Diagnostics and Ancillary Tests of Neurologic Dysfunction in the Ruminant.

A variety of diagnostic tests can be used to help further characterize and diagnose neurologic disease in ruminant species. Cerebrospinal fluid is easily collected, and analysis can help in defining the broad category of disease. Diagnostic imaging, including radiography, myelography, ultrasonography, computed tomography, and MRI, have all been used to varying degrees in ruminants. Advanced cross-sectional imaging techniques have the capacity to aid greatly in diagnosis, but their cost can often be prohibitive. Currently, electrodiagnostic tests are not well evaluated or used in the diagnosis of neurologic disease in ruminants.

Application of polymerase chain reaction on cerebrospinal fluid for diagnosis of cerebral coenurosis in small ruminants.

Sheep and goats serve as intermediate hosts for the canine tapeworm Taenia multiceps. The cysts produced by the intermediate stage of parasite are usually found in the cerebral hemispheres of small ruminants, and the resulting disease is commonly known as coenurosis. Coenurosis is clinically manifested in the form of various nervous symptoms, depending on the exact location of the cyst. The variety of neurological symptoms contributes to the complexity of clinical diagnosis and reinforces the need for a more specific and acceptable diagnostic approach. We demonstrated here, for the first time, that the T. multiceps DNA is present in the cerebrospinal fluid (CSF) of the infected sheep and goats. In addition, the molecular genetic marker of the mitochondrial DNA was applied phylogenetically to show that our isolates together with other T. multiceps strains comprised a monophyletic group that is a sister to Taenia krabbei. Pairwise comparison between the cox1 sequences of our study and other T. multiceps genotypes existing in the GenBank showed similarity ranging from 98 to 100%. Accordingly, the polymerase chain reaction (PCR) can be used for amplification of DNA of the parasite originated from the CSF and provides a valuable method for accurate identification of coenurosis cases.

Ontogeny of inter-alpha inhibitor proteins in ovine brain and somatic tissues.

Inter-alpha inhibitor proteins (IAIPs) found in relatively high concentrations in human plasma are important in inflammation. IAIPs attenuate brain damage in young and adult subjects, decrease during sepsis and necrotizing enterocolitis in premature infants, and attenuate sepsis-related inflammation in newborn rats. Although a few studies have reported adult organ-specific IAIP expression, information is not available on age-dependent IAIP expression. Given evidence suggesting IAIPs attenuate brain damage in young and adult subjects, and inflammation in newborns, we examined IAIP expression in plasma, cerebral cortex (CC), choroid plexus (CP), cerebral spinal fluid (CSF), and somatic organs in fetal, newborn, and adult sheep to determine the endogenous expression patterns of these proteins during development. IAIPs (enzyme-linked immunosorbent assay) were higher in newborn and adult than fetal plasma (P < 0.05). Western immunoblot detected 125 kDa PaI (Pre-alpha Inhibitor) and 250 kDa IaI (Inter-alpha Inhibitor) in plasma, CNS, and somatic organs. PaI expression in CC and CP was higher in fetuses than newborns and adults, but IaI expression was higher in adults than fetuses and newborns. Both PaI and IaI were higher in fetal than newborn CSF. IAIPs exhibited organ-specific ontogenic patterns in placenta, liver, heart, and kidney. These results provide evidence for the first time that plasma, brain, placenta, liver, heart, and kidney express IAIPs throughout ovine development and that expression patterns are unique to each organ. Although exact functions of IAIPs in CNS and somatic tissues are not known, their presence in relatively high amounts during development suggests their potential importance in brain and organ development.

Cisternal cerebrospinal fluid analysis in 24 sheep with chronic coenurosis.

Coenurosis, a neurological parasitic infection of ruminants caused by the larval stage of Taenia multiceps, is commonly reported in Sardinia, the most representative region for ovine population in Italy. Chronic form appears as a consequence of cyst development, frequently reported in the brain and spinal cord. Diagnostic suspect of coenurosis is based on physical and neurological examination. The aim of this article is to describe physical, biochemical and cytological aspects of cisternal cerebrospinal fluid of 24 sheep with chronic coenurosis and to evaluate whether these alterations are helpful in the diagnosis of coenurosis. Cerebrospinal fluid was altered in 20 animals (83.3%). Increase of total protein was revealed in 7 animals (29.2%); an increase of total nucleated cell count was observed in 18 samples (75%). Cytological examination revealed mononuclear pleocytosis in 17 animals (70.1%). Eosinophils were observed in 16 animals in various degree (66.7%). Our results show that cerebrospinal fluid confirms signs of Central Nervous System inflammation in 20 animals out of 24 (83.3%) and in particular it was useful to identify a parasitic inflammation in 66.7% of the animals in which eosinophils were observed. Considering the results of this study, the very absence of significant neutrophilic pleocytosis could be considered useful to diagnose chronic cerebral coenurosis.

Identification of Sarcocystis capracanis in cerebrospinal fluid from sheep with neurological disease.

Protozoal merozoites were identified in the cerebrospinal fluid of two sheep with neurological disease in the UK. Polymerase chain reaction (PCR) identified the merozoites as Sarcocystis capracanis, a common protozoal pathogen of goats. This is the first report of this species infecting sheep and may represent an aberrant infection with sheep acting as dead end hosts, or alternatively could indicate that sheep are able to act as intermediate hosts for S. capracanis, widening the previously reported host range of this pathogen. It is possible that S. capracanis is a previously unrecognised cause of ovine protozoal meningoencephalitis (OPM) in the UK.

[Comparative cytopathological and histopathological studies of sheep with suspected Coenurus cerebralis infection]. / Coenurus cerebralis süpheli koyunlarda karsilastirmali sitopatolojik ve histopatolojik çalismalar.

Cerebrospinal fluid (CSF) smears were compared with brain imprints and histopathological sections of sheep with suspected Coenurus cerebralis infection. There was an increase of eosinophils, neutrophils, lymphocytes, phagocytic and epithelial cells in CSF smears. Similarly, purulent eosinophilic or necrotic-granulomatous infections were observed in histopathologic sections. Cytological exfoliation was similar to histopathological details and it was concluded that CSF cytology is useful as a pre-method in diagnosis of Coenurus cerebralis infection.

Development of a diagnostic DNA probe to detect Setaria digitata: the causative parasite of cerebrospinal nematodiasis in goats, sheep and horses.

Two repetitive sequences (IpSdM and IpSdS) have been cloned and sequenced from the genome of Setaria digitata. When IpSdM (214 bp) and IpSdS (201 bp) were aligned, a high degree of homology (85%) was observed, indicating that they belong to the same family of repeats. IpSdM represents a complete repeating element while IpSdS consists of two partial repeating elements arranged in tandem. The elements are present in about 10 000 copies comprising 2.8% of the S. digitata genome. As a diagnostic probe IpSdM detects as little as 100 pg DNA of both S. digitata and S. labiato-papillosa. It can also detect a single microfilaria and a L3 larva making it a valuable tool to monitor cattle and mosquito vector populations in the prevention of cerebrospinal nematodiasis.

Cerebrospinal fluid and plasma glucose concentrations of ovine pregnancy toxaemia cases, inappetant ewes and normal ewes during late gestation.

Cerebrospinal fluid (CSF) and plasma glucose concentrations of spontaneous ovine pregnancy toxaemia cases, determined within 24 h of the onset of clinical signs, were significantly lower (P < 0.01) compared to inappetant ewes and healthy ewes at a similar stage of gestation. A highly significant correlation (P < 0.001, r = 0.91) was present between the plasma and CSF glucose concentrations when the data from the three groups were combined. The data suggest that plasma glucose concentration accurately reflects CSF glucose concentration across the range of energy states in pregnant ewes and may provide support for the postulate that the neurological signs of ovine pregnancy toxaemia result from cerebral hypoglycaemia, as reflected by CSF glucose concentration. No cerebral glucose estimations were undertaken in this series.

A field study of ovine bacterial meningoencephalitis.

Bacterial meningoencephalitis most commonly affected lambs two to four weeks old (median three weeks, range three days to six months) with clinical signs of episcleral congestion, lack of suck reflex, weakness, altered gait and depression extending to stupor, but hyperaesthesia to auditory and tactile stimuli. Opisthotonos was observed during the agonal stages of the disease. Analysis of lumbosacral cerebrospinal fluid revealed a highly significant increase in protein concentration (P < 0.01) with a neutrophilic pleocytosis, but bacteriological culture yielded organisms in only a few cases. A response was achieved with high doses of dexamethasone and chloramphenicol in only one of 20 cases. Polyarthritis and liver abscesses in a number of lambs provided evidence of a previous bacteraemic or septicaemic episode but no definite source of the central nervous system infection was identified. In common with other infectious bacterial conditions which are prevalent during the early life of sheep, control measures should ensure an adequate transfer of passive antibody, repeated treatments of the navel, and hygienic conditions in the lambing and rearing environments.

Total protein and electrophoretic pattern of cerebrospinal fluid in sheep with some common neurological disorders.

Cerebrospinal fluid (CSF) samples were collected from normal sheep and cases of some common ovine neurological diseases and analysed by agarose gel electrophoresis. Protein fraction concentrations determined from clinically normal sheep of mixed ages were used to establish reference values. The CSF albumin and globulin concentrations were significantly increased in meningo-encephalitis cases (P < 0.05) compared to healthy sheep. The group mean CSF albumin percentage for each of the neurological diseases studied was not significantly different from the mean CSF albumin concentration for control sheep (P > 0.05). In the ovine neurological diseases studied in this series, agarose gel electrophoresis of CSF did not add further to the information already gathered from the total CSF protein concentration.

Physicochemical alterations in blood, cerebrospinal fluid and urine in experimental lactic acidosis in sheep.

Ruminal acidosis was induced in six adult sheep by oral feeding of wheat grain at 90 g kg-1 body-weight. Ruminal fluid, blood, cerebrospinal fluid (CSF) and urine samples were collected before grain feeding (0 h) and thereafter at 12, 24, 48, 72, 96 and 120 hour intervals. Decrease in the rumen pH was associated with decreased pH in blood, CSF and urine and increased total lactic acid concentrations in rumen liquor, blood, CSF and urine. Significantly (P < 0.05) increased levels of sodium, inorganic phosphorus and decreased levels of potassium and calcium were observed in the serum of acidotic sheep. CSF analysis revealed decreased potassium and chloride levels and increased glucose concentration and total leucocyte count within 12 hours of the grain feeding. Pandy's test was positive in half of the surviving sheep at 12 hours and in all the sheep at 96 and 120 hours of observation. In urine, sodium and chloride levels decreased while potassium and inorganic phosphorus increased. The changes in the biochemical parameters started within 12 hours and lasted up to 48 to 120 hours of the observation period.

A field study of ovine listerial meningo-encephalitis with particular reference to cerebrospinal fluid analysis as an aid to diagnosis and prognosis.

In a field study of listerial meningo-encephalitis involving 21 sheep from six silage-fed flocks, the neurological signs included profound depression, circling, involvement of the trigeminal and facial cranial nerves and lateral recumbency with propulsive limb movements. Within the six flocks the incidence of listerial meningo-encephalitis did not exceed 1% of the adult sheep at risk. Eleven of 18 (61%) adult animals were 2 years old. Evidence of an intrathecal inflammatory response in suspected listerial meningo-encephalitis cases was indicated by an increased cerebrospinal fluid (CSF) protein concentration greater than 0.4 g/l in 18 of 21 cases (86%), increased white cell count above 0.012 x 10(9)/l in 17 cases (81%) and lymphocyte percentage below 50% in all animals. None of the CSF parameters proved to be a reliable prognostic indicator because of the range of CSF values obtained and the small number of sheep which recovered.

Analysis of cerebrospinal fluid from field cases of some common ovine neurological diseases.

Analysis of cerebrospinal fluid (CSF) samples from normal sheep and from cases of some common neurological diseases revealed a significant increase (P less than 0.05) in the group mean CSF protein concentration for meningitis, listeriosis and spinal abscess but not for scrapie, spinal injury, ovine pregnancy toxaemia or polioencephalomalacia. The CSF white blood cell count (WBC) was significantly increased (P less than 0.05) in the meningitis group and in those cases of listeriosis which failed to respond to antibiotic therapy. All cases of bacterial infection of the central nervous system (CNS) could be identified by the combined interpretation of the protein concentration and the differential WBC count. It is concluded that CSF analysis is useful clinically in differentiating traumatic from infective spinal lesions and toxic or metabolic lesions from bacterial meningitis in sheep.

A report of Froin's syndrome in five ovine thoracolumbar epidural abscess cases.

An epidural abscess involving the thoracolumbar spinal cord was considered the probable cause of pelvic limb paresis in those sheep where analysis of lumbar cerebrospinal fluid (CSF) samples revealed a significant increase in protein concentration (P less than 0.05) and some increase in total white blood cell concentration and neutrophil percentage. There was no significant increase in protein concentration in the corresponding cisternal samples. This phenomenon caused by blockage to CSF flow is not dissimilar to that of Froin's syndrome in man which has been reported as a result of localized spinal meningitis (Brain, 1985).

Physiopathologic changes in lambs fed with Astragalus lusitanicus Lam.

A study was made of acute experimental poisoning of lambs with A lusitanicus Lam. The animals suffered a nervous syndrome with physiopathologic changes in blood and cerebrospinal fluid indicative of nervous alterations. A lusitanicus Lam causes a form of "locoism" whose development may involve a thiamine deficiency.

Copper, zinc and iron levels in the cerebrospinal fluid of copper poisoned sheep.

Copper, zinc and iron levels were measured in cerebrospinal fluid (CSF) of normal and copper poisoned sheep. Copper values were within the range recorded for humans but zinc levels were six to 20 times and iron levels were 20 to 30 times higher than values reported for humans. The amount of copper, zinc and iron in the CSF did not increase in sheep dosed with copper and hence it is unlikely that the level of copper in the CSF is related to the changes in the nervous system that have been reported in copper poisoned sheep.

An ultrastructural study of the cerebrospinal fluid in visna.

An electron microscopic examination was done on 8 samples of cerebrospinal fluid (CSF) from Icelandic sheep infected by the intracerebral route with visna virus. The specimens were collected 1 month, 2 months, and 4 years after infection. A differentail cell count done on low-power electron micrographs showed that the cellular exudate was composed of mononuclear cells mainly macrophages and lymphocytes with a few plasma cells. Macrophages were with one exception more numerous than lymphocytes and an increased proportion of macrophages showed evidence of phagocytosis with time after infection. Reactive lymphocytes were in general more numerous than small lymphocytes. Various stages in the maturation of plasma cells were observed. The cellular composition in the CSF is compatible with the view that visna is an immunopathological process. Myelin figures and fragments of myelinated axons were observed in two specimens indicating an active myelin-breakdown. The possibility that escape of myelin into the CSF may lead to sensitization to myelin antigens and perpetuation of this chronic neurologic affection is discussed. Visna virions could not be demonstrated.