Topic:Neurological Diseases
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.
Fumonisin B(1): a neurotoxic mycotoxin. Fumonisin B(1) (FB(1)) is a mycotoxin produced by Fusarium spp. moulds that contaminate crop, predominantly maize, all around the world. More than 15 types of fumonisins have been indentified so far, but FB(1) is the most abundant and toxicologically the most significant one. FB(1) has a wide range of toxic effects, depending on animal species. In horses FB(1) causes equine leukoencephalomalacia (ELEM), in pigs pulmonary oedema and in experimental rodents nephrotoxicity and hepatotoxicity. In humans exposure to FB(1) is linked with higher incidence of primary liver cancer and oesophageal cance...
West Nile Virus outbreak in Sardinia, Italy, in 2011. West Nile Virus (WNV) is an enveloped, positive-sense RNA virus belonging to the genus Flavivirus, antigenically related to the Japanese encephalitis complex in the family Flaviviridae. The principal vectors are mosquitoes, in particular Culex spp, and virus amplification seems to occur in susceptible birds that are the principal vertebrate reservoir hosts, whereas humans, horses and other vertebrates are considered incidental or dead-end hosts. The first Italian equine outbreak was reported in late summer of 1998 in Tuscany, in the area surrounding the Fucecchio marshes, where 14 clinical cas...
The first investigation of west nile virus in horses using real time rt-PCR in middle black sea region in Turkey. West Nile Virus (WNV) is a mosquito-borne disease that can cause fatal infection in mammals including humans, dogs, horses, birds and reptiles. Although West Nile Virus is an asymptomatic infection, especially it can cause neurologic disorders in humans and horses. The aim of this study was to the investigate virological presence of WNV in horses in the Black Sea Region of Turkey using real time RT-PCR (rRT-PCR). Methods: Totally, 120 horse sera were collected equally from 4 provinces in Middle Black Sea Region of Turkey and investigated for WNV presence by Taqman based rRT-PCR. Results: WNV n...
Epidemiology and host spectrum of Borna disease virus infections. Borna disease virus (BDV) has gained lot of interest because of its zoonotic potential, ability to introduce cDNA of its RNA transcripts into host genomes, and ability to cause severe neurobehavioural diseases. Classical Borna disease is a progressive meningoencephalomyelitis in horses and sheep, known in central Europe for centuries. According to current knowledge, BDV or a close relative also infects several other species, including humans at least occasionally, in central Europe and elsewhere, but the existence of potential 'human Borna disease' with its suspected neuropsychiatric symptoms ...
Pedigree analysis and exclusion of alpha-tocopherol transfer protein (TTPA) as a candidate gene for neuroaxonal dystrophy in the American Quarter Horse. Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) is a neurodegenerative disorder affecting young horses of various breeds that resembles ataxia with vitamin E deficiency in humans, an inherited disorder caused by mutations in the alpha-tocopherol transfer protein gene (TTPA). To evaluate variants found upon sequencing TTPA in the horse, the mode of inheritance for NAD/EDM had to be established. Objective: NAD/EDM in the American Quarter Horse (QH) is caused by a mutation in TTPA. Methods: 88 clinically phenotyped (35 affected [ataxia score ≥2], 53 unaffected) QH...
Role of KCNQ2 and KCNQ3 genes in juvenile idiopathic epilepsy in Arabian foals. Juvenile idiopathic epilepsy (JIE) in Arabian foals resembles benign-familial neonatal convulsion (BFNC) syndrome, a rare idiopathic epilepsy of new-born humans. BFNC syndrome exhibits genetic heterogeneity, as has been hypothesised to occur in Arabian foals, and is known to be caused by mutations in the voltage-gated potassium channel subunit KCNQ2 and KCNQ3 genes. The close phenotypic characteristics of both Arabian foals and children suggest these epileptic syndromes are caused by the same genetic disorder. In horses, the KCNQ2 and KCNQ3 genes are located on the terminal region of chromosom...
A review on epilepsy in the horse and the potential of Ambulatory EEG as a diagnostic tool. Epilepsy in the horse is diagnosed based on clinical signs, but diagnosing can be difficult if a grand mal is not present. The future prospects of the horse and potentially the safety of the owner depend on an accurate diagnosis. This review presents information on epilepsy and focuses on the diagnostic potential of (Ambulatory) electroencephalography ((A) EEG). An epileptic seizure is a brain disorder, which expresses itself as a recurrent episode of involuntary abnormal behaviour. The aetiology can originate from inside or outside the brain or is idiopathic. Besides those categories, seizure...
Pneumocephalus in five horses. Pneumocephalus is occasionally encountered in horses but poorly described in the literature. The study aimed to describe historical, clinical and diagnostic imaging findings and outcome in horses to increase the awareness and recognition of the condition amongst equine practitioners, allowing appropriate management of these cases. Cases of pneumocephalus from 4 participating institutions were identified and case details extracted from the medical records. Five cases of pneumocephalus were identified. Head trauma with suspected or confirmed fractures of the sinuses was the underlying cause in 4...
Diagnostic sensitivity of subjective and quantitative laryngeal ultrasonography for recurrent laryngeal neuropathy in horses. Recurrent laryngeal neuropathy (RLN) is the most common cause of laryngeal hemiplegia in horses and causes neurogenic atrophy of the intrinsic laryngeal muscles, including the cricoarytenoideus lateralis muscle. Recurrent laryngeal neuropathy results in paresis to paralysis of the vocal fold and arytenoid cartilage, which limits performance through respiratory compromise. Ultrasound has previously been reported to be a useful diagnostic technique in horses with RLN. In this report, the diagnostic sensitivity of subjective and quantitative laryngeal ultrasonography was evaluated in 154 horses p...
Concurrent ivermectin and Solanum spp. toxicosis in a herd of horses. Representatives from a herd of horses with acute onset of neurologic signs after administration of ivermectin presented for evaluation and treatment. Objective: Describe clinical signs of horses intoxicated by ingestion of Solanum sp. and administered ivermectin. Methods: Six of 11 affected unrelated horses presented for evaluation and treatment. The remaining 5 affected horses were treated at the farm. Four additional horses, housed separately, were unaffected. Methods: Case series is presented. Serum ivermectin concentrations were evaluated in the 6 hospitalized horses. The remnants of the t...
Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice. Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left-right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favourable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is exp...
Differential expression of TAR DNA-binding protein (TDP-43) in the central nervous system of horses afflicted with equine motor neuron disease (EMND): a preliminary study of a potential pathologic marker. Equine motor neuron disease (EMND) is a neurodegenerative disorder of unknown etiology affecting horses worldwide. Trans-Active Response DNA Binding Protein of 43Â 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...
Pyogranulomatous lesion causing neurological signs localised to the sacral region in a horse. This case report describes neurological signs associated with a pyogranulomatous lesion within the sacral vertebral canal of a horse. The clinical findings included urinary overflow incontinence and reduced anal, perianal and tail tone. The horse failed to respond to medical management and a guarded prognosis for return to athletic performance initiated the decision for euthanasia.
Plasma neurofilament pNF-H concentration is not increased in acute equine grass sickness. Although a presumptive diagnosis of acute grass sickness (AGS) can be made on the basis of clinical signs, a definitive ante mortem diagnosis currently requires histological examination of enteric ganglia. Development of an accurate noninvasive ante mortem diagnostic test is therefore warranted. The objective of this study was to determine whether quantification of the plasma concentrations of the heavily phosphorylated form of major neurofilament subunit NF-H (pNF-H), which mirror the degree of axonal degeneration in some human and animal neurodegenerative disorders, could distinguish AGS-aff...
West nile virus disease and other arboviral diseases – United States, 2011. Arthropodborne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. Symptomatic infections most often manifest as a systemic febrile illness and, less commonly, as neuroinvasive disease (e.g., meningitis, encephalitis, or acute flaccid paralysis). West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the United States. However, several other arboviruses also cause seasonal outbreaks and sporadic cases. In 2011, CDC received reports of 871 cases of nationally notifiable arboviral diseases (excluding deng...
Kunjin flaviviral encephalomyelitis in an Arabian gelding in New South Wales, Australia. Flaviviruses, including Kunjin virus, are arboviruses that cause encephalomyelitis in humans and horses. This case report describes an Arabian gelding exhibiting neurological signs of flavivirus encephalomyelitis, the diagnostic investigation and confirmation of an unreported case of Kunjin virus equine encephalomyelitis in Australia.
Presumed case of “stiff-horse syndrome” caused by decreased gamma-aminobutyric acid (GABA) production in an American Paint mare. Glutamic acid decarboxylase (GAD) converts glutamic acid into the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Increased serum GAD (auto) antibody concentrations were found in a mare with increased postural musculature tone resulting in stiffness and recumbence. The mare was treated with dexamethasone which resulted in resolution of clinical signs and decreased GAD antibody concentrations. La glutamate décarboxylase (GAD) convertit l’acide glutamique en acide gamma-aminobutyrique (GABA), un inhibiteur des neurotransmetteurs. Des concentrations sériques accrues d’anticorps (a...
Serum iron parameters and acute experimental EHV-1 infection in horses. Research in humans has demonstrated that high serum iron (sFe) concentration can predispose to infection, and many infections subsequently result in alterations of host sFe. A decrease in sFe concentration is an early and sensitive indicator of systemic inflammation caused by tissue necrosis, bacterial infections, or endotoxemia in horses. Serum iron parameters in acute equine herpesvirus type 1 (EHV-1) infection have not been evaluated previously. Objective: To document the sFe response to EHV-1 infection and to determine whether or not significant differences in sFe concentration exist betwe...
Hippotherapy effects on trunk, pelvic, and hip motion during ambulation in children with neurological impairments. This study investigated the effects of a 10-week hippotherapy program on trunk, pelvis, and hip joint positioning during the stance phase of gait. Methods: Eleven children (6 boys and 5 girls; 7.9 ± 2.7 years) with neurological disorders and impaired ambulation participated. Joint range of motion data were collected via 3-dimensional computerized gait analysis before and after the program. Paired t tests were performed on kinematic data for each joint. Results: Significant improvements (P ≤ .008) and large effect sizes (ESs) for sagittal plane hip positions at initial contact and toe-off we...
Murray Valley encephalomyelitis in a horse. A 5-year-old Thoroughbred mare presented with signs of severe pain and was taken to exploratory laparotomy based on suspicion of an acute abdominal lesion. A mild gastrointestinal lesion was discovered, but was considered disproportional to the severity of signs displayed. The mare was later euthanased because of intractable pain. Comprehensive postmortem examination, including polymerase chain reaction testing of central nervous system tissue samples, allowed a definitive diagnosis of Murray Valley encephalomyelitis to be made. This case demonstrates the variability of clinical presentations ...
Mycotic encephalitis, sinus osteomyelitis, and guttural pouch mycosis in a 3-year-old Arabian colt. Mycotic encephalitis caused severe ataxia and other neurologic deficits in a horse. The finding of a single, large focus of cerebral malacia, with histopathologic evidence of fungal elements, suggested infection was a result of direct transfer from the frontal sinuses, rather than hematogenous spread from the guttural pouch. Une encéphalite mycotique a causé une ataxie grave et d’autres déficits neurologiques chez un cheval. La découverte d’un grand foyer unique de malacie cérébrale avec une preuve histopathologique d’éléments fongiques a suggéré que l’infection était un tr...
Episodic blindness and ataxia in a horse with cholesterinic granulomas. An 11-year-old Oldenburg mare presented following three episodes of acute, transient blindness, ataxia, and disorientation within the preceding 7 months. Clinical improvement, including return of vision, occurred within 1 week of initiating corticosteroid therapy for each of the three episodes. However, mild right-sided miosis was a consistent finding on ophthalmic examinations. Routine clinicopathologic testing revealed no significant abnormalities, and testing of cerebral spinal fluid for selected infectious diseases was unrewarding. Computed tomography of the brain demonstrated a hyperatten...
[‘Laryngeal neuropathy’ and ‘irritable larynx syndrome’: synonyms or distinct entities?]. The term 'laryngeal neuropathy' (LN) has first been used in veterinary medicine to describe an idiopathic and typically exercise induced inspiratory noise in horses.Nowadays, the term is often used in relation with intermittent vocal cord pareses in humans. Some authors use the term 'irritable larynx syndrome' (ILS) in a similar context. This article reviews the state of knowledge regarding LN and ILS and discusses the somewhat confusing terminology.For this systematic review a selective literature research in PubMed has been carried out.35 articles were found, which report on LN in animals an...
Feeding the foal for immediate and long-term health. The nutrition and nutritional status of the mare, as well as foal's nutrient intake from colostrum, milk and creep feed, are critical factors that are known to influence the growth period of the foal. Long-term effects of mare and foal nutrition are not well recognised or understood in the horse but may have the greatest impact on the animal's health and use when mature. Both under- and overfeeding can negatively influence important characteristics such as bone development and neurological function The risk of developing debilitating diseases such as metabolic syndrome may also be increased by...
Clinical findings in 10 foals with bacterial meningoencephalitis. Bacterial meningoencephalitis is a severe complication in septic foals and there is scarce and often unclear information in the equine literature. Objective: To report the most frequent clinical signs, clinicopathological findings, causative agents, treatments given and outcome of a group of foals with confirmed bacterial meningoencephalitis. Methods: Foals aged < 6 months of age admitted to the Universitat Autonoma de Barcelona (2004-2009) with confirmed bacterial meningoencephalitis were retrospectively included in the study Diagnosis of bacterial meningoencephalitis was made by cerebrospina...
Allopregnanolone infusion induced neurobehavioural alterations in a neonatal foal: is this a clue to the pathogenesis of neonatal maladjustment syndrome? Increased plasma progestagen concentrations have been reported in foals with neonatal maladjustment syndrome (NMS). These steroids may cross the blood-brain barrier and have dampening effects in the central nervous system. Objective: To evaluate if the infusion of a progesterone derivative (allopregnanolone) in a healthy neonatal foal would induce clinical signs compatible with NMS. Methods: A healthy neonatal foal from a healthy mare with a normal gestation (length, no complications), birth and placenta was infused with allopregnanolone to observe its neurobehavioural effects. Heparinised blo...
Poisoning by Indigofera lespedezioides in horses. Poisoning by Indigofera lespedezioides is reported in horses in the state of Roraima, northern Brazil. The main clinical signs are anorexia, sleepiness, unsteady gait, severe ataxia, weakness, stumbling, and progressive weight loss. To induce the disease experimentally, a 7-year-old horse was introduced in a small paddock invaded by the plant. The first nervous signs were observed 44 days from the start of grazing. The animal was euthanized on day 59. No significant gross lesions were observed upon necropsies of the experimental horse as well as one spontaneously affected horse. Upon histologi...
The use of magnetic resonance imaging in evaluating horses with spinal ataxia. To determine the accuracy of magnetic resonance imaging for diagnosing cervical stenotic myelopathy in horses, 39 horses with spinal ataxia and 20 control horses underwent clinical and neurologic examinations, cervical radiographs, euthanasia, magnetic resonance (MR) imaging of the cervical spine and necropsy. Twenty-four horses were diagnosed with cervical stenotic myelopathy, 5 with cervical vertebral stenosis, 7 with idiopathic ataxia, 3 horses had other causes of ataxia, and 20 were controls. The MR images were assessed for spinal cord intensity changes, presence of spinal cord compression...
Vascular mineralization in the brain of horses. Vascular mineralization (siderocalcinosis) in the brain of horses has been usually assumed to be an incidental age-related finding with no clinic significance. In the present study, eight 15-32-year-old horses of different breeds with cerebral siderocalcinosis were studied. Four of these horses had acute and severe central nervous system clinical signs of unknown etiology, 2 horses had neurological signs of known cause, and 2 horses did not have neurological signs. Gross examination of the brains in 4 animals revealed symmetrical foci of malacia in the cerebellar white matter. Histologically, ...