Cerebrospinal fluid (CSF) is a clear, colorless fluid found within the central nervous system of horses, circulating around the brain and spinal cord. It serves multiple physiological functions, including cushioning the brain and spinal cord, maintaining intracranial pressure, and facilitating the exchange of nutrients and waste products. In equine medicine, CSF analysis is a valuable diagnostic tool for assessing neurological conditions, as changes in its composition can indicate the presence of diseases such as infections, inflammations, or trauma. This page compiles peer-reviewed research studies and scholarly articles that explore the composition, function, and clinical relevance of cerebrospinal fluid in horses.
Daft BM, Barr BC, Gardner IA, Read D, Bell W, Peyser KG, Ardans A, Kinde H, Morrow JK.To determine sensitivity and specificity of western blot testing (WBT) of CSF and serum for diagnosis of equine protozoal myeloencephalitis (EPM) in horses with and without neurologic abnormalities. Methods: Prospective investigation. Methods: 65 horses with and 169 horses without neurologic abnormalities. Methods: CSF and serum from horses submitted for necropsy were tested for Sarcocystis neurona-specific antibody with a WBT. Results of postmortem examination were used as the gold standard against which results of the WBT were compared. Results: Sensitivity of WBT of CSF was 87% for horses w...
Furr M.Eighteen normal horses were assigned to 1 of 3 treatment groups to investigate the effects of IM or intrathecal (IT) administration of ovalbumin on serum and cerebrospinal fluid (CSF) antibody production. Horses of group 1 were injected intramuscularly with ovalbumin and adjuvant, while horses in treatment groups 2 and 3 received ovalbumin intrathecally or intravenously, followed by IM injection as in group 1. Serum and CSF antibody titers were tested in group I every 30 days for 4 months, while serum and CSF were collected in group 2 and 3 horses at postvaccination day 60. Horses of group 1 (...
Cook AG, Maxwell VB, Donaldson LL, Parker NA, Ward DL, Morrow JK.To determine whether antibodies against Sarcocystis neurona could be detected in CSF from clinically normal neonatal (2 to 7 days old) and young (2 to 3 months old) foals. Methods: Prospective study. Methods: 15 clinically normal neonatal Thoroughbred foals. Methods: Serum and CSF samples were obtained from foals at 2 to 7 days of age and tested for antibodies against S. neurona by means of western blotting. Serum samples from the mares were also tested for antibodies against S. neurona. Additional CSF and blood samples were obtained from 5 foals between 13 and 41 days after birth and between ...
Puppione DL, MacDonald MH.To measure apolipoproteins in cerebrospinal fluid (CSF) from healthy mares and to determine whether CSF concentrations of apolipoproteins change during pregnancy and lactation. Methods: 5 healthy pregnant mares. Methods: 2 sets of CSF samples were obtained; initial samples were obtained 10 to 30 days before parturition (mean, 18 days; median, 17 days), and second samples were obtained 19 to 26 days after parturition (mean, 23 days; median, 23 days). Cerebrospinal fluid was collected from the lumbosacral subarachnoid space of standing horses by use of routine collection techniques. Cerebrospina...
Njoku CJ, Saville WJ, Reed SM, Oglesbee MJ, Rajala-Schultz PJ, Stich RW.Equine protozoal myeloencephalitis (EPM) is a disease of horses that is primarily associated with infection with the apicomplexan Sarcocystis neurona. Infection with this parasite alone is not sufficient to induce the disease, and the mechanism of neuropathogenesis associated with EPM has not been reported. Nitric oxide (NO) functions as a neurotransmitter, a vasodilator, and an immune effector and is produced in response to several parasitic protozoa. The purpose of this work was to determine if the concentration of NO metabolites (NO(x)(-)) in the cerebrospinal fluid (CSF) is correlated with...
Furr M, Pontzer C.The following experiment was performed to test the hypothesis that transforming growth factor beta (TGF-beta) concentration varies in the cerebrospinal fluid and serum of horses with EPM and to determine if cerebrospinal fluid (CSF) alters the interferon-gamma (IFN-gamma) rersponse of equine peripheral blood mononuclear cells (PBMCs). The concentration of transforming growth factor-beta (TGF-beta2) was investigated in the serum and cerebrospinal fluid (CSF) of 18 horses (9 normal, 9 affected with equine protozoal myeloencephalitis [EPM]). The TGF-beta2 assay was validated in a group of 6 norma...
Furr M, Pontzer C, Gasper P.The percentages of T-lymphocytes, lymphocyte subsets CD4+ and CD8+ T-cells, and lymphocyte adhesion molecule CD11a/CD18 were determined in the peripheral blood and cerebrospinal fluid (CSF) of seven normal horses and four horses with equine protozoal myeloencephalitis (EPM) using flow cytometry. There was a greater percentage of CD5+ cells in the CSF (79.0%) than in peripheral blood (67.0%), although this did not achieve statistical significance. Furthermore, the lymphocyte population in CSF comprises a significantly greater (P = .01) percentage of CD8+ T-cells, resulting in a decrease of the ...
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...
Haines GR, Brown MP, Gronwall RR, Merritt KA, Baltzley LK.Pharmacokinetics and distribution of orbifloxacin into body fluids and endometrium was studied in 6 mares after intragastric (IG) administration at a single dose rate of 7.5 mg/kg body weight. Orbifloxacin concentrations were serially measured in serum, synovial fluid, peritoneal fluid, urine, cerebrospinal fluid, and endometrial tissues over 24 hours. Minimum inhibitory concentrations of orbifloxacin were determined for 120 equine pathogens over an 11-month period. The mean peak serum concentration (Cmax) was 2.41+/-0.30 microg/mL at 1.5 hours after administration and decreased to 0.17+/-0.01...
Furr M, Kennedy T, MacKay R, Reed S, Andrews F, Bernard B, Bain F, Byars D.Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses most commonly caused by the protozoan parasite Sarcocystis neurona. Until recently the only treatment option was the combination of a sulfonamide with pyrimethamine. The present study was performed to assess the efficacy of ponazuril, an anticoccidial triazine-based compound, as a treatment for naturally occurring EPM. One hundred one horses with EPM were randomly allocated to treatment with ponazuril 15% oral paste at either 5 or 10 mg/kg body weight for 28 consecutive days. Horses were evaluated clinically and by anal...
Furr M, Kennedy T.Ponazuril was administered orally to 10 adult horses at 5 mg/kg body weight, once a day for 28 days. Blood was collected once a week from each horse from Days 0 through 35, daily from Days 35 through 42, and on Day 49. Cerebrospinal fluid (CSF) was also collected once a week from Day 0 through Day 49. Concentrations of ponazuril in the serum and CSF were determined, and pharmacokinetic calculations were performed. Ponazuril was readily absorbed following oral administration; and after 7 days of dosing, the serum concentration was 4.33 +/- 1.10 mg/L, and the mean CSF concentration was 0.162 +/-...
Downar J, Willey BM, Sutherland JW, Mathew K, Low DE.We report a case of group C streptococcal meningitis in a woman with a history of close animal contact as well as head trauma as a result of a kick by a horse. Blood and cerebrospinal fluid cultures grew Streptococcus equi subsp. zooepidemicus, as did a throat culture taken from the colt that had kicked her 2 weeks prior to admission.
Cutler TJ, MacKay RJ, Ginn PE, Gillis K, Tanhauser SM, LeRay EV, Dame JB, Greiner EC.Equine protozoal myeloencephalitis is a common neurologic disease of horses in the Americas usually caused by Sarcocystis neurona. To date, the disease has not been induced in horses using characterized sporocysts from Didelphis virginiana, the definitive host. S. neurona sporocysts from 15 naturally infected opossums were fed to horses seronegative for antibodies against S. neurona. Eight horses were given 5x10(5) sporocysts daily for 7 days. Horses were examined for abnormal clinical signs, and blood and cerebrospinal fluid were harvested at intervals for 90 days after the first day of chall...
Lindsay DS, Dykstra CC, Williams A, Spencer JA, Lenz SD, Palma K, Dubey JP, Blagburn BL.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. A horse model of EPM is needed to test the efficacy of chemotherapeutic agents and potential vaccines. Five horses that were negative for antibodies to S. neurona in their serum and cerebrospinal fluid (CSF) were injected in the subarachnoid space with living merozoites of the SN2 isolate of S. neurona. None of the horses developed clinical disease or died over a 132-day observation period. All five horses develope...
Sweeney CR, Russell GE.To examine total protein concentration and cell counts of sequentially collected samples of CSF to determine whether blood contamination decreases in subsequent samples and whether formulas used to correct nucleated cell count and total protein concentration are accurate. Methods: Case series. Methods: 22 horses. Methods: For each horse, 3 or 4 sequential 2-ml samples of CSF were collected from the subarachnoid space in the lumbosacral region into separate syringes, and blood was obtained from the jugular vein. Total protein concentration, nucleated cell count, and RBC counts were determined i...
Furr M, Kennedy T.Toltrazuril 5% suspension (Baycox, Bayer Canada, Ontario, Canada) was administered to six adult horses followed by blood collection and assay to determine the concentration of toltrazuril and its principal metabolites, toltrazuril sulfone and toltrazuril sulfoxide. From this data, the maximum concentration (C(max)), elimination half-life (T 1/2), and mean residence times of the plasma were determined from standard pharmacokinetic formulas. After a single oral dose of 10 mg/kg body weight a rapid absorption was found, with a mean peak serum concentration of 11.17 mg/L at 18 hours. Elimination w...
Dirikolu L, Lehner F, Nattrass C, Bentz BG, Woods WE, Carter WG, Karpiesiuk W, Jacobs J, Boyles J, Harkins JD, Granstrom DE, Tobin T.Diclazuril (4-chlorophenyl [2,6-dichloro-4-(4,5-dihydro-3H-3,5-dioxo-1,2,4-triazin-2-yl)pheny l] acetonitrile), is a benzeneacetonitrile antiprotozoal agent (Janssen Research Compound R 64433) marketed as Clinacox . Diclazuril may have clinical application in the treatment of Equine Protozoal Myeloencephalitis (EPM). To evaluate its bioavailability and preliminary pharmacokinetics in the horse we developed a sensitive quantitative high-pressure liquid chromatography (HPLC) method for diclazuril in equine biological fluids. MS/MS analysis of diclazuril in our HPLC solvent yielded mass spectral ...
Sloet van Oldruitenborgh-Oosterbaan MM, Schipper FC, Goehring LS, Gremmels JF.In the course of several days most of the 40 riding-school horses turned out in paddocks developed ataxia of variable severity. Five of these horses showed severe ataxia and tremors, became paralyzed and were euthanized. Eleven privately-owned horses which were stabled on the same premises showed no clinical signs. The most likely diagnosis seemed to be the 'neurological form of EHV1', although the signs were not entirely typical. A few weeks later a second outbreak occurred among the riding-school horses and one of the privately-owned horses also showed signs of ataxia. In the meantime it had...
Natalini CC, Robinson EP.To evaluate the effects of long duration subarachnoid catheterization in horses on cerebrospinal fluid (CSF) cellularity and bacteriology, arterial blood pressure, heart rate, respiratory rate, rectal body temperature, and spontaneous locomotor activity. Methods: Prospective experimental study. Methods: Five clinically normal healthy adults horses weighing 511 +/- 47 kg. Methods: Subarachnoid catheters were placed using sedation and local anesthesia and maintained for 48 hours in standing horses. Cerebrospinal fluid samples were tested for cellularity and bacteria growth. Heart rate, respirato...
Dubey JP, Kerber CE, Granstrom DE.To determine serologic prevalence of Sarcocystis neurona, Toxoplasma gondii, and Neospora caninum in horses in Brazil. Methods: Prevalence survey. Methods: 101 Thoroughbreds in Brazil. Methods: Blood samples were obtained from horses and tested for serum antibodies against S neurona by use of an immunoblot procedure with culture-derived S neurona merozoites as antigen, and for serum antibodies against T gondii and N caninum by use of a modified agglutination test with formalin-preserved tachyzoites and mercaptoethanol. Results: Antibodies against S neurona and T gondii were detected in 36 and ...
Miller MM, Sweeney CR, Russell GE, Sheetz RM, Morrow JK.To determine effects of blood contamination on western blot (WB) analysis of CSF samples for detection of anti-Sarcocystis neurona antibodies, and on CSF albumin and IgG concentrations, albumin quotient (AQ), and IgG index in horses. Methods: Prospective in vitro study. Methods: Blood with various degrees of immunoreactivity against S neurona was collected from 12 healthy horses. Cerebrospinal fluid without immunoreactivity against S neurona was harvested from 4 recently euthanatized horses. Methods: Blood was serially diluted with pooled nonimmunoreactive CSF so that final dilutions correspon...
Hamir AN, Tornquist SJ, Gerros TC, Topper MJ, Dubey JP.Equine protozoal myeloencephalitis (EPM) was clinically diagnosed in a 20-year-old horse with severe ataxia. The cerebrospinal fluid was positive for Sarcocystis neurona antibodies by western blot. The horse was administered corticosteroids to facilitate in vitro culture of S. neurona from its spinal cord following necropsy. Microscopic lesions of EPM were present in the brain and in the spinal cord, including multifocal inflammatory cellular infiltrates and several large groups of protozoa. Immunohistochemical, and light and electron microscopic examinations revealed that the protozoa were Ne...
Donaldson MT, Sweeney CR.To determine results of CSF analysis in horses with equid herpesvirus myeloencephalopathy (EHM) and to determine whether results of CSF analysis were associated with outcome. Methods: Retrospective study. Methods: 11 horses. Methods: Medical records of all horses admitted to the veterinary teaching hospital between February 1982 and March 1996 in which EHM was diagnosed were reviewed. Results: 7 horses were < or = 4 years old; 8 were admitted during January, February, or March. Six horses were febrile prior to admission, but none was febrile on the day of admission. Five horses had been sta...
Pedrick TP, Moon PF, Ludders JW, Erb HN, Gleed RD.To describe the effects of tromethamine, a putative treatment for metabolic acidosis, and to compare its biochemical effects with those of sodium bicarbonate. Methods: Randomized intervention study with repeated measures. Methods: 16 healthy horses, 3 to 17 years old, weighing 391 to 684 kg. Methods: Ten horses received 3 mEq/kg tromethamine and six received 3 mEq/kg sodium bicarbonate. Samples of venous blood and cerebrospinal fluid (CSF) were collected at intervals before and after drug administration. Heart rate and breathing rate were also recorded at intervals. Results: Median standard ba...
Luna SP, Taylor PM.Cannulation of the pituitary effluent in horses is a useful method for investigating the release of pituitary hormones in loco (Irvine and Alexander 1987). Adrenocorticotropic hormone (ACTH) and arginine vasopression (AVP) concentrations in plasma collected from the intercavemous sinus, which receives all the pituitary outflow, were several times greater than those measured in peripheral plasma (Redekopp et at 1986). However, no studies evaluating the pituitary contribution to endogenous opioid secretion have been reported in the equine species. Cerebrospinal fluid (CSF) directly reflects CNS ...
Moore LA, Johnson PJ, Messer NT, Kline KL, Crump LM, Knibb JR.Unlike the incidence of equine protozoal myeloencephalitis (EPM), which appears to be increasing, headshaking is an uncommon problem for horses in Missouri and the adjacent states. Equine protozoal myeloencephalitis was incriminated in three horses examined for the treatment of headshaking on the basis of a neurological examination, an analysis of cerebrospinal fluid and their response to treatment. The headshaking and stereotypical behaviour associated with EPM was successfully treated with potentiated sulphonamides and pyrimethamine.
Furr M, Chickering WR, Robertson J.To determine normal CSF electrophoresis patterns in horses, and to determine whether the electrophoretic scans from horses with cervical compression differ from those of neurologically normal horses. Methods: 32 horses assigned to 1 of 2 groups: neurologically normal (n = 18) or cervical compression (n = 14). Methods: CSF was collected from 18 neurologically normal horses referred to the Marion duPont Scott Equine Medical Center, and protein electrophoresis was performed to describe the normal equine CSF electrophoretogram. Results of CSF electrophoresis from 14 horses with cervical compressio...
Scrivani PV, Barthez PY, Léveillé R, Schrader SC, Reed SM.Three patients (1 dog, 2 horses) are described where myelography was complicated, purportedly by injection of contrast medium into the meninges superficial to the subarachnoid space. Contrast medium injected in this location in a cadaver tended to accumulate dorsally within the vertebral canal, deep to the dura mater but superficial to the subarachnoid space. The ventral margin of the pooled contrast medium had a wavy or undulating margin and the dorsal margin was smooth. Pooled contrast medium was believed to be sequestered within the structurally weak dural border cell layer between the dura...
Luna SP, Taylor PM, Bloomfield M.To investigate the effects of inhalation and total IV anesthesia on pituitary-adrenal activity in ponies. Methods: 9 healthy ponies: 5 geldings and 4 mares. Methods: Catheters were placed in the cavernous sinus below the pituitary gland and in the subarachnoid space via the lumbosacral space. After 72 hours, administration of acepromazine was followed by induction of anesthesia with thiopentone and maintenance with halothane (halothane protocol), or for the IV protocol, anesthesia induction with detomidine and ketamine was followed by maintenance with IV infusion of a detomidine-ketamine-guaif...
Beech J.The cytology of cerebrospinal fluid samples from horses is described. The samples were obtained from 24 normal horses, 35 horses with axonal degeneration and/or spinal cord compression, 29 horses with encephalomyelitis, 14 horses with other lesions of the nervous system, and eight horses with signs of neurologic dysfunction of undetermined origin. (Three of the latter were suspected botulinum intoxications.) Fluid was aspirated from the atlanto-occipital space following general anesthesia or immediately after a lethal dose of barbiturate. In two horses, fluid also was aspirated from the lumbos...
Andrade DGA, Cerri FM, Barbosa GVM, Basso RM, Takahira RK, Pantoja JCF, Oliveira-Filho JP, Borges AS.Analysis of the cerebrospinal fluid (CSF) is important as a complementary test in horses with neurologic diseases, and sequential analysis may provide information about the treatment response or evolution and quantitative measures of the CSF drug concentration during treatment. The aim of this study was to compare erythrocyte and nucleated cell counts and protein concentration in multiple CSF samples obtained sequentially from two different puncture sites in clinically healthy horses. Eight and 12 horses, with no evidence of neurologic disease, were subjected to CSF collection from the atlanto...
Wamsley HL, Alleman AR, Porter MB, Long MT.To evaluate CSF in horses with confirmed West Nile virus encephalomyelitis. Methods: Retrospective study. Methods: 30 horses. Methods: Results of CSF analyses from horses with acute neurologic signs attributed to West Nile virus infection that was confirmed by immunoglobulin M antibody capture ELISA were reviewed and analyzed. Results: Among 30 CSF samples, findings in 8 (27%) were within reference ranges and in 22 (73%) were abnormal. Among the 22 abnormal samples, mononuclear pleocytosis was found in 16 (73%) and high protein concentration with nucleated cell count within reference range was...
Keane DP, Little PB, Wilkie BN, Artsob H, Thorsen J.A survey was conducted by testing 115 paired equine serum and cerebrospinal fluid samples by hemagglutination-inhibition for antibodies to Powassan and snowshoe hare viruses, and by virus neutralization for antibodies to equine herpesvirus type 1. Twenty-five samples were from horses with spontaneous neurological disease and the remainder from horses euthanized because of various nonneurological disorders. All sera and cerebrospinal fluids were negative for antibodies to Powassan virus. Fifty-one sera (44.3%) and 15 cerebrospinal fluids (13.0%) had antibodies to snowshoe hare virus. Ninety-eig...
Witonsky S, Morrow JK, Leger C, Dascanio J, Buechner-Maxwell V, Palmer W, Kline K, Cook A.A vaccine against Sarcocystis neurona, which induces equine protozoal myeloencephalitis (EPM), has received conditional licensure in the United States. A major concern is whether the immunoglobulin G (IgG) response elicited by the vaccine will compromise the use of Western blotting (WB) as a diagnostic tool in vaccinated horses with neurologic disease. Our goals were to determine if vaccination (1) causes seroconversion: (2) causes at least a transient increase in S neurona-specific IgG in the cerebrospinal fluid (CSF); and (3) induces an IgG response that can be differentiated from that induc...
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...
Intan-Shameha AR, Divers TJ, Morrow JK, Graves A, Olsen E, Johnson AL, Mohammed HO.The current study aimed at the investigating the potential use of phosphorylated neurofilament H (pNF-H) as a diagnostic biomarker for neurologic disorders in the horse. Paired serum and cerebrospinal fluid (CSF) samples (n=88) and serum only (n=30) were obtained from horses diagnosed with neurologic disorders and clinically healthy horses as control. The neurologic horses consisted of equine protozoal myeloencephalitis (EPM) (38 cases) and cervical vertebral malformation (CVM) (23 cases). Levels of pNF-H were determined using an ELISA. The correlation between CSF and serum concentrations of p...
Hayes TE.The examination of cerebrospinal fluid (CSF) is often part of the diagnostic work-up of a patient exhibiting signs of disease involving the central nervous system. Awareness of the capabilities and limitations of these laboratory tests is important in assessing the benefit-to-risk ratio of performing such procedures. Collection of CSF is a relatively simple procedure, and together with a thorough history, physical examination, and other diagnostic tests, may be a valuable aid in arriving at a diagnosis or prognosis.
The Journal of parasitologyAugust 4, 2006
Volume 92, Issue 3 637-643 doi: 10.1645/0022-3395(2006)92[637:PAOPRC]2.0.CO;2
Furr M, McKenzie H, Saville WJ, Dubey JP, Reed SM, Davis W.The ability of ponazuril to prevent or limit clinical signs of equine protozoal myeloencephalitis (EPM) after infection with Sarcocystis neurona was evaluated. Eighteen horses were assigned to 1 of 3 groups: no treatment, 2.5 mg/kg ponazuril, or 5.0 mg/kg ponazuril. Horses were administered ponazuril, once per day, beginning 7 days before infection (study day 0) and continuing for 28 days postinfection. On day 0, horses were stressed by transport and challenged with 1 million S. neurona sporocysts per horse. Sequential neurologic examinations were performed, and serum and cerebrospinal fluid w...
Furr MO, Bender H.To determine the effects of age on each analyte, CSF variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential WBC counts, RBC count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of ag...
Barrowman PR.This paper is a record of observations on the transmission and clinical signs of dourine in naturally infected cases of known duration, and of temporal and quantitative aspects of the immune response in blood and cerebro-spinal fluid. Included in the record are observations on the presence of Trypanosoma equiperdum parasites in these body fluids and methods for their detection. There is evidence that the occurrence of nervous symptoms and lesions in infected horses is associated with the presence of Trypanosoma equiperdum parasites in cerebro-spinal fluid. The suitability of cerebro-spinal flu...
Donnelly CG, Finno CJ.Phosphorylated neurofilament heavy, a marker of neuroaxonal damage, is increased in horses with equine neuroaxonal dystrophy. However, the temporal dynamics of this biomarker during the post-natal risk period are not understood. Objective: To measure serum and cerebrospinal fluid phosphorylated neurofilament heavy concentrations in juvenile foals across the post-natal window of susceptibility for equine neuroaxonal dystrophy. Methods: Case-control in vivo experimental study. Methods: Concentrations of phosphorylated neurofilament heavy were measured using frozen serum and cerebrospinal fluid c...
Johnson PJ, Lin TL, Jennings DP.Cholesterinic granulomas, commonly found at necropsy in aged horses, may cause neurologic signs by obstructing the interventricular foramina, resulting in hydrocephalus. Diffuse cerebral disease in horses may not always result in rapid progression of clinical signs. Intermittency of neurologic signs may be associated with intermittent increases in CSF pressure.
Furr M, Pontzer C.The following experiment was performed to test the hypothesis that transforming growth factor beta (TGF-beta) concentration varies in the cerebrospinal fluid and serum of horses with EPM and to determine if cerebrospinal fluid (CSF) alters the interferon-gamma (IFN-gamma) rersponse of equine peripheral blood mononuclear cells (PBMCs). The concentration of transforming growth factor-beta (TGF-beta2) was investigated in the serum and cerebrospinal fluid (CSF) of 18 horses (9 normal, 9 affected with equine protozoal myeloencephalitis [EPM]). The TGF-beta2 assay was validated in a group of 6 norma...
Orr JA, Bisgard GE, Forster HV, Rawlings CA, Buss DD, Will JA.Cardiopulmonary measurements were determined in 19 nonanesthetized, normal ponies. Mean values for arterial pressure, pulmonary arterial pressure, cardiac output, heart rate, packed cell volume, and hemoglobin are reported, as well as acid-base determinations of arterial blood and cerebrospinal fluid. Respiratory function test data include total ventilation, respiratory rate, alveolar ventilation, oxygen uptake, and carbon dioxide output. The data compare favorably with the available data from previous reports on ponies. Because of large day-to-day variations in total ventilation, alveolar ven...
Brown MP, Gronwall RR, Houston AE.Six healthy adult mares were each given an oral loading dose of ormetoprim(OMP)-sulfadimethoxine (SDM) at a dosage of 9.2 mg of OMP/kg and 45.8 mg of SDM/kg, followed by four maintenance doses of 4.6 mg of OMP/kg and 22.9 mg of SDM/kg, at 24 h intervals. Ormetoprim and SDM concentrations were measured in serum, synovial fluid, peritoneal fluid, cerebrospinal fluid, urine and endometrium. The highest mean serum OMP concentration was 0.92 micrograms/mL 0.5 h after the first dose; the highest mean SDM concentration was 80.9 micrograms/mL 8 h after the first dose. The highest mean synovial fluid c...
Blythe LL, Mattson DE, Lassen ED, Craig AM.Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Schumacher SA, Toribio RE, Scansen B, Lakritz J, Bertone AL.The objectives of this study were to describe pharmacokinetic and pharmacodynamic changes as a result of a single intravenous administration of magnesium sulfate (MgSO ) to healthy horses. MgSO is a magnesium salt that has been used to calm horses in equestrian competition and is difficult to regulate because magnesium is an essential constituent of all mammals. Six healthy adult female horses were administered a single intravenous dose of MgSO at 60 mg/kg of body weight over 5 min. Blood, urine, and cerebrospinal fluid (CSF) samples were collected, and cardiovascular parameters were monitor...
Murphy JE, Marsh AE, Reed SM, Meadows C, Bolten K, Saville WJ.Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses caused primarily by the protozoal parasite Sarcocystis neurona. Currently available antemortem diagnostic testing has low specificity. The hypothesis of this study was that serum and cerebrospinal fluid (CSF) of horses experimentally challenged with S neurona would have an increased S neurona-specific IgM (Sn-IgM) concentration after infection, as determined by an IgM capture enzyme linked immunoassay (ELISA). The ELISA was based on the S neurona low molecular weight protein SNUCD-1 antigen and the monoclonal an...
Tofflemire KL, Whitley RD, Wong DM, Waller KR, Myers RK, Pillatzki AE, Ben-Shlomo G.An 11-year-old Oldenburg mare presented following three episodes of acute, transient blindness, ataxia, and disorientation within the preceding 7 months. Clinical improvement, including return of vision, occurred within 1 week of initiating corticosteroid therapy for each of the three episodes. However, mild right-sided miosis was a consistent finding on ophthalmic examinations. Routine clinicopathologic testing revealed no significant abnormalities, and testing of cerebral spinal fluid for selected infectious diseases was unrewarding. Computed tomography of the brain demonstrated a hyperatten...
Conrado FO, Beatty SSK.Fluid analysis is an important part of the diagnostic work-up of equine patients presenting with disorders of the nervous system, musculoskeletal system, and abdominal cavity. Proper specimen handling and processing are paramount for complete and accurate interpretation of fluid samples. Normal cerebrospinal fluid is a low-cellularity, low-protein fluid requiring specific sample handling to ensure accurate results. Joint and abdominal fluid analyses are completed in practice or submitted for analysis to a reference laboratory. This article discusses fluid sample handling and processing conside...
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 ...
Maclean AA, Jeffcott LB, Lavelle RB, Friend SC.The use of iohexol as a contrast agent for myelography is reported in two groups of horses. Group 1 (n = 6) were used only for myelography and to assess the clinical and pathological effects of intrathecal administration of iohexol. A volume of 20 ml at a concentration of 300 or 350 mg iodine/ml gave satisfactory myelographic detail with no serious clinical or neurological side effects. Only a minimal inflammatory response could be demonstrated in cerebrospinal fluid at four and 14 days after injection. At post mortem examination 14 days after myelography there was no evidence of meningitis no...
Mück WM, Henion JD.The performance of microbore high-performance liquid chromatography and capillary zone electrophoresis, both equipped with on-line tandem mass spectrometric detection capability, was evaluated critically for the determination of endogenous amounts of leucine enkephalin and methionine enkephalin in equine cerebrospinal fluid. Using an identical sample clean-up and enrichment procedure, capillary zone electrophoresis-mass spectrometry is limited in its concentration detection capacity owing to its much smaller injection volume. Leucine enkephalin was identified in post-mortem equine cerebrospina...
Garré B, Baert K, Nauwynck H, Deprez P, De Backer P, Croubels S.The aim of the current study was to investigate whether multiple oral dosing of valacyclovir could result in plasma concentrations exceeding the EC(50)-value of acyclovir against equine herpesvirus 1 (EHV1) during the majority of the treatment period. Additionally, we wanted to determine the concentration of acyclovir in nasal mucus and cerebrospinal fluid (CSF). Valacyclovir was administered to four horses and two ponies, three times daily, at a dosage of 40 mg/kg, for four consecutive days. Blood was collected prior to each administration and 1 h after dosing. Nasal mucus samples and CSF wer...
Prades M, Brown MP, Gronwall R, Houston AE.After single oral administration of ketoconazole (30 mg/kg bodyweight [bwt]) in 50 ml of corn syrup to a healthy mare, the drug was not detected in serum. Ketoconazole in 0.2 N HC1 was administered intragastrically to six healthy adult horses in five consecutive doses of 30 mg/kg bwt at 12 h intervals. Ketoconazole concentrations were measured in serum, synovial fluid, peritoneal fluid, cerebrospinal fluid (CSF), urine and endometrium. Mean peak serum ketoconazole concentration was 3.76 micrograms/ml at 1.5 to 2 h after intragastric administration. Mean peak synovial concentration was 0.87 mic...
Furr M.Diagnosis of neuro-inflammatory conditions in the horse can be challenging. Current methods include evaluation of cerebrospinal fluid (CSF) for inflammation and determination of specific antibody status. The antibody index (AI) and Goldman-Witmer coefficient (C-value) can be used to aid in the interpretation. Objective: The null hypothesis to be tested was that the Al and C-values do not change in horses with neuroinflammation. Methods: Twelve horses of various ages (3-17 years) and breeds (Thoroughbred, Thoroughbred cross, draft, and Arabian) were included in the study. Methods: The study was...
Luna SP, Taylor PM, Bloomfield M.To investigate the effects of inhalation and total IV anesthesia on pituitary-adrenal activity in ponies. Methods: 9 healthy ponies: 5 geldings and 4 mares. Methods: Catheters were placed in the cavernous sinus below the pituitary gland and in the subarachnoid space via the lumbosacral space. After 72 hours, administration of acepromazine was followed by induction of anesthesia with thiopentone and maintenance with halothane (halothane protocol), or for the IV protocol, anesthesia induction with detomidine and ketamine was followed by maintenance with IV infusion of a detomidine-ketamine-guaif...
