Neurological diseases in horses encompass a range of disorders affecting the central and peripheral nervous systems. These conditions can arise from various etiologies, including infectious agents, genetic predispositions, trauma, or metabolic imbalances. Common neurological diseases in horses include equine protozoal myeloencephalitis (EPM), equine herpesvirus myeloencephalopathy (EHM), and cervical vertebral stenotic myelopathy (CVSM), also known as wobbler syndrome. Clinical signs associated with these diseases may include ataxia, weakness, altered gait, and changes in behavior or mental status. Diagnosis typically involves a combination of clinical evaluation, imaging techniques, and laboratory testing. This page compiles peer-reviewed research studies and scholarly articles that investigate the pathophysiology, diagnostic approaches, and treatment options for neurological diseases in equine populations.
Mansfield KL, Hernández-Triana LM, Banyard AC, Fooks AR, Johnson N.Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with approximately 10,000 fatalities. The virus contains a positive sense RNA genome within a host-derived membrane and is classified within the family Flaviviridae. Like many flaviviruses, it is transmitted by mosquitoes, particularly those of the genus Culex in a natural cycle involving birds and some livestock species. Spill-over into domestic animals results in a spectrum of disease ranging from asymptomatic infection in some species t...
Franz M, Goodman LB, Van de Walle GR, Osterrieder N, Greenwood AD.A point mutation in the DNA polymerase gene in equine herpesvirus type 1 (EHV-1) is one determinant for the development of neurological disease in horses. Three recently conducted infection experiments using domestic horses and ponies failed to detect statistically significant differences in viral shedding between the neuropathogenic and non-neuropathogenic variants. These results were interpreted as suggesting the absence of a consistent selective advantage of the neuropathogenic variant and therefore appeared to be inconsistent with a systematic increase in the prevalence of neuropathogenic ...
Sadaba SA, Madariaga GJ, Botto CM, Carino MH, Zappa ME, García PP, Olguín SA, Massone A, Díaz S.Evidence of cerebellar abiotrophy (CA) was found in a six-month-old Arabian filly with signs of incoordination, head tremor, wobbling, loss of balance and falling over, consistent with a cerebellar lesion. Normal hematology profile blood test and cerebrospinal fluid analysis excluded infectious encephalitis, and serological testing for Sarcocystis neurona was negative. The filly was euthanized. Postmortem X-ray radiography of the cervical cephalic region identified not abnormalities, discounting spinal trauma. The histopathological analysis of serial transverse cerebellar sections by electron ...
Yamada K, Sato F, Hada T, Horiuchi N, Ikeda H, Nishihara K, Sasaki N, Kobayashi Y, Nambo Y.Five Thoroughbred foals (age, 8-33 weeks; median age, 31 weeks; weight, 122-270 kg; median weight, 249 kg) exhibiting ataxia with suspected cervical myelopathy (n=4) and limb malformation (n=1) were subjected to computed tomographic (CT) myelography. The areas of the subarachnoid space and cervical cord were measured on transverse CT images. The area of the cervical cord was divided by the area of subarachnoid space, and stenosis ratios were quantitatively evaluated and compared on the basis of histopathological examination. The sites with a ratio above 52.8% could have been primary lesion sit...
Singh S, Sardhara J, Singh AK, Srivastava AK, Bhaisora KS, Das KK, Mehrotra A, Sahu RN, Jaiswal AK, Behari S.This study aims to focus on a rare presentation of spinal hydatid cyst as cauda equine syndrome and misdiagnosed as intradural extramedullary (IDEM) benign lesion on magnetic resonance imaging. In this article, we report a case of spinal hydatid cyst masquerading as IDEM tumor, and intraoperatively, we accidently find clumped granuloma with severe arachnoiditis and hydatid cyst in lumber region, which was present as bilateral S1 radiculopathy with cauda equina syndrome. An 11-year-old boy who presented with symptoms and signs of cauda equina syndrome and planned for surgical excision. His radi...
Emond AL, Bertoni L, Seignour M, Coudry V, Denoix JM.OBJECTIVE To describe the clinical features, diagnostic procedures, management, and outcome of horses with peripheral neuropathy of a forelimb. DESIGN Retrospective case series. ANIMALS 27 horses. PROCEDURES Records from 2000 to 2013 were reviewed to identify horses with peripheral neuropathy of a forelimb. Horses were grouped as having predominant lesions of a suprascapular nerve, axillary nerve, or radial nerve (alone or in association with other brachial plexus nerves) on the basis of physical examination and diagnostic imaging findings. Treatments were primarily conservative. Signalment, h...
Finno CJ, Bordbari MH, Valberg SJ, Lee D, Herron J, Hines K, Monsour T, Scott E, Bannasch DL, Mickelson J, Xu L.Specific spontaneous heritable neurodegenerative diseases have been associated with lower serum and cerebrospinal fluid α-tocopherol (α-TOH) concentrations. Equine neuroaxonal dystrophy (eNAD) has similar histologic lesions to human ataxia with vitamin E deficiency caused by mutations in the α-TOH transfer protein gene (TTPA). Mutations in TTPA are not present with eNAD and the molecular basis remains unknown. Given the neuropathologic phenotypic similarity of the conditions, we assessed the molecular basis of eNAD by global transcriptome sequencing of the cervical spinal cord. Differential...
Matters of physical and medical rehabilitation of children with organic lesions of the nervous system, in particular, with cerebral palsy, are actual in countries around the world. Hippotherapy is neurophysiologically oriented therapy using horses. Determine whether a combination of hippotherapy as a method of rehabilitation in the aftermath of outpatient comprehensive impact on MS on a stationary phase; Study of the effect of hippotherapy as securing and preparation method for learning new postures and movements in children with spastic cerebral palsy forms; The study of the possible optimiza...
Scott EY, Penedo MCT, Murray JD, Finno CJ.Equine cerebellar abiotrophy (CA) is a hereditary neurodegenerative disease that affects the Purkinje neurons of the cerebellum and causes ataxia in Arabian foals. Signs of CA are typically first recognized either at birth to any time up to 6 months of age. CA is inherited as an autosomal recessive trait and is associated with a single nucleotide polymorphism (SNP) on equine chromosome 2 (13074277G>A), located in the fourth exon of TOE1 and in proximity to MUTYH on the antisense strand. We hypothesize that unraveling the functional consequences of the CA SNP using RNA-seq will elucidate the m...
McGorum BC, Jago RC, Cillan-Garcia E, Pirie RS, Keen JA, Reardon RJM, Saffu PY, Miller NJ.The aetiology of equine grass sickness (EGS) is currently unknown. We hypothesised that an acute deficiency of niacin (vitamin B3), which plays a key role in neural homeostasis, may contribute to neurodegeneration in EGS. Niacin deficiency can potentially result from ingestion of niacin antagonists produced by pasture mycotoxigenic fungi. Objective: To compare the niacin status of EGS and control grazing horses. A secondary objective was to compare blood concentrations of vitamins B1, B2 and B6 in EGS and control grazing horses to determine if the status of these vitamins was altered in EGS. M...
Sasaki N, Imamura Y, Sekiya A, Itoh M, Furuoka H.In this study, fasciculation of the limbs and tongue was observed in four horses kept by a riding club. Neurogenic muscle atrophy was also observed in biopsy of pathological tissues. In addition, in two cases that subjected to autopsy, Bunina-like bodies of inclusion in the cell bodies of neurons in the spinal cord ventral horn were confirmed, leading to a diagnosis of equine motor neuron disease (EMND). Serum vitamin E concentrations varied between 0.3 and 0.4µg/ml, which is significantly lower than the levels in normal horses. Although lack of vitamin E is speculated to be a contributory fa...
Brockman T."Stringhalt" is a horse condition that causes one or both hind legs to spasm when walking, trotting or backing. The condition is thought to be related to a neurological cause from either plant toxicity or peripheral nerve injury. The prognosis is poor and the horse's performance and quality of life can be affected. Treatment has included surgically cutting the digital extensors with varied results. The objective of the study is to utilize soft tissue release via acupressure, trigger point and myofascial release to decrease symptoms of stringhalt. The case study is a 12 year old Akhal-Teke hors...
Cruz Villagrán C, Schumacher J, Donnell R, Dhar MS.Transplantation of mesenchymal stromal cells (MSCs) to sites of experimentally created nerve injury in laboratory animals has shown promising results in restoring nerve function. This approach for nerve regeneration has not been reported in horses. In this study, we first evaluated the ability of equine bone marrow-derived MSCs (EBM-MSCs) to trans-differentiate into Schwann-like cells and subsequently tested the MSCs for their potential to regenerate a transected nerve after implantation. The EBM-MSCs from three equine donors were differentiated into SCLs for 7 days, , in the presence of s...
Rigoglio NN, Barreto RS, Favaron PO, Jacob JC, Smith LC, Gastal MO, Gastal EL, Miglino MA.The neural system is one of the earliest systems to develop and the last to be fully developed after birth. This study presents a detailed description of organogenesis of the central nervous system (CNS) at equine embryonic/fetal development between 19 and 115 days of pregnancy. The expression of two important biomarkers in the main structure of the nervous system responsible for neurogenesis in the adult individual, and in the choroid plexus, was demonstrated by Nestin and glial fibrillary acid protein (GFAP) co-labeling. In the 29th day of pregnancy in the undifferentiated lateral ventricle...
Finno CJ, Kaese HJ, Miller AD, Gianino G, Divers T, Valberg SJ.A pigment retinopathy has been reported in adult horses with equine motor neuron disease (EMND) arising from chronic α-tocopherol (α-TP) deficiency. A pigment retinopathy has not been identified in horses with neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) that affects genetically susceptible young horses with α-TP deficiency. The objective of this report is to describe, for the first time, a pigment retinopathy in a family of α-TP-deficient Warmbloods (WB) with clinically apparent NAD/EDM or EMND. Unassigned: Twenty-five WB horses from one farm underwent complete ...
Mentoor JL, Lubisi AB, Gerdes T, Human S, Williams JH, Venter M.We report here the complete genome sequence of a lineage 2 West Nile virus (WNV) strain that resulted in fatal neurological disease in a horse in South Africa. Several recent reports exist of neurological disease associated with lineage 2 WNV in humans and horses in South Africa and Europe; however, there are a lack of sequencing data from recent fatal cases in Southern Africa, where these strains likely originate. A better understanding of the genetic composition of highly neuroinvasive lineage 2 strains may facilitate the identification of putative genetic factors associated with increased v...
Nout-Lomas YS, Page KM, Kang HG, Aanstoos ME, Greene HM.There is poor agreement between observers of equine neurological gait abnormalities using the modified Mayhew grading scale. Objective: To stimulate a dose-dependent ataxia in horses through xylazine administration and identify quantifiable relevant gait parameters. Methods: Balanced, randomised, 2-way crossover design. Methods: Eight horses were assessed before and after administration of xylazine (low dose and high dose). Gait analyses performed before and after xylazine administration included: 1) kinematic data collected on an equine high-speed treadmill (flat and 10% decline) and from acc...
Husulak ML, Lohmann KL, Gabadage K, Wojnarowicz C, Marqués FJ.Two horses from Saskatchewan were presented with signs of sweating, muscle fasciculations, weight loss, and generalized weakness. The horses were diagnosed with equine motor neuron disease (EMND), by histological assessment of a spinal accessory nerve or sacrocaudalis dorsalis medialis muscle biopsy. This is the first report of EMND in western Canada. Maladie équine des motoneurones chez 2 chevaux de la Saskatchewan. Deux chevaux de la Saskatchewan ont été présentés avec des signes de sudation, de fibrillations musculaires, de perte de poids et de faiblesse généralisée. On a diagnostiq...
Shrauner B, Blikslager A, Davis J, Campbell N, Law M, Lustgarten M, Prange T.The large size of the adult horse prevents the use of advanced imaging modalities in most areas of the axial skeleton, including the lumbosacral vertebral column. Traditional imaging techniques are frequently unable to pinpoint the underlying pathology in horses with caudal back pain. In man, lumbosacral epiduroscopy is used to diagnose and treat subjects with chronic back and leg pain. This technique may close the diagnostic gap in horses with similar clinical signs. Objective: To evaluate the safety and feasibility of lumbosacral epiduroscopy in the standing adult horse. Methods: Descriptive...
Centonze R, Agostini E, Massaccesi S, Toninelli S, Morabito L.A large variety of biological and artificial materials are employed in dural repair, each of them with major limitations. Autologous grafts have limited availability and require an additional incision and surgical time. Cadaveric preparations and heterologous materials entail the risk of iatrogenic transmission of prions, whereas synthetic substitutes have been reported to cause inflammatory reactions and graft rejection. An equine-derived pericardium membrane has been developed (Heart(®), Bioteck, Vicenza, Italy) with mechanical and safety-related features that could make it suitable for neu...
Johnstone S, Barsova J, Campos I, Frampton AR.Equine herpesvirus myeloencephalopathy (EHM), a disease caused by equine herpesvirus type 1 (EHV-1), is characterized by severe inflammation, thrombosis, and hypoxia in central nervous system (CNS) endothelial cells, which can result in a spectrum of clinical signs including urinary incontinence, ataxia, and paralysis. Strains of EHV-1 that contain a single point mutation within the viral DNA polymerase (nucleotide A2254>G2254: amino acid N752→D752) are isolated from EHM afflicted horses at higher frequencies than EHV-1 strains that do not harbor this mutation. Due to the correlation between...
Nguyen HS, Lew S.Equestrian activities can be undertaken for competition or leisure. Accidents can lead to bodily injuries. In particular, traumatic brain injury (TBI) can be devastating. Limited data exist regarding the pediatric population with respect to patterns of injury and related neurosurgical intervention. Methods: We retrospectively reviewed data for all pediatric patients diagnosed with equestrian-related injuries with neurological injuries from 2005 through June 2015. Results: Nine patients (1 male and 8 females) had neurological injuries. Their mean age was 10.4 years (range 2.9-16.8 years). Intra...
Peters M, Grafen J, Kuhnen C, Wohlsein P.A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine d...
Díez de Castro E, Zafra R, Acevedo LM, Pérez J, Acosta I, Rivero JL, Aguilera-Tejero E.Equine motor neuron disease (EMND) is a neuromuscular disorder that affects adult horses. Although EMND has been linked to vitamin E deficiency, its etiopathogenesis is poorly understood. Objective: To describe clinical features, laboratory results, and postmortem findings in a series of young horses with motor neuron disease (MND). Methods: A herd of 15 young Andalusian horses with weakness, weight loss, muscle atrophy, and muscle fasciculations related to restricted intake of green forage. Methods: A case series is presented in which horses were subjected to a clinical examination and plasma...
Hyun GJ, Jung TW, Park JH, Kang KD, Kim SM, Son YD, Cheong JH, Kim BN, Han DH.Equine-assisted activity and training (EAAT) is thought to improve body balance and clinical symptoms in children with attention deficit hyperactivity disorder (ADHD). The study hypostheses were that EAAT would improve the clinical symptoms and gait balance in children with ADHD and that these improvements would be associated with increased brain connectivity within the balance circuit. Methods: A total of 12 children with ADHD and 12 age- and sex-matched healthy control children were recruited. EAAT consisted of three training sessions, each 70 minutes long, once a week for 4 weeks. Brain fun...
Lyle-Dugas J, Giguère S, Mallicote MF, Mackay RJ, Sanchez LC.Neonatal encephalopathy is the most common neurological abnormality identified in neonatal foals, but its clinical course has been rarely characterised. Objective: To describe factors associated with nonsurvival in a population of foals diagnosed with neonatal encephalopathy. Methods: Retrospective cross-sectional clinical study. Methods: Cases were selected from equine neonatal (≤14 days of age) admissions between 1996 and 2007. Multivariable logistic regression was used to identify clinical parameters, laboratory variables and therapeutic interventions associated with nonsurvival. Results:...
Cabiddu R, Borghi-Silva A, Trimer R, Trimer V, Ricci PA, Italiano Monteiro C, Camargo Magalhães Maniglia M, Silva Pereira AM, Rodrigues das Chagas G....Neurological disorders are associated with autonomic dysfunction. Hippotherapy (HT) is a therapy treatment strategy that utilizes a horse in an interdisciplinary approach for the physical and mental rehabilitation of people with physical, mental and/or psychological disabilities. However, no studies have been carried out which evaluated the effects of HT on the autonomic control in these patients. Therefore, the objective of the present study was to investigate the effects of a single HT session on cardiovascular autonomic control by time domain and non-linear analysis of heart rate variabilit...
Gennari SM, Pena HF, Lindsay DS, Lopes MG, Soares HS, Cabral AD, Vitaliano SN, Amaku M.Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT...
Taylor KR, MacKay RJ, Nelson EA, Stieler AL, Roberts JF, Castleman WL.Two horses euthanized for neurologic deficits were diagnosed with hamartomatous myelodysplasia of the spinal cord. One was a 5-week-old Holsteiner colt exhibiting spasms of muscle rigidity in the extensor muscles of the limbs and epaxial muscles, and the other was a 3-year-old Thoroughbred colt exhibiting progressive ataxia and hypermetria in the pelvic limbs. Each had focal disorganization of the white and gray matter of the spinal cord forming a mass interspersed with neurons, glial cells, and disoriented axon bundles. In the Holsteiner colt, the mass was at the level of C5 and included isla...
Sellon DC, Knowles DP, Greiner EC, Long MT, Hines MT, Hochstatter T, Hasel KM, Ueti M, Gillis K, Dame JB.Sarcocystis neurona is an apicomplexan parasite that is the primary etiologic agent of equine protozoal myeloencephalitis in horses. Protective immune responses in horses have not been determined, but interferon-gamma (IFN-gamma) is considered critical for protection from neurologic disease in mice. The role of adaptive and innate immune responses in control of parasites was explored by infecting BALB/c, IFN-gamma knockout (GKO), and severe combined immune deficient (SCID) mice with S. neurona (10(4) sporocysts/mouse). Immune competent BALB/c mice eliminated parasites within 30 days, with no s...
Wijnberg ID, van der Ree M, van Someren P.Short-duration electroencephalography (EEG) recordings in horses are helpful in diagnosing intracranial disorders. Potentially, long-duration ambulatory EEG (AEEG) recordings in horses will enhance the chance of detecting abnormal brain activity independent of the presence of an insult. Objective: The objective of this study was to test if AEEG recordings in unsedated horses can be acquired and benefit diagnosing abnormal brain activity. Methods: Recordings were taken from 8 adult control horses and 10 patients suspected of intracranial abnormalities. Self-adhesive electrodes and the 'Porti-5'...
Prange T, Carr EA, Stick JA, Garcia-Pereira FL, Patterson JS, Derksen FJ.A 3-year-old Thoroughbred gelding presented with a history of neurological signs, including incoordination in his hindlimbs, of about 7 months' duration. On initial examination, the horse exhibited ataxia and paresis in all limbs with more severe deficits in the hindlimbs. Cervical radiographs displayed severe osteoarthritis of the articular processes between C5 and C6. On subsequent cervical myelography the dorsal contrast column was reduced by 90% at the level of the intervertebral space between C5 and C6. Cervical vertebral canal endoscopy, including epidural (epiduroscopy) and subarachnoid...
Aleman M, Borchers A, Kass PH, Puchalski SM.To describe ultrasonographic landmarks for use in collection of CSF from the lumbosacral region in equids. Methods: Prospective study. Methods: 37 equids (27 with neurologic disease and 10 with nonneurologic disease). Methods: Standing equids (n = 17) were sedated with detomidine hydrochloride (0.006 to 0.01 mg/kg [0.003 to 0.005 mg/lb], IV) followed by butorphanol tartrate (0.01 mg/kg, IV) and restrained with a nose twitch for collection of CSF. The CSF was collected from 20 laterally recumbent equids (10 sedated and 10 immediately after euthanasia). Anatomic landmarks were identified ultraso...
Wobeser BK, Godson DL, Rejmanek D, Dowling P.A protozoal parasite identified as Neospora hughesi was found in inflammatory lesions in the central nervous system of a Canadian-born adult horse presented with neurological signs. This is believed to be the first case of equine protozoal myeloencephalitis (EPM) caused by Neospora hughesi in a horse outside of the United States. Un parasite protozoaire identifié comme a été trouvé dans les lésions inflammatoires du système nerveux central d’un cheval adulte né au Canada présentant des signes neurologiques. On croit qu’il s’agit du premier cas d’encéphalomyélite protozoai...
Marshall AE, Byars TD, Whitlock RH, George LW.Brainstem auditory evoked response (BAER) testing was done to evaluate inner ear/VIIIth cranial nerve (CN8) function in the horse. The BAER test consisted of stimulating the auditory system with clicks and recording far-field responses of the brainstem auditory components via cutaneous electrodes and a signal averaging system. The normal response was shown to be a series of waves occurring within the first 10 msec after the stimulus click. Functional loss of the auditory receptor organ (cochlea) or CN8 results in loss of the entire response on the side of the injury. Because of the anatomic re...
Gordon AN, Marbach CR, Oakey J, Edmunds G, Condon K, Diviney SM, Williams DT, Bingham J.A 5-year-old Australian stock horse in Monto, Queensland, Australia, developed neurological signs and was euthanized after a 6-day course of illness. Histological examination of the brain and spinal cord revealed moderate to severe subacute, nonsuppurative encephalomyelitis. Sections of spinal cord stained positively in immunohistochemistry with a flavivirus-specific monoclonal antibody. Reverse transcription polymerase chain reaction assay targeting the envelope gene of flavivirus yielded positive results from brain, spinal cord, cerebrospinal fluid, and facial nerve. A flavivirus was isolate...
Morrison LR, Freel K, Henderson I, Hahn C, Smith SH.Lymphoma (malignant lymphoma, lymphosarcoma) is uncommon in horses in the United Kingdom. This report describes an unusual form of lymphoproliferative disease with features of lymphoma restricted to the central nervous system (CNS) and with no evidence of a primary lesion elsewhere. Immunohistochemical examination defined an overwhelming predominance of T lymphocytes with admixed B lymphocytes and activated macrophages. This case exemplifies the challenges associated with definitive diagnosis of lymphoproliferative disease of the equine CNS.
Mungun-Ochir B, Horiuchi N, Altanchimeg A, Koyama K, Suganuma K, Nyamdolgor U, Watanabe KI, Baatarjargal P, Mizushima D, Battur B, Yokoyama N....Dourine is an equine protozoan disease caused by Trypanosoma equiperdum. Dourine-afflicted animals die after developing neurological clinical signs, such as unilateral paresis. The disease has been a problem for many years; however, the pathogenesis regarding the neurological clinical signs of dourine has been unclear. In the present study, we conducted a histopathological examination in order to investigate the mechanisms by which dourine-afflicted horses develop the accompanying neurological clinical signs. Four dourine-afflicted horses in Mongolia were evaluated. An apparently healthy horse...
Kodama A, Yanai T, Yomemaru K, Sakai H, Masegi T, Yamada S, Fukushi H, Kuraishi T, Hattori S, Kai C.Equine herpesvirus 9 (EHV-9) is a new neurotropic equine herpesvirus which induced encephalitis in a variety of animals. However, there was no information on the susceptibility of EHV-9 in primates. Methods: To assess the infectivity of EHV-9, four common marmosets (Callithrix jacchus) were inoculated by the nasal route with 10(6) plaque-forming units of EHV-9. Conclusions: All of the inoculated animals exhibited various neurological signs progressing to collapse. Histologically, the affected animals had severe encephalitis characterized by neuronal degeneration and necrosis with intranuclear ...
McClure JJ, Lindsay WA, Taylor W, Ochoa R, Issel CJ, Coulter SJ.In 4 horses with equine infectious anemia (EIA), the predominant clinical sign was ataxia. Other clinical and laboratory findings often associated with EIA included weight loss, anemia, pyrexia, thrombocytopenia, hemorrhages, hypergammaglobulinemia, and high activity of biliary epithelial enzymes. Neuropathologic findings were nonsuppurative granulomatous ependymitis, meningitis, and encephalomyelitis and plasmacytic-lymphocytic infiltration of the brain and spinal cord. The onset of neurologic signs corresponded to the acute stage of infection in at least 2 horses, and the signs developed at ...
Kinde H, Bettey RL, Ardans A, Galey FD, Daft BM, Walker RL, Eklund MW, Byrd JW.An episode of nervous system dysfunction was observed in horses on 17 premises in 4 counties of southern California. Thirty-eight horses were affected, and 31 of those died. The common clinical signs of disease in the affected horses were: increased appetite; anxious attitude; rythmic, intermittent muscle tremors in the area of the tricep muscles; decreased palpebral tone; mydriasis; small hard fecal balls; and tendency to become sternally recumbent with the neck extended. The temporal distribution of cases on all 17 premises suggested a relationship between exposure to a common batch of alfal...
Ferrell EA, Gavin PR, Tucker RL, Sellon DC, Hines MT.Magnetic resonance (MR) imaging was used as a neurodiagnostic modality in the assessment of 12 horses with neurologic disease localized cranial to the foramen magnum. This retrospective study included a mixed population of horse breeds and consisted of three foals and nine adult horses. MR sequences of the head and central nervous system of each horse were acquired. Routine MR sequences included transverse T1 weighted (T1wt), T2 weighted (T2wt), and proton density images. Additional imaging sequences were obtained on a patient-dependent basis. Eight neurologic related diseases were diagnosed. ...
Depecker M, Bizon-Mercier C, Couroucé-Malblanc A.The atlanto-occipital site (AO) is convenient for retrieving an adequate volume and quality of cerebrospinal fluid (CSF) in the diagnosis of neurological disease in horses. However, general anaesthesia is not always possible for horses displaying severe neurological signs, or for economical reasons. The objectives of the present work were to determine the feasibility and safety of ultrasound-guided CSF puncture at the AO site on the standing horse. Seven horses (six healthy and one mildly ataxic) were sedated with acepromazine (0.02 mg/kg bodyweight intravenously or 0.04 mg/kg bodyweight intra...
Murphy AJ, Mansfield LS.Sarcocystis neurona is a protozoan parasite that causes a neurological disease in horses called equine protozoal myeloencephalitis. The route of transmission is speculated to be by fecal-oral transfer of sporocysts shed from opossums. Controversy exists regarding both the natural life cycle for this parasite as well as the species identity of opossum Sarcocystis. To provide stage-specific material for species comparison, 27 opossums from southern Michigan were screened for Sarcocystis spp. sporocysts. Seven opossums were positive for Sarcocystis sporocysts by fecal flotation. A simplified, eff...
Mayhew IG, Washbourne JR.Brainstem auditory evoked potential (BAEP) waveforms were recorded as a means of objectively evaluating auditory and brainstem function in horses. BAEP recordings were readily and repeatably recorded from horses, under minimal restraint, using signal averaging equipment. Clearly identified BAEP waveforms were obtained with compression clicks of 30-100 dB (HHL) at 10 Hz applied in the external auditory meatus of one ear and masking white noise (10 dB lower) in the other ear. Vertex positive (upwards) waveforms I through V were obtained with an active, subdermal electrode over the ipsilateral an...
Tanner J, Spriet M, Espinosa-Mur P, Estell KE, Aleman M.Temporohyoid osteoarthropathy is a well-recognized cause of equine neurologic disease. Temporal bone fractures associated with temporohyoid osteoarthropathy have been recognized with CT, however, little information is available regarding these fractures. The aims of this retrospective analytical study were to assess the prevalence of these fractures and to describe the specific configurations and associated imaging and clinical features. Fracture of the temporal bone was identified with CT in 16 of 39 included horses. All fractures were unilateral, minimally displaced and extended through the ...
Magouras I, Schoster A, Fouché N, Gerber V, Groschup MH, Ziegler U, Fricker R, Griot C, Vögtlin A.Reports on acute tick-borne encephalitis virus (TBEV) infections with signs of neurologic disease in horses are limited. Objective: To describe the epidemiological, clinical, and laboratory findings of suspected acute TBEV infections in 6 horses. Methods: Six horses originating from TBEV endemic regions of Switzerland were presented to equine hospitals with acute onset of neurologic disease between 2011 and 2019. Methods: Retrospective case series. Horses with acute onset of signs of neurologic disease that were subjected to clinical and microbiological examinations to rule out infectious dise...
Yamada K, Sato F, Hada T, Horiuchi N, Ikeda H, Nishihara K, Sasaki N, Kobayashi Y, Nambo Y.Five Thoroughbred foals (age, 8-33 weeks; median age, 31 weeks; weight, 122-270 kg; median weight, 249 kg) exhibiting ataxia with suspected cervical myelopathy (n=4) and limb malformation (n=1) were subjected to computed tomographic (CT) myelography. The areas of the subarachnoid space and cervical cord were measured on transverse CT images. The area of the cervical cord was divided by the area of subarachnoid space, and stenosis ratios were quantitatively evaluated and compared on the basis of histopathological examination. The sites with a ratio above 52.8% could have been primary lesion sit...
Hammerschmitt ME, Henker LC, Lichtler J, da Costa FVA, Soares RM, Llano HAB, Pavarini SP.Sarcocystis neurona is the main agent associated with equine protozoal myeloencephalitis (EPM). Apart from horses, S. neurona has been occasionally described causing neurologic disease in several other terrestrial animals as well as mortality in marine mammals. Herein, we describe the clinical, pathological, and molecular findings of a fatal case of S. neurona-associated meningoencephalitis in a domestic cat. The causing agent was analyzed by multilocus genotyping, confirming the presence of S. neurona DNA in the tissue samples of the affected animal. Significant molecular differences were fou...
Hébert L, Guitton E, Madeline A, Géraud T, Zientara S, Laugier C, Hans A, Büscher P, Cauchard J, Petry S.The aim of this study was to evaluate the ability of melarsomine hydrochloride (Cymelarsan) to cure horses suffering from a nervous form of dourine, a sexually-transmitted disease caused by Trypanosoma equiperdum. The recently described experimental model for assessing drug efficacy against horse trypanosomosis allowed us to obtain eight horses (Welsh pony mares) infected by T. equiperdum with parasites in their cerebrospinal fluid. The Cymelarsan treatment evaluated consisted of the daily administration of 0.5 mg/kg of Cymelarsan over 7 days. Two control horses remained untreated, three hor...
Kraft KA, Weisberg J, Finch MD, Nickel A, Griffin KH, Barnes TL.This report assesses functional mobility in children with neurological impairments and documented gross motor delays, before and after receiving either hippotherapy or standard outpatient physical therapy (PT). This is a case-series report using data previously collected for a discontinued randomized controlled trial, in which participants received hippotherapy or standard outpatient clinic PT for a 12-week treatment period. Results demonstrated both subjective and objective functional mobility improvements after treatment in participants receiving hippotherapy and standard outpatient PT, as d...
Cao X, Yang D, Parvathareddy J, Chu YK, Kim EJ, Fitz-Henley JN, Li X, Lukka PB, Parmar KR, Temrikar ZH, Dhole P, Adcock RS, Gabbard J, Bansal S....Venezuelan and eastern equine encephalitis viruses (VEEV and EEEV, respectively) are mosquito-borne, neuroinvasive human pathogens for which no FDA-approved therapeutic exists. Besides the biothreat posed by these viruses when aerosolized, arthropod transmission presents serious health risks to humans, as demonstrated by the 2019 outbreak of EEE disease in the United States that resulted in 38 confirmed cases, 19 deaths, and neurological effects in survivors. Here, we describe the discovery of a 2-pyrrolidinoquinazolinone scaffold, efficiently synthesized in two to five steps, whose structural...
Rockx B, van Asten L, van den Wijngaard C, Godeke GJ, Goehring L, Vennema H, van der Avoort H, van Pelt W, Koopmans M.West Nile virus (WNV) is an arthropod-borne flavivirus that is endemic in Africa, Europe, and Eastern Asia. The recent introduction and rapid dissemination of the virus in the United States as well as an increase in WNV outbreaks in Europe, has raised concerns for its spread in Europe. A surveillance system was developed to allow timely detection of an introduction of WNV infections in The Netherlands. This program focuses on cases presenting with neurological disease and includes the monitoring of hospital discharge diagnoses, trends in cerebrospinal fluid (CSF) diagnostic requests, laborator...
Katz JB, Alstad D, Jenny AL, Carbone KM, Rubin SA, Waltrip RW.Borna disease was originally described as an equine neurologic syndrome over 200 years ago, although the infectious etiology of the disorder was unproven until the early 20th century. Borna disease virus (BDV) was finally isolated from horses dying of the disorder, and that virus has been used to experimentally reproduce Borna disease in several species of laboratory animals. However, BDV has never been inoculated back into horses to experimentally and etiologically confirm the classic clinical, pathologic, and serologic characteristics of the disease in that species. Three ponies were intrace...
Bingham J, Payne J, Harper J, Frazer L, Eastwood S, Wilson S, Lowther S, Lunt R, Warner S, Carr M, Hall RA, Durr PA.West Nile virus (WNV; family Flaviviridae; genus Flavivirus) group members are an important cause of viral meningoencephalitis in some areas of the world. They exhibit marked variation in pathogenicity, with some viral lineages (such as those from North America) causing high prevalence of severe neurological disease, whilst others (such as Australian Kunjin virus) rarely cause disease. The aim of this study was to characterize WNV disease in a mouse model and to elucidate the pathogenetic features that distinguish disease variation. Tenfold dilutions of five WNV strains (New York 1999, MRM16 a...
Motlou TP, Williams J, Venter M.The genus, family , contains several important emerging and re-emerging arboviruses of veterinary and medical importance. These viruses may cause mild febrile illness, to severe encephalitis, fetal deformity, abortion, hemorrhagic fever and death in humans and/or animals. Shuni virus (SHUV) is a zoonotic arbovirus thought to be transmitted by hematophagous arthropods. It was previously reported in a child in Nigeria in 1966 and horses in Southern Africa in the 1970s and again in 2009, and in humans with neurological signs in 2017. Here we investigated the epidemiology and phylogenetic relatio...
Marsh AE, Hyun C, Barr BC, Tindall R, Lakritz J.Equine protozoal myeloencephalitis (EPM), caused by a protozoal parasite infection of the central nervous system, is the most commonly diagnosed neurologic disease of horses in North America. In specific regions of the United States approximately 50% of the horse population is seropositive to Sarcocystis neurona. However, not all seropositive horses develop clinical signs. Detailed clinical examination, along with cerebrospinal fluid antibody evaluation are often used to diagnose EPM. Postmortem evaluation of the brain stem and spinal cord for histopathologic lesions compatible with nonsuppura...
Maia L, da Cruz Landim-Alvarenga F, Taffarel MO, de Moraes CN, Machado GF, Melo GD, Amorim RM.Recent studies have demonstrated numerous biological properties of mesenchymal stem cells and their potential application in treating complex diseases or injuries to tissues that have difficulty regenerating, such as those affecting the central and peripheral nervous system. Thus, therapies that use mesenchymal stem cells are promising because of their high capacity for self-regeneration, their low immunogenicity, and their paracrine, anti-inflammatory, immunomodulatory, anti-apoptotic and neuroprotective effects. In this context, the purpose of this study was to evaluate the feasibility and s...
Nappert G, Vrins A, Breton L, Beauregard M.A retrospective study of 19 ataxic horses admitted to the College of Veterinary Medicine of the University of Montreal during the period of January 1985 to December 1988 is presented. There were 11 cases of cervical vertebral malformation, four of equine degenerative myeloencephalopathy, two of equine protozoal myeloencephalitis, one each of vertebral osteomyelitis and intervertebral disc protrusion. The clinical diagnosis of ataxia in horses requires neurological, radiographic, myelographic, and laboratory examinations.
