Pathogenesis in horses refers to the biological mechanisms that lead to the development and progression of diseases within equine species. This process involves a complex interaction between the horse's immune system, genetic predispositions, environmental factors, and infectious agents such as bacteria, viruses, or parasites. Understanding pathogenesis is essential for identifying how diseases manifest and progress in horses, which can inform diagnostic and therapeutic strategies. Research in this area often focuses on specific diseases, examining factors such as pathogen entry, immune response, tissue damage, and recovery processes. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of pathogenesis in equine health.
Senior M.To review information on the pathogenesis, diagnosis and treatment of post-anaesthetic pulmonary oedema in horses. Methods: Pubmed 1970-present, personal files.
Patel JR, Heldens J.This review concentrates on the epidemiology, latency and pathogenesis of, and the approaches taken to control infection of horses by equine herpesvirus types 1 (EHV-1) and 4 (EHV-4). Although both viruses may cause febrile rhinopneumonitis, EHV-1 is the main cause of abortions, paresis and neonatal foal deaths. The lesion central to these three conditions is necrotising vasculitis and thrombosis resulting from lytic infection of endothelial cells lining blood capillaries. The initiation of infection in these lesions is likely to be by reactivated EHV-1 from latently infected leukocytes. Howev...
Mullaney T, Murphy AJ, Kiupel M, Bell JA, Rossano MG, Mansfield LS.Opossums (Didelphis spp.) are the definitive host for the protozoan parasite Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis (EPM). Opossums shed sporocysts in feces that can be ingested by true intermediate hosts (cats, raccoons, skunks, armadillos and sea otters). Horses acquire the parasite by ingestion of feed or water contaminated by opossum feces. However, horses have been classified as aberrant intermediate hosts because the terminal asexual sarcocyst stage that is required for transmission to the definitive host has not been found in their tissues despite...
Larsen KS, Eydal M, Mencke N, Sigurdsson H.Lice infestations on horses caused by the lice Werneckiella (Damalinia) equi and Haematopinus equi are observed worldwide. In this study, the distribution and clinical manifestations of lice on Icelandic horses were examined. Thirty-eight out of 93 animals (40.86%) were identified as infested with W. equi. Sixty-eight animals (73.12%) presented dermatological lesions associated with lice infestation, while only 32 of these animals presented lice. Six animals had no clinical signs although of being lice-positive, and 19 animals (20.43%) showed neither lice nor clinical manifestations. Lice burd...
Rüfenacht S, Marti E, von Tscharner C, Doherr MG, Forster U, Welle M, Roosje PJ.The pathogenesis of equine urticaria is not well understood. In man, urticaria has been associated with immunological and nonimmunological mechanisms leading to the release of various mediators by mast cells. Skin biopsies of 32 horses with a history of urticaria were stained with toluidine blue, a double-labelling method for chymase and tryptase, and immunohistochemistry for immunoglobulin (Ig)E. These horses were compared with horses with pemphigus foliaceus, insect bite hypersensitivity and control horses with healthy skin. Neither formalin fixation time nor biopsy site influenced the stain...
Goehring LS, van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM.The presence of toxins or infectious agents combined with environmental factors in combination with a susceptible host can be the cause for neurological disease in groups of horses. During a 5 year observational period outbreaks of neurological diseases among horses were evaluated. Causes of occurring neurological diseases were equine botulism, lolitrem intoxications, equine herpesvirus type 1-associated myelo(encephalo)pathy, and encephalitis caused by (disseminated) Streptococcus equi subspecies equi infection. This article focuses on the first three syndromes because of their predominant in...
Maury W, Thompson RJ, Jones Q, Bradley S, Denke T, Baccam P, Smazik M, Oaks JL.Equine infectious anemia virus (EIAV) is a lentivirus with in vivo cell tropism primarily for tissue macrophages; however, in vitro the virus can be adapted to fibroblasts and other cell types. Tropism adaptation is associated with both envelope and long terminal repeat (LTR) changes, and findings strongly suggest that these regions of the genome influence cell tropism and virulence. Furthermore, high levels of genetic variation have been well documented in both of these genomic regions. However, specific EIAV nucleotide or amino acid changes that are responsible for cell tropism changes have ...
McFarlane D, Dybdal N, Donaldson MT, Miller L, Cribb AE.Equine pituitary pars intermedia dysfunction (PPID) is a spontaneously occurring progressive disease affecting aged horses and ponies. The pathogenesis of PPID is poorly understood, but the available evidence supports a loss of dopaminergic inhibition of the melanotropes of the pars intermedia. Horses with PPID have increased plasma concentrations of pars intermedia pro-opiomelanocortin-derived peptides that decrease in response to dopamine or dopamine agonist administration. Dopamine and dopamine metabolite concentrations are decreased in the pars intermedia of affected horses compared to age...
Debrue M, Hamilton E, Joubert P, Lajoie-Kadoch S, Lavoie JP.Recent finding suggests that T-cells may be involved in the pathogenesis of heaves in horses. However, little is known concerning their possible contribution to pulmonary neutrophilia, a characteristic finding in heaves. Interleukin (IL)-17 is a cytokine secreted by activated T-cells that indirectly promotes the maturation, chemotaxis and activation of neutrophils. We therefore hypothesized that IL-17 may be involved in the recruitment of neutrophils into the airways and that its mRNA expression would be increased in bronchoalveolar lavage (BAL) cells of horses with heaves. Heaves susceptible ...
Simonen-Jokinen T, Pirie RS, McGorum B, Maisi P.Airway matrix metalloproteinases (MMPs) increase after endotoxin (LPS) exposure, but there are no reports describing dose-dependent increases or activation following exposure. Objective: To study matrix metalloproteinase-9 (MMP-9) and -2 (MMP-2) responses in bronchoalveolar lavage fluid (BALF) from heaves-susceptible and control horses following inhalation of hay dust suspension (HDS), LPS and Aspergillus fumigatus extract (AFE). Methods: Heaves-susceptible (n = 7) and control (n = 6) horses received inhalation challenges with 3 different doses of HDS and LPS. Heaves-susceptible horses (n = 6)...
Cook CP, Scott DW, Erb HN, Miller WH.A retrospective study using light microscopy was performed to assess the prevalence of surface and follicular bacteria and fungi in skin biopsy specimens from 247 horses with inflammatory dermatoses and from 27 horses with healthy skin. Cocci were found on the surface of specimens from 23% (95% confidence interval 18%, 29%) and 7% (95% confidence interval, 0%, 19%), respectively, of horses with skin disease and horses with healthy skin. Of the nine dermatoses with at least 10 cases in our series of horses, bacterial folliculitis had a higher prevalence of surface bacteria (57%; 95% confidence ...
Little CB, Flannery CR, Hughes CE, Goodship A, Caterson B.To determine whether the focal susceptibility to cartilage degeneration in joints is related to a differential response to cytokine stimulation. Methods: Compare aggrecan and collagen catabolism in in-vitro models of cartilage degradation induced by retinoic acid (RA), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF) and IL-1 plus oncostatin M (OSM). Glycosaminoglycan (GAG) and hydroxyproline (HyPro) quantification and Western immunoblot analyses of aggrecan and collagen degradation products were undertaken in explant cultures of normal cartilage from regions of equine joints with a kno...
Schlacher C, Peham C, Licka T, Schobesberger H.Mechanical properties of the equine back are the bases for realistic modelling of the back, which is recognised as an important step towards improved understanding of the pathogenesis of equine back conditions. Objective: The stiffness of the equine back depends on the direction of the applied force and on the position of the spine. Methods: Fourteen dissected spines were tested in a tensile testing machine. In 3 different positions, simulating dorsoventral, laterolateral and dorsoventral-30 degree rotated movement, force was applied on the dorsal spinous process of T12 to reach an excursion o...
Clayton HM, Sha D, Stick JA, Mullineaux DR.Descriptions of 3D kinematics assist in understanding joint function and dysfunction, and are an essential step toward 3D inverse dynamic analysis. Objective: To measure 3D carpal joint motion during trotting. Methods: Three-dimensional trajectories of bone-fixed markers on the radius and third metacarpus of the right forelimb of 3 healthy horses were recorded at 120 Hz using a 6-camera analysis system. Joint kinematics were calculated in terms of helical angles between the 2 segments using a spatial attitude method. Results: All horses showed carpal extension and internal rotation of the meta...
Peham C, Schobesberger H.Knowledge of load effects is crucial for the understanding of the aetiology and pathogenesis of equine back problems. Objective: To investigate different load scenarios of the equine back, such as being ridden or increased muscle tone, using biomechanical simulations. Methods: Kinetic and kinematic data of 15 sound horses and the electromyelograph of their long back muscles were recorded. A biomechanical simulation model was used for simulations under different biomechanical scenarios (ridden/unridden, localised increased stiffness) using ADAMS. Results: The vertical forces acting through a ri...
Chateau H, Degueurce C, Denoix JM.Sharp turns are suspected to increase expression of several distal forelimb lamenesses even at the walk but the biomechanical consequences of such a movement remain unknown. Objective: To quantify the effects of a sharp turn at the walk on the 3-dimensional movements of the distal segments of the forelimb. Methods: Kinematics of the distal segments were measured in 4 healthy horses invasively with an ultrasonic system. Three-dimensional rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained for a turn at the walk were compared to those obtained in a ...
Ekman S, Skiöldebrand E, Heinegård D, Hultenby K.One of the most common causes of lameness in racehorses is osteoarthritis (OA). Pathogenesis is not clear and pathological processes of the different joint tissues interact in often progressive events. The interface between cartilage and newly synthesised bone has been shown to be particularly enriched in bone sialoprotein (BSP), a cell-binding matrix protein. Objective: To establish whether changes in the concentration of BSP may serve as a marker for early biochemical changes of the subchondral bone. Methods: Articular cartilage, cartilage/bone interface and subchondral bone of the proximal ...
Aleman M, Lecouteur RA, Nieto JE, Williams DC, Stanke NJ, Shelton GD.Sarcoplasmic masses in humans have been associated with various myopathies, although the significance remains elusive. Similar structures have also been observed in equine muscle. The aim of this study was to determine the frequency of such structures in normal and abnormal equine muscle, and to characterize these structures using histological, histochemical, immunohistochemical, ultrastructural, and morphometric analyses. The histological and histochemical appearance was similar to that of human sarcoplasmic masses with a central or subsarcolemmal distribution. Of interest was a predilection ...
Johnson PJ, Slight SH, Ganjam VK, Kreeger JM.The administration of exogenously administered GCs and syndromes associated with GC excess are both attended by increased risk for the development of laminitis in adult horses. However, there exists substantial controversy as to whether excess GCs cause laminitis de novo. If true, the pathogenesis of laminitis arising from the effects of GC excess is probably different from that associated with diseases of the gastrointestinal tract and endotoxemia. Although a satisfactory explanation for the development of laminitis as a consequence of GC action is currently lacking, numerous possible and pla...
van der Kolk JH, Heinrichs M, van Amerongen JD, Stooker RC, in de Wal LJ, van den Ingh TS.To determine size and weight of the pituitary gland and associations between pituitary gland size and weight and sex and age in horses without clinical signs associated with pituitary pars intermedia adenoma (PPIA) and horses and ponies with PPIA. Methods: Pituitary glands from 100 horses without clinical signs of PPIA and 19 horses and 17 ponies with PPIA. Methods: Pituitary glands were weighed, measured, and examined histologically by use of H&E stain. Masson trichrome and periodic acid-Schiff staining were used, when appropriate. Histologic lesions in the pars intermedia, pars distalis,...
Malisauskas M, Ostman J, Darinskas A, Zamotin V, Liutkevicius E, Lundgren E, Morozova-Roche LA.In amyloid diseases, it is not evident which protein aggregates induce cell death via specific molecular mechanisms and which cause damage because of their mass accumulation and mechanical properties. We showed that equine lysozyme assembles into soluble amyloid oligomers and protofilaments at pH 2.0 and 4.5, 57 degrees C. They bind thioflavin-T and Congo red similar to common amyloid structures, and their morphology was monitored by atomic force microscopy. Molecular volume evaluation from microscopic measurements allowed us to identify distinct types of oligomers, ranging from tetramer to oc...
Tydén E, Olsén L, Tallkvist J, Larsson P, Tjälve H.The intestinal enterocytes provide the initial site for cytochrome P450 (CYP)-mediated metabolism of orally absorbed xenobiotics. In man and some animal species, the CYP3A subfamily is highly expressed in the intestines and considered to be important in the first-pass metabolism of drugs and other xenobiotics. The aim of the present study was to investigate the mRNA expression, immunohistochemical localization and catalytic activity of CYP3A in the intestines of horse. Real-time RT-PCR analyses showed that the highest CYP3A mRNA expression was present in the duodenum with a decreasing level to...
Balasuriya UB, MacLachlan NJ.The members of the family Arteriviridae, genus Arterivirus, include equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), lactate dehydrogenase-elevating virus (LDV) of mice, and simian hemorrhagic fever virus (SHFV). PRRSV is the newest member of the family (first isolated in North America and Europe in the early 1990s), whereas the other three viruses were recognized earlier (EAV in 1953, LDV in 1960, and SHFV in 1964). Although arterivirus infections are strictly species-specific, the causative agents share many biological and molecular properties, inclu...
Shirato K, Kimura T, Mizutani T, Kariwa H, Takashima I.West Nile (WN) virus is a mosquito-borne flavivirus that can cause lethal encephalitis in humans and horses. The WN virus endemic in New York City (NY) in 1999 caused large-scale mortality of wild birds that was not evident in endemic areas in other parts of the world, and the pathogenesis of the WN virus strain isolated in NY (NY strain) appears to differ from that of previously isolated strains. However, the pathogenesis of NY strain infection remains unclear. This study examined CC (RANTES/CCL5, MIP-1 alpha/CCL3, MIP-1 beta/CCL4) and CXC (IP-10/CXCL10, B lymphocyte chemoattractant (BLC/CXCL...
May JP, Walker CA, Maskell DJ, Slater JD.Streptococcus equi subsp. equi is the causative agent of the equine disease strangles. In this study we describe the development of an in vivo Himar1 transposon system for the random mutagenesis of S. equi and, potentially, other Gram-positive bacteria. We demonstrate efficient and random transposition of a modified mini-transposon onto the chromosome by Southern blot analysis and insertion site sequencing. Non-haemolytic mutants were isolated at a frequency of 0.2%, and acapsular mutants at a frequency of 0.04%. Taken together, these data demonstrate that in vivo Himar1 mutagenesis can be use...
van de Lest CH, Brama PA, van El B, DeGroot J, van Weeren PR.Osteochondrosis (OC) is the most important developmental orthopaedic disease in the horse. Despite some decades of research, much of the pathogenesis of the disorder remains obscure. Increasing knowledge of articular cartilage development in juvenile animals led to the presumption that the role of collagen in OC might be more important than previously thought. To study collagen characteristics of both cartilage and subchondral bone in young (5 and 11 months of age) horses, samples were taken of subchondral bone and articular cartilage from a group of 43 Dutch Warmblood foals and yearlings that...
Ueki H, Kowatari Y, Oyamada T, Oikawa M, Yoshikawa H.Thyroid tumours occur in older horses, and most such tumours have been considered to be of follicular epithelial origin. However, their immunohistochemical characterization has not been investigated. The purpose of this study was to confirm a suspicion that most of these tumours are in fact parafollicular cell (C cell)-derived adenomas, and to evaluate their pathogenesis and functional state. Thyroid glands from 38 horses aged 10-29 years were evaluated, all tissue samples being examined histologically, immunohistochemically and ultrastructurally. Nodular tumour masses were found in the thyroi...
Lindsay DS, Mitchell SM, Vianna MC, Dubey JP.Equine protozoal myeloencephalitis is a major cause of neurological disease in horses from the Americas. Horses are considered accidental intermediate hosts. The structure of sporocysts of the causative agent, Sarcocystis neurona, has never been described. Sporocysts of S. neurona were obtained from the intestines of a laboratory-raised opossum fed skeletal muscles from a raccoon that had been fed sporocysts. Sporocysts were 11.3 by 8.2 microm and contained 4 sporozoites. The appearance of the sporocyst residuum was variable. The residuum of some sporocysts was composed of many dispersed granu...
Wilkie DA, Gilger BC.Glaucoma is a diverse group of vision-impairing disorders that have as a common bond an elevation of intraocular pressure(IOP) to a level incompatible with the health of the eye. Glaucoma can be congenital, primary, or secondary. Congenital equine glaucoma is associated with developmental abnormalities of the iridocorneal angle or, in many cases, with the more severe anterior segment dysgenesis.
Castillo-Olivares J, Wood J.West Nile virus (WNV) is a flavivirus closely related to Japanese encephalitis and St. Louis encephalitis viruses that is primarily maintained in nature by transmission cycles between mosquitoes and birds. Occasionally, WNV infects and causes disease in other vertebrates, including humans and horses. West Nile virus has re-emerged as an important pathogen as several recent outbreaks of encephalomyelitis have been reported from different parts of Europe in addition to the large epidemic that has swept across North America. This review summarises the main features of WNV infection in the horse, ...
Grulke S, Benbarek H, Caudron I, Deby-Dupont G, Mathy-Hartert M, Farnir F, Deby C, Lamy M, Serteyn D.Myeloperoxidase (MPO) is a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Thanks to a radioimmunoassay of equine myeloperoxidase, the authors have observed a significantly higher plasma level of MPO in horses operated for strangulation obstruction of the large intestine (n = 6) than in horses suffering from a non-strangulating displacement of the large intestine (n = 9). For the 2 groups, 3 phases were distinguished: reception (P1), intensive care (P2) and terminal phase (P3). The mean peak values of MPO for these phases were 121.6 ng/mL (P1), 168.6 ng/mL ...
Horsington JJ, Gilkerson JR, Hartley CA.Equine rhinitis B virus (ERBV) is the single species in the genus Erbovirus, family Picornaviridae. Equine rhinitis B viruses exist in three serotypes and are associated with respiratory disease in horses. Members of the species vary in stability at acid pH. To date there has been discordance in genotype, serotype and acid stability phenotype groupings. To identify capsid regions associated with acid stability, two viruses were serially treated at pH 3.3 to isolate acid-stable mutants. An acid-stable mutant of the prototype acid-labile serotype 1 virus contained a single amino acid change in t...
Turk MA, Breeze RG, Gallina AM.The pathologic features of bronchiolitis were studied in horses and ponies from 30 minutes to 27 days after an oral dose of 3-methylindole (3MI). From 30 minutes to 3 hours, lesions were limited to nonciliated bronchiolar epithelial (Clara) cells, which lost apical caps and cytoplasmic granules and had dilated smooth endoplasmic reticulum (SER). At 12 hours, necrotic Clara cells were exfoliated; degeneration and necrosis were evident, in bronchiolar ciliated cells. Rare epithelial cells with hyperplastic SER appeared on the denuded basal lamina at 24 hours. Inflammatory cells, epithelia, fibro...
Erkert RS, Macallister CG.Isoxsuprine hydrochloride has been suggested for use in horses for treatment of navicular syndrome and laminitis. The drug has been shown to be a beta-adrenoreceptor antagonist with beta-adrenoreceptor agonistic properties, with both characteristics contributing to vasodilation and uterine relaxation. In addition, the drug is capable of decreasing blood viscosity and platelet aggregation. Studies have shown i.v. isoxsuprine to have a plasma half-life of <3 h with a large apparent volume of distribution. Cardiovascular effects resolve rapidly following i.v. administration, but are absent wit...
Skowronek AJ, LaFranco L, Stone-Marschat MA, Burrage TG, Rebar AH, Laegreid WW.Infection of naive North American horses with 10(4) cell culture infectious doses (CCID50) of virulence variants of African horsesickness virus (AHSV), designated AHSV/4SP, AHSV/9PI, and AHSV/4PI, reproduced three classical forms of African horsesickness: acute (pulmonary), subacute (cardiac), and febrile, respectively. Distinct clinicopathologic and hemostatic abnormalities were associated with each form of disease. Hemostatic abnormalities included increased concentration of fibrin degradation products and prolongation of prothrombin, activated partial thromboplastin, and thrombin clotting t...
Tantaoui-Elaraki A, Mekouar SL, el Hamidi M, Senhaji M.From 10 moldy straw samples collected in a Moroccan area with an apparent equine stachybotryotoxicosis outbreak in November 1991, 8 isolates of Stachybotrys atra were obtained. They all showed toxigenesis, however they were variable in nature and intensity. While 1 isolate had only mild toxicity when fed to mice as moldy barley, another revealed very high toxicity to Artemia saline larvae, or rat skin, and to mice. The toxicity of the other 6 isolates were between these 2 limits. This study indicates that the November 1991 outbreak was due to toxigenic strains of Stachybotrys atra.
Fjordbakk CT, Chalmers HJ, Holcombe SJ, Strand E.The pathogenesis of dynamic bilateral laryngeal collapse (DLC) associated with poll flexion is unknown. Diagnosis is dependent upon exercise endoscopy while replicating the flexed head position harness racehorses experience during racing. Objective: To describe the effects of poll flexion on rostrocaudal laryngeal positioning and laryngeal lumen width in resting horses diagnosed with DLC compared to controls, and to establish diagnostic criteria for DLC by use of diagnostic imaging. Methods: Case-control study. Methods: Fifty harness racehorses were prospectively included in the study: 25 case...
Jacobsen S, Mortensen CD, Høj EA, Vinther AM, Berg LC, Adler DMT, Verwilghen D, van Galen G.Neutrophil gelatinase-associated lipocalin (NGAL) has been suggested to be a highly sensitive and specific marker of joint infection in humans. The aim of the study was to investigate NGAL concentrations in synovial fluid (SF) from horses with septic synovitis, horses without septic synovitis, and horses with uncertain status. NGAL was measured in 177 admission samples obtained from 152 horses. From a subset of horses ( = 35), additional samples obtained sequentially over the course of treatment were available. Concentrations of NGAL were significantly higher in septic synovitis ( = 47 samples...
Blunden AS, Hannant D, Livesay G, Mumford JA.Welsh Mountain ponies were inoculated with an isolate of Streptococcus pneumoniae, SPE 1618 (capsular type 3) recovered from the equine respiratory tract: 10 ml of a suspension of 10(8) or 10(9) cfu/ml were instilled intratracheally. Fever was observed after either dose but the greater concentration also produced coughing, ocular and nasal discharge, depression and enlargement of submandibular lymph nodes. Cytological evidence of infection was also observed in tracheal washings during the first week after inoculation and corresponded with isolation of S. pneumoniae from the washes. Morbid anat...
Fink C, Tatar M, Failing K, Hospes R, Kressin M, Klisch K.Serotonin (5-hydroxytryptamine, 5-HT), a regulatory amine of mucosal enterochromaffin cells plays an important role in the control of gastrointestinal smooth muscle contraction and epithelial secretion. Serotonin has also been associated with gastric ulcers, diarrhoea and abdominal pain. In spite of the high incidence of these gastrointestinal disorders in newborn foals and adult horses, no data are available regarding 5-HT immunoreactive cells (i.c.) in the gastrointestinal tract (GIT) of foals, and for adult horses, data are incomplete and contradictory. In this study, the distribution and r...
El-Assaad I, Di Bari JA, Yasuda K, Divers TJ, Summers BA, de Lahunta A, Mohammed H.Equine motor neuron disease (EMND) is a neurodegenerative disorder of unknown etiology affecting horses worldwide. Trans-Active Response DNA Binding Protein of 43 kDa (TDP-43) has been reported in the central nervous system (CNS) of several neurodegenerative conditions in humans including Amyotrophic Lateral Sclerosis (ALS) and assumed to play role in the disease. We examined whether horses afflicted with EMND express the TDP-43 in CNS. Ten horses with EMND and 6 controls of different ages and breed we enrolled. Detection of presence of TDP-43 protein in the CNS was analyzed by immunohistoche...
Hooper PT.Severe spongy degeneration of the central nervous system (CNS) was seen in 11 cattle, 19 sheep, 4 pigs and 1 goat, associated with a variety of hepatic diseases, particularly those caused by hepatotoxic pyrrolizidine alkaloids. It was also seen in a milder form in 2 of 8 horses examined, 1 dog of 5 dogs examined, and in 1 rabbit only of a large number of laboratory animals examined. This paper reports results of experiments which confirmed initially that the CNS disease cold be caused by pyrrolizidine alkaloid intoxication. This was done by poisoning lambs with lasiocarpine. As the disease was...
Holcombe SJ, Derksen FJ, Robinson NE.Determining the respiratory related activity of the palatinus and palatopharyngeus muscles in exercising horses is relevant because dysfunction of these muscles has been implicated in the pathogenesis of dorsal displacement of the soft palate. Objective: To determine if the palatinus and palatopharyngeus muscles have respiratory activity that increases with intensity in exercising horses. Methods: Electromyographic activity was measured in the palatinus and palatopharyngeus muscles using bipolar fine-wire electrodes while the horses completed an incremental exercise treadmill protocol. Results...
Bolfa P, Nolf M, Cadoré JL, Catoi C, Archer F, Dolmazon C, Mornex JF, Leroux C.EIA (Equine Infectious Anemia) is a blood-borne disease primarily transmitted by haematophagous insects or needle punctures. Other routes of transmission have been poorly explored. We evaluated the potential of EIAV (Equine Infectious Anemia Virus) to induce pulmonary lesions in naturally infected equids. Lungs from 77 EIAV seropositive horses have been collected in Romania and France. Three types of lesions have been scored on paraffin-embedded lungs: lymphocyte infiltration, bronchiolar inflammation, and thickness of the alveolar septa. Expression of the p26 EIAV capsid (CA) protein has been...
Eades SC, Stokes AM, Johnson PJ, LeBlanc CJ, Ganjam VK, Buff PR, Moore RM.To quantify changes in endothelium-derived factors and relate those changes to various aspects of digital hemodynamics during the prodromal stages of carbohydrate overload (CHO)-induced laminitis in horses. Methods: 20 adult horses without abnormalities of the digit. Methods: Digital and jugular venous blood samples were collected at 1-hour intervals (for assessment of endothelin-1 [ET-1] immunoreactivity and measurement of glucose, insulin, and nitric oxide [NO] concentrations) or 4-hour intervals (CBC and platelet-neutrophil aggregate assessment) for 8 hours or 16 hours after induction of CH...
MacLeod JN, Fubini SL, Gu DN, Tetreault JW, Todhunter RJ.To determine whether steady-state levels of type-II procollagen, aggrecan core protein, or fibronectin mRNA in articular chondrocytes are altered by synovitis or administration of methylprednisolone acetate (MPA). Methods: Articular cartilage specimens collected from 10 ponies, 2.5 to 3.5 years old and 200 to 300 kg. Methods: 4 experimental groups were compared, using the cartilage specimens: control, MPA-treated, lipopolysaccharide-induced synovitis, and lipopolysaccharide-induced synovitis with MPA treatment. RNA was isolated from articular cartilage and compared by northern blot analysis, u...
Bone reportsJune 21, 2018
Volume 9 19-26 doi: 10.1016/j.bonr.2018.06.003
Semevolos SA, Duesterdieck-Zellmer KF, Larson M, Kinsley MA.Osteochondrosis (OC) is a naturally occurring disease of the articular-epiphyseal cartilage and subchondral bone layers, leading to pain and decreased mobility. The objective of this study was to characterize gene and protein expression of apoptotic markers in chondrocytes surrounding cartilage canals and along the osteochondral junction of osteochondrosis (OC)-affected and normal cartilage, using naturally occurring disease in horses. Paraffin-embedded osteochondral samples (6 OC, 8 normal controls) and cDNA from chondrocytes captured with laser capture microdissection (4 OC, 6 normal control...
Kuhnert P, Berthoud H, Christensen H, Bisgaard M, Frey J.Equine Actinobacillus species were analysed phylogenetically by 16S rRNA gene (rrs) sequencing focusing on the species Actinobacillus equuli, which has recently been subdivided into the non-haemolytic A. equuli subsp. equuli and the haemolytic A. equuli subsp. haemolyticus. In parallel we determined the profile for RTX toxin genes of the sample of strains by PCR testing for the presence of the A. equuli haemolysin gene aqx, and the toxin genes apxI, apxII, apxIII and apxIV, which are known in porcine pathogens such as Actinobacillus pleuropneumoniae and Actinobacillus suis. The rrs-based phylo...
Ziemer EL, Pappagianis D, Madigan JE, Mansmann RA, Hoffman KD.Fifteen confirmed cases of equine coccidioidomycosis that originated in California and Arizona were studied retrospectively. Age, breed, and sex varied among affected horses. The most common historical problems were chronic weight loss (53% of cases) and persistent cough (33% of cases). The most frequent physical examination abnormalities were related to the respiratory tract (60% of cases). In 27% of cases, horses had signs of musculoskeletal pain. Horses consistently had hyperproteinemia, hyperfibrinogenemia, leukocytosis, and neutrophilia. An antemortem etiologic diagnosis was made for 11 (...
Murakami S, Kobayashi T, Sekigawa Y, Torii Y, Kanesaki Y, Ishige T, Yokoyama E, Ishiwata H, Hamada M, Tamura T.The name "Actinomyces suis" was applied to each actinomycete isolate from swine actinomycosis by Grässer in 1962 and Franke in 1973. Nevertheless, this specific species was not included in the "Approved List of Bacterial Name" due to absence of the type cultures. Therefore, "Actinomyces suis" based on the description of Franke 1973 has been considered as "species incertae sedis". We isolated a number of Actinomyces strains from swine. The representative strains of them was designated as Chiba 101 that was closely similar to the description in "Actinomyces suis" reported by Franke in 1973. Int...
Turowska A, Pajak B, Godlewski MM, Dzieciatkowski T, Chmielewska A, Tucholska A, Banbura M.Viruses can reorganize the cytoskeleton and restructure the host cell transport machinery. During infection viruses use different cellular cues and signals to enlist the cytoskeleton for their mission. However, each virus specifically affects the cytoskeleton structure. Thus, the aim of our study was to investigate the cytoskeletal changes in homologous equine dermal (ED) and heterologous Vero cell lines infected with either equine herpesvirus 1 (EHV-1) strain Rac-H or Jan-E. We found that Rac-H strain disrupted actin fibers and reduced F-actin level in ED cells, whereas the virus did not infl...
Viitanen M, Bird J, Smith R, Tulamo RM, May SA.The study hypothesis was that navicular disease is a process analogous to degenerative joint disease, which leads to changes in navicular fibrocartilage and in deep digital flexor tendon (DDFT) matrix composition and that the process extends to the adjacent distal interphalangeal joint. The objectives were to compare the biochemical composition of the navicular articular and palmar cartilages from 18 horses with navicular disease with 49 horses with no history of front limb lameness, and to compare navicular fibrocartilage with medial meniscus of the stifle and collateral cartilage of the hoof...
Wellman KY, Dixon PM.Thirty-nine equine cheek teeth diagnosed as having anachoretic apical infections and also having occlusal fissure fractures, but without occlusal pulpar exposure, that had been orally extracted without causing occlusal damage and 10 control teeth were used in this study. The teeth were individually imaged by computed tomography, occlusally stained with methylene blue and visually reexamined, then sectioned subocclusally at 5 mm intervals until the fissure fractures could no longer be detected. A limited histological study was then performed on 7 apically infected and 5 control teeth. Standard ...
Meng Q, Li S, Liu L, Xu J, Liu Y, Zhang Y, Zhang X, Shao Y.Equine Infectious Anemia Virus (EIAV), like other lentiviruses, has a transmembrane glycoprotein with an unusually long cytoplasmic tail (CT). Viral envelope (Env) proteins having CT truncations just downstream the putative membrane-spanning domain (PMSD) are assumed to exist among all wild-type budded virions, and also in some cell-adapted strains. To determine whether CT-truncated Env proteins can cause particularly deleterious effects on the Env expressing cells and/or their neighboring cells, plasmids encoding codon-optimized env gene including full-length (pE863) or CT-truncated (pE686* a...
Muhktar MM, Timoney JF.Streptococcus equi infection in horses is characterised by intense infiltration of lymph nodes by polymorphonuclear leucocytes (PMNs) suggesting a potent chemotactic response to the organism or its products. Equine PMNs were separated using Ficoll-Hypaque medium and used in an assay of chemotaxis under agarose to study the components of S equi involved in this response. Results showed that complement-derived chemotactic factors generated by activation of the alternative complement pathway were important in chemotactic responses to S equi. Both whole bacteria and peptidoglycan preparations were...
Goehring LS, Brandes K, Ashton LV, Wittenburg LA, Olea-Popelka FJ, Lunn DP, Soboll Hussey G.Equine herpesvirus-associated myeloencephalopathy is the result of endothelial cell infection of the spinal cord vasculature with equine herpesvirus-1 (EHV-1) during cell-associated viraemia. Endothelial cell infection requires contact between infected peripheral blood mononuclear and endothelial cells. Inflammation generated during viraemia likely upregulates adhesion molecule expression on both cell types increasing contact and facilitating endothelial cell infection. Objective: Evaluating the role of anti-inflammatory drugs in decreasing endothelial cell infection with EHV-1. Methods: In vi...
Dahm AM, de Bruin A, Linat A, von Tscharner C, Wyder M, Suter MM.We describe the establishment and characterisation of equine keratinocyte cultures with maintenance of a high proliferative capacity up to the second passage. Improved attachment and growth were obtained by seeding primary cells on equine feeder layers. Subcultured keratinocytes showed optimal growth when seeded on collagen type I. The proliferation rate of cells on this substrate exceeded that seen for cells seeded on equine feeder layers. By immunohistochemistry, epithelial origin and state of differentiation of the equine keratinocytes were determined. They expressed keratin and desmoplakin...
Occhiogrosso L, Capozza P, Buonavoglia A, Decaro N, Trotta A, Marin C, Corrente M.Equine periodontal disease (EPD) is a painful oral inflammatory syndrome characterized by multifactorial pathogenesis. Although it is well known that bacterial proliferation and consequent gingivitis are caused by the decomposition process of food residues, in hypsodont species, the pathogenetic role and the different bacterial species involved in the progression of EPD must be fully clarified. This study aimed to investigate the association of bacteria, including the complex red bacteria (RCB), with EPD, and to evaluate possible EPD risk factors. Bacterial species, including , , (belonging t...
Shoraba M, Shoulah SA, Arnaout F, Selim A.Surra caused by () is widely distributed and has significant impact on equine sector and international trades. However, there are no available data about the genetic characterization of this parasite in horses in Egypt. So, the goal of this study was to study the molecular characterization of in horses and determine the changes in hematological parameters and oxidative stress associated with infection. A total of 12 horses were examined using PCR targeting RoTat 1.2 VSG gene, and we evaluated the changes in hematological and oxidative stress between infected and healthy animals. The results...
Rubin CJ, Hodge M, Naboulsi R, Beckman M, Bellone RR, Kallenberg A, J'Usrey S, Ohmura H, Seki K, Furukawa R, Ohnuma A, Davis BW, Tozaki T, Lindgren G....The Greying with age phenotype in horses involves loss of hair pigmentation whereas skin pigmentation is not reduced, and a predisposition to melanoma. The causal mutation was initially reported as a duplication of a 4.6 kb intronic sequence in Syntaxin 17. The speed of greying varies considerably among Grey horses. Here we demonstrate the presence of two different Grey alleles, G2 carrying two tandem copies of the duplicated sequence and G3 carrying three. The latter is by far the most common allele, probably due to strong selection for the striking white phenotype. Our results reveal a rem...
