Neurology in horses encompasses the study of the equine nervous system, including its structure, function, and associated disorders. The equine nervous system is divided into the central nervous system (CNS), consisting of the brain and spinal cord, and the peripheral nervous system (PNS), which includes nerves extending throughout the body. Neurological conditions in horses can manifest as gait abnormalities, behavioral changes, or sensory deficits. Common neurological disorders include equine protozoal myeloencephalitis (EPM), cervical vertebral stenotic myelopathy (CVSM), and equine herpesvirus myeloencephalopathy (EHM). Diagnostic approaches may involve clinical evaluation, imaging techniques, and laboratory tests. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, pathophysiology, diagnosis, and management of neurological disorders in horses.
de Preux M, Precht C, Becker R, Stieglitz L, Easley J, Koch C.Trigeminal-mediated headshaking is a neuropathic disorder in horses, characterized by signs of regional pain similar to trigeminal neuralgia in humans. The injection of glycerol into the trigeminal cistern to ablate pain-conducting nerve fibers within the trigeminal ganglion -known as glycerol rhizotomy- is a well-established treatment in human medicine. This study compares two approaches to the equine trigeminal cistern using a navigation system for guiding needle placement, a previously described ventral and a newly developed transmandibular lateral approach. The surgical accuracy and risk o...
Harte T, Smith D, Moore J, Wells B.An article published in 1992 by Marion M. Pollin and I.R. Griffiths reviewed the topic of primary dysautonomias of the autonomic nervous system of unidentified origin in multiple domestic species, specifically cats, dogs and horses. Thirty-one years later, we appear no closer to identifying the causal agents of these strikingly similar diseases. This article reviews the similarities and differences in clinical presentation and pathology of dysautonomia in canids, felids, equids, leporids and other less frequently reported species.
de Fátima Coccia V, Rodacki ALF, Pavão SL.Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder affecting sensorimotor systems, potentially disturbing postural control and stability. Considering the treatment options for these children, hippotherapy (HPOT) is based on horse movements to provide sensory stimuli and motor challenges, potentially contributing to improvements in postural control. Objective: To investigate the immediate effects of a 30-min HPOT session on the center of pressure (CoP) displacement of children with ASD (ASDG) and children with typical development (TDG). Methods: 120 children (60 ASDG; 60 TD...
Käfer-Karrer MJ, de Preux M, Van der Vekens E, Mattei LI, Kuhlmann J, Klopfenstein Bregger MD, Easley JT, Koch C.To describe the repair of a fractured cranial articular process (AP) of the sixth cervical vertebra (C6) with cortex screws placed in lag fashion using computer-assisted surgery. Methods: A 12-year-old Swiss Warmblood gelding. Methods: Case report. Methods: The gelding was presented with neck pain and ataxia after a fall. A fracture of the right cranial AP of C6 was identified on radiographs. The fracture was repaired by internal fixation with two 4.5 mm cortex screws of 58 and 48 mm length placed in lag fashion using computer-assisted surgery. Results: During general anesthesia, it was su...
Lloyd-Edwards RA, Mulders E, Sloet van Oldruitenborgh-Oosterbaan MM, Veraa S. Headshaking is a common condition in horses, most cases are presumed idiopathic/trigeminal-nerve mediated. Diagnostic work-up of a headshaking horse may involve computed tomography (CT) of the head to exclude causative structural pathology. The relevance of the presence and severity of hyoid apparatus findings at CT to headshaking is unknown. A retrospective analysis of CT changes in the hyoid apparatus in horses was carried out. Comparisons were performed between horses with signs of headshaking and a control population and a subgroup of horses with signs of headshaking and no other 'likely...
Vitale V, Velloso Álvarez A, de la Cuesta-Torrado M, Neira-Egea P, Vandecandelaere M, Tee E, Gimeno M, van Galen G.In human medicine, neurological diseases have been associated with transient cardiac abnormalities. In horses, myocardial disease is rarely diagnosed and has been associated with a wide variety of causes. The aim of this article is to describe three horses with no previous cardiac disease, which all developed severe cardiomyopathy following neurological disease. A 5-year-old Shetland pony stallion was diagnosed with cardiomyopathy with arrhythmias following an episode of seizures caused by an accidental intra-arterial xylazine injection. A 20-year-old crossbred mare was hospitalised for an ope...
Connolly KM, Estell K.Dysphagia describes a clinical sign of pathologies of the oral cavity, pharynx, and oesophagus that carries potentially serious consequences for horses. Given the diversity of differential diagnoses that may cause dysphagia, an understanding of the prevalence of dysphagia in hospitalised patients, the distribution of aetiologies and clinical outcomes could inform diagnosis, treatment, and prognosis. Objective: This study aims to describe the incidence, signalment, history, aetiology, treatment, and outcome of horses presenting to a referral hospital for dysphagia. Methods: Retrospective case s...
Maurer T, de Preux M, Precht C, Vidondo B, Koch C.To assess the accuracy of computer-assisted surgery (CAS) of equine cervical vertebrae using a purpose-built cervical frame (CF) for neck stabilization. Methods: Experimental cadaveric study. Methods: Six whole fresh equine cadavers. Methods: Cadavers were positioned in dorsal recumbency with the neck extended within the CF. A cone-beam computed tomography (CBCT)-based surgical navigation system with optical tracking was used. A ventral approach exposed cervical vertebrae C3-C5. In each cadaver, 12 drill corridors were prepared with the patient tracker on the CF (position CF), followed by 12 c...
de Sousa ALV, de Sousa DER, de Macêdo IL, de Albuquerque Cerqueira L, da Fonseca YNG, Oliveira AB, das Chagas LVS, Gonçalves GB, Veado HC....This report describes the first documented case of intracerebral hemorrhage (ICH) in a horse following Bothrops snakebite envenomation. A 3-year-old mare developed acute kidney injury, systemic hemorrhage, and neurological signs before euthanasia. Postmortem findings confirmed massive ICH with intralesional venom identified by immunohistochemistry. Delayed treatment and insufficient antivenom likely contributed to the outcome. This case highlights the potential for cerebrovascular complications following Bothrops snakebite envenomation in horses, which may present as subtle neurological signs....
Oshida J, Ito H, Ubukata K, Takata M, Ohkusu K, Ohba S, Saida A, Nakamura S, Kobayashi D.Streptococcus suis is a Gram-positive zoonotic pathogen primarily associated with pigs, but its potential transmission from other animals remains unclear. We report a case of S. suis serotype 2 meningitis in a 56-year-old Filipino stable worker with no known contact with pigs but a history of direct exposure to horses. He presented with fever and persistent headache following a head injury sustained one month prior. Cerebrospinal fluid (CSF) analysis revealed bacterial meningitis, and blood and CSF cultures identified S. suis serotype 2. Despite appropriate antibiotic therapy, the patient deve...
Brown KA, Engiles JB, de Solis CN, Bills KW, Johnson AL, Davidson EJ.To determine the accuracy of a dorsal ultrasound-guided approach for perineural injection of the sixth and seventh cervical spinal nerves (CSNs) with the use of a clinically relevant volume of injectate (2 mL). We hypothesized that the majority of injections would result in identification of contrast solution in the intervertebral foramen (IVF) on CT and corresponding methylene blue dye staining of the CSN on postmortem evaluation, and distribution of injectate into the epidural space would not occur. Unassigned: 7 horses donated to the University of Pennsylvania New Bolton Center for euthanas...
May A, Hanche-Olsen S, Goehring LS, Matiasek K, Jäderlund KH, Zablotski Y, Gröndahl G.Acquired equine polyneuropathy in Nordic horses (AEP) is the most prevalent equine polyneuropathy in Norway, Sweden, and Finland and is characterised by pelvic limb knuckling due to metatarsophalangeal extension dysfunction. Objective: To evaluate the function of descending motor pathways in AEP using transcranial magnetic stimulation (TMS). Methods: An analytical, observational cohort design. Methods: Clinical findings and TMS results of 20 horses from an AEP outbreak in Sweden were evaluated at 5-month intervals. Latency time (LT) in milliseconds (ms) between coil discharge and onset of musc...
Hellige M, Geburek F.A number of indications exist that necessitate radiologic examination of the equine cervical spine. Different neurologic and pain-associated clinical signs within the scope of lameness or poor performance may be associated to pathologies of the cervical spine. Moreover, the number of requests for radiographic examinations of the cervical spine, for example as part of the pre-purchase examination, has increased significantly in recent years. However, the interpretation of radiographs represents a challenge, particularly in the case of clinically sound horses, as it often necessitates the resolu...
Yokomori T, Tozaki T, Segawa T, Itou T.Previous studies have examined the relationship between hair characteristics and temperament traits in various animals. A partial genetic association has been suggested in humans because whorl formation and neurological development occur simultaneously during the fetal period. In the horse industry, anecdotal evidence suggests a link between the forehead whorl position and temperament. In our previous study, the heritability of forehead whorl positioning was h=0.653, indicating significant genetic contributions in thoroughbreds. Therefore, in this study, we designed a genome-wide association s...
Holz N, Suárez J, Hetzel U, Rampazzo A, Stoppini R.A 15-year-old Swiss Warmblood gelding was presented to the ophthalmology service of Zurich University due to severe visual impairment. Ophthalmic and neurologic examinations were performed, raising suspicion of post-retinal blindness. Standing contrast computed tomography (CT) of the head revealed a partially calcified, soft tissue attenuating mass in the sphenopalatine sinus with concurrent compression of the optic nerves and chiasm. Differential diagnosis included neoplasia and granulomatous disease. The horse was euthanized, and the head was subsequently examined by magnetic resonance imagi...
Oyaneder L, Lagos N, Dörner C.The present study was conducted to evaluate the safety and the long-lasting anesthetic properties of Neosaxitoxin (NeoSTX) when injected into the intercoccygeal space in standing horses. A group of eighteen (n = 18) healthy client-owned mature crossbreed horses were enrolled in this study. Caudal epidural injection was ascertained by two methods, the "hanging drop" technique and radiographs. Horses were allocated into three groups (n = 6) each group receiving different dosages of NeoSTX. To assess the onset of action and duration of anesthesia, six horses received 20 μg in 2 mL, six 20...
Mota-Rojas D, Whittaker AL, Coria-Avila GA, Martínez-Burnes J, Mora-Medina P, Domínguez-Oliva A, Hernández-Avalos I, Olmos-Hernández A....The growing interest in managing and recognizing pain in animals has led to the search for more sensitive methods to evaluate it, especially because some species conceal any visible changes associated with pain or are not easily assessed. Research has shown that an animal's facial expression changes when exposed to painful stimuli. Thus, developing several pain scales (grimace scales) in species such as horses, cattle, pigs, sheep, donkeys, rabbits, rats, mice, and cats has helped to improve the study of pain in veterinary medicine. The possibility of using facial expression as an indicator of...
de Oliveira Ferreira LV, Maia L, de Andrade DGA, da Costa Kamura B, de Carvalho M, Amorim RM.Cell-based therapy has emerged as a promising strategy for treating peripheral nervous system (PNS) injuries across different species. However, there is a scarcity in the literature regarding the transplantation of mesenchymal stem cells (MSCs) for treating PNS injuries in horses. This report aims to describe the therapeutic potential of equine MSC transplantation in two horses with chronic traumatic facial nerve paralysis. Both horses presented with lip ptosis and right deviation of the nostril and upper lip, being clinically diagnosed with left facial nerve paralysis. Due to the refractorine...
Primo ALM, Assis DM, Santos VGS, de Melo LRB, da Nóbrega LD, Medeiros Dantas AF, Maciel TA.Cerebellar abiotrophy is a neurodegenerative disease that affects the Purkinje cells of the cerebellum, resulting in premature neuronal death. In horses, its occurrence has been reported mainly in the Arabian breed as a congenital mutation inherited in an autosomal recessive manner. The objective of this study was to describe the case of cerebellar abiotrophy in a Quarter Horse foal. An 8-day-old foal was treated after presenting signs of ataxia, hypermetria, difficulty maintaining a standing position, and decreased menace response. The foal was hospitalized for 26 days, received treatment wit...
Bercovitz GR, Sullivan SN, Reed RA, Ryan CA, Diehl KA.To evaluate the effect of intravenous mannitol and hypertonic saline (HS) on intraocular pressure (IOP) and biometry parameters of horses with elevated intracranial pressure (ICP). Methods: Seven horses with normal ophthalmic exams were anesthetized and placed in lateral recumbency. A subarachnoid transducer was placed, and the head was lowered until ICP measured 40 mmHg +/- 2 mmHg. Five intravenous boluses of mannitol 20% (0.4 g/kg) or HS 7.2% (1 mL/kg) were administered, each 15 min apart. A 2-day washout period ensued, and the procedure was repeated with the other hyperosmotic age...
Aleman M.Muscle disease has various clinical manifestations that range from exertional and non-exertional rhabdomyolysis, fasciculations, weakness, rigidity, stiffness, gait abnormalities, poor performance, and alterations in muscle mass and tone. Neurogenic disorders and non-neurogenic disorders such as primary muscle disease can cause muscle atrophy and changes in muscle tone. Myotonic disorders can have a genetic (eg, inherited channelopathies) or acquired (eg, electrolyte derangements) origin. Normal muscle enzyme activities do not rule out a myopathic disorder as the underlying cause of muscle atr...
Sharma S, Reardon LM, Guda R, Carr MM, Man LX, Alicea D.Our primary objective was to identify and describe demographic trends in head and neck injuries incurred while participating in horseback riding. Methods: Cross-sectional analysis. Methods: National Database. Methods: Head and neck injuries related to horseback riding over a ten-year period (2014-2023) were analyzed using data from the National Electronic Injury Surveillance System (NEISS). A total of 3,177 cases were identified. Inclusion criteria encompassed injuries to the head, neck, face, mouth, or ear. Variables included age, gender, injury type, anatomical location, and patient disposit...
Domańska-Kruppa N, Stefanik E, Wierzbicka M, Kleinpeter A.Cervical spine injuries that impact young horses and foals can result in mild to severe neurological signs or even result in sudden death. There are only a few reports on conservative treatment options for this condition in the scientific literature. If the condition is left untreated, it can lead to the development of degenerative joint disease, resulting in chronic neurological symptoms and discomfort. We present the case of a two-day-old Arabian foal that showed signs of ataxia following a neck injury, being the result of cervical spine subluxation. Radiological examination revealed a dislo...
Haussler KK, le Jeune SS, MacKechnie-Guire R, Latif SN, Clayton HM.The defining characteristic of laterality is the dominance of one side of the brain controlling specific functions of paired organs or on one side of the body. Structural and functional asymmetries are ubiquitous in horses and range from anatomical features (e.g., the length of long bones) to the gathering of sensory information (e.g., which eye is used to observe unfamiliar scenes) and motor functions (e.g., left-right differences in locomotion). There is a common tendency to assign observed structural or functional asymmetries to lateralization, which often involves more than a simple left-r...
Parashar B, Malviya R, Sridhar SB, Wadhwa T, Talath S, Shareef J.Eastern equine encephalitis virus (EEEV) is a lethal transmitted by mosquitoes that primarily cycles between birds. Although rare, infections in humans and horses are associated with high mortality rates and severe neurological effects. Climate change appears to be increasing the spread of this virus. This study aims to provide a comprehensive analysis of EEEV, including its transmission dynamics, pathogenesis, induced host immune response, and long-term impacts on survivors. It also highlights the virus's unique immune evasion strategies that complicate disease management and contribute to ...
Mohamed E, Zarak I, Vereecke N, Theuns S, Laval K, Nauwynck H.Varicellovirus equidalpha 1, formerly known as Equid alphaherpesvirus 1 (EHV-1), is highly prevalent and can lead to various problems, such as respiratory problems, abortion, neonatal foal death, and neurological disorders. The latter is known as equine herpes myeloencephalopathy (EHM). Cases of EHM have significantly increased since the beginning of the twenty-first century. The genomic sequences of five isolates associated with the fatal neurological outbreak in Valencia, Spain, in 2021 were analyzed and documented. The genome and replication kinetics of the Belgian EHM isolate 21P40, associ...
McGivney CL, McGivney BA, Farries G, Gough KF, Han H, Holtby AR, MacHugh DE, Katz LM, Hill EW.Equine recurrent laryngeal neuropathy (RLN) is an economically important upper respiratory tract (URT) disease with a genetic contribution to risk, but genetic variants independent of height have not been identified for Thoroughbreds. The method of clinical assessment for RLN is critical to accurately phenotype groups for genetic studies. Objective: To identify genetic risk loci for RLN in Thoroughbreds in a genome-wide association study (GWAS) following high-resolution phenotyping. Methods: Case-control. Methods: Thoroughbred horses were characterised as RLN cases and controls using resting a...
King MR, Colla S.Rehabilitation following muscle injury is critical in restoring the equine athlete to full function. Rehabilitation protocols should be tailored to each patient's global functional assessment, taking into account sports-specific demands, goals for return-to-performance, and overall prognosis. Rehabilitation protocols are often designed to modulate pain, enhance repair, improve proprioception, increase flexibility, restore muscle strength, joint range-of-motion, and neuromotor control. This article will review mechanisms of muscle injury, various physical modalities commonly employed in the reh...
Jungbäck N, Vollmuth Y, Mögele T, Grochowski P, Schlegel J, Schaller T, Märkl B, Herden C, Matiasek K, Tappe D, Liesche-Starnecker F.Borna disease, which is a severe encephalitis that primarily affects horses and sheep, has been recognised for over two centuries. Borna disease virus 1 (BoDV-1) has been identified as a cause of a predominantly fatal encephalitis in humans. Little scientific data exist regarding the virus' transmission, entry portal, and excretion routes. Lesional patterns, immunological responses, and pathogenetic mechanisms remain largely unexplored in both reservoir and dead-end hosts. This systematic review compiles current knowledge on these aspects and provides guidance for future research. PubMed, Scie...
Schmidt MJ, Knemeyer C, Heinsen H.In this study, the morphology of the horse brain (Equus caballus) is decribed in detail using high field MRI. The study includes sagittal, dorsal, and transverse T2-weighted images at 0.25 mm resolution at 3 Tesla and 3D models of the brain presenting the external morphology of the brain. Representative gallocyanin stained histological slides of the same brain are presented. The images represent a useful tool for MR image interpretation in horses and may serve as a starting point for further research aiming at in vivo analysis in this species.
Rohrbach H, Korpivaara T, Schatzmann U, Spadavecchia C.To evaluate and compare the antinociceptive effects of the three alpha-2 agonists, detomidine, romifidine and xylazine at doses considered equipotent for sedation, using the nociceptive withdrawal reflex (NWR) and temporal summation model in standing horses. Methods: Prospective, blinded, randomized cross-over study. Methods: Ten healthy adult horses weighing 527-645 kg and aged 11-21 years old. Methods: Electrical stimulation was applied to the digital nerves to evoke NWR and temporal summation in the left thoracic limb and pelvic limb of each horse. Electromyographic reflex activity was reco...
Magee C, Foradori CD, Bruemmer JE, Arreguin-Arevalo JA, McCue PM, Handa RJ, Squires EL, Clay CM.The purpose of the present study was to evaluate the effects of kisspeptin (KiSS) on LH and FSH secretion in the seasonally estrous mare and to examine the distribution and connectivity of GnRH and KiSS neurons in the equine preoptic area (POA) and hypothalamus. The diestrous mare has a threshold serum gonadotropin response to iv rodent KiSS decapeptide (rKP-10) administration between 1.0 and 500 microg. Administration of 500 microg and 1.0 mg rKP-10 elicited peak, mean, and area under the curve LH and FSH responses indistinguishable to that of 25 microg GnRH iv, although a single iv injection...
Lacombe VA, Sogaro-Robinson C, Reed SM.The use of computer tomography (CT) and contrast-enhanced CT (CCT) to image the head is common. However, the validity of CT as a neurodiagnostic indicator of intracranial diseases in horses is unknown. Objective: To define the validity of CT and CCT in horses with suspected intracranial disorders. Methods: The validity of CT imaging was estimated by comparing clinical, clinicopathological and histopathological findings to CT findings in 15 horses presented for intracranial disorders, for which pre- and post contrast CT images and post mortem examination of the brain and skull were reviewed. Po...
Rochais C, Sébilleau M, Menoret M, Oger M, Henry S, Hausberger M, Cousillas H.Lateralization of brain functions has been suggested to provide individuals with advantages, such as an increase of neural efficiency. The right hemisphere is likely to be specialized for processing attention for details and the left hemisphere for categorization of stimuli. Thus attentional processes actually may underlie lateralization. In the present study, we hypothesized that the attentional state of horses could be reflected in the lateralization of brain responses. We used i) a recently developed attention test to measure horses' visual attentional responses towards a standardized stimu...
Down SS, Henson FM.Arthropathy of the caudal cervical articular process joints (APJs) in the horse is documented as a cause of ataxia and paresis secondary to spinal cord compression. Enlargement of the caudal APJs is reported to increase with age, but there are no known associations of any other factors. No association of the degree of APJ enlargement with neurological signs seen has been documented. This study investigated the associations of cervical APJ enlargement at the C5-C6 and C6-C7 articulations with case subject details (breed, age, sex, usage) and clinical signs. Objective: To ascertain if there are ...
Finno CJ, Valberg SJ, Shivers J, D'Almeida E, Armién AG.Equine degenerative myeloencephalopathy (EDM) is characterized by a symmetric general proprioceptive ataxia in young horses, and is likely underdiagnosed for 2 reasons: first, clinical signs overlap those of cervical vertebral compressive myelopathy; second, histologic lesions--including axonal spheroids in specific tracts of the somatosensory and motor systems--may be subtle. The purpose of this study was (1) to utilize immunohistochemical (IHC) markers to trace axons in the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts in healthy horses and (2) to dete...
Mayhew IG.Methods for atlanto-occipital and lumbosacral collection of cerebrospinal fluid from the horse are described in detail, and the techniques and complications discussed.
Simonsen U, Prieto D, Sánez de Tejada I, García-Sacristán A.1. The involvement of nitric oxide (NO) and the signal transduction mechanisms mediating neurogenic relaxations were investigated in deep intracavernous penile arteries with an internal lumen diameter of 600-900 microns, isolated from the corpus cavernosum of young horses. 2. The presence of nitric oxide synthase (NOS)-positive nerves was examined in cross and longitudinal sections of isolated penile arteries processed for NADPH-diaphorase (NADPH-d) histochemistry. NADPH-d-positive nerve fibres were observed in the adventitia-media junction of deep penile arteries and in relation to the trabec...
Dickey EJ, Long SN, Hunt RW.Hypoxic ischemic encephalopathy (HIE) is a condition that occurs in both human newborns and foals. The condition is the subject of extensive current research in human infants, but there have been no direct studies of HIE in foals, and hence, knowledge of the condition has been extrapolated from studies in humans and other animal models. The purpose of this review article is to highlight the most up-to-date and relevant research in the human field, and discuss how this potentially might have an impact in the management of foals with HIE.
Wright JD, Kelly WR, Waddell AH, Hamilton J.Verminous encephalomyelitis due to Angiostrongylus cantonensis larvae was diagnosed in 2 foals at necropsy. The principal clinical feature was tetraparesis, although history and neurological examination revealed progressive and multifocal neurological disease. At presentation, a tentative diagnosis of parasitic larval migration involving the central nervous system (CNS), presumably due to Strongylus vulgaris, was proposed. Dissection of the spinal cord in one case resulted in recovery of intact larvae of both sexes of A. cantonensis. In both foals, histopathology of the brain and spinal cord r...
Deeg CA, Amann B, Lutz K, Hirmer S, Lutterberg K, Kremmer E, Hauck SM.Müller glial cells are important regulators of physiological function of retina. In a model disease of retinal inflammation and spontaneous recurrent uveitis in horses (ERU), we could show that retinal Müller glial cells significantly change potassium and water channel protein expression during autoimmune pathogenesis. The most significantly changed channel protein in neuroinflammatory ERU was aquaporin 11 (AQP11). Aquaporins (AQP, 13 members) are important regulators of water and small solute transport through membranes. AQP11 is an unorthodox member of this family and was assigned to a thi...
Whishaw IQ, Sacrey LA, Gorny B.An animal that has stepped over an obstacle with its forelimbs uses a memory of the obstacle to guide the hind limbs so that they also clear the obstacle, even in situations in which long pauses are introduced between forelimb and hind limb stepping. To further clarify the features of hind limb obstacle clearance memory, the present study examined hind limb obstacle clearance in the horse. A rider guided horses over obstacles and paused the horse over obstacles in tests that examined the relationship between forelimb and hind limb stepping, with the following results. First, the horses display...
Burns EN, Finno CJ.Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy is an inherited neurodegenerative disorder affecting many horse breeds. Clinical signs include a symmetric ataxia and an abnormal stance at rest, similar to cervical vertebral compressive myelopathy, equine protozoal myeloencephalitis, and equine herpesvirus 1 myeloencephalopathy. This review will provide an update on the disease prevalence, management, impact, and ongoing research.
Hermosilla C, Coumbe KM, Habershon-Butcher J, Schöniger S.A fatal case of eosinophilic and granulomatous meningoencephalitis caused by the free-living panagrolaimid nematode Halicephalobus gingivalis is reported in a 10-year-old Welsh gelding in the United Kingdom. Clinical examination first revealed behavioural abnormalities which rapidly progressed to severe ataxia, reduced mentation status and cranial nerve signs. Despite symptomatic treatment no amelioration of neurological signs was achieved and the horse was subjected to euthanasia. A complete post mortem examination revealed eosinophilic and granulomatous meningoencephalitis mainly affecting t...
Johnson PJ, Janvier V, Luh WM, FitzMaurice M, Southard T, Barry EF.There is growing interest in the horse for behavioral, neuroanatomic and neuroscientific research due to its large and complex brain, cognitive abilities and long lifespan making it neurologically interesting and a potential large animal model for several neuropsychological diseases. Magnetic resonance imaging (MRI) is a powerful neuroscientific research tool that can be performed , with adapted equine facilities, or in the research setting. The brain atlas is a fundamental resource for neuroimaging research, and have been created for a multitude animal models, however, none currently exist f...
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...
Stankov B, Cozzi B, Lucini V, Fumagalli P, Scaglione F, Fraschini F.Melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125I]iodomelatonin as labelled ligand. Although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. Apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for direct interspecies comparison under the same methodological conditions. 2-[125I]iodomelatonin labe...
Cozzi B, De Giorgio A, Peruffo A, Montelli S, Panin M, Bombardi C, Grandis A, Pirone A, Zambenedetti P, Corain L, Granato A.The architecture of the neocortex classically consists of six layers, based on cytological criteria and on the layout of intra/interlaminar connections. Yet, the comparison of cortical cytoarchitectonic features across different species proves overwhelmingly difficult, due to the lack of a reliable model to analyze the connection patterns of neuronal ensembles forming the different layers. We first defined a set of suitable morphometric cell features, obtained in digitized Nissl-stained sections of the motor cortex of the horse, chimpanzee, and crab-eating macaque. We then modeled them using a...
Gibson SJ, Polak JM, Anand P, Blank MA, Morrison JF, Kelly JS, Bloom SR.The distribution of VIP-immunoreactivity was studied in the spinal cord and dorsal root ganglia of 6 mammalian species. Immunoreactive fibres and cell bodies were most apparent in the dorsal horn, dorsolateral funiculus, intermediolateral cell columns and the area around the central canal. The distribution of VIP immunoreactivity was similar in all species studied, mouse, rat, guinea pig, cat, horse and the marmoset monkey. There were fewer VIP fibres in the dorsal horn of cervical and thoracic segments than in lumbosacral segments. Using radioimmunoassay this gradient increase was quantitativ...
Graïc JM, Peruffo A, Corain L, Finos L, Grisan E, Cozzi B.Cetartiodactyls include terrestrial and marine species, all generally endowed with a comparatively lateral position of their eyes and a relatively limited binocular field of vision. To this day, our understanding of the visual system in mammals beyond the few studied animal models remains limited. In the present study, we examined the primary visual cortex of Cetartiodactyls that live on land (sheep, Père David deer, giraffe); in the sea (bottlenose dolphin, Risso's dolphin, long-finned pilot whale, Cuvier's beaked whale, sperm whale and fin whale); or in an amphibious environment (hippopotam...
Kuczyński M, Słonka K.Stability of quiet upright stance was investigated in 25 children with cerebral palsy at the beginning and the end of a 3-month period of therapy involving 20 min microprocessor-controlled saddle riding, performed twice a week. The traditional parameters of postural sway based on the centre-of-pressure analysis (range, standard deviation, mean speed and mean radius) dropped significantly over time confirming advantageous influence of this treatment. As a complementary tool, an autoregressive modelling technique was used allowing us to establish after each single ride considerable decreases in ...
Blanco A, Moyano R, Vivo J, Flores-Acuña R, Molina A, Blanco C, Monterde JG.Purkinje cerebellar cells were studied in three Arabian horses aged between 6 and 8 months with clinical disorders in their movements, tremors and ataxia; the occurrence of apoptosis in this cell population was investigated by the (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labelling (TUNEL) method. Both optical and electron microscopical images showed a scant number of Purkinje cells, most of them with morphological features of apoptosis such as condensation of the nucleus and cytoplasm as well as segregation and fragmentation of the nucleus into apoptotic bodies. The TUNEL te...
Roberts VL, McKane SA, Williams A, Knottenbelt DC.REASONS FOR DESIGNING AND REPORTING TECHNIQUE: Idiopathic headshaking has remarkable similarities to human neuropathic facial pain syndromes associated with post herpetic and trigeminal neuralgia. These derive from abnormal sensory function within the peripheral or central pathways of the trigeminal nerve (TgN). Limiting input from the TgN can be helpful in controlling the perception of pain. Rhizotomy of the infraorbital branch of the TgN as it emerges from the infraorbital canal has been reported but has a poor efficacy. A novel technique involves compression of the nerve at a more caudal lo...
Eydal M, Bambir SH, Sigurdarson S, Gunnarsson E, Svansson V, Fridriksson S, Benediktsson ET, Sigurdardóttir ÓG.Opportunistic infections with the free living nematode Halicephalobus gingivalis are infrequently reported in horses but the cases are widespread geographically. The nematodes are believed to penetrate wounds and subsequently reproduce within the host tissues. This paper reports two cases of a fatal disease in stallions of the Icelandic breed in Iceland. Case 1: a stallion, which sustained injuries to the mouth after an accident, developed severe neurological signs and had to be euthanatized. Histological examination revealed mild inflammation and malacia in the cerebellum associated with the ...
Boucher S, Arribarat G, Cartiaux B, Lallemand EA, Péran P, Deviers A, Mogicato G.Tractography, a noninvasive technique tracing brain pathways from diffusion tensor magnetic resonance imaging (DTI) data, is increasingly being used for brain investigation of domestic mammals. In the equine species, such a technique could be useful to improve our knowledge about structural connectivity or to assess structural changes of white matter tracts potentially associated with neurodegenerative diseases. The goals of the present study were to establish the feasibility of DTI tractography in the equine brain and to provide a morphologic description of the most representative tracts in t...
Guedes A.There has been great progress in the understanding of basic neurobiologic mechanisms of pain, but this body of knowledge has not yet translated into new and improved analgesics. Progress has been made regarding pain assessment in horses, but more work is needed until sensitive and accurate pain assessment tools are available for use in clinical practice. This review summarizes and updates the knowledge concerning the cornerstones of pain medicine (understand, assess, prevent, and treat). It highlights the importance of understanding pain mechanisms and expressions to enable a rational approach...
Mayhew IG, deLahunta A, Whitlock RH, Geary JC.Five horses of mixed breeding and 1 zebra with symmetric tetraparesis and ataxia were studied. There were 2 females and 4 males. Signs of illness were first noticed from birth to 12 months of age. Clinical and pathologic studies were performed when the animals were 4 to 24 months old. Two of the horses were related. All of the subjects had diffuse degenerative myeloencephalopathy. The degeneration was most pronounced in thoracic segments of the spinal cord. Ventral and dorsolateral funiculi were most severely affected. Axonal swelling and abnormal neuronal cell bodies were seen in the gray mat...
Nollet H, Deprez P, van Ham L, Dewulf J, Decleir A, Vanderstraeten G.Cervical spinal cord dysfunction is a common problem in equine medicine and the currently available tests give no objective information about the functionality of the nervous tracts. Therefore, transcranial magnetic stimulation (TMS) was performed in 84 healthy horses of different height in order to have an objective measure for the integrity of the descending motor tracts in normal horses. Objective: To obtain reference values for onset latency and peak-to-peak amplitude of magnetic motor evoked potentials (MMEPs) and to evaluate the possible effect of height, age and gender on the neurophysi...
