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.
McCarty CA, Thomason JJ, Gordon K, Hurtig M, Bignell W.To add to the existing data on impact loading of the metacarpophalangeal (MCP) joint as a precursor to assessing the potential role of impact in joint disease. Objective: To examine the effect of impact loading on contact areas of the first phalanx (P1) and proximal sesamoids (PS) with the third metacarpal (McIII) under 3 hoof-strike conditions (toe-first, flat, heel-first). Methods: Randomised, repeated controlled experiment using cadaver material. Methods: Eight cadaver limbs were subjected to randomised, repeated controlled trials where the hoof was struck by a pendulum impact machine (impa...
Newman SJ.Equine pancreatic disease is considered rare, and successful treatment is limited. Additionally, antemortem diagnosis of equine pancreatitis is difficult because of the lack of definitive diagnostic tests. Although a paucity of information exists on this entity in the horse, pancreatic disease has typically been shown to be secondary to other gastrointestinal, hepatic, and endocrine conditions. No predisposition based on age, sex, or breed appears to exist, but several conditions predispose a horse to pancreatitis, including grain overload, endocrine disease, and parasite migration. A retrospe...
Miller CA, Durham AC, Schaffer PA, Ehrhart EJ, Powers BE, Duncan CG.Equine cutaneous lymphoma is an uncommon disease that can present with variable clinical signs, immunosuppression, and rapid systemic disease progression. Various subtypes of equine lymphoma have been described and classified according to a veterinary adaptation of the World Health Organization classification system, but little data is available regarding the association between lymphoma subtypes and epidemiological criteria and/or clinical outcome. The objective of the current study was to classify previously diagnosed cases of equine cutaneous lymphoma and correlate subtypes with clinical da...
Steinbach F, Westcott DG, McGowan SL, Grierson SS, Frossard JP, Choudhury B.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids, which is notifiable in some countries including the Great Britain (GB) and to the OIE. Herein, we present the case of a persistently infected stallion and the phylogenetic tracing of the virus strain isolated. Discussing EAV occurrence and phylogenetic analysis we review features, which may aid to harmonise and enhance the classification of EAV.
Weese JS, Holcombe SJ, Embertson RM, Kurtz KA, Roessner HA, Jalali M, Wismer SE.Disruptions in the gastrointestinal microbiota may trigger development of post partum colic. Objective: To determine the effects of the periparturient period on the faecal microbiome and identify associations between the faecal microbiota and post partum colic. Methods: Longitudinal case-control study. Methods: Pre- and post partum faecal samples were collected from mares on 3 farms in central Kentucky. Next generation sequencing of the V4 region of the 16S rRNA gene was performed on samples from 13 mares that developed colic, 13 mares that did not display colic and 5 nonpregnant controls. Res...
Hackett ES, Embertson RM, Hopper SA, Woodie JB, Ruggles AJ.Large colon volvulus results in strangulating obstruction requiring surgical treatment. Duration of this disease prior to surgical treatment is likely to influence survival directly. Objective: The primary objective of this study was to evaluate the influence of duration of large colon volvulus on patient survival to discharge. Relationships between other factors and survival following large colon volvulus were also examined. Methods: Retrospective case analysis. Methods: Medical records of Thoroughbred mares aged ≥2 years undergoing surgical treatment for large colon volvulus between 1 Marc...
van den Hurk AF, Hall-Mendelin S, Webb CE, Tan CS, Frentiu FD, Prow NA, Hall RA.In 2011, a variant of West Nile virus Kunjin strain (WNVKUN) caused an unprecedented epidemic of neurological disease in horses in southeast Australia, resulting in almost 1,000 cases and a 9% fatality rate. We investigated whether increased fitness of the virus in the primary vector, Culex annulirostris, and another potential vector, Culex australicus, contributed to the widespread nature of the outbreak. Methods: Mosquitoes were exposed to infectious blood meals containing either the virus strain responsible for the outbreak, designated WNVKUN2011, or WNVKUN2009, a strain of low virulence th...
Sánchez-Matamoros A, Sánchez-Vizcaíno JM, Rodríguez-Prieto V, Iglesias E, Martínez-López B.African horse sickness (AHS) is one of the most important vector-borne viral infectious diseases of equines, transmitted mainly by Culicoides spp. The re-emergence of Culicoides-borne diseases in Europe, such as the recent bluetongue (BT) or Schmallenberg outbreaks, has raised concern about the potential re-introduction and further spread of AHS virus (AHSV) in Europe. Spain has one of the largest European equine populations. In addition, its geographical, environmental and entomological conditions favour AHSV infections, as shown by the historical outbreaks in the 1990s. The establishment of ...
Scháňková Š, Maršálek M, Wagnerová P, Langrová I, Starostová L, Stupka R, Navrátil J, Brožová A, Truněčková J, Kudrnáčová M....Nine ponies, aged 12 months at the time of infection, were randomly allocated to one of three groups. Each pony was infected with 30,000 infective cyathostome larvae stored 4 weeks under the natural environmental conditions of the Czech Republic. Horses of Group A were infected with larvae conditioned from August 16 to September 12 (the first phase of the experiment). Horses of Group B were inoculated with larvae conditioned from October 10 to November 4 (the second phase of the experiment). In the third phase, horses from Group C received larvae stored under natural conditions (from 8.11 to 1...
Archer DC, Costain DA, Sherlock C.Idiopathic focal eosinophilic enteritis (IFEE) is an emerging cause of abdominal pain (colic) in horses that frequently requires surgical intervention to prevent death. The epidemiology of IFEE is poorly understood and it is difficult to diagnose pre-operatively. The aetiology of this condition and methods of possible prevention are currently unknown. The aims of this study were to investigate temporal and spatial heterogeneity in IFEE risk and to ascertain the effect of horse age on risk. Results: A retrospective, nested case-control study was undertaken using data from 85 IFEE cases and 848 ...
Van Driessche K, Ducatelle R, Chiers K, Van Coster R, van der Kolk JH.Very few mitochondrial myopathies have been described in horses. Objective: To examine the ultrastructure of muscle mitochondria in equine cases of myopathy of unknown origin. Methods: Biopsies of vastus lateralis of the Musculus quadriceps femoris were taken predominantly immediately post mortem and processed for transmission electron microscopy. As a result, electron micrographs of 90 horses in total were available for analysis comprising 4 control horses, 16 horses suffering from myopathy and 70 otherwise diseased horses. Results: Following a thorough clinical and laboratory work-up, four o...
Equine influenza in England and Scotland, Significant numbers of outbreaks of equine herpesvirus 1 neurological disease in the USA, Summary of surveillance testing, April to June 2014. These are among matters discussed in the most recent quarterly equine disease surveillance report, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
Hughes K.Cases of Hendra virus infection in horses in Australia have been seen regularly since the virus was first isolated in 1994. Kristopher Hughes, associate professor of equine medicine at Charles Sturt University in Australia, gives an overview of how knowledge of the virus has developed in the past 20 years.
Hébert L, Touzain F, de Boisséson C, Breuil MF, Duquesne F, Laugier C, Blanchard Y, Petry S.Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We herein report the genome sequence of T. equigenitalis strain MCE529, isolated in 2009 from the urethral fossa of a 15-year-old Belgian Warmblood horse in France.
Olstad K, Østevik L, Carlson CS, Ekman S.Osteochondrosis arises as a result of focal failure of the blood supply to growth cartilage. The current aim was to examine the pathogenesis of pseudocysts and true cysts in subchondral bone following failure of the blood supply to the articular-epiphyseal cartilage complex in horses. Cases were recruited based on identification of lesions (n = 17) that were considered likely to progress to or to represent pseudocysts or true cysts in epiphyseal bone in histological sections and included 10 horses ranging in age from 48 days to 5 years old. Cases comprised 3 warmbloods, 3 Standardbreds, 1 Quar...
van der Vekens N, Decloedt A, de Clercq D, Ven S, Sys S, van Loon G.Studies on the use of atrial natriuretic peptide (ANP) as a biomarker for left atrial dilatation in horses have produced variable results. Few have been performed, and the results may have been influenced by ANP instability, differences in sampling protocol and changes in the assay over time. N-Terminal proANP (NT-proANP) is a more stable molecule and might be a good alternative for clinical use. Objective: To compare ANP and NT-proANP in terms of the detection of left atrial dilatation and to determine the influence of sample storage at temperatures of -80 and -20°C. Methods: Prospective cli...
Hughes K, Scase TJ, Foote AK.Equine mammary tumors are uncommon, and relatively sparse histopathologic and molecular data exist. The present study describes the histopathologic features of 7 such tumors, which exhibited infiltrative growth, intermediate to high mitotic rates, and focally extensive necrosis. The tumors exhibited variably strong staining for vimentin and cytokeratin 14, as well as frequently weak cytoplasmic staining for pan-cytokeratin. E-cadherin expression was strong. Interestingly, a subgroup of the tumors exhibited strong nuclear staining for estrogen receptor α. Three of 7 tumors exhibited nuclear ex...
Jiang L, Campagne C, Sundström E, Sousa P, Imran S, Seltenhammer M, Pielberg G, Olsson MJ, Egidy G, Andersson L, Golovko A.Constitutive activation of the ERK pathway, occurring in the vast majority of melanocytic neoplasms, has a pivotal role in melanoma development. Different mechanisms underlie this activation in different tumour settings. The Grey phenotype in horses, caused by a 4.6 kb duplication in intron 6 of Syntaxin 17 (STX17), is associated with a very high incidence of cutaneous melanoma, but the molecular mechanism behind the melanomagenesis remains unknown. Here, we investigated the involvement of the ERK pathway in melanoma development in Grey horses. Methods: Grey horse melanoma tumours, cell lines ...
Wolff C, Egenvall A, Hanche-Olsen S, Gröndahl G.Acquired equine polyneuropathy (AEP) is an emerging disease in horses in Sweden, Norway and Finland since 1995. Affected horses show bilateral pelvic limb knuckling and weakness, sometimes progressing to recumbency and euthanasia. The aetiology is unknown but is thought to be non-infectious and non-genetic, though possibly toxic or toxico-infectious. The objectives of this study were to describe the spatial, temporal and spatio-temporal features of AEP in Norway and Sweden for the period of 1995 to 2012. Data from all documented case farms (n = 136) were used. Space-time interaction cluste...
Santos VG, Bettencourt EM, Ginther OJ.Mares with persistent CL (PCL) with no known etiology (idiopathic) were matched with mares with an interovulatory interval (IOI) of apparent physiological length, so that ovulation at the beginning of each PCL and IOI occurred during the same month (n = 6/group). Blood samples were collected daily from Days 12 to 22 (Day 0 = ovulation). Mean progesterone (P4) decreased in both groups on Days 14 and 15 and then diverged with a continued decrease in the IOI group and the beginning of constant and greater (P < 0.05) P4 concentration on each day in the PCL group. Before P4 divergence betw...
Fjordbakk CT, Revold T, Goodwin D, Piercy RJ.The pathogenesis of bilateral dynamic laryngeal collapse associated with poll flexion (DLC) of horses is unknown but might be associated with intrinsic laryngeal muscle weakness. Objective: To investigate histopathological characteristics of the cricoarytenoideus dorsalis, the cricothyroid (CT) and the cricoarytenoideus lateralis muscles in DLC-affected horses and compare these with unaffected controls. Our hypotheses were that evidence of neurogenic atrophy of the CT or cricoarytenoideus dorsalis muscles would be found in DLC-affected horses and that observed changes would be symmetrically (l...
Lewis SR, Ellison SP, Dascanio JJ, Lindsay DS, Gogal RM, Werre SR, Surendran N, Breen ME, Heid BM, Andrews FM, Buechner-Maxwell VA, Witonsky SG.Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, an...
Balasuriya UB.Equine arteritis virus (EAV), the causative agent of equine viral arteritis (EVA), is a respiratory and reproductive disease that occurs throughout the world. EAV infection is highly species-specific and exclusively limited to members of the family Equidae, which includes horses, donkeys, mules, and zebras. EVA is an economically important disease and outbreaks could cause significant losses to the equine industry. The primary objective of this article is to summarize current understanding of EVA, specifically the disease, pathogenesis, epidemiology, host immune response, vaccination and treat...
Issel CJ, Cook RF, Mealey RH, Horohov DW.In the absence of an effective vaccine, the success of the test and removal approach for the control of equine infectious anemia (EIA) cannot be overstated, at least in those areas where testing has been traditionally routine. This article addresses 4 main aspects: what has been learned about EIA virus, host control of its replication, and inapparent carriers; international status regarding the control of EIA; diagnostic and laboratory investigation; and reducing the spread of blood-borne infections by veterinarians. An attempt is made to put these issues into practical contemporary perspectiv...
Howe DK, MacKay RJ, Reed SM.Equine protozoal myeloencephalitis (EPM) can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S. neurona is the most frequent etiologic pathogen. Horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. Risk factors for the development of EPM include the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses but have not consistently produced acut...
Andersson MG, Faverjon C, Vial F, Legrand L, Leblond A.In this work we propose the adoption of a statistical framework used in the evaluation of forensic evidence as a tool for evaluating and presenting circumstantial "evidence" of a disease outbreak from syndromic surveillance. The basic idea is to exploit the predicted distributions of reported cases to calculate the ratio of the likelihood of observing n cases given an ongoing outbreak over the likelihood of observing n cases given no outbreak. The likelihood ratio defines the Value of Evidence (V). Using Bayes' rule, the prior odds for an ongoing outbreak are multiplied by V to obtain the post...
Ploeg M, Gröne A, Saey V, de Bruijn CM, Back W, van Weeren PR, Scheideman W, Picavet T, Ducro BJ, Wijnberg I, Delesalle C.Megaesophagus appears to be more common in Friesian horses than in other breeds. A prevalence of approximately 2% was observed among Friesian horses presented to the Wolvega Equine Clinic and the Utrecht University Equine Clinic. In this study, morphologic changes in the esophagi of Friesian horses with megaesophagus were compared with those of 6 control horses. Of 18 horses with clinically observed megaesophagus, only 12 animals had esophageal dilation at necropsy, usually involving the thoracic portion. Muscular hypertrophy of the distal esophagus was present in only one-third of the affecte...
Martineau H, Thompson H, Taylor D.Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach. Objective: To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem. Methods: Stomachs were removed from a mixed population of 21 horses at post ...
Alford P, Geller S, Richrdson B, Slater M, Honnas C, Foreman J, Robinson J, Messer M, Roberts M, Goble D, Hood D, Chaffin M.Risk factors for equine laminitis were examined in a prospective case-control study of the 258 cases seen at six collaborating veterinary teaching hospitals over a 32-month period. Case-control pairs were matched on institution, clinician, and season of diagnosis. The 90% of case-control pairs (78 acute, 155 chronic) that had complete data for age, gender, and breed were used in separate conditional logistic-regression models for acute and chronic laminitis. There was an increase in risk for horses with acute laminitis from 5 to 7 years of age (OR 4.7, 95% CI 1.3-16) and from 13 to 31 years of...
Wang L, Pawlak EA, Johnson PJ, Belknap JK, Alfandari D, Black SJ.Matrix metalloproteinases (MMP) are hypothesized to degrade structurally important components of the laminar extracellular matrix (ECM) in horses with laminitis. Objective: To compare levels of expression of stromelysin-1 (MMP-3), collagenases (MMP-1, -13), and membrane type-MMPs (MMP-14, -15, -16), and the distribution of their ECM substrates, in laminae of healthy horses and horses with carbohydrate overload laminitis. Methods: Twenty-five adult horses. Methods: Gene and protein expression were determined in extracts of laminae using real-time quantitative polymerase chain reaction and Weste...
Bailey SR, Menzies-Gow NJ, Marr CM, Elliott J.Disturbances of digital blood flow are thought to be fundamental to the pathophysiology of acute laminitis. However, factors linking the initiating events in the equine hindgut with these disturbances in the foot remain to be determined. Objective: Amine compounds, formed by bacteria in the equine hindgut, have digital vasoconstrictor effects in vivo. Methods: Tryptamine (1.6 microg/kg/min) and phenylethylamine (2.13 microg/kg/min) were infused i.v. into standing nonsedated horses. Digital blood flow was measured by Doppler ultrasound and foot surface temperature was monitored. Plasma 5-hydrox...
Lyons ET, Kuzmina TA, Tolliver SC, Collins SS.Early development and maturation of species of small strongyles have not been studied extensively. Most information is on the first appearance of strongyle eggs in feces of foals. However, species cannot be determined in this manner because of similarity of the morphological features of the eggs. To determine more definitive knowledge on development and species composition of natural infections of small strongyles, eight equid foals were necropsied and examined at various ages (31 to 92 days of age). The entire contents of the large intestine were examined, and all worms (6,671) recovered were...
Slauson DO, Lewis RM.Glomerulonephritis constitutes an important category of renal diseases in animals and has been recognized with increasing frequency in the last decade. We report here the comparative morphologic aspects of glomerulonephritis as a naturally occurring disease of animals. We briefly review the immunopathogenesis of glomerulonephritis. The morphology of renal lesions occurring in glomerulonephritis in dogs, cats, cattle, sheep, horses and swine has been reviewed with emphasis on the range and specificity of various glomerular lesions and on the comparison of lesions between various species. A dist...
Kyaw-Tanner M, Pollitt CC.The dysadhesion and destruction of lamellar basement membrane of laminitis may be due to increased lamellar metalloproteinase activity. Characterising lamellar metalloproteinase-2 (MMP-2) and locating it in lamellar tissues may help determine if laminitis pathology is associated with increased MMP-2 transcription. Objective: To clone and sequence the cDNA encoding lamellar MMP-2, develop antibody and in situ hybridisation probes to locate lamellar MMP-2 and quantitate MMP-2 transcription in normal and laminitis tissue. Methods: Total RNA was isolated, fragmented by RT-PCR, cloned into vector a...
Roczo-Farkas S, Kirkwood CD, Bines JE.The Australian Rotavirus Surveillance Program, together with collaborating laboratories Australia-wide, reports the rotavirus genotypes responsible for the hospitalisation of children with acute gastroenteritis during the period 1 January to 31 December 2015. During the survey period, 1,383 faecal samples were referred for rotavirus G and P genotype analysis, and of these, 1,031 were confirmed as rotavirus positive. A total of 634 specimens had been collected from children under 5 years of age, while 397 were from older children and adults. Genotype analysis of samples from both children an...
Parkes RS, Richard Newton J, Dyson SJ.Lameness relating to the foot of the horse is common, but the majority of information concerning risk factors for injury is anecdotal. The objectives of this study were to investigate risk factors for foot-related pain in a referral population of horses, with particular reference to injury/disease of the podotrochlear apparatus (PTA), by comparison with the remainder of the clinic population. It was hypothesised that there would be an increased risk of foot pain associated with breed, work discipline, age, height and bodyweight (BW). A retrospective study of all horses examined at a referral c...
Uhl PB, Szober CM, Amann B, Alge-Priglinger C, Ueffing M, Hauck SM, Deeg CA.Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye and plays an important role in pathogenesis of the sight threatening disease equine recurrent uveitis (ERU). ERU is a spontaneous autoimmune mediated inflammatory disease characterised by the breakdown of the outer blood-retinal barrier and an influx of autoaggressive T-cells into the inner eye. Therefore, identification of molecular mechanisms contributing to changed function of blood-retinal barrier in ERU is important for the understanding of pathophysiology. Cell surface proteins of RPE collected from health...
Banse HE, Frank N, Kwong GP, McFarlane D.In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic...
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...
Journal of proteomicsSeptember 23, 2020
Volume 230 103989 doi: 10.1016/j.jprot.2020.103989
Weigand M, Hauck SM, Deeg CA, Degroote RL.Equine recurrent uveitis (ERU) is a spontaneous, remitting-relapsing autoimmune disease driven by the adaptive immune system. Although T cells are described as the main effector cells in pathogenesis, granulocytes have also emerged as possible disease mediators. To explore the role of these innate immune cells, we investigated the whole cell proteome of granulocytes from equine recurrent uveitis cases and healthy controls. Among the 2362 proteins identified by mass spectrometry, we found 96 proteins with significantly changed abundance between groups (p < 0.05, fold change >1.2), representin...
Noble P, Singer ER, Jeffery NS.Sagittal fractures of the first phalanx are a common, potentially catastrophic injury in racehorses. These fractures are often linked to an acute, one time, biomechanical event; however, recent evidence implies that chronic exposure to stress can lead to the accumulation of bony changes that affect the structural integrity of the bone and increase the likelihood of fracture. The aim of the study was to compare variations of two common metrics of bone adaptation - subchondral bone density and thickness across the proximal articular surface of the first phalanx in Thoroughbred horses that (1) ra...
Philpott M.This review summarizes the major infectious diseases of the three major agricultural species (cattle, sheep and pigs) and horses, and presents the evidence for and against the possibility of infectious agents being transmitted between animals via the venereal route or by the use of semen or early embryos in commercial artificial insemination (AI) or embryo transfer (ET). Cattle feature most prominently in the widespread distribution of frozen semen, and national and international organizations have set out guidelines to work towards disease-free bull studs with semen free from potential pathog...
Cargnelutti JF, Olinda RG, Maia LA, de Aguiar GM, Neto EG, Simões SV, de Lima TG, Dantas AF, Weiblen R, Flores EF, Riet-Correa F.The current article describes outbreaks of vesicular stomatitis (VS) in horses and cattle in Paraiba and Rio Grande do Norte states, northeastern Brazil, between June and August 2013. The reported cases affected 15-20 horses and 6 cattle distributed over 6 small farms in 4 municipalities, but additional data indicated the involvement of a large number of animals on several farms. The disease was characterized by blisters; eruptive lesions in coronary bands, lips, mouth, and muzzle; salivation; claudication and loss of condition. Swollen lower limbs and lips, and ulcerated and erosive areas in ...
Knickelbein KE, Lassaline ME, Singer-Berk M, Reilly CM, Clode AB, Famula TR, Michau TM, Bellone RR.Belgian horses are commonly affected with ocular squamous cell carcinoma (SCC), the most common cancer of the equine eye. A missense mutation in damage-specific DNA binding protein 2 (DDB2 c.1013C>T, p.Thr338Met) has been established as a recessive genetic risk factor for ocular SCC in the Haflinger breed. A sample of Belgian horses with unknown SCC phenotype was shown to possess this variant at a similar frequency to the Haflinger breed. Retrospective studies indicate that chestnut coat colour may predispose to the development of SCC. Objective: To determine if DDB2 c.1013C>T is a risk ...
Chang HT, Rumbeiha WK, Patterson JS, Puschner B, Knight AP.Chronic ingestion of yellow star thistle (Centaurea solstitialis) or Russian knapweed (Acroptilon repens) causes nigropallidal encephalomalacia (NPE) in horses with an abrupt onset of neurologic signs characterized by dystonia of lips and tongue, inability to prehend food, depression, and locomotor deficits. The objectives of this study were to reexamine the pathologic alterations of NPE and to conduct an immunohistochemistry study using antibodies to tyrosine hydroxylase and α-synuclein, to determine whether NPE brains show histopathologic features resembling those in human Parkinson disease...
Pollin MM, Griffiths IR.Primary dysautonomias appear to be the result of initial damage to the protein synthetic pathway of a specific neuronal population, but despite detailed morphological study of several species there is, as yet, no indication of the precise lesion or the nature of the causal agent. The very marked similarities between the species with regard to lesion type, distribution, the age group affected and the geographical restrictions of occurrence would suggest a very similar, if not common, aetiology. There is no explanation, however, for the 70 year gap between its appearance in horses and its subseq...
Fife TM, Gemensky-Metzler AJ, Wilkie DA, Colitz CM, Bras ID, Klages DC.To identify visual outcome and postoperative complications following phacoemulsification of equine cataracts. Methods: Records of 39 horses (55 eyes) with cataracts were reviewed. Methods: Eyes with cataracts removed by phacoemulsification were included in the study. Data collected included age, breed, sex, stage and etiology of cataract, unilateral vs. bilateral involvement, and ultrasound findings. Horses were grouped by etiology of the cataract. Visual outcome and complications were evaluated for each group and the overall population. Results: Immediately postoperatively 46 out of 47 eyes (...
Katepalli MP, Adams AA, Lear TL, Horohov DW.Telomeres, specialized structures present at the ends of linear eukaryotic chromosomes, function to maintain chromosome stability and integrity. Telomeres shorten with each cell division eventually leading to replicative senescence, a process thought to be associated with age-related decline in immune function. We hypothesized that shortened PBMC telomere length is a factor contributing to immunosenescence of the aged horse. Telomere length was assessed in 19 horses ranging in age from 1 to 25 years. Mitogen-induced 3H-thymidine incorporation, total serum IgG, and pro-inflammatory cytokine exp...
Hansson I, Johansson KE, Persson M, Riihimäki M.Nicoletella semolina, a member of the family Pasteurellaceae, can be isolated from the airways of horses with respiratory disorders. However, its role as a potential or opportunistic pathogen is not clear nor is its presence as part of the normal flora. We therefore investigated the presence and bacterial load of N. semolina in healthy and diseased horses. Samples from a healthy control group were compared with samples from the routine analysis of horses with a clinical history of respiratory disorders. A total of 1770 nose swabs and 1132 tracheal aspirate samples were analysed and subjected t...
Tuomola K, Mäki-Kihniä N, Valros A, Mykkänen A, Kujala-Wirth M.Bit-related lesions in competition horses have been documented, but little evidence exists concerning their potential risk factors. Objective: To explore potential risk factors for oral lesions in Finnish trotters. Methods: Cross-sectional study. Methods: The rostral part of the mouth of 261 horses (151 Standardbreds, 78 Finnhorses and 32 ponies) was examined after a harness race. Information on bit type, equipment and race performance was collected. Results: A multivariable logistic regression model of Standardbreds and Finnhorses showed a higher risk of moderate or severe oral lesion stat...
Wyatt CR, Magnuson NS, Perryman LE.Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Quintero Vélez JC, Aguirre-Acevedo DC, Rodas JD, Arboleda M, Troyo A, Vega Aguilar F, Osorio Quintero L, Rojas Arbeláez C.Most of the studies related to rickettsial infection in Colombia are cross-sectional because of the challenge in conducting prospective studies on infectious disease that may have a difficult diagnosis. Although cross-sectional studies are essential to detect people exposed to rickettsiae, they are not suited to demonstrate the recent circulation of this pathogen in areas at risk of transmission. To characterize the epidemiology of incident cases of Spotted fever group (SFG) rickettsial infection in humans and equines from rural areas of Urabá region in Colombia where outbreaks of rickettsiae...
Raza F, Ivanek R, Freer H, Reiche D, Rose H, Torsteinsdóttir S, Svansson V, Björnsdóttir S, Wagner B.Culicoides hypersensitivity (CH) is induced in horses by salivary allergens of Culicoides midges. In Iceland, the causal Culicoides species for CH are not present. Previous epidemiological data indicated that Icelandic horses are more susceptible to CH when they are exported from Iceland and first exposed to Culicoides at adult age. Horses born in countries where Culicoides is endemic, develop the disease less frequently. Here, we established a longitudinal allergy model to identify predictive and diagnostic serological biomarkers of CH. Results: Sixteen adult Icelandic horses from Iceland wer...
de Laat MA, Patterson-Kane JC, Pollitt CC, Sillence MN, McGowan CM.Lamellar pathology in experimentally-induced equine laminitis associated with euglycaemic hyperinsulinaemia is substantial by the acute, clinical phase (∼48h post-induction). However, lamellar pathology of the developmental, pre-clinical phase requires evaluation. The aim of this study was to analyse lamellar lesions both qualitatively and quantitatively, 6, 12 and 24h after the commencement of hyperinsulinaemia. Histological and histomorphometrical analyses of lamellar pathology at each time-point included assessment of lamellar length and width, epidermal cell proliferation and death, base...
Keller LE, Tait Wojno ED, Begum L, Fortier LA.To gain insight into Treg interactions with synovial tissues in early OA, an equine tri-culture model of OA was used to test the hypothesis that Tregs, in the absence of T Helper 17 cells, are sufficient to resolve inflammation elicited by IL-1β. Unassigned: To model normal and OA joints, synoviocytes were co-cultured with chondrocytes in a transwell system and ± stimulated with IL-1β. Tregs were activated and enriched, then added to co-cultures, creating tri-cultures. At culture end, synoviocytes and chondrocytes were analyzed for gene expression, Treg Foxp3 expression was reexamined b...
McCarty CA, Thomason JJ, Gordon KD, Burkhart TA, Milner JS, Holdsworth DW.To assess whether the transient stresses of foot impact with the ground are similar to those found during midstance loading and if the location of high stress correlate with the sites most commonly associated with mechanically induced osteoarthritis (OA). We compared impact stresses in subchondral bone between two subject-specific, three-dimensional, finite-element models of the equine metacarpophalangeal (MCP) joint-one with advanced OA and one healthy, and with similar published data on the stresses that occur at midstance. Methods: Two right MCP joints (third metacarpal and proximal phalanx...
Walker H, Chinn E, Holmes S, Barwise-Munro L, Robertson V, Mould R, Bradley S, Shaw DJ, Dixon PM.Cheek teeth (CT) diastemata are now recognised as a clinically significant equine disorder, but their prevalence in the general equine population is unknown. There is also limited information on the signalment of affected horses; the more commonly affected Triadan sites; and the shape and clinical characteristics of CT diastemata. During the 12-month study period (2008 to 2009), standardised records were obtained during routine dental examinations performed by five veterinarians in a first-opinion equine practice. Cheek teeth diastemata were identified in 49.9 per cent of all horses (n=471) of...
