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.
Frazer LL, Santschi EM, Fischer KJ.Subchondral lucency (SCL), also referred to as subchondral bone cysts, can cause clinical problems in horses and humans. In humans, SCLs occur in youths and adolescents [1] due to mechanical factors (often related to athletics) and in skeletally mature individuals secondary to osteoarthritis (OA). In horses, SCL most commonly occurs in the medial femoral condyle (MFC) of growing horses (without OA), and causes lameness. The cause of equine SCL is debated, but bone trauma due to overload is the likely mechanism. Investigating the biomechanics of the healthy and cystic MFC is important to unders...
Ross SE, Murray JK, Roberts VLH.Headshaking in horses has been reported to be most commonly due to idiopathic neuropathic facial pain (trigeminal-mediated headshaking). The prevalence of headshaking in horses in the UK is unknown. Objective: To estimate owner-reported prevalence of headshaking in horses in the UK and to report their case background and disease characteristics, as reported by owners. Methods: Cross-sectional web based owner questionnaire. Methods: The questionnaire was advertised online via social media, horse forums, veterinary websites and equestrian magazines from 17th June 2016, until >1000 responses had ...
Pollard D, Wylie CE, Verheyen KLP, Newton JR.Use of owner-reported data could further epidemiological knowledge of equine laminitis. However, owner recognition of laminitis has not previously been assessed. Objective: The primary objective was to establish whether cases of owner-suspected laminitis would be confirmed as laminitis by the attending veterinary surgeon. Secondary objectives were to compare owner- and veterinary-reported information from veterinary-confirmed cases of equine laminitis. Methods: Cross-sectional study. Methods: Twenty-five British veterinary practices were invited to submit laminitis reporting forms (LRFs) for a...
Wylie CE, McManus P, McDonald C, Jorgensen S, McGreevy P.Monitoring racehorse fatality and associated jockey falls provides benchmarks for intervention strategies. The aims of this study were to describe the incidence of and reasons for fatalities in Thoroughbred horses during flat races in the Australian Capital Territory and New South Wales (NSW), Australia, and to describe reported jockey falls and injuries associated with racehorse fatalities. A cohort study identified all racehorse fatalities reported through Racing NSW for the 2009-2010 to 2013-2014 racing seasons. Risks of racehorse fatality, fatal musculoskeletal injury, spontaneous death (a...
Weissenböck H, Bagó Z, Kolodziejek J, Hager B, Palmetzhofer G, Dürrwald R, Nowotny N.Borna disease, a lethal infection with Borna disease virus-1 (BoDV-1), was diagnosed in four horses from Upper Austria in 2015 and 2016. All cases occurred in winter (two cases in February 2015 and two cases in December 2016), and the maximal distance of the affected stables was 17 km. To demonstrate whether the causative agent was also harbored by its reservoir host, the bicolored white-toothed shrew (Crocidura leucodon), 28 shrews from this geographic area were collected in 2015 and investigated for the presence of BoDV-1. The shrew species were identified according to taxonomic clues and ...
González-Medina S, Ireland JL, Piercy RJ, Newton JR, Votion DM.Equine atypical myopathy (AM) is a toxic rhabdomyolysis associated with ingestion of hypoglycin A, derived typically in Europe, from Acer pseudoplatanus tree. Despite the wide distribution of this tree species in the UK, the number of cases reported annually varies, and there has been an apparent increase in prevalence in recent years. Although AM was first recognised in the UK, epidemiological studies have never been conducted focused solely on this country. Objective: To describe the spatiotemporal distribution, presentation, treatment and outcome of AM cases reported in the UK. Methods: Ret...
Hanche-Olsen S, Matiasek K, Molín J, Rosati M, Hahn C, Hultin Jäderlund K, Gröndahl G.Acquired equine polyneuropathy (AEP), formerly also known as Scandinavian knuckling syndrome, is one of the most prevalent polyneuropathies in equids in Norway and Sweden, with more than 400 cases registered since first observations in 1995. Despite geographical clustering and an association to forage feeding, its aetiology remains unknown. Clinically AEP is characterized by knuckling due to dysfunction of metatarsophalangeal extensor muscles. This neuropathological study aimed to gain further insights in the pathobiology of AEP and its underlying aetiopathogenesis. We thereby confirmed that a...
Knickelbein KE, Scherrer NM, Lassaline M.To compare corneal sensitivity and tear production in horses with keratitis to horses with other ocular disease. Methods: Retrospective medical record review was used to identify equine patients presented during a 1-year period for an ocular complaint who had Schirmer Tear Test (STT) or Corneal Touch Threshold (CTT) measured. Variables studied included patient age and sex; affected eye; category of presenting ocular complaint (keratitis vs. other ocular complaint); STT; and CTT. Patients with a complaint of ulcerative keratitis, immune-mediated keratitis, and stromal abscess were categorized i...
Kinne J, Joseph M, Wernery U, Nogradi N, Hagen F.During the past decades there has been an increase in cryptococcal infections caused by the basidiomycetous yeast species Cryptococcus gattii sensu lato, among humans and animals that live in endemic regions in Australia, Europe and the Americas. Unlike human cryptococcosis, little epidemiological data are available about C. gattii sensu lato infections in horses. Methods: A fatal case of a disseminated C. gattii sensu lato infection in an 11-year-old Arabian gelding imported from South Africa into the United Arab Emitares is reported. Tissue samples were studied by conventional mycology proce...
Engiles JB, Stewart H, Janes J, Kennedy LA.As a pathologist, postmortem examination of the equine carpus can be daunting. The anatomy is complex and oftentimes, small or subtle lesions have significant impact on lameness and secondary lesions such as catastrophic musculoskeletal fractures and other injuries. In performance horses, particularly racehorses, the carpus is a common site of injury and source of lameness. Given the predisposition of racehorses to developing carpal disease, familiarity with clinically relevant anatomy and common developmental, degenerative, traumatic, and inflammatory processes are imperative for thorough pos...
Plumlee Q, Meason-Smith C, Dieterly A, Gomez G, Porter BF, Rodrigues Hoffmann A.Many previously unrecognized fungi are emerging as potential pathogens. One such group is dematiaceous fungi of the Chaetomiaceae family (phylum Ascomycota, class Sordariomycetes). These fungi are rare causes of opportunistic, neurotropic phaeohyphomycosis in humans but are not known to cause similar infections in animals. The aims of this study were to investigate equine hyphal mycotic encephalitis, characterize key histopathologic features, and classify causative organisms with molecular diagnostic techniques. Seven cases were evaluated by histopathology. Panfungal PCR targeting the ribosoma...
Adamska M, Skotarczak B.The purpose of this study was to detect piroplasms, which are pathogens of veterinary and zoonotic importance in ticks, that were collected from ponies and field vegetation and to determine the role of Shetland ponies as potential reservoir hosts for piroplasms. A total of 1737 feeding and 371 questing Ixodes ricinus collected from horses or vegetation were tested for the presence of Babesia and Theileria DNA. Piroplasm 18S rRNA gene amplification was conducted, and the obtained amplicons were sequenced. Babesia DNA was detected in only three ticks (one tick collected from a pony and two colle...
Johansson MK, Jäderkvist Fegraeus K, Lindgren G, Ekesten B.The syndrome Multiple Congenital Ocular Anomalies (MCOA) is a congenital eye disorder in horses. Both the MCOA syndrome and the Silver coat colour in horses are caused by the same missense mutation in the premelanosome protein (PMEL) gene. Horses homozygous for the Silver mutation (TT) are affected by multiple ocular defects causing visual impairment or blindness. Horses heterozygous for the Silver mutation (CT) have less severe clinical signs, usually cysts arising from the ciliary body iris or retina temporally. It is still unknown if the vision is impaired in horses heterozygous for the Sil...
Boegheim IJM, Leegwater PAJ, van Lith HA, Back W.Impairment of bone growth at a young age leads to dwarfism in adulthood. Dwarfism can be categorised as either proportionate, an overall size reduction without changes in body proportions, or disproportionate, a size reduction in one or more limbs, with changes in body proportions. Many forms of dwarfism are inherited and result from structural disruptions or disrupted signalling pathways. Hormonal disruptions are evident in Brooksville miniature Brahman cattle and Z-linked dwarfism in chickens, caused by mutations in GH1 and GHR. Furthermore, mutations in IHH are the underlying cause of creep...
Boyle AG, Smith MA, Boston RC, Stefanovski D.OBJECTIVE To develop a risk prediction model for factors associated with an SeM-specific antibody titer ≥ 3,200 in horses after naturally occurring outbreaks of Streptococcus equi subsp equi infection and to validate this model. DESIGN Case-control study. ANIMALS 245 horses: 57 horses involved in strangles outbreaks (case horses) and 188 healthy horses (control horses). PROCEDURES Serum samples were obtained from the 57 cases over a 27.5-month period after the start of outbreaks; serum samples were obtained once from the 188 controls. A Bayesian mixed-effects logistic regression model was us...
Huppes T, Hermans H, Ensink JM.Implants are often used to improve the cosmetic appearance of horses after enucleation of the eye. When surgical site infection (SSI) occurs, the implant will almost always be lost. The aim of this study is to collect data on the risk factors for SSIs and report long-term follow-up (cosmetic results and return to work) after transpalpebral enucleations. In this retrospective study, records of horses undergoing transpalpebral enucleation were reviewed (2007-2014) and telephone interviews were used to obtain long term follow-up. The potential risk factors for SSIs (indication for enucleation, us...
Sykora S, Brandt S.Squamous cell carcinoma (SCC) is a common disease that seriously impairs the health and welfare of affected horses and other equids. In humans, almost all cervical carcinomas, a high percentage of anogenital SCCs and a subset of SCCs of the head and neck are caused by high-risk human papillomavirus (hrHPV) infection. Since hrHPV-induced human cancers and equine SCC have similar cytological and histopathological features, it has been hypothesised that equine SCCs could also be induced by papillomaviruses. This review provides an overview of the current evidence for an aetiological association b...
Schoster A, Staempfli HR, Guardabassi LG, Jalali M, Weese JS.Diarrhea in foals affects up to 60% of foals during the first six months of life. The effect of diarrhea on the fecal bacterial microbiota in foals has not been investigated. Little is known on the fecal bacterial microbial richness and diversity of foals at a young age. The objective was to compare the fecal bacterial microbiota of healthy foals to foals with diarrhea at two and four weeks of life. Methods: Fecal samples were collected from foals (n = 20) at 1-14 (T1) and 15-28 (T2) days of age and analyzed using high throughput sequencing. Differences in relative abundance of bacterial tax...
Semevolos SA.This article reviews current knowledge of osteochondritis dissecans (OCD) development in horses, including normal cartilage development, early osteochondrosis pathogenesis, and factors that result in healing or advancement to OCD fragments. Discussion includes current theories, detection, and therapeutic options.
Guan M, Dai D, Li L, Wei J, Yang H, Li S, Zhang Y, Lin Y, Xiong S, Zhao Z.High levels of triacylglycerols (TGs) have been linked to cardiovascular disease and liver diseases. Comprehensively analyzing TGs is helpful to understand the TGs functions in these diseases. However, due to the existence of a large number of isomers TGs and the lack of commercial standards, precise analysis of individual triacylglycerol (TG) with specific fatty acid chain composition is full of challenge. In this work, ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) mass spectrometry (MS) were employed for comprehensive qualification and quantificati...
Emmerich IU.In 2016, only one newly developed active pharmaceutical ingredient for horses and food-producing animals was released on the German market for veterinary drug products. The immunomodulator Pegbovigrastim is now available as an injection solution for cattle (Imrestor). Four established veterinary active pharmaceutical ingredients are available for further species: the ectoparasitic Amitraz (Apitraz) from the triazapentadiene group was additionally authorized for honeybees, the expectorant Bromhexine (Exflow Vet) for chickens, turkeys and ducks and the macrolide antibiotic Gamithromycin (Zactran...
Roberts VL, Fews D, McNamara JM, Love S.Trigeminal-mediated headshaking is an idiopathic neuropathic facial pain syndrome in horses. There are clinical similarities to trigeminal neuralgia, a neuropathic facial pain syndrome in man, which is usually caused by demyelination of trigeminal sensory fibers within either the nerve root or, less commonly, the brainstem. Our hypothesis was that the neuropathological substrate of headshaking in horses is similar to that of trigeminal neuralgia in man. Trigeminal nerves, nerve roots, ganglia, infraorbital, and caudal nasal nerves from horse abattoir specimens and from horses euthanized due to...
Ludwig EK, Byron CR, Lahmers KK, Santos MP.An adult horse was diagnosed with a frontal and caudal maxillary sinus lipoma, which was surgically removed. This is the first known report of a sinus lipoma in a horse. Lipomas should be considered in the differential diagnoses of equine sinus masses; complete surgical excision appears to be curative. Un cheval adulte a été diagnostiqué avec un lipome du sinus maxillaire frontal et caudal qui a été enlevé par chirurgie. Il s’agit du premier rapport d’un lipome de sinus chez un cheval. Les lipomes devraient être considérés dans les diagnostics différentiels des masses des sinus ...
Jäderkvist Fegraeus K, Lawrence C, Petäjistö K, Johansson MK, Wiklund M, Olsson C, Andersson L, Andersson LS, Røed KH, Ihler CF, Strand E....The Swedish-Norwegian Coldblooded trotter (CBT) is a local breed in Sweden and Norway mainly used for harness racing. Previous studies have shown that a mutation from cytosine (C) to adenine (A) in the doublesex and mab-3 related transcription factor 3 (DMRT3) gene has a major impact on harness racing performance of different breeds. An association of the DMRT3 mutation with early career performance has also been suggested. The aim of the current study was to investigate this proposed association in a randomly selected group of CBTs. 769 CBTs (485 raced, 284 unraced) were genotyped for the DMR...
Gutiérrez-Expósito D, García-Bocanegra I, Howe DK, Arenas-Montes A, Yeargan MR, Ness SL, Ortega-Mora LM, Álvarez-García G.Equine besnoitiosis, caused by Besnoitia bennetti, and equine protozoal myeloencephalitis (EPM), caused by Sarcocystis neurona and Neospora hughesi are relevant equine diseases in the Americas that have been scarcely studied in Europe. Thus, a serosurvey of these cystogenic coccidia was carried out in Southern Spain. A cross-sectional study was performed and serum samples from horses (n = 553), donkeys (n = 85) and mules (n = 83) were included. An in-house enzyme-linked immunosorbent assay (ELISA) was employed to identify a Besnoitia spp. infection and positive results were confirmed by ...
Bellone RR, Liu J, Petersen JL, Mack M, Singer-Berk M, Drögemüller C, Malvick J, Wallner B, Brem G, Penedo MC, Lassaline M.Squamous cell carcinoma (SCC) is the most common cancer of the equine eye, frequently originating at the limbus, with the potential to invade the cornea, cause visual impairment, and result in loss of the eye. Several breeds of horses have a high occurrence of limbal SCC implicating a genetic basis for limbal SCC predisposition. Pedigree analysis in the Haflinger breed supports a simple recessive mode of inheritance and a genome-wide association study (N = 23) identified a 1.5 Mb locus on ECA12 significantly associated with limbal SCC (Pcorrected = 0.04). Sequencing the most physiologicall...
Wohlfender FD, Barrelet FE, Doherr MG, Straub R, Meier HP.Neonatal diseases have been grouped and analysed but up-to-date statistically significant information about the incidence and prevalence of diseases in foals is limited. Since the 1950s it has been a common management practice to administer a 3 day course of antimicrobial drugs to neonatal foals. This was shown to significantly reduce the incidence of infections (Platt 1977). Since then management practices have improved and it is widely believed that prophylactic antimicrobial drugs are no longer necessary in foal rearing. Objective: To determine the 30 day incidences or prevalences (dependin...
The Journal of nutritionJune 15, 2006
Volume 136, Issue 7 Suppl 2094S-2098S doi: 10.1093/jn/136.7.2094S
Treiber KH, Kronfeld DS, Geor RJ.Insulin is a major regulatory hormone in glucose and fat metabolism, vascular function, inflammation, tissue remodeling, and the somatotropic axis of growth. Insulin resistance alters insulin signaling by decreasing insulin action in certain resistant pathways while increasing insulin signaling in other unaffected pathways via compensatory hyperinsulinemia. In humans, altered insulin signaling is implicated in reduced glucose availability to insulin-sensitive cells, vasoconstriction and endothelial damage, and inflammatory response. Although no direct evidence exists for insulin's role in thes...
Dutta SK, Vemulapalli R, Biswas B.Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), which continues to be an important disease of horses. Commercial inactivated whole-cell vaccines are regularly used for immunization of horses against the disease. However, PHF is occurring in large numbers of horses in spite of vaccination. In a limited study, 43 confirmed cases of PHF occurred between the 1994 and 1996 seasons; of these, 38 (89%) were in horses that had been vaccinated for the respective season, thereby clearly indicating vaccine failure. A field study of horses vaccinated with two PHF vaccines indicated...
Divers TJ, Mohammed HO, Cummings JF, Valentine BA, De Lahunta A, Jackson CA, Summers BA.Over a three and one-half year period, 28 adult horses were diagnosed with equine motor neuron disease (EMND). The most commonly identified environmental risk factors for a horse having EMND were absence of grazing for more than a year and provision of poor quality hay. Quarter Horses were 5.4 times more at risk than other breeds but this was thought to be an epiphenomenon related to the frequency of Quarter Horses at boarding stables. Weight loss, excessive recumbency and/or trembling were the first signs noted. Other clinical diagnostic signs included: constant shifting of the weight in the ...
Lacombe VA, Mayes M, Mosseri S, Reed SM, Fenner WR, Ou HT.In contrast with reports in man and small animals, a systematic classification of seizures in horses is lacking. Objective: The purpose of this study was to classify seizures based on their aetiology and to characterise epilepsy in 104 horses presented for seizures at the Ohio State University Veterinary Medical Center between 1988 and 2009. Methods: In a retrospective observational study, seizures were classified by aetiology based on history, clinical observations, diagnostic investigations (e.g. electroencephalograms, cerebrospinal fluid and computed tomography imaging of the head) and post...
Mumford EL, Traub-Dargatz JL, Salman MD, Collins JK, Getzy DM, Carman J.To develop a system to monitor and detect acute infections of the upper respiratory tract (i.e., nares, nasopharynx, and pharynx) in horses and to assess the association among specific viral infections, risk factors, and clinical signs of disease. Methods: Prospective study. Methods: 151 horses with clinical signs of acute infectious upper respiratory tract disease (IURD) from 56 premises in Colorado. Methods: Health management data, blood samples, and nasal or nasopharyngeal swab samples were obtained for 151 horses with clinical signs of acute IURD. Of these horses, 112 had an additional blo...
Walter I, Handler J, Miller I, Aurich C.Periglandular arrangement of myofibroblasts, associated with the deposition of extracellular matrix (ECM), is a cardinal feature of endometrosis in mares. We hypothesized that a disturbance in the expression of matrix degrading enzymes such as matrix metalloproteinases (MMP's) and matrix cross-linking proteins might lead to an imbalance in deposition and degradation of extracellular matrix components and thereby accentuate degeneration. Therefore, distributions of MMP-2, capable of collagen IV and laminin degradation, and tissue transglutaminase (TG2), a cross-linker of extracellular matrix pr...
Hultgren BD.The congenital absence of myenteric ganglia in the terminal portion of the ileum, cecum, and entire colon of white foals with overo spotted parents was reported. Males as well as females were affected. The foals were generally normal at birth but did not defecate. Signs of colic were noticed between 5 and 24 hours after birth, with death occurring at 23 to 132 hours.
Miller RI, Campbell RS.During a clinical study of equine phycomycosis in tropical northern Australia 3 specific forms of phycomycosis were identified. Of 266 cases diagnosed in 5 different laboratories, hyphomycosis caused by Hyphomyces destruens was responsible for 76.7%, basidiobolomycosis caused by Basidiobolus haptosporus for 18.0%, and entomophthoramycosis caused by Conidiobolus coronatus for 5.3%. Most cases of hyphomycosis were observed between March and July, that is after the monsoonal wet summer, but were calculated from clinical histories to originate in the wet season between November and May. Basidiobol...
Paterson DL, Murray PK, McCormack JG.Twenty-three horses and three humans in Queensland, Australia, were infected with a novel member of the Paramyxoviridae family of viruses in two geographically distinct outbreaks. Two of the humans died-one died of rapid-onset respiratory illness, and the other died of encephalitis. The third infected human developed an influenza-like illness and made a complete recovery. All infected humans had close contact with sick horses. Since the two outbreaks occurred at sites 1,000 km apart and no known contact between the two groups of humans and horses occurred, extensive testing of animals and bird...
Schrock P, Lüpke M, Seifert H, Staszyk C.This study investigated the hypothetical contribution of biomechanical loading to the onset of equine odontoclastic tooth resorption and hypercementosis (EOTRH) and to elucidate the physiological age-related positional changes of the equine incisors. Based on high resolution micro-computed tomography (μCT) datasets, 3-dimensional models of entire incisor arcades and the canine teeth were constructed representing a young and an old incisor dentition. Special attention was paid to constructing an anatomically correct model of the periodontal ligament (PDL). Using previously determined Young's m...
Mair TS, Sutton DG, Love S.This report describes the clinical and pathological features of 4 horses affected by caecocaecal or caecocolic intussusceptions associated with larval cyathostomiasis. In each case, there was clinical and/or pathological evidence of concurrent larval cyathostomosis. They all demonstrated variable signs including diarrhoea, pyrexia, weight loss and subcutaneous oedema and cyathostome larvae were identified in the faeces of 3 of the horses. These cases highlight the need to consider caecal intussusceptions as a possible complication in horses affected by larval cyathostomosis, especially where s...
Norrdin RW, Stover SM.Mechanical overload leads to a common arthrosis in the metacarpal condyle of the fetlock joint of racehorses. This is usually asymptomatic but severe forms can cause lameness. Subchondral bone failure is often present and the predictability of the site provided an opportunity to study of the progression of bone failure from microcracks to actual collapse of subchondral bone. Twenty-five fetlock condyles from racehorses with various stages of disease were selected. Stages ranged from mild through severe subchondral bone sclerosis, to the collapse of bone and indentation or loss of cartilage kno...
Geburek F, Ohnesorge B, Deegen E, Doeleke R, Hewicker-Trautwein M.We report the historical, clinical and histopathological characteristics of skin lesions in biopsies from 37 heavy draught horses with chronic pastern dermatitis. The skin lesions were divided into four macroscopic groups: scaling (group I, n=5), hyperkeratotic and hyperplastic plaque-like lesions (group II, n=14), nodular skin masses (group III, n=16) and verrucous skin lesions (group IV, n=2). The principal histological findings were hyperkeratosis and epidermal hyperplasia. There was a gradual increase in epidermal hyperplasia from groups I to IV, suggesting that the lesions represent diffe...
Slocombe JO.This review summarizes information on the clinical signs, gross and microscopic lesions associated with nematode and cestode infections and discusses the development of these conditions in the equine host.
Han H, Randhawa IAS, MacHugh DE, McGivney BA, Katz LM, Dugarjaviin M, Hill EW.Thousands of years of natural and artificial selection since the domestication of the horse has shaped the distinctive genomes of Chinese Mongolian horse populations. Consequently, genomic signatures of selection can provide insights into the human-mediated selection history of specific traits and evolutionary adaptation to diverse environments. Here, we used genome-wide SNPs from five distinct Chinese Mongolian horse populations to identify genomic regions under selection for the population-specific traits, gait, black coat colour, and hoof quality. Other global breeds were used to identify r...
Blythe LL, Hultgren BD, Craig AM, Appell LH, Lassen ED, Mattson DE, Duffield D.A clinical, viral, hematologic , and genetic study was conducted over a 4-year period on a family of Appaloosas with high incidence of clinical ataxia and pathologic features of equine degenerative myeloencephalopathy. Marginal to deficient serum vitamin E (alpha-tocopherol) and blood selenium values were the only other consistent antemortem abnormalities in the affected horses. Members of this family were all descendants of a clinically normal mare and were raised in 3 separate environments with variable quality of feed. All horses had access to pasture grasses. Normal chromosomal karyotypes ...
Eydal M, Bambir SH, Sigurdarson S, Gunnarsson E, Svansson V, Fridriksson S, Benediktsson ET, Sigurdardóttir ÓG.Opportunistic infections with the free living nematode Halicephalobus gingivalis are infrequently reported in horses but the cases are widespread geographically. The nematodes are believed to penetrate wounds and subsequently reproduce within the host tissues. This paper reports two cases of a fatal disease in stallions of the Icelandic breed in Iceland. Case 1: a stallion, which sustained injuries to the mouth after an accident, developed severe neurological signs and had to be euthanatized. Histological examination revealed mild inflammation and malacia in the cerebellum associated with the ...
Brown CC, McClure JJ, Triche P, Crowder C.Excisional biopsy specimens were received from 8 horses with lesions suspected of being caused by Pythium sp. Pythium sp was isolated from all specimens. An indirect peroxidase technique was applied to formalin-fixed tissues from the biopsy material and there was distinct staining of hyphal cell walls in all specimens. Sections containing hyphae, other than those of Pythium sp, failed to stain. The indirect peroxidase technique could be used for confirmation of suspected cases of pythiosis.
Larson EM, Babasyan S, Wagner B.Human IgE-binding monocytes are identified as allergic disease mediators, but it is unknown whether IgE-binding monocytes promote or prevent an allergic response. We identified IgE-binding monocytes in equine peripheral blood as IgE+/MHCIIhigh/CD14low cells that bind IgE through an FcεRI αɣ variant. IgE-binding monocytes were analyzed monthly in Culicoides hypersensitive horses and nonallergic horses living together with natural exposure to Culicoides midges. The phenotype and frequency of IgE-binding monocytes remained consistent in all horses regardless of Culicoides exposure. All horses ...
Yasunaga S, Maeda K, Matsumura T, Kai K, Iwata H, Inoue T.Recently, a type-specific ELISA using equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) glycoprotein Gs (gGs) was developed by Crabb and Studdert [1993]. To investigate the dissemination of EHV-1 and -4 among horses in Japan, we applied their ELISA as suitable for discriminating between EHV-1 and -4 infections serologically. Type-specificity of the ELISA was confirmed by using paired sera of infected horses with either EHV-1 or -4. Application of the ELISA to sera collected before and after the winter season of 1995-1996 from 80 racehorses revealed that 30 horses showed significant antibody...
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...
Palmer JE, Whitlock RH, Benson CE.Equine ehrlichial colitis (Potomac horse fever), a newly identified colitis of the horse, was first recognized in Maryland. In this report, we document occurrence of the disease in Pennsylvania, New Jersey, New York, Ohio, Idaho, and Connecticut. Enzootic areas were recognized by a characteristic pattern. Frequently there was a seasonal pattern and high prevalence of sporadic colitis in unstressed horses. The attack rate per farm generally was low. Horses on pasture, as well as those stabled, were affected. Clinical signs varied from fever and depression to severe diarrhea and laminitis. Occas...