The equine brain is a complex organ responsible for processing sensory information, regulating behavior, and controlling motor functions in horses. It plays a part in cognitive processes such as learning, memory, and decision-making. The equine brain is divided into several regions, each with distinct functions, including the cerebrum, cerebellum, and brainstem. Research in this area often focuses on understanding the neurological pathways and mechanisms that underlie equine behavior and performance. This topic encompasses studies that explore brain anatomy, neurophysiology, and the effects of various factors such as stress, training, and disease on brain function in horses. This page compiles peer-reviewed research studies and scholarly articles that investigate the structure, function, and health of the equine brain.
MacKay RJ.Brain injury after impact to the head is due to both immediate mechanical effects and delayed responses of neural tissues. In horses, traumatic brain injury occurs in three main settings: (1) poll impact in horses that flip over backwards; (2) frontal/parietal impact in horses that run into a fixed object, and (3) injury to the vestibular apparatus secondary to temporohyoid osteoarthropathy. Distinct forebrain, vestibular, midbrain, hindbrain, or multifocal syndromes may be encountered in horses with traumatic brain injury. The most important components of treatment are those consistent with p...
Smith JJ, Provost PJ, Paradis MR.To determine clinical features of horses with bacterial meningitis or brain abscesses secondary to infectious disease processes involving the head. Methods: Retrospective study. Methods: 7 adult horses. Methods: Medical records of Tufts University, the University of Pennsylvania, and the Livestock Disease Diagnostic Center (Lexington, Ky) were reviewed to identify adult (> 12 months old) horses in which a postmortem diagnosis of bacterial meningitis or brain abscess had been made. Horses were included in the study if an intracranial infection was confirmed, the horse had a primary infectious d...
Verdegaal EJ, Kroeze EJ, Dik KJ, van Oijen LA, Sloet van Oldruitenborgh-Oosterbaan MM.A 9-year-old Dutch Warmblood mare was presented with a history of abnormal behaviour and acute facial nerve paralysis on the left side. Clinical examination revealed a slight head tilt and a corneal ulcer of the left eye. The base of the left ear was warm and painful. Endoscopic examination of the left guttural pouch showed thickening of the proximal part of the stylohyoid bone. Computer tomography revealed a left-sided prominent bony enlargement of the middle and proximal part of the stylohyoid bone and the tympanic bulla, fusion of the temporrhoid joint, and osseous proliferation of the pars...
Hellyer PW, Bai L, Supon J, Quail C, Wagner AE, Mama KR, Magnusson KR.To test the hypothesis that the distribution, density, and subtype of opioid and alpha (alpha)-2 adrenergic receptors within the central nervous system (CNS) are significantly different between horse and dog. Methods: Prospective experimental study. Methods: Three dogs (3 years of age) and three horses (2-5 years of age). Animals were opioid- and alpha-2 agonist-free at the time of euthanasia. Methods: Brain tissue was obtained at 126 days post-surgery from dogs and 72 days post-surgery from horses. The brains were removed, sectioned coronally into 1-cm slabs, frozen in methylbutane, which was...
Peters M, Brandt K, Wohlsein P.An intracranial epidermoid cyst was diagnosed in a Haflinger gelding aged 12 years suffering from episodes of neurological disturbance, apathy and fever. The extracerebral cyst was located in the region of the tentorium cerebelli and measured 9 x 8 x 5 cm. It displaced the cerebral hemispheres anteriorly and compressed the cerebellum and brainstem underneath. Histologically, the cyst was lined by keratinizing, stratified squamous epithelium and contained keratin scales, debris, focal haemorrhages, and degenerating inflammatory cells. The epithelium was supported by a vascularized fibrous capsu...
Ionatamishvili NI, Tsverava DM, Loriia MSh, Avaliani LA.One hundred children with cerebral palsy, aged 3-14 years, were divided into two equal groups, the first one including 50 children assigned to ride therapy and the second one--to Bobath therapeutic gymnastics. All the patients underwent a functional examination, which was rated using score system worked out by the authors, thus enabling a quantitative evaluation of treatment efficacy. In all the cases, physical rehabilitation resulted in a positive but not the same effect, with ride therapy being significantly (p < 0.001) more beneficial treatment compared to therapeutic gymnastics. Ride thera...
Spoormakers TJ, Ensink JM, Goehring LS, Koeman JP, Ter Braake F, van der Vlugt-Meijer RH, van den Belt AJ.The occurrence of unexpectedly high numbers of horses with neurological signs during two outbreaks of strangles required prompt in-depth researching of these cases, including the exploration of magnetic resonance imaging (MRI) as a possible diagnostic technique. Objective: To describe the case series and assess the usefulness of MRI as an imaging modality for cases suspected of space-occupying lesions in the cerebral cavity. Methods: Four cases suspected of suffering from cerebral damage due to Streptococcus equi subsp. equi infection were examined clinically, pathologically, bacteriologically...
Gonzalez-Salazar D, Estrada-Franco JG, Carrara AS, Aronson JF, Weaver SC.To assess the role of horses as amplification hosts during the 1993 and 1996 Mexican Venezuelan equine encephalitis (VEE) epizootics, we subcutaneously infected 10 horses by using four different equine isolates. Most horses showed little or no disease and low or nonexistent viremia. Neurologic disease developed in only 1 horse, and brain histopathologic examination showed meningeal lymphocytic infiltration, perivascular cuffing, and focal encephalitis. Three animals showed mild meningoencephalitis without clinical disease. Viral RNA was detected in the brain of several animals 12-14 days after...
Chou CC, Vickroy TW.To determine the presence of adenosine receptor subtypes A1 and A2a in equine forebrain tissues and to characterize the interactions of caffeine and its metabolites with adenosine receptors in the CNS of horses. Methods: Brain tissue specimens obtained during necropsy from 5 adult male research horses. Methods: Membrane-enriched homogenates from cerebral cortex and striatum were evaluated by radioligand binding assays with the A1-selective ligand [3H]DPCPX and the A2a-selective ligand [3H]ZM241385. Functional responses to adenosine receptor agonists and antagonists were determined by a nucleot...
Brosnan RJ, Steffey EP, LeCouteur RA, Imai A, Farver TB, Kortz GD.To measure the effects of isoflurane end-tidal concentration and mode of ventilation (spontaneous vs controlled) on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in horses. Methods: adult horses of various breeds. Methods: Anesthesia was induced and maintained with isoflurane in O2 in 6 healthy, unmedicated, adult horses. Using a subarachnoid strain gauge transducer, ICP was measured. Blood gas tensions and carotid artery pressures also were measured. Four isoflurane doses were studied, corresponding to the following multiples of the minimum alveolar concentration (MAC): 1....
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. ...
Colavizza M, Hervagault JF.After extraction and purification, the kinetic behavior of the Ca(2+)/calmodulin-dependent protein kinase II (CaM kinase II) from horse brain was investigated as a function of ATP and a synthetic substrate, syntide-2. Both phospho- and dephospho- forms of the enzyme obey a bi-bi random mechanism. The K(M)s for ATP (K(M,ATP)) and syntide-2 (K(M,syntide-2)) were determined as equal to 80 and 30 microM, respectively. However, the maximum reaction yield is decreased by 50% when the enzyme is (auto)phosphorylated. In addition, this phosphorylated form of the enzyme leads to the formation of a total...
Lian WC, Liau MY, Mao CL.Nervous disorders were found in two horses and verified as aseptic encephalitis by necropsy in the summer of 2000. To investigate agents that affected the horses, diagnostic procedures involving virus isolation, neutralization test and reverse transcription-polymerase chain reaction (RT-PCR) were performed. We intracranially inoculated litters of suckling mice with tissues suspected of containing aseptic encephalitis, including cerebrum, cerebellum, brain stem, thalamus, and cerebrospinal fluids; the mice were then observed for 14 days. Neutralizing antibodies against Japanese encephalitis (JE...
Brosnan RJ, LeCouteur RA, Steffey EP, Imai A, Kortz GD.To develop a method for surgical placement of a commercial microsensor intracranial pressure (ICP) transducer and to characterize normal ICP and cerebral perfusion pressures (CPP) in conscious adult horses. Methods: 6 healthy castrated male adult horses (1 Holsteiner, 1 Quarter Horse, and 4 Thoroughbreds). Methods: Anesthesia was induced and maintained by use of isoflurane as the sole agent. Catheters were inserted percutaneously into the jugular vein and carotid artery. A microsensor ICP transducer was inserted in the subarachnoid space by means of right parietal craniotomy. The burr hole was...
Brosnan RJ, Steffey EP, LeCouteur RA, Imai A, Farver TB, Kortz GD.Inhalant anesthetics may interfere with normal cerebrovascular autoregulation. It was, therefore, hypothesized that intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in isoflurane-anesthetized horses would be especially sensitive to body and head position because of the potential for large hydrostatic gradients between the brain and heart in this species. Anesthesia was induced and maintained in six clinically healthy, unmedicated geldings with 1.57% isoflurane in O(2); mechanical ventilation was used to maintain normocapnia. ICP was measured by using a subarachnoid strain-gaug...
Rozovsky I, Hoving S, Anderson CP, O'Callaghan J, Finch CE.Premarin, which contains several equine estrogens, as well as estradiol (E2) as a minor component, is widely used for replacement therapy of estrogen deficits, but little is known of its direct actions on brain cells. In mixed glial cultures, apolipoprotein E (apoE) and glial fibrillary acidic protein (GFAP) are induced by estrogens. GFAP induction showed an inverted-U shape E2 dose response, with a maximum induction at 1 pM, whereas apoE mRNA induction was greatest at 100 pM. GFAP and ApoE mRNAs were induced by equine estrogens in the following order: E2=equilin>estrone>17 alpha-dihydro...
Dauphin G, Legay V, Pitel PH, Zientara S.For over two centuries, Borna disease (BD) has been described as a sporadically occurring infectious meningoencephalomyelitis affecting horses and sheep in Central Europe. Over the last decade, the BD epidemiology has been discussed. Firstly, its geographical distribution seems larger than what was previously thought. Secondly, the disease can affect a large number of warm-blooded animal species, including humans. The aetiological agent is the Boma disease virus (BDV), an enveloped, nonsegmented negative-stranded RNA virus classified in the new virus family Bornaviridae (Mononegavirales order)...
Szalay F.The purpose of the present study was to demonstrate the structural maturation of the horse brain in the critical period of development emergence of coordinated locomotion. Equine brains from 14 days before expected birth to adulthood were fixed in formaldehyde and embedded in paraffin. After taking the outer parameters of the brains, full series of large-area coronal sections were prepared on a special microtome and stained with Nissl's cresyl violet and Haidenhain's iron-haematoxylin. Microscopic images of sections were digitized and were subjected to computer-aided image analysis. The gross ...
Ito M, Itou T, Sakai T, Santos MF, Arai YT, Takasaki T, Kurane I, Ito FH.Brain samples from different animal species including humans: five vampire bats, 14 cattle, 12 dogs, 11 cats, two horses, one pig, one sheep and three humans collected from various geographical regions of Brazil were found to be positive for rabies by means of the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). The brain samples were retested for rabies by means of the reverse transcription and polymerase chain reaction (RT-PCR) with 2 primer sets (P1/P2 and RHNI/RHNS3), which amplified full or partial regions on the nucleoprotein (N) gene of the rabies virus, respectivel...
Rosypal AC, Lindsay DS, Duncan R, Ahmed SA, Zajac AM, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. Little is known about the role of immunobiological mediators to this parasite. Nitric oxide (NO) is important in resistance to many intracellular parasites. We, therefore, investigated the role of inducible and endothelial NO in resistance to clinical disease caused by S. neurona in mice. Groups of interferon-gamma gene knockout (IFN-gamma-KO) mice, inducible nitric oxide synthase gene knockout (iNOS-KO) mice, endo...
Bedenice D, Hoffman AM, Parrott B, McDonnel J.Two previously healthy 14-year-old horses developed right-sided unilateral vestibular signs after they had possibly been struck by lightning. Repeated radiographic and endoscopic evaluations did not reveal any significant changes. A brainstem auditory evoked response test indicated a subtle left to right interaural latency difference of waves I, III and V in the more severely affected pony, but its central conduction time remained normal.
Furrer E, Bilzer T, Stitz L, Planz O.Experimental Borna disease virus (BDV) infection of rats and natural infection of horses and sheep leads to severe central nervous system disease based on immunopathological pathways. The virus replicates slowly, and the cellular immune response results in immunopathology. CD8(+) T cells exert effector cell functions, and their activity results in the destruction of virus-infected cells. Previously, Oldach and colleagues (D. Oldach, M. C. Zink, J. M. Pyper, S. Herzog, R. Rott, O. Narayan, and J. E. Clements, Virology 206:426-434, 1995) have reported protection against Borna disease after inocu...
Arencibia A, Vazquez JM, Ramirez JA, Ramirez G, Vilar JM, Rivero MA, Alayon S, Gil F.The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, ...
Hahn CN, Mayhew IG, de Lahunta A.Equine grass sickness (EGS) is an acquired disease of unknown aetiology affecting horses kept at grass. The disease is characterised by postganglionic sympathetic and parasympathetic neuronal pathology and is categorised as a dysautonomia. This study undertook a systematic examination of brain stem cranial nerve nuclei in 59 cases of EGS. Pathology consisting of neuronal chromatolysis was most consistently noted in the lower motor neurons of the general visceral efferent nucleus of CN III and X and the general somatic efferent nuclei of CN III, V, VII and XII. The prevalence of chromatolysis d...
Gray LC, Magdesian KG, Sturges BK, Madigan JE.A two-month-old Appaloosa colt developed neurological signs shortly after birth involving deficits affecting cranial nerves IV, VII, VIII, IX, X and XII, and possibly nerve VI. The most likely differential diagnoses were congenital anomalies, meningoencephalitides, trauma or nutritional causes. The foal was investigated by the analysis of cerebrospinal fluid (CSF), electromyelography (EMG), brain auditory evoked responses, magnetic resonance imaging (MRI), peripheral nerve biopsy, and Western blot analysis for the presence of intrathecal antibodies to Sarcocystis neurona, the causative agent o...
Fleming PR, Crompton JL, Simpson DA.The aim of this study was to highlight the neuro-ophthalmological dangers associated with horse riding, and working around horses, and the importance of wearing adequate headgear to protect the rider from neuro-ophthalmic injuries. It raises the questions of whether the current laws regarding helmet use are satisfactory, and whether helmets currently used are of an adequate standard. Methods: The records over a 20-year period of one neuro-ophthalmologist in Adelaide were reviewed producing 22 patients with neuro-ophthalmological sequelae of head injuries as a result of horse-related accidents....
Lima EF, Riet-Correa F, Gardner DR, Barros SS, Medeiros RM, Soares MP, Riet-Correa G.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...
Morton DB.Animals with relatively highly developed brains are likely to experience some degree of self-awareness and the ability to think. As well as being interesting in its own right, self-consciousness matters from an ethical point of view, since it can give rise to forms of suffering above and beyond the immediate physical sensations of pain or distress. This article surveys the evidence for animal self-consciousness and its implications for animal welfare.
Williamson LH, Farrell RL.A case of intracranial schwannoma is described in a young horse. Clinical signs developed slowly and were suggestive of a lesion involving the left cerebrum. The filly exhibited a change in mentation, and circled to the left. Visual impairment and decreased facial sensation were noted on the right side. A solitary schwannoma which compressed the left cerebrum was found at necropsy.
Melrose PA, Pickel C, Cheramie HS, Henk WG, Littlefield-Chabaud MA, French DD.Recent reports have indicated that analysis of changes in the staining characteristics of gonadotropin-releasing hormone (GnRH) neurons and characterization of morphological plasticity of the related structural framework may help to elucidate the physiological mechanisms involved in neuroendocrine control of mammalian reproduction. Whether comparative studies will facilitate this process or simply elucidate species-specific mechanisms is not yet clear. The present study was performed in order to begin analysis of GnRH neurons in a seasonally breeding species that exhibits an unusually long ovu...
Pirie RS, Mayhew IG, Clarke CJ, Tremaine WH.Intraoperative brain ultrasonography is commonly used clinically
in human and canine neonates (Johnson and Rumack 1980;
Babock and Han 1981; Cappe and Lam 1985; Hudson et al. 1990,
1991) and a single report exists of its use to assist in defining
hydrocephalus in an equine neonate (Foreman et al. 1983). This
technique has also been reported to be clinically useful in human
adults (Rubenstein et al. 1984) and ultrasound-guided brain biopsy
has also been described in mature dogs (Thomas et al. 1993).
%ours of the central nervous system in the horse are
extremely rare, with the exception...
Madigan JE, Higgins RJ.Equine protozoal myeloencephalitis (EPM) is a disease that produces neurologic signs of brain or spinal cord dysfunction. The causative organism is believed to be a Sarcocystis species of protozoa. A definitive diagnosis can only be made on histopathology of affected spinal cord or brain. No preventive measures or documented treatment is available at this time for suspected cases of EPM.
Henshall C, Randle H, Francis N, Freire R.Horse training exposes horses to an array of cognitive and ethological challenges. Horses are routinely required to perform behaviours that are not aligned to aspects of their ethology, which may delay learning. While horses readily form habits during training, not all of these responses are considered desirable, resulting in the horse being subject to retraining. This is a form of cognitive flexibility and is critical to the extinction of habits and the learning of new responses. It is underpinned by complex neural processes which can be impaired by chronic or repeated stress. Domestic horses...
Sanders SG, Tucker RL, Bagley RS, Gavin PR.Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encep...
Fox J, Duncan R, Friday P, Klein B, Scarratt W.A 12-month-old American Miniature horse colt was presented to the Virginia Tech Veterinary Teaching Hospital with a 7-month history of progressive ataxia. Physical examination revealed a head intention tremor, base-wide stance, and ataxia. Necropsy findings were confined to the brain. There were bilateral areas of liquefactive necrosis and cavitation corresponding to the dorsal accessory olivary and lateral (accessory) cuneate nuclei. Cerebellar folia of the dorsal vermis were thin. Microscopically, the cerebellar cortex was characterized by patchy areas of Purkinje cell loss with associated v...
Meyer EE, Morris PG, Elcock LH, Weil J.Rabies was diagnosed in 2 adult Quarter Horses with hindlimb hyperesthesia and progressive weakness. Microscopic examination of the cord and brain of the first horse revealed nonsuppurative meningomyelitis and ganglioneuritis in the cord extending cranially to the 6th cervical segment. Fluorescent antibody test results of both horses were positive for rabies in hindlimb peripheral nerve specimens, but negative in sections of the upper lip. Salivary gland, cerebrum, cerebellum, hippocampus, musculocutaneous nerve, cornea, and optic nerve specimens were tested for rabies by fluorescent antibody ...
Scott TW, Olson JG, All BP, Gibbs EP.Sensitivity and specificity of an antigen-capture ELISA vs virus isolation in cell culture were evaluated for the detection of eastern equine encephalomyelitis (EEE) virus in the brain tissue of naturally infected equids. Brain specimens from 16 equids with neurologic disease were examined by ELISA and by inoculation onto baby hamster kidney cell cultures. Of 10 brain samples from which virus was isolated in the cell culture bioassay, all were correctly identified as containing EEE virus antigen by ELISA. None of the remaining 6 specimens, without detectable infectious EEE virus, contained det...
Estell K.Acute central nervous system (CNS) trauma in the field is best approached by a systematic and thorough physical and neurologic examination that allows the practitioner to localize the brain or spinal cord injury. The skull and vertebral canal are complex 3-dimensional structures, and orthogonal radiographic views are necessary for an accurate diagnosis. Therapeutics aimed at decreasing pain, inflammation, and edema or increased intracranial pressure in the case of traumatic brain injury should be administered. Survival and return to athleticism can be achieved even in moderate-to-severe trauma...
Rech R, Barros C.This article focuses on the gross examination of the brain and spinal cord and outlines the main lesions and neuroanatomic location related to neurologic diseases in horses.
Mifune H, Richter R, Forssmann WG.The distribution of immunoreactivity (IR) for cardiodilatin/atrial natriuretic peptide (CDD/ANP) and brain natriuretic peptide (BNP) was examined immunohistochemically and immuno-electron-microscopically in the equine atrium, using specific antibodies. In the immunohistochemical studies, IR-CDD/ANP and IR-pBNP-26 (porcine BNP-26 immunoreactivity) was detected in the cytoplasm of the auricular cardiocytes, but IR-hBNP-32 (human BNP-32 immunoreactivity) was not. The double immunogold labelling method for IR-hBNP-28 and IR-pBNP-26 revealed that gold particles of different sizes were located in th...
Clark EG, Townsend HG, McKenzie NT.Two cases of nonsuppurative myeloencephalitis are reported which clinically and pathologically resemble equine protozoal myeloencephalitis. Lesions in both horses were associated with Toxoplasma-like organisms visible in microscopic sections. Clinical signs and lesions in one case primarily involved the brain and in the other case principally involved the spinal cord and associated meninges. Positive identification of the organisms was not achieved; however, the etiological agent is unlikely to be a species of Toxoplasma. Recently published studies suggest a species of Sarcocystis is involved....
Ford EJ, Adam SE.In the horse, 5'-nucleotidase (5'-NT) activity is found mainly in homogenates of lung, kidney, small intestine, mammary gland, liver and pancreas. Lower activities are present in brain and muscle. Activity can be demonstrated histochemically in the glomeruli and tubules of the kidney, in the sinusoidal borders of the hepatocytes and the bile duct epithelium as well as in the blood vessels of all organs. There is no significant difference between the 5'-NT activity in serum and plasma of normal horses and of horses suffering from a range of orthopaedic conditions. Previous findings that gamma g...
Martin L, Kaswan R, Chapman W.Traumatic optic nerve atrophy is characterised clinically by a unilateral or bilateral sudden onset of blindness. Dilated, fixed pupils and a lack of a menace reflex are the only abnormalities noted soon after the trauma. Within three to four weeks the optic disc becomes paler and the retinal vasculature is markedly decreased. The pathological lesion is a rupture of the nerve axons from stretching forces produced by the posterior movement of the brain against the fixed canalicular portion of the optic nerves. Medical therapy has not been successful.
Pumarola M, Vidal E, Trens JM, Serafín A, Marquez M, Ferrer I.Neuronal intranuclear inclusion disease (NIID) is reported in a 16-year-old Pure Spanish breed female horse suffering from progressive ataxia and motor deficiencies. The neuropathological study revealed NIIs throughout the central nervous system, although mainly in the brain stem and spinal cord. This distribution did not correlate with neuron loss, which was marked in the hippocampus and moderate in the neocortex, particularly in the occipital cortex. As in humans, NIIs in the horse were hyaline autofluorescent inclusions composed of non-membrane-bound aggregates of filaments and fine granule...
Stefani M, Berti A, Camici G, Manao G, Degl'Innocenti D, Prakash G, Marzocchini R, Ramponi G.Two structurally different acylphosphatases found in horse brain were purified; they were not immunologically related. The molecular masses were almost identical and the kinetic parameters were rather similar. The data reported indicate that one of the purified brain acylphosphatases and an enzyme, previously isolated from horse muscle, are the same protein. The presence of this acylphosphatase form in the brain has not been reported before. The other acylphosphatase seemed to be the same as the enzyme which had been purified from calf brain and partially characterized by Diederich and Grisoli...
King JM, Roth L, Haschek WM.Focal myocardial necrosis secondary to neural lesions was diagnosed in 2 dogs and 1 horse. In each case, the neural lesions were traumatic in origin. Spinal cord injury was evident in 1 dog; brain damage was evident in the other dog and presumably in the horse. Retrospective analysis of necropsy material showed that many species were affected, without apparent age or sex predisposition. Central nervous system injury resulting from trauma, infection or space-occupying lesions was associated with acute myocardial necrosis in all cases. The myocardial necrosis was rarely fatal; however, it did ca...
Fu DJ, Ramachandran A, Miller C.A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. should be considered as a cau...
Barakat-Walter I, Deloulme JC, Sensenbrenner M, Labourdette G.We have previously shown that neuroblasts from cerebral hemispheres of 6-day-old chick embryos are able to proliferate when grown in the presence of fetal calf serum. We report here that in the presence of horse serum alone the proliferative rate of neuroblasts is strongly reduced. A high proliferative rate is restored upon the addition of bovine transferrin and to a lesser extent with added FeSO4 or hemin. These findings suggest that the transferrin of horse serum cannot be used by chick neuroblasts in vitro, while bovine transferrin exogenously added is active in promoting cell proliferation...
Ferrando Meseguer E, Roig Sánchez S, Pino Almero L, Romano Bataller A, Mínguez Rey MF.Talipes equinovarus or clubfoot is a congenital deformity of the foot with bone, muscle, and tendon involvement. It's one of the most frequent foot malformations in pediatric orthopedics. Although generally idiopathic, it may have a syndromic cause and be associated with musculoskeletal, neurological, or connective tissue conditions. The treatment of choice in idiopathic clubfoot is the Ponseti method based on manipulation and fixation with serial casts that seek progressive correction of the deformity. The Ponseti method effectiveness has been demonstrated in arthrogryposis and myelomeningoce...
Brosnan RJ, LeCouteur RA, Steffey EP, Imai A, Kortz GD.To develop a method for surgical placement of a commercial microsensor intracranial pressure (ICP) transducer and to characterize normal ICP and cerebral perfusion pressures (CPP) in conscious adult horses. Methods: 6 healthy castrated male adult horses (1 Holsteiner, 1 Quarter Horse, and 4 Thoroughbreds). Methods: Anesthesia was induced and maintained by use of isoflurane as the sole agent. Catheters were inserted percutaneously into the jugular vein and carotid artery. A microsensor ICP transducer was inserted in the subarachnoid space by means of right parietal craniotomy. The burr hole was...
Freeman DE, Staller GS, Maxson AD, Sweeney CR.A mare with hemorrhage caused by guttural pouch mycosis was treated by insertion of a balloon-tipped catheter into the left internal carotid artery. During recovery from general anesthesia, the mare had profuse epistaxis, and was anesthetized again to determine the site of hemorrhage. The affected guttural pouch was opened to confirm that hemorrhage was from the left internal carotid artery. The mare was euthanatized, and, at necropsy, the balloon catheter was found in an aberrant branch that arose from the internal carotid artery and joined the basilar artery. The mycotic plaque was on the le...
Dees WL, Sorensen AM, Kemp WM, McArthur NH.Immunohistochemical localization of the decapeptide gonadotropin releasing hormone (GnRH) in neural structures in the pony brain and infundibulum (INF) was conducted at the light-microscopic level. This procedure utilized an antiserum generated against GnRH conjugated to bovine serum albumin. In the rostral INF, GnRH was distributed mainly in the external layer, with greatest concentrations adjacent to the long capillary loops of the hypophyseal portal system. The intermediate portion of the INF contained the hormone throughout the external layer, especially in the dorsolateral regions just ve...
Brosnan RJ, Steffey EP, LeCouteur RA, Esteller-Vico A, Vaughan B, Liu IK.To test a hypothesis predicting that isoflurane would interfere with cerebrovascular autoregulation in horses and to evaluate whether increased mean arterial blood pressure (MAP) would increase cerebral blood flow and intracranial pressure (ICP) during isoflurane anesthesia. Methods: 6 healthy adult horses. Methods: Horses were anesthetized with isoflurane at a constant end-tidal concentration sufficient to maintain MAP at 60 mm Hg. The facial, carotid, and dorsal metatarsal arteries were catheterized for blood sample collection and pressure measurements. A sub-arachnoid transducer was used to...
Bonilla AG, Scansen BA, Hurcombe SD, Mudge MC.2 horses were examined for chronic nasal discharge secondary to unilateral guttural pouch mycosis. Results: Initial endoscopic examination of both horses confirmed the presence of a fungal plaque on the dorsomedial aspect of the medial compartment of the guttural pouch (auditory tube diverticulum) involving the internal carotid artery (ICA). No signs of hemorrhage or neurologic deficits were present at admission. Results: Transarterial stainless steel coil embolization of the affected ICA was performed under general anesthesia, with fluoroscopic guidance. During treatment, an aberrant branch o...
