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.
Morrow KL, Park RD, Spurgeon TL, Stashak TS, Arceneaux B.The head from three horses euthanized due to diseases unrelated to the head and neck was imaged using computed tomography (CT). Gross cross-sectional slices of equine head #1 and skeleton of equine head #2 were compared with the CT images of the three equine heads to identify normal structures of the cranium, brain, paranasal sinuses, nasal cavity, and teeth. Labeled transverse CT images of the equine head are presented sequentially as a reference for normal anatomy.
Huxtable CR, de Lahunta A, Summers BA, Divers T.Marginal siderosis is recognized in humans as an uncommon clinicopathologic entity characterized by degeneration of neural tissue at the surface of the brain and spinal cord, in association with the accumulation of hemosiderin, and resulting from chronic subarachnoid hemorrhage. The sources of hemorrhage are various and include neoplasms, malformations, cysts, and vasculopathy. Marginal siderosis of the spinal cord due to a myxopapillary ependymoma was diagnosed in a 19-year-old Dutch Warm Blood horse with clinical signs of myelopathy. There is only one previous report of marginal siderosis in...
Frazier K, Liggett A, Hines M, Styer E.We describe a fatal case of mushroom intoxication in an 18-y-o horse presumably due to Amanita verna. Horses are normally regarded as too fastidious to eat the ill-flavored toadstools. In this case, the horse had a rare benign brain tumor, meningioangiomatosis, which may have altered the horse's normal eating behavior resulting in consumption of the mushrooms.
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...
Olivares R, Michalland S, Aboitiz F.A cross-species morphometric study of the corpus callosum was performed in the rat, rabbit, cat, dog, horse, cow and human. Across species, the results indicate a strong, although less than linear, dependency of callosal size on brain weight. This relation tends to lose significance within species. This is consistent with other morphometric studies indicating a tendency to decrease the correlations between morphometric variables in within-species analyses as compared to between-species analyses. There are species differences in the relative size of some callosal segments particularly in the po...
Hagiwara K, Kamitani W, Takamura S, Taniyama H, Nakaya T, Tanaka H, Kirisawa R, Iwai H, Ikuta K.A pregnant mare showing pyrexia, reduced appetite, ataxia and paresis was euthanized and examined for the presence of Borna disease virus (BDV). Her brain, showing multiple neuronal degeneration and necrosis with hemorrhage, and the histologically normal brain of the fetus were both positive for BDV RNA. The BDV nucleotide sequences were identical in the mare and fetus in the second open reading frame (ORF). This is the first report of the possible vertical transmission of BDV in a horse.
Yachida Y, Kashiwagi M, Mikami T, Tsuchihashi K, Daino T, Akino T, Gasa S.A novel galactosylalkylglycerol modified with a long-chain cyclic acetal at the sugar moiety, 3-O-(4'6'-plasmalogalactosyl) 1-O-alkylglycerol, was isolated from equine brain. The presence of cyclic acetal linkage, its linked position, and the length of the acetal chain of the natural plasmalo lipid were determined by proton NMR spectroscopy and fast-atom bombardment;-mass spectrometry, as well as gas chromatography;-mass spectrometry and gas;-liquid chromatography. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from 3-O-galac...
Tunev SS, Ehrhart EJ, Jensen HE, Foreman JH, Richter RA, Messick JB.An 18-year-old Morgan mare was presented to the Veterinary Medical Teaching Hospital, University of Illinois, with a 10-day history of watery diarrhea, depression, and dysphagia. On admission, the animal was severely dehydrated, depressed, and unable to swallow and had no clinical signs of diarrhea. The respiratory and heart rate and body temperature were within normal limits. Following fluid therapy, the mare developed severe watery diarrhea and continued to be depressed, incoordinated, and dysphagic. The animal died on the fourth day after admission and was sent to the Laboratories of Veteri...
Gardelle O, Feige K, Geissbühler U, Geyer H, Schmucker N, Sydler T, Kaser-Hotz B.For the past 2 years computed tomography is used at the Veterinary School, University of Zürich. This new imaging modality enables the detection of abnormalities occurring in small and large animals which were previously not visible with imaging techniques. Subjects of this study were a foal and a small pony, both with suspected head trauma. Routine radiography could not explain any of the neurological deficiencies. In the first case a basilar skull fracture along with a focal brain hemorrhage was detected, in the second case multiple basilar skull fractures were seen. The computed tomographi...
Paradis MR.Neoplasia of the central nervous system (CNS) can be divided into two main categories: nonpituitary CNS neoplasia and pituitary adenomas. Nonpituitary CNS neoplasias are generally compressive in nature, although some are also invasive. The majority of reported CNS tumors are secondary with only a few originating from nervous tissue. Pituitary adenomas predominantly occur in the pars intermedia of the older horse. Clinical signs, diagnostic testing, and possible treatments are discussed.
Vink-Nooteboom M, Junker K, van den Ingh TS, Dik KJ.Cholesterinic granulomas are tumor-like masses in the choroid plexuses of horses. This report describes the computed tomographic findings in four horses with cholesterinic granulomas, including the clinical and the pathologic features. All four horses had bilateral cholesterinic granulomas in the lateral ventricles. Computed tomographic images clearly delineated the masses, the opacity of the granulomas, and the enhancement pattern after intravenous bolus injection of contrast medium; these factors varied considerably. Additional CT findings were symmetric or asymmetric widening of the lateral...
Poonacha KB, Gregory CR, Vickers ML.The primary lesions of eastern equine encephalomyelitis (EEE) virus infection in the horse are limited to the brain and spinal cord. Intestinal lesions in addition to the changes in the central nervous system were found in a 6-month-old male Tennessee Walking Horse. One week prior to death, this colt was vaccinated for EEE virus, western equine encephalomyelitis virus, influenza virus, equine rhinopneumonitis virus, and tetanus. The clinical signs consisted of ataxia and rear-end weakness, with a body temperature of 102.8 F. Gross lesions consisted of yellowish discoloration, swelling, edema, ...
Ramirez O, Jorgensen JS, Thrall DE.Due to the complex nature of the anatomy of the equine head, superimposition of numerous structures, and poor soft tissue differentiation, radiography may be of limited value in the diagnosis of basilar skull fractures. However, in many horses radiographic changes such as soft tissue opacification of the guttural pouch region, irregular bone margination at the sphenooccipital line, attenuation of the nasopharynx, ventral displacement of the dorsal pharyngeal wall and the presence of irregularly shaped bone fragments in the region of the guttural pouches are suggestive of a fracture of the skul...
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...
Holly EA, Bracci PM, Mueller BA, Preston-Martin S.Nineteen counties from San Francisco and Los Angeles, California and Seattle, Washington were the United States sites for a large population-based case-control study of childhood brain tumors (CBTs), sponsored by the National Cancer Institute. CBT patients who were 1 year and were first on a farm when they were < 6 months of age also had increased risk for CBTs (OR = 3.9, 95% CI = 1.2-13). A somewhat increased risk for CBTs was found for children of mothers who ever had worked on livestock farms compared with mothers who never had worked on a farm (OR = 7.4, 95% CI = 0.86-64, based on five...
Bacon Miller C, Wilson DA, Martin DD, Pace LW, Constantinescu GM.A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the normally reported distance (13-15 cm), but was observed endoscopically during placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respiratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmortem examination revealed an aberrant le...
Röhrs M, Ebinger P.Analysed were the brain case capacities and brain weights of wild przewalski horses, przewalski horses from zoological gardens and domesticated horses. Domesticated horses have about 14% less brain case capacity and 16% less brain weight than wild przewalski horses. Przewalski horses from zoological gardens also have about 14% less brain capacity than wild przewalski horses. The brain weight of przewalski horses from zoological gardens shows no difference to the brain weight of domesticated horses. If we look at the brain size, przewalski horses from zoological gardens are domesticated horses....
Mikami T, Tsuchihashi K, Kashiwagi M, Yachida Y, Daino T, Hashi K, Akino T, Gasa S.A sulfatide, O-fatty-acylated 3-sulfogalactosylceramide at C6-O on galactoside, was isolated from equine brain and the chemical structure was characterized by proton NMR and MS. The O-acylation site of the acylated sulfatide was determined by the down-field shift of protons attached to a carbon having an O-acyl group in the NMR spectrum and by analysis of a partially methylated derivative before and after acetalization of the intact sulfatide using GC-MS. The O-acyl chain length was determined by GLC, revealing that it exclusively had palmitoyl and stearoyl residues as the major fatty acids. T...
Manohar M, Goetz TE.To examine regional distribution of blood flow in the brain of horses at rest and during exercise. Methods: 9 clinically normal horses. Methods: Regional brain blood flow was measured using radionuclide-labeled 15-microns-diameter microspheres injected into the left ventricle, while reference blood samples were obtained from the aorta. Results: At rest, cerebral cortex and caudate nuclei received significantly higher blood flow, compared with cerebral white matter. A similar perfusion heterogeneity existed in the cerebellum. In the brain stem, a gradual tapering of blood flow from thalamus-hyp...
Caplazi P, Ehrensperger F.Borna disease (BD) has been recognized as a virally induced T-cell dependent immunopathological disorder of the central nervous system (CNS), as shown by experimental infection of rats with Borna disease virus (BDV). In contrast to the rat model, little is known about the pathogenesis of spontaneous BD in sheep and horses. The present study describes the brain lesions of 12 ovine and 11 equine cases of naturally occurring BD. A set of monoclonal and polyclonal antibodies was used in order to determine the cells operative in encephalitic lesions and to detect expression of MHC-I and MHC-II prod...
Yachida Y, Kashiwagi M, Mikami T, Tsuchihashi K, Daino T, Akino T, Gasa S.Modified galactosylceramide with a long-chain cyclic acetal at the sugar moiety, plasmalogalactosylceramide, was isolated from equine brain. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from galactosylceramide through acetalization. The presence of cyclic acetal linkage, the linked position and length of the acetal chain of the synthesized and natural products were determined by proton nuclear magnetic resonance spectroscopy and fast-atom bombardment-mass spectrometry, as well as gas chromatography-mass spectrometry and gas...
Mikami T, Kashiwagi M, Tsuchihashi K, Daino T, Akino T, Gasa S.Equine brain gangliosides were isolated and their structures were characterized, to examine whether equine brain has N-glycolyl neuraminic acid in gangliosides, since other mammals predominantly possess N-acetyl neuraminic acid in brain gangliosides, and equine erythrocytes and organs except the brain have gangliosides exclusively containing N-glycolyl neuraminic acid. The gangliosides purified from the brain were identified by proton NMR spectroscopy and mass spectrometry, as well as GLC, resulting in their identification as GM4, GM3, GM2, GM1, GD1a, GD1b, and GT1b. Of these gangliosides, GM3...
Baptiste KE.The equine guttural pouch is a large, air-filled diverticulum of the auditory tube whose function is not clear. Since the horse does not possess a known, well-developed brain-cooling mechanism that could satisfy cerebral thermoregulatory demands, an hypothesis is proposed that respiratory air enters the guttural pouches, when needed, to ventilate and cool the internal carotid arteries (ICA). Experiments were initially carried out on nine cadavers, where blood flow was mimicked with warmed saline propelled by peristaltic pumps. Subsequent experiments were conducted on an anaesthetized horse whe...
Hagiwara K, Momiyama N, Taniyama H, Nakaya T, Tsunoda N, Ishihara C, Ikuta K.Sero- and molecular-epidemiological studies on Borna disease virus (BDV) infection show that BDV RNA is not always detected in the peripheral blood mononuclear cells (PBMCs) from serum anti-BDV antibody-positive individuals such as horses, sheep, cattle, cats, and humans. In this study we demonstrated BDV RNA signals by polymerase chain reaction only in restricted regions of the brain from horses with locomotor disease. Four of six horses examined showed apparently positive reactions for anti-BDV antibodies. Specific regions of the brain of these four horses were positive for BDV RNA but the i...
Chaffin MK, Walker MA, McArthur NH, Perris EE, Matthews NS.Magnetic resonance imaging (MRI) was performed on the brain of 5 normal, anesthetized, neonatal (age 3-to-6 days) Quarter Horse foals. The objectives of the study were to develop a technique for imaging the brain of neonatal foals, and to ascertain their normal brain anatomy. Intravenous propofol was administered for induction and maintenance of general anesthesia. Using spin echo MR techniques, T1 weighted sagittal and transverse views, and spin density and T2 weighted transverse views were successfully made of each foal. MR images provided excellent visualization of many anatomic structures ...
Plumlee KH, Tor ER.The research evaluates cholinesterase activity across different brain regions in horses to better understand its role in neuromuscular function and how it can be affected by certain toxic exposures. Cholinesterase […]
Schultheiss PC, Collins JK, Hotaling SF.Equine herpesvirus-1 (EHV-1) infection in a few widely scattered neurons and astrocytes plus endothelial cells in brain and spinal cord of two horses with naturally occurring paralytic disease was demonstrated by use of an immunoperoxidase technique. These horses were euthanatized less than 48 hours after the onset of clinical signs. No staining for EHV-1 was demonstrated in brain or spinal cord of three horses that had a longer duration of clinical disease or in two uninfected horses.
Mayhew IG, Washbourne JR.Brainstem auditory evoked potentials (BAEPs) were recorded from 27 ponies. The peak and inter-peak (IP) latencies, V:I ratios and dispersal values were determined and the results from each category were compared with each other and with the authors' Thoroughbred BAEP data. Peak latencies were faster for ponies. The V:I ratios and dispersal values had similar characteristics in horses and ponies. In ponies there was a strong trend for IP latencies to be positively correlated with height, inter-aural distance and age. A positive relationship between I-V IP latency and inter-aural distance was co...
Manso-Díaz G, García-Real MI, Casteleyn C, San-Román F, Taeymans O.Noncontrast magnetic resonance angiography (MRA) is widely used in human and small animal medicine. However, this technique has not yet been described in the horse, and compared to other angiographic techniques MRA could be more cost efficient and potentially safer. Objective: The aim of this study was to provide a comprehensive anatomical reference of the normal equine head vasculature using a noncontrast MRA technique, on both low- and high-field MRI. Methods: Five healthy adult horses were examined, 4 with a low-field magnet (0.23T) and the remaining one with a high-field magnet (1.5T). The...
Oikawa M, Ohnami Y, Koike M, Park CH, Oyamada T.To evaluate the effects of endotoxin on the morphology of the equine central, autonomic and enteric nervous system and intestinal muscularis, six Thoroughbred horses with experimentally induced endotoxaemia were examined. The lesions in the central nervous system consisted of perivascular oedema around arterioles, suggesting brain oedema, and ring haemorrhages around veins, similar to those in human patients with septic shock. In the cranial mesenteric ganglia, neuronal cell bodies became pink or red, with shrinkage of cytoplasm indicative of ischaemic changes; intramural and perivascular infi...
Brosnan RJ, LeCouteur RA, Steffey EP, Imai A, Farver TB.To determine whether high intracranial pressure (ICP) during spontaneous ventilation (SV) in anesthetized horses coincides with an increase in intracranial elastance (ie, change in ICP per unit change of intracranial volume). Methods: 6 adult horses. Methods: Anesthesia was induced and maintained in each horse for 5 hours with isoflurane at a constant dose equal to 1.2 times the minimum alveolar concentration. Direct ICP measurements were obtained by use of a strain gauge transducer inserted in the subarachnoid space, and arterial blood pressure was measured from a carotid artery. Physiologic ...
Ellero N, Lanci A, Baldassarro VA, Alastra G, Mariella J, Cescatti M, Giardino L, Castagnetti C.The importance of trophic factors, such as nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) during the perinatal period, is now emerging. Through their functional activities of neurogenesis and angiogenesis, they play a key role in the final maturation of the nervous and vascular systems. The present study aims to: (i) evaluate the NGF and VEGF levels obtained at parturition from the mare, foal and umbilical cord vein plasma, as well as in amniotic fluid; (ii) evaluate NGF and VEGF content in the plasma of healthy foals during t...
Hudson LC, Weinstock D, Jordan T, Bold-Fletcher NO.Twelve naive and nine test-vaccinated horses which developed clinical signs of rabies as a result of the required protocol of a vaccine trial were prospectively observed. Nineteen of the 21 cases were confirmed positive for rabies infection of the brain by fluorescent antibody test. The two horses with negative results had ganglioneuritis of the trigeminal ganglion or lymphocytic perivascular cuffing in the brain stem in addition to clinical signs. Average incubation period was 12.3 days and average morbidity was 5.5 days. Naive animals had significantly shorter incubation and morbidity period...
Poss M, Young S.A 4-year-old horse was evaluated at the Colorado State University Veterinary Teaching Hospital for rapidly progressing cerebellar disease. Euthanasia was elected and at postmortem examination a proliferative mass encompassing the right side of the cerebellum was discovered. The lesion was characterized by large, convoluted, vascular folia and absence of the core of central white matter. Histologically, there was a diminution or loss of the internal granule cell layer, cavitation of the central white matter, and absence of Purkinje cells. The molecular layer was thickened with myelinated axons ...
Swor TM, Whittenburg JL, Chaffin MK.3 adult Quarter Horses were evaluated for acute, progressive neurologic signs 18 hours after oral administration of 1 dose of 1.87% ivermectin paste. Results: Clinical signs included depression, forelimb and hind limb ataxia, drooping of the superior and inferior lips, and muscle fasciculations. Bilateral mydriasis, decreased pupillary light reflexes, and absent menace reflexes were evident. Clinical signs progressed in severity for 36 hours after administration of the ivermectin. Results: All horses were treated supportively with IV administration of fluids and anti-inflammatory medications. ...
Yachida Y, Kashiwagi M, Mikami T, Tsuchihashi K, Daino T, Akino T, Gasa S.A novel galactosylalkylglycerol modified with a long-chain cyclic acetal at the sugar moiety, 3-O-(4'6'-plasmalogalactosyl) 1-O-alkylglycerol, was isolated from equine brain. The presence of cyclic acetal linkage, its linked position, and the length of the acetal chain of the natural plasmalo lipid were determined by proton NMR spectroscopy and fast-atom bombardment;-mass spectrometry, as well as gas chromatography;-mass spectrometry and gas;-liquid chromatography. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from 3-O-galac...
Anderson BG, Anderson WD.The use of methyl methacrylate corrosion-casts has made it possible to examine the intracranial microvasculature on a three-dimensional scale with the scanning electron microscope. By this means we have compared regions of four cerebral and cerebellar arteries among three domestic animal species. The results of this study suggest that there are from one to three different levels of interarteriolar anastomosis between branches of the same or adjacent vessels. In the horse and ox anastomoses were demonstrated (1) at the level of the precapillary arterioles, (2) along the arterioles, and (3) betw...
Lund JR, Ketover HR, Hetzel S, Waller K, Brounts SH.To evaluate with CT the characteristics of brain tissue disruption and skull damage in cadaveric heads of adult horses caused by each of 6 firearm-ammunition combinations applied at a novel anatomic aiming point. Methods: 53 equine cadaveric heads. Methods: Heads placed to simulate that of a standing horse were shot with 1 of 6 firearm-ammunition combinations applied at an aiming point along the external sagittal crest of the head where the 2 temporalis muscles form an inverted V. Firearm-ammunition combinations investigated included a .22-caliber long rifle pistol firing a 40-grain, plated le...
Wong D, Wilkins PA, Bain FT, Brockus C.Neonatal encephalopathy is a common central nervous system disorder of neonatal foals and human infants, resulting in clinical signs such as lethargy, inappropriate behavior, seizures, and other neurologic deficits. Although neonatal encephalopathy is frequently seen in equine practice, a paucity of veterinary clinical and basic science research data is available. Therefore, the pathophysiologic mechanisms of this disorder in equids, such as energy deprivation, excess excitatory amino acids, and free radical injury, have been extrapolated from human medicine. Equine veterinarians have used var...
Dybdal N, Horgan M, Costa L, Davis E, Lucero S, Nieves S, Quiroz V, Weberg K, Madigan JE.Challenges and issues related to the use of pentobarbital euthanasia and disposal of animal remains within the US have recently been reviewed. Environmental and public health challenges increasingly necessitate consideration of alternative methods such as gunshots, an American Veterinary Medical Association (AVMA) "acceptable with conditions" method, for the humane euthanasia of horses. A recent study reported a correctly aimed gunshot provides a humane option for euthanizing horses. However, although aiming guidelines exist, studies examining bullet trajectories in animals euthanized by gunsh...
Torquato RBC, Iamamoto K, Fernandes ER, Achkar S, Silva SR, Katz ISS, Guedes F.Laboratory diagnosis of rabies in equines is essential for distinguishing the disease from other sources of encephalitis. Diagnosis by conventional techniques such as a direct fluorescent antibody test (dFAT) or viral isolation in mice or cell culture can be difficult, and the application of molecular biological methods may be necessary. We performed an indirect rapid immunohistochemistry test (iRIT) for the detection of the rabies virus (RABV) antigen in the central nervous system (CNS) of equines and compared the results with those of other diagnostic techniques. We reviewed result records f...
Prakoso D, Dark MJ, Barbet AF, Salemi M, Barr KL, Liu JJ, Wenzlow N, Waltzek TB, Long MT.West Nile virus (WNV), a small, positive sense, single stranded RNA virus continues to encroach into new locales with emergence of new viral variants. Neurological disease in the equine can be moderate to severe in the face of low to undetectable virus loads. Physical methods of virus enrichment may increase sensitivity of virus detection and enhance analysis of viral diversity, especially for deep sequencing studies. However, the use of these techniques is limited mainly to non-neural tissues. We investigated the hypothesis that elimination of equine brain RNA enhances viral detection without...
Hunter B, Nation PN.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...
Manohar M.It has been reported in exercising ponies that O2 supply to all regions of the brain increased primarily due to a large increment in CaO2 and it was implied that this may reflect a generalized increase in brain metabolism during strenuous exercise. Splenectomy ameliorates the rise in CaO2 observed with exercise in ponies. Thus, the objective of the present study was to examine changes in regional brain blood flow and O2 supply of splenectomized ponies with sub-maximal and maximal exercise and to compare these data with previous observations in normal ponies. It was reasoned that in the absence...
Dittmer H.Injuries are relatively rare in horse riding compared to other sports, but when they occur they are rather severe and dangerous: about 40% of the injured suffer from fractures, for instance and only 15% from sprains. About 20% have to be admitted to the hospital. Roughly 30% of the injuries involve the arm and 7.5%-10% the spine. The head is injured in 20%, the brain in 8% and the lower extremity in only about 20%. That means that the majority of injuries involve the upper half of the body. One quarter of all lethal sport injuries are caused by horse riding.
Palmer AC, Rossdale PD.Brains from eighteen Thoroughbred foals suffering from the convulsive foal syndrome were examined neuropathologically and compared with brains from nine foals dying from different causes. In the brains of nine convulsive foals there was necrosis of the cerebral cortex, accompanied in three by severe necrosis of the diencephalon and brain stem; haemorrhage into the cerebral cortex was also present in most of this group. In the other nine brains from convulsive foals there was haemorrhage, often severe, especially in the white and grey matter of the cerebral cortex and in the cerebellum. Minimal...
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 ...
Garcia-Tamayo J.The mode of development of Venezuelan equine encephalomyelitis virus and the activity of acid phosphatase in the central nervous system of newborn mice were investigated. Precursor particles appeared to be formed in masses of viroplasm, migrating to the membrane of the Golgi cisterns and vacuoles or to the plasma membrane and being transformed into mature viral particles by budding. Mature viral particles were also found in the lumen of the blood vessels and around the myelin sheath of axons. Increased number of Golgi complexes and depletion of polysomes were the main ultrastructural alteratio...
Velloso Alvarez A, Jose-Cunilleras E, Dorrego-Rodriguez A, Santiago-Llorente I, de la Cuesta-Torrado M, Troya-Portillo L, Rivera B, Vitale V....Real-time PCR is the diagnostic technique of choice for the diagnosis and control of equine herpesvirus-1 (EHV-1) in an outbreak setting. The presence of EHV-1 in nasal swabs (NS), whole blood, brain and spinal cord samples has been extensively described; however, there are no reports on the excretion of EHV-1 in urine, its DNA detection patterns, and the role of urine in viral spread during an outbreak. Objective: To determine the presence of EHV-1 DNA in urine during natural infection and to compare the DNA detection patterns of EHV-1 in urine, buffy coat (BC) and NS. Methods: Descriptive st...
de Preux M, Precht C, Guevar J, Graubner C, Thenhaus-Schnabel S, Buser L, Lukes A, Koch C.A 16-year-old warmblood mare was referred with a progressive history of behavioral changes and left-sided blindness. Following neuroanatomical localization to the forebrain, magnetic resonance imaging of the head revealed a well-delineated, 4.5 cm in diameter, round pituitary mass causing marked compression of the midbrain and optic chiasm. Euthanasia was recommended but declined by the owners. Veterinary specialists and a human neurosurgeon collaboratively prepared for surgical case management. A novel navigated transmandibular lateral transsphenoidal approach was developed to access the re...
Moscovice LR, Sobczak B, Niittynen T, Koski SE, Gimsa U.Although best known for its established role in mediating parturition and lactation, the highly-conserved neuropeptide hormone oxytocin also mediates a range of social and stress-buffering processes across mammalian species. Measurements of peripheral oxytocin in plasma have long been considered the gold standard, but there is increasing interest in developing methods to detect oxytocin non-invasively in saliva. Here we present an analytical and biological validation of a novel method to measure salivary oxytocin (sOXT) in an under-studied research group: farm animals. Given their similarities...
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...
Bombardi C, Salamanca G, Tagliavia C, Grandis A, Zamith Cunha R, Gramenzi A, De Silva M, Zannoni A, Chiocchetti R.The amygdala is composed of several nuclei, including the lateral nucleus which is the main receiving area for the input from cortical and subcortical brain regions. It mediates fear, anxiety, stress, and pain across species. Evidence suggests that the endocannabinoid system may be a promising target for modulating these processes. Cannabinoid and cannabinoid-related receptors have been identified in the amygdala of rodents, carnivores, and humans, but not in horses. This study aimed to investigate the gene expression of cannabinoid receptors 1 (CB1R) and 2 (CB2R), transient receptor potential...
Cheng X, Qian L, Fan Y, Tang Q, Wu H.Inhibitory control (IC), an important component of executive function, plays an important role in the overall development of children and has not been better studied in the field of equine-assisted activity (EAA). Therefore, this study investigated the effects of EAA on IC and the underlying brain neural mechanisms in children aged 7-8 years. Conclusions: Collectively, EAA demonstrated a positive impact on IC and could effectively activate R-DLPFC in children aged 7-8 years. Furthermore, it enhanced the activation of the brain regions related to IC and increased cognitive ability in children a...
Moore RM, Trims CM.Lumbosacral CSF pressure was measured in 6 horses via a catheter inserted through the lumbosacral space. Heart rate, facial artery pressure, central venous pressure, and CSF pressure were measured before IV injection of a saline solution control, for 15 minutes after saline solution injection, and for 60 minutes after the IV injection of 1.1 mg of xylazine/kg of body weight. Arterial pH and blood gases were analyzed before saline solution injection, 15 minutes after saline solution injection, and at 15, 30, and 60 minutes after xylazine injection. Constant craniocervical posture was maintained...
Domange C, Schroeder H, Violle N, Peiffer J, Canlet C, Paris A, Priymenko N.Mining the brain metabolome to understand behavioural disruptions induced in mouse fed Hypochoeris radicata (L.), a neurotoxic plant for horse. C57BL/6J mice orally exposed to 9% H. radicata (HR) are metabolically competent laboratory animals which can be used as model of Australian stringhalt, a neurological horse disease induced by HR ingestion. So, the present study was conducted to assess the brain metabolome and the behavioural performances of mice fed with a 9%-HR-based diet for 21 days. By the end of the period of exposure, mice were investigated for motor activity and coordination, anx...
Beaver BV.Accurate diagnosis of the cause of aggression in horses is essential to determining the appropriate course of action. The affective forms of aggression include fear-induced, pain-induced, intermale, dominance, protective, maternal, learned, and redirected aggressions. Non-affective aggression includes play and sex-related forms. Irritable aggression and hypertestosteronism in mares are medical problems, whereas genetic factors, brain dysfunction, and self-mutilation are also concerns.
