrix protein of equine morbillivirus (EMV) was determined to be 1062 nucleotides and coded for a deduced protein of M(r) 40148 having a net charge of + 19 at neutral pH. The matrix protein gene was separated from the P and F genes by intercistronic regions of 546 and 469 nucleotides, respectively. The nucleotide sequence which coded for the F protein was 1641 nucleotides and coded for a deduced protein of 546 amino acids having an M(r) of 60,447 and a charge + 4 at neutral pH. Partial sequence information was also determined for the P/V proteins. M, P and F pro...
Felix K, Ferrándiz R, Einarsson R, Dreborg S.Some patients who are allergic to horses have reported that they can tolerate certain breeds, and the presence of breed-specific allergens has been suggested. Breeders and patients with asthma have claimed that Bashkir horses are nonallergenic. We used sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting to determine IgE-binding profiles of extracts of dander obtained from horses of several breeds. We found considerable inter-breed and within-breed variation but no breed-specific allergens. Danders from all breeds investigated contained the most important allergens, and ...
Nagata K, Tsukita S, Tamura T, Sone N.A Helicobacter pylori membrane fraction oxidized yeast and equine cytochrome c, and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). When ascorbate was used as reductant, the Vmax and apparent Km values were 612 nmol electron min-1 (mg protein)-1 and 14 microM for yeast, and 419 nmol electron min-1 (mg protein)-1 and 19 microM for equine cytochrome c, respectively. For TMPD oxidation, the Vmax and Km values were 640 nmol electron min-1 (mg protein)-1 and 182 microM, respectively. These oxidase activities showed a high affinity for oxygen. Inhibition of both cytochrome-c and TMPD oxidase activi...
Palmer JL, Bertone AL, Malemud CJ, Mansour J.The effects of inflammation on the biochemical and biomechanical properties of articular cartilage at two sites (dorsal and palmar) from the radial facet of the equine third carpal bone were examined in response to a synovitis induced with Escherichia coli lipopolysaccharide (LPS). Four groups were studied. In group 1 synovitis was induced at time zero and evaluated at week 6. Group 2 was the sham-treated control for group 1. In group 3 synovitis was induced at time zero and evaluated at week 2. Group 4 was the sham-treated control for group 3. There was a significant increase (P palmar). The...
Nishita T, Ohohashi T, Asari M.The concentration of carbonic anhydrase III isoenzyme (CA-III) in serum samples from 216 clinically normal Thoroughbreds was determined by use of an enzyme immunoassay. The concentration range of CA-III was from 16.0 to 254.5 ng/ml (mean, 56.5 +/- 11.9 ng/ml). Significant differences were not detected according to age or sex. To confirm whether serum CA-III concentration was high in horses with muscle disease, serum samples of 11 horses with exertional rhabdomyolysis were analyzed by enzyme immunoassay. Their serum CA-III concentration was about 56 times (3,136 +/- 2,610 ng/ml) that of healthy...
Carmalt JL, Gordon JR, Allen AL.It has been suggested that dental abnormalities lead to temporomandibular joint inflammation and pain that may be mitigated by regular dental care. There is considerable literature on the pathophysiology of equine joint disease including studies on cytokine profiles in diseased appendicular joints. This study examined the effects of age and dental malocclusions summarized as a dental pathology score on equine temporomandibular joint cytokine (IL-1, IL-6, IL-8, TNF alpha and TGF-beta1, -beta2, -beta3) concentrations. TGF-beta3 was not detected in any joint sample. IL-1, IL-6 and TNF alpha were ...
Mundis SJ, Harrison S, Pelley D, Durand S, Ryan SJ.Eastern equine encephalitis virus (EEEV) is a mosquito-borne virus that affects humans and horses, with a high case fatality rate in both species. The virus can be transmitted by several mosquito species and maintained in multiple reservoir hosts, making EEEV dynamics difficult to anticipate. In this study, we identified spatial and temporal factors that precede EEEV detection using sentinel chicken surveillance data from Orange County, Florida, from 2003 to 2017. We first examined the land cover and mosquito species composition associated with sentinel chicken sites. We then fit distributed l...
Ayad A, Almarzook S, Besseboua O, Aissanou S, Piórkowska K, Musiał AD, Stefaniuk-Szmukier M, Ropka-Molik K.Genetic disorders in horses are mostly fatal or usually cause significant economic losses for breeders and owners. Here we studied a total of 177 Arabian, Barb and Arab-Barb horses from the Middle East and North Africa (MENA) using Sanger Sequencing and PCR-ACRS (polymerase chain reaction-artificially created restriction site) approaches to examine the genetic disorders in the studied horse breeds. We identified the genetic variations related to Cerebellar Abiotrophy (CA), Severe Combined Immunodeficiency (SCID) occurrence, and the studied population was free of the mutant allele determined La...
Smith LCR, Wylie CE, Palmer L, Ramzan PHL.There is a need for investigation of associations between intrasynovial medication and fracture risk in racehorses. Objective: To document the proportion and type of fracture occurring following intrasynovial medication. Methods: Retrospective longitudinal study. Methods: Review of clinical records from all Thoroughbred flat racehorses receiving intrasynovial medication under the care of a first-opinion veterinary practice between 2006 and 2011. Fractures pre- and post-medication were categorised by location, type, and severity; analysis of fractures sustained within 56-days of medication was ...
Lejeune JP, Serteyn D, Gangl M, Schneider N, Deby-Dupont G, Deberg M, Henrotin Y.Several breeds of draft horses suffer from degenerative digital osteoarthropathy, resulting in a reduced active lifespan. A group of 30 Ardenner horses was followed, in standardized conditions, from 15 to 28 months of age to detect the early manifestations of the disease. The severity of the disease was assessed according to a personal grading system including clinical and radiographic items. Coll 2-1, a peptide of the helical region of type II collagen, and its nitrated form (Coll 2-1 NO(2)) were assayed in blood plasma collected at 452 +/- 18 days, 504 +/- 20 days, 558 +/- 18 days, 613 +/- 1...
Menzies-Gow NJ, Wakeel F, Little H, Buil J, Rickards K.Laminitis causes lameness in donkeys, but its prevalence and factors associated with disease remain uncertain. Objective: To determine the prevalence of and identify factors associated with laminitis in donkeys. Methods: Retrospective cross-sectional study. Methods: All donkeys at the Donkey Sanctuary, UK, October 2015 to March 2019 were included. For animals that had laminitis during this period, age, sex, weight, body condition score, and the onset date and type of each episode (first or recurrent, acute or chronic) were recorded. Additionally, management data, foot lesion score, endocrine d...
Valentine BA.A retrospective study examined data on cutaneous nodular and proliferative lesions in horses, donkeys and mules submitted to the Veterinary Diagnostic Laboratory at Oregon State University in a 3.5-year period. One hundred and sixteen non-neoplastic nodular and proliferative lesions were identified, comprising 18% of all lesions studied and 6.4% of total equine pathology accessions. Exuberant granulation tissue, eosinophilic granuloma, fungal granuloma, cysts and habronaemiasis were most common, and constituted 91% of non-neoplastic lesions, 16% of all lesions studied, and 5.85% of total equin...
Grandguillot L, Fairbrother JM, Vrins A.A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheai and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy u...
Duarte PC, Morley PS, Traub-Dargatz JL, Creekmore LH.To identify factors associated with development of vesicular stomatitis (VS). Methods: Case-control study. Methods: 138 livestock premises and 118 horses suspected of having VS in Texas, New Mexico, and Colorado. Methods: Premises with >or= 1 animal with clinical signs and laboratory confirmation of infection were classified as case premises. Premises where laboratory confirmation results were negative were control premises. Among equine premises, case and control horses were selected on the basis of premises status. A survey was conducted to identify factors associated with VS for premises an...
Easton-Jones CA, Madigan JE, Barnum S, Maxwell LK, Taylor SD, Arnesen T, Pusterla N.Equine herpesvirus-5 is commonly isolated from the lungs of horses with EMPF, suggesting an etiological link. Valacyclovir is used empirically to treat EMPF; however, no data is available concerning its impact on EHV-5 viral kinetics. Objective: To determine the effect of oral administration of valacyclovir on EHV-5 viral load measured by qPCR in blood, nasal secretions (NS) and BALF in horses with EMPF. Methods: Six horses diagnosed with EMPF. Methods: A prospective clinical trial was performed. Horses received 10 days of PO administered valacyclovir (loading dose 30 mg/kg, maintenance dose 2...
Watts AE, Johnson AL, Felippe MJ, Divers TJ.A Thoroughbred gelding in North America was evaluated for Actinobacillus peritonitis on three different occasions over a 4-year period. At each presentation, peritoneal fluid had an elevated nucleated cell count (220,000-550,000 cells/µL) characterised by non-degenerate neutrophils, no visible bacteria, an elevated total protein (4.6-5.5 g/dL) and bacterial culture yielding Actinobacillus spp. Actinobacillus peritonitis appears to be a regional disease occurring in Australia and less commonly in New Zealand and North America. Recurrence, other than incomplete resolution, has not been previous...
Scudamore CL, Pemberton A, Watson ED, Miller HR.Studies have demonstrated that as a result of proteolytic inactivation or complex formation (with neutrophil elastase), human alpha-1-proteinase inhibitor (API) becomes a potent chemoattractant for human neutrophils. The present study aimed to investigate the in vitro chemotactic response of equine neutrophils to an equivalent complex of equine API and neutrophil elastase. No evidence of neutrophil migration was observed towards purified complex derived from equine neutrophil elastase and the Spi 1 isoform of equine API, or to crude mixtures of porcine pancreatic elastase and unseparated equin...
Burns TA, Watts MR, Weber PS, McCutcheon LJ, Geor RJ, Belknap JK.In EMS-associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5'-Adenosine-monophosphate-activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR. Objective: To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge. Methods: Twenty-two mixed-breed ponies. Methods: Immunohistochemistry and immunoblotting for total AMPK and phospho(P)-AMPK and RT-qPCR for AMPK-responsive genes were performed on laminar...
Weiss DJ, Evanson OA, MacLeay J, Brown DR.To determine whether mucosal permeability is altered during the prodromal stages of alimentary laminitis. Methods: 15 healthy adult ponies. Methods: intestinal permeability was evaluated for control ponies (n = 5) and for ponies 4 to 12 (n = 5) and 20 to 28 (n = 5) hours after administration of carbohydrate overload. Mucosal permeability was determined by measuring the percentage of orally administered technetium Tc99m diethylenetriaminopentaacetate (99mTc-DTPA) excreted in urine during an 8-hour period, then measuring blood radioactivity at hourly intervals. Plasma endotoxin-like activity was...
Hamilton NA, Tammen I, Raadsma HW.Angiotensin converting enzyme (ACE) is essential for control of blood pressure. The human ACE gene contains an intronic Alu indel (I/D) polymorphism that has been associated with variation in serum enzyme levels, although the functional mechanism has not been identified. The polymorphism has also been associated with cardiovascular disease, type II diabetes, renal disease and elite athleticism. We have characterized the ACE gene in horses of breeds selected for differing physical abilities. The equine gene has a similar structure to that of all known mammalian ACE genes. Nine common single nuc...
Fosgate GT, Cohent ND.The primary purposes of epidemiological investigations are to learn about causal mechanisms related to disease incidence and identify factors for therapy and prevention. Epidemiological studies can be observational--further categorised as descriptive or analytical--or experimental. Investigators performing experimental studies, or randomised controlled trials (RCTs), randomly assign treatments or exposures to study participants for the expressed purpose of the study. The most frequently encountered observational epidemiological studies employed to investigate issues of equine health are cohort...
Ceusters JD, Mouithys-Mickalad AA, Franck TJ, Derochette S, Vanderplasschen A, Deby-Dupont GP, Serteyn DA.Horses are particularly sensitive to excessive inflammatory reaction where myeloperoxidase, a marker of inflammation, may contribute to mitochondrial dysfunctions. This study investigated the interaction between myeloperoxidase and cultured primary equine skeletal myoblasts, particularly its effect on mitochondrial respiration combined or not with anoxia followed by reoxygenation (AR). We showed that active myeloperoxidase entered into the cells, interacted with mitochondria and decreased routine and maximal respirations. When combined with AR, myeloperoxidase caused a further decrease of thes...
Dolvik NI, Klemetsdal G.The purpose of this study was to evaluate the impact of arthritis of the carpal joint on performance of Norwegian cold-blooded trotters. Two performance variables were used in the analyses. The first was the start status, for which horses that had started in one or more races within a certain age received the value 1, and horses that had not raced were correspondingly assigned the value 0. The second variable was the accumulated, transformed and standardized earnings (ATSE), which is the power transformation of earnings (earnings .2, with unraced horses assigned a value of zero) expressed as a...
Silva GTA, Guest BB, Gomez DE, McGregor M, Viel L, O'Sullivan ML, Runciman J, Arroyo LG.Calcification of the tunica media of the axial pulmonary arteries (PA) has been reported in a large proportion of racehorses. In humans, medial calcification is a significant cause of arterial stiffening and is implicated in the pathogenesis of cardiac, cerebral, and renal microvascular diseases. Pulse wave velocity (PWV) provides a measure of arterial stiffness. This study aimed to develop a technique to determine PA-PWV in horses and, secondarily, to investigate a potential association between PA-PWV and arterial fibro-calcification. A dual-pressure sensor catheter (PSC) was placed in the ma...
Leiva M, Peña T, Armengou L, Cesarini C, Monreal L.Septicemia in humans is described as a leading cause of uveitis, which eventually can induce blindness. Objective: Uveal inflammatory findings could be related to sepsis severity in newborn foals and might be used as an indirect indicator for survival. Methods: Seventy-four septic foals, 54 nonseptic foals, and 42 healthy foals. Methods: Prospective observational clinical study. A detailed blinded, ophthalmic examination was performed by boarded ophthalmologists on all admitted newborn foals. Foals were grouped as septic (when blood culture resulted positive or the sepsis score was > or =14...
Dart AJ, Snyder JR, Pascoe JR, Farver TB, Galuppo LD.The signalment, clinical and laboratory findings of surgical conditions, treatment, and outcome of 102 cases of descending colon disease in horses were reviewed. Abnormal conditions were categorized as enteroliths, impactions, strangulating lipomas, fecaliths, foreign body obstruction, volvulus, nephrosplenic entrapment, and other conditions. Eleven breed categories of horses were seen during this period. Arabians, ponies, and American miniature horses were more predisposed to descending colon disease than other breeds (P less than 0.05). Female horses and animals greater than 15 years old wer...
Gerber V, Straub R, Frey J.In Switzerland, the incidence of equine botulism and acute pasture myodystrophy have remarkably increased in the last five years. Equine fodder-borne botulism in Europe is most likely caused by Clostridium botulinum types C and D that produce the toxins BoNT/C and BoNT/D. Horses showing signs suggestive of botulism (muscle weakness and tremors, reduced tongue tone, slow chewing, salivation and difficulties swallowing, drooping eyelids, mydriasis), especially patients that have fed on suspect fodder (mostly haylage), must be treated with anti-serum as soon as possible. They also need intensive ...
Díez de Castro E, Zafra R, Acevedo LM, Pérez J, Acosta I, Rivero JL, Aguilera-Tejero E.Equine motor neuron disease (EMND) is a neuromuscular disorder that affects adult horses. Although EMND has been linked to vitamin E deficiency, its etiopathogenesis is poorly understood. Objective: To describe clinical features, laboratory results, and postmortem findings in a series of young horses with motor neuron disease (MND). Methods: A herd of 15 young Andalusian horses with weakness, weight loss, muscle atrophy, and muscle fasciculations related to restricted intake of green forage. Methods: A case series is presented in which horses were subjected to a clinical examination and plasma...
Putnam JR, Holmes LM, Green MJ, Freeman SL.Lameness is a common problem in the horse. Despite this, information on the incidence of lameness in horses in the UK is restricted to studies of lameness in performance horses, racehorses or referral hospital populations. Objective: To determine the overall incidence and common causes of lameness in a working horse population and incidence, duration and outcome of conditions observed. Methods: Prospective questionnaire study. Methods: Questionnaires were used to record lameness episodes in 294 horses in an equine military establishment. Information recorded included age, years of service, typ...
Rickard LG, Black SS, Rashmir-Raven A, Hurst G, Dubey JP.Sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (EPM) in horse in the Americas. The only known definitive host for this parasite in the United States is the opossum (Didelphis virginiana); however, despite the importance of the disease, the epidemiology of the parasite in the definitive host is poorly understood. To begin addressing these data gaps, potential risk factors were evaluated for their association with the presence of sporocysts of S. neurona in opossums live-trapped in March 1999 and November 1999 to May 2000. Sporocysts of S. neurona were foun...
Shilton CA, Kahler A, Roach JM, Raudsepp T, de Mestre AM.Embryonic and foetal loss remain one of the greatest challenges in equine reproductive health with 5-10% of established day 15 pregnancies and a further 5-10% of day 70 pregnancies failing to produce a viable foal. The underlying reason for these losses is variable but ultimately most cases will be attributed to pathologies of the environment of the developing embryo and later foetus, or a defect intrinsic to the embryo itself that leads to lethality at any stage of gestation right up to birth. Historically, much research has focused on the maternal endometrium, endocrine and immune responses ...
Banfield J, Lisak R, Omar A, Domingos W, Fiaschitello A, Morales-Gomez A, Divers TJ, Mohammed HO.We carried out an investigation to identify the factors that predispose to the risk of equine motor neuron disease (EMND) and evaluated the long-term impact of an intervention. Data on several biomarkers, including antioxidants (α-tocopherols, β-carotenes, glutathione peroxidase (GSHPx)), and superoxide dismutase (SOD1), neurofilaments, and other putative risk factors hypothesized to associate with the likelihood of EMND were collected. The data were analyzed for their significance of association with the condition. The EMND outbreak started in 1991 and continued until 1998. A total of 69 EM...
Smith FL, Magdesian KG, Michel AO, Vaughan B, Reilly CM.A new syndrome of hematuria in horses has been documented. Objective: Hemorrhagic cystitis is a novel cause of stranguria and hematuria in horses. This syndrome may be difficult to differentiate from bladder neoplasia because they share several clinical features. Methods: Eleven horses with idiopathic hemorrhagic cystitis and 7 horses with bladder neoplasia. Methods: Retrospective cohort study. Results: Hemorrhagic cystitis was detected on cystoscopy of affected horses, with hemorrhagic and thickened apical bladder mucosa. Clinical signs and endoscopic appearance of the bladder resolved within...
Raisbeck MF, Dahl ER, Sanchez DA, Belden EL, O'Toole D.A review of Wyoming State Veterinary Laboratory records for 1947-1987 revealed no substantiated cases of naturally occurring selenosis. However, older reports attributed thousands of animal deaths to selenium each year in this area. Beginning in August 1988, cases of suspected selenosis and selenium deficiency were solicited from veterinarians and producers by announcements in various statewide livestock publications. As of August 1991, 4 cases (all horses) of naturally occurring selenosis have been confirmed. Clinical signs were most often referable to epithelial damage, e.g., hoof lesions an...
