A novel machine learning-based web application for field identification of infectious and inflammatory disorders of the central nervous system in cattle.

BACKGROUND: Central nervous system (CNS) infections in cattle are a major cause of economic loss and mortality. Machine learning (ML) techniques are gaining widespread application in solving predictive tasks in both human and veterinary medicine. OBJECTIVES: Our primary aim was to develop and compare ML models that could predict the likelihood of a CNS disorder of infectious or inflammatory origin in neurologically-impaired cattle. Our secondary aim was to create a user-friendly web application based on the ML model for the diagnosis of infection and inflammation of the CNS. ANIMALS: Ninety-eight cattle with CNS infection and 86 with CNS disorders of other origin. METHODS: Retrospective observational study. Six different ML methods (logistic regression [LR]; support vector machine [SVM]; random forest [RF]; multilayer perceptron [MLP]; K-nearest neighbors [KNN]; gradient boosting [GB]) were compared for their ability to predict whether an infectious or inflammatory disease was present based on demographics, neurological examination findings, and cerebrospinal fluid (CSF) analysis. RESULTS: All 6 methods had high prediction accuracy (≥80%). The accuracy of the LR model was significantly higher (0.843 ± 0.005; receiver operating characteristic [ROC] curve 0.907 ± 0.005 ) than the other models and was selected for implementation in a web application. CONCLUSION AND CLINICAL IMPORTANCE: Our findings support the use of ML algorithms as promising tools for veterinarians to improve diagnosis. The open-access web application may aid clinicians in achieving correct diagnosis of infectious and inflammatory neurological disorders in livestock, with the added benefit of promoting appropriate use of antimicrobials.

Complex central nervous system malformations in a Dutch Warmblood foal.

A neonatal Dutch Warmblood colt was evaluated for inability to stand, incoordination and intention tremor. Despite partial improvement in clinical signs during the first 4 days of hospitalization, neurological deficits remained. Magnetic resonance imaging identified a unilateral infratentorial arachnoid cyst-like lesion with ipsilateral compression and displacement of the cerebellar hemisphere, absent corpus collosum, polymicrogyria, suspect leukoencephalopathy, and noncompressive occipitoatlantal malformation. Improvement in clinical signs during the first 6 months of life suggests that horses can survive with complex congenital neurological malformations, but prognosis for athletic performance is poor. The accessibility of magnetic resonance imaging should improve the diagnostic accuracy of central nervous system disorders in neonatal foals in which congenital malformations are suspected. Euthanasia often is elected in foals with suspected congenital central nervous system disorders because of poor prognosis for athletic performance, limiting understanding of clinical progression in these cases.

Neuroinflammatory diseases of the central nervous system of dogs: A retrospective study of 207 cases (2008-2019).

In this study we describe 207 cases of neuroinflammatory diseases of the central nervous system (CNS) in dogs autopsied at the Athens Veterinary Diagnostic Laboratory (University of Georgia, United States) from 2008 to 2019. Idiopathic and infectious diseases were diagnosed in 111 cases (53.6%) and 96 cases (46.4%), respectively. Idiopathic diseases consisted of granulomatous meningoencephalomyelitis (n = 42; 37.8% of idiopathic cases), nonspecific lymphoplasmacytic meningoencephalomyelitis (n = 39; 35.1%), necrotizing meningoencephalomyelitis (n = 22; 19.8%), presumed steroid-responsive meningitis-arteritis (n = 6; 5.4%), and necrotizing leukoencephalitis (n = 2; 1.8%). Infectious diseases consisted of bacterial infections (n = 49; 51% of infectious cases), viral infections (n = 39; 40.6%), fungal infections (n = 5; 5.2%), and parasitic infections (n = 3; 3.1%). Our study provides an overview of the most frequent neuroinflammatory diseases of the CNS of dogs in our diagnostic routine; indicates that a comprehensive diagnostic approach, including a thorough evaluation of the pathology findings and ancillary laboratory testing results, is important for an adequate diagnosis of neurologic diseases in dogs; and underscores the problems associated with the variability in tissue sample collection methods among cases. The great number of nonspecific lymphoplasmacytic meningoencephalitis also highlights the need for development of molecular laboratory tests to identify potential infectious agents in these cases.

Maladies neuro-inflammatoires du système nerveux central du chien : étude rétrospective de 207 cas (2008­2019). Dans cette étude, nous décrivons 207 cas de maladies neuro-inflammatoires du système nerveux central (SNC) chez des chiens autopsiés au Athens Veterinary Diagnostic Laboratory (University of Georgia, États-Unis) de 2008 à 2019. Des maladies idiopathiques et infectieuses ont été diagnostiquées dans 111 cas (53,6 %) et 96 cas (46,4 %), respectivement. Les maladies idiopathiques consistaient en : méningo-encéphalomyélite granulomateuse (n = 42; 37,8 % des cas idiopathiques), méningo-encéphalomyélite lymphoplasmocytaire non spécifique (n = 39; 35,1 %), méningo-encéphalomyélite nécrosante (n = 22; 19,8 %), méningite-artérite corticosensible présumée (n = 6; 5,4 %) et leucoencéphalite nécrosante (n = 2; 1,8 %). Les maladies infectieuses comprenaient des infections bactériennes (n = 49; 51 % des cas infectieux), des infections virales (n = 39; 40,6 %), des infections fongiques (n = 5; 5,2 %), et des infections parasitaires (n = 3; 3,1 %). Notre étude donne un aperçu des maladies neuro-inflammatoires du SNC des chiens les plus fréquentes dans notre routine de diagnostic; indique qu'une approche diagnostique complète, comprenant une évaluation approfondie des résultats de la pathologie et des résultats des tests de laboratoire auxiliaires, est importante pour un diagnostic adéquat des maladies neurologiques chez les chiens; et souligne les problèmes associés à la variabilité des méthodes de prélèvement d'échantillons de tissus entre les cas. Le grand nombre de méningo-encéphalites lymphoplasmocytaires non spécifiques souligne également la nécessité de développer des tests de laboratoire moléculaire pour identifier les agents infectieux potentiels dans ces cas.(Traduit par Dr Serge Messier).

Vascular endothelial growth factor concentrations in the cerebrospinal fluid of dogs with neoplastic or inflammatory central nervous system disorders.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a key molecular driver of angiogenesis and vascular permeability and is expressed by a wide variety of neoplasms. Although blood VEGF concentrations have been quantified in intracranial tumors of dogs, cerebrospinal fluid (CSF) VEGF concentration might be a more sensitive biomarker of disease. OBJECTIVE: Concentrations of VEGF in CSF are higher in dogs with central nervous system (CNS) neoplasia compared to those with meningoencephalomyelitis and other neurologic disorders. ANIMALS: One hundred and twenty-six client-owned dogs presented to a veterinary teaching hospital. METHODS: Case-control study. Cerebrospinal fluid was archived from dogs diagnosed with CNS neoplasia and meningoencephalomyelitis. Control dogs had other neurological disorders or diseases outside of the CNS. A commercially available kit was used to determine VEGF concentrations. RESULTS: Detectable CSF VEGF concentrations were present in 49/63 (77.8%) neoplastic samples, 22/24 (91.7%) inflammatory samples, and 8/39 (20.5%) control samples. The VEGF concentrations were significantly different between groups (P < .0001), and multiple comparison testing showed that both neoplastic and inflammatory groups had significantly higher concentrations than did controls (P < .05), but did not differ from each other. Gliomas and choroid plexus tumors had significantly higher VEGF concentrations than did the control group (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Cerebrospinal fluid VEGF concentrations may serve as a marker of neoplastic and inflammatory CNS disorders relative to other conditions.

Central nervous system lesions caused by canine distemper virus in 4 vaccinated dogs.

We examined the cerebellum and cerebrum of 4 vaccinated dogs, 3-60-mo-old, that displayed clinical signs of canine distemper virus (CDV) infection, and died 7-40 d after developing neurologic signs. The main histologic lesions were demyelination, gliosis, meningitis, perivascular lymphocytic cuffing, and inclusion bodies. These lesions were similar in all 4 cases regardless of the time since vaccination, except that meningoencephalitis and gliosis were subacute in 3 dogs and chronic in 1 dog. However, these differences did not appear to be related to their vaccination status. Immunohistologically, a CDV-positive immunoreaction was seen mainly in astrocytes, neurons and their axons, lymphocytes around and in the blood vessels of the pia mater and choroid plexus, ependymal cells of each ventricle, and the cells of the choroid plexus. The histologic and immunohistologic changes were similar in the cerebellum and cerebrum. The genetic characterization of the virus strains in 2 of these naturally occurring canine distemper cases confirmed that they were South American wild-type strains (Kiki and Uy251) belonging to the EU1/SA1 lineage. These strains are not included in the commercial CDV vaccines available in Uruguay.

Comparative Pathology of the Peripheral Nervous System.

The peripheral nervous system (PNS) relays messages between the central nervous system (brain and spinal cord) and the body. Despite this critical role and widespread distribution, the PNS is often overlooked when investigating disease in diagnostic and experimental pathology. This review highlights key features of neuroanatomy and physiology of the somatic and autonomic PNS, and appropriate PNS sampling and processing techniques. The review considers major classes of PNS lesions including neuronopathy, axonopathy, and myelinopathy, and major categories of PNS disease including toxic, metabolic, and paraneoplastic neuropathies; infectious and inflammatory diseases; and neoplasms. This review describes a broad range of common PNS lesions and their diagnostic criteria and provides many useful references for pathologists who perform PNS evaluations as a regular or occasional task in their comparative pathology practice.

Resuscitation Compression for Newborn Sheep.

Neonatal maladjustment syndrome is characterized by depressed consciousness, neurologic signs, and reduced or nonexistent suckle reflex. Resuscitation compression (squeezing) has been used in newborn foals and calves to reduce the behavioral symptoms of neonatal maladjustment syndrome. In this review, the authors describe how resuscitation compression can be used in newborn sheep. This technique can improve abnormal neonatal lamb behavior and encourage suckling in resistant lambs.

Diseases of the central nervous system in swine in Southern Brazil / Doenças do sistema nervoso central de suínos no Sul do Brasil

Brazil is the fourth largest exporter of pork worldwide, with its production concentrated in the Southern region of the country. To reduce the economic impacts and increase herd health, an efficient diagnosis of diseases is necessary. The frequency, seasonal, and annual distribution of diseases that affecting the swine nervous system in Southern Brazil were determined through a retrospective study conducted from 2008 to 2018. A total of 231 pigs were evaluated, and distributed in the following phases: suckling piglets, nursery, growing, finishing, and adults. Piglets in the nursery phase were the most affected with 58.01%. Infectious diseases accounted for 87.01% (201/231) of lesions in the nervous system. Bacterial meningitis was observed in 58.87% of cases, presenting an endemic distribution, and a propensity to occur in the months of autumn/winter. The highest number of cases of porcine circovirus-2 were observed in 2008 and 2009, with a subsequent decline. Porcine circovirus, salt poisoning, and brain abscesses exhibited no association between the seasonal occurrence and annual distribution. Salt poisoning was observed more frequently in the last years of this study. Both, non-suppurative encephalomyelitis and selenium toxicosis exhibited an association between their occurrence and seasonal distribution in, the months of winter, and summer, respectively.(AU)

Brasil é o quarto maior exportador de carne suína do mundo, com sua produção concentrada na região Sul do país. Para reduzir os impactos econômicos e aumentar a saúde do rebanho, é necessário o diagnóstico eficiente das doenças. A frequência, distribuição sazonal e anual das doenças que afetam o sistema nervoso de suínos no Sul do Brasil foram determinadas através de um estudo retrospectivo no período de 2008 a 2018. Foram avaliados 231 suínos, distribuídos nas seguintes fases: maternidade, creche, crescimento, terminação e adultos. Leitões da fase de creche foram os mais afetados com 58,01%. As doenças de origem infecciosa foram responsáveis por 87,01% (201/231) das causas de lesões no sistema nervoso. Meningite bacteriana foi observada em 58,87% dos casos, apresentando distribuição endêmica, e uma tendência a ocorrer nos meses de outono/inverno. O maior número de casos de circovírus suíno foram observados em 2008 e 2009, com declínio posterior. Circovírus suíno, intoxicação por sal e os abscessos encefálicos não apresentaram associação entre a ocorrência sazonal e distribuição anual. A intoxicação por sal foi observada com maior frequência nos últimos anos deste estudo. A encefalomielite não supurativa e a intoxicação por selênio exibiram associação entre a sua ocorrência e distribuição sazonal, nos meses de inverno e verão, respectivamente.(AU)

Association between cerebrospinal fluid lactate concentration and central nervous system disease in dogs.

BACKGROUND: Cerebrospinal fluid (CSF) analysis is a sensitive tool for evaluating patients with neurologic diseases but is rarely specific. Biomarkers can be measured from any bodily fluid and can be useful indicators for the presence, severity, and prognosis of diseases. OBJECTIVES: This study was designed to evaluate if CSF lactate can be used as a biomarker in dogs with central nervous system disease. METHODS: Peripheral venous blood and CSF were collected from 49 dogs with various intracranial diseases to evaluate correlations between blood and CSF lactate levels. Total nucleated cell count (TNCC) and CSF protein concentrations were also evaluated. All samples obtained were divided into normal (NG) and abnormal (AG) dogs based on a TNCC of ≤5 and >5 cells/µL and a protein concentration of ≤25 and >25 mg/dL, respectively. The AG dogs were further subdivided into those having <100 TNCCs/µL (AGL) and those having >100 TNCCs/µL (AGH). They were also subdivided into groups based on seizure activity (AGS), and inflammatory (AGI), or neoplastic diseases (AGN), and the respective lactate concentrations were then compared. RESULTS: Lactate concentrations were significantly increased in CSF and venous blood samples in the AG compared with the NG dogs, but no differences were found among the individual disease processes. In all dogs, CSF lactate concentrations were higher than venous blood lactate levels; however, no direct correlation between CSF and blood lactate concentrations was identified. CONCLUSIONS: Cerebrospinal fluid lactate can be used as a biomarker in clinical settings as it can be measured via a commercially available lactometer immediately after collection without the need for special instrumentation or laboratory personnel.

Facial nerve paralysis in 64 equids: Clinical variables, diagnosis, and outcome.

BACKGROUND: Facial nerve paralysis (FNP) in equids is not well described in the veterinary literature. OBJECTIVE: To investigate the causes of FNP and associations among clinical variables, diagnosis, and outcome. ANIMALS: Sixty-four equids presenting with FNP between July 2000 and April 2019. Cases of postanesthetic FNP were excluded. METHODS: Medical records were retrospectively reviewed. Variables were evaluated for associations with outcomes (diagnosis and case outcome) using logistic regression. RESULTS: The most common cause of FNP was trauma (n = 20). Additional diagnoses included central nervous system (CNS) disease (n = 16), idiopathic (n = 12, 4 of which had adequate diagnostic investigation and were considered "true" idiopathic, and 8 of which were considered "not investigated" idiopathic), temporohyoid osteoarthropathy (n = 10), otitis media-interna (n = 3), lymphoma (n = 1), iatrogenic as a consequence of infiltration of local anesthetic (n = 1), and clostridial myositis (n = 1). Follow-up was available for 55 (86%) cases. Twenty-nine (53%) equids had full resolution of FNP, 14 (25%) were euthanized, 6 (11%) partially improved, and 6 (11%) were unchanged or worse. CONCLUSIONS AND CLINICAL IMPORTANCE: If FNP is the consequence of CNS disease, successful treatment of the primary disease likely leads to resolution of FNP. Most cases of FNP in equids are traumatic in origin. True idiopathic cases are uncommon.

PROGNOSTIC INDICATORS FOR SURVIVAL OF ORPHANED NEONATAL AND JUVENILE EASTERN COTTONTAIL RABBITS (SYLVILAGUS FLORIDANUS): 1,256 CASES (2012-17).

Orphaned eastern cottontail rabbits (ECRs; Sylvilagus floridanus) often present to wildlife clinics within their geographic range and require considerable dedication of time and resources. The objective of this analytical cross-sectional study was to assess initial examination findings to be used as prognostic indicators for orphaned neonatal and juvenile ECRs. The medical records of the University of Illinois Wildlife Medical Clinic were searched for ECRs presenting between 2012 and 2018. This criterion identified 1,256 ECRs that were then classified as survivors (survived and released) or as nonsurvivors (euthanized or natural death) within 72 h of admission. Presenting weight, body system abnormalities, hydration status, intervention prior to presentation, and singleton versus group presentation were categorically recorded for each individual ECR. The data were modeled using a series of logistic regression models fitted using the general linear model. Individuals were significantly more likely to be nonsurvivors if they presented as singletons (P<0.0001), presented with moderate/severe (P<0.001) or mild integumentary signs (P=0.0261), presented with multi-organ disease (P<0.001), presented with neurologic signs (P<0.0003), or had treatment provided prior to presentation (P=0.031). Factors that did not predict survival status in ECRs included body weight (P=0.210), presence of respiratory signs (P=0.674), and presence of dehydration (P=0.356). These findings may be used at wildlife medical clinics to make triage criteria for euthanasia as well as dedicate limited funds and labor to cases with the best prognosis for survival.

Canine Nonstructural Megaesophagus as a Clinical Sign of Potential Neurological Disease: 99 Cases.

Knowledge regarding the etiology and prognosis for canine megaesophagus (ME) is currently limited to small case series that may now be out of date in light of recent advances in the understanding of neurological syndromes and the availability of advanced diagnostic testing. Ninety-nine dogs diagnosed with nonstructural ME were included. Congenital idiopathic ME was present in 10 cases, with complete resolution of clinical signs in a single case. Eighty-nine cases were considered acquired, with most cases being either idiopathic (42.7%) or associated with myasthenia gravis (38.2%). Idiopathic cases represented a smaller percentage of acquired ME than previously reported. Death or euthanasia directly related to ME occurred in almost 50% of acquired cases, whereas clinical signs persisted in ∼20% of cases and resolved in 30% of cases. A diagnosis of an underlying etiology, in particular myasthenia gravis, was associated with a better outcome in acquired ME. ME continues to be a challenging condition to manage, with a guarded-to-poor prognosis, particularly when an underlying etiology is not identified. Thorough diagnostic testing for an underlying neurological disorder is important in cases with ME as this may allow institution of appropriate treatment and the potential for a better prognosis.

Challenges and standardization of microRNA profiling in serum and cerebrospinal fluid in dogs suffering from non-infectious inflammatory CNS disease.

Non-infectious inflammatory (NII) central nervous system (CNS) conditions are primarily diagnosed by the demonstration of inflammatory changes in the cerebrospinal fluid (CSF). However, less-invasive methods and peripheral biomarkers are desired. Changes in circulating microRNA (miRNA), which are short non-coding regulatory RNAs, may serve as biomarkers of disease. The aim of this pilot study was to investigate selected miRNAs in serum and CSF, hypothesizing that the levels of specific miRNAs in serum correlate with their presence in CSF, and that changes in serum miRNAs levels may reflect CNS disease. We profiled serum and CSF samples using quantitative real-time PCR (qPCR) searching for selected and previously profiled miRNAs in serum (let-7a, let-7c, miR-15b, miR-16, miR-21, miR-23a, miR-24, miR-26a, miR-146a, miR-155, miR-181c and miR-221-3p) and in CSF (let-7c, miR-16, miR-21, miR-24, miR-146a, miR-155, miR-181c and miR-221-3p) from 13 dogs with NII CNS disease and six control dogs. We demonstrated the presence of several miRNAs in CSF (let-7c and miR-21 dominating) and serum (miR-23a and miR-21 dominating). However, we generally failed to reproduce consistent results in CSF samples due to several reasons: unacceptable PCR efficiency, a wide variation between cDNA replicates and/or no-amplification in qPCR suggesting very low levels of the investigated miRNAs in canine CSF. Serum samples performed better, and 10 miRNAs qPCR assays were qualified for analysis. We were nevertheless unable to detect a difference in the expression of miRNA levels between cases and controls. Moreover, we could not confirm the results of recent miRNA investigations of canine CNS diseases. We believe that these disagreements highlight the significant effect of methodological/analytical variation, rather than the incapacity of circulating miRNAs as biomarkers of CNS disease. A secondary aim was therefore to communicate methodological challenges in our study and to suggest recommendations for circulating miRNA profiling, including pre-, post- and analytical methods based on our experience, in order to reach reproducible and comparable results in veterinary miRNA research.

Presence of cerebrospinal fluid antibodies associated with autoimmune encephalitis of humans in dogs with neurologic disease.

BACKGROUND: Presumed autoimmune diseases affecting the central nervous system (CNS) of dogs are common. In people, antibodies against neuronal cell surface antigens that are associated with a wide variety of neurological syndromes have been identified. The presence of cerebrospinal fluid (CSF) autoantibodies that target neuronal cell surface proteins has not been reported in dogs with neurologic disorders. OBJECTIVES: Autoantibodies to neuronal cell surface antigens can be found in the CSF of dogs with inflammatory CNS disease. Our aim was to determine whether 6 neuronal cell surface autoantibodies were present in the CSF of dogs diagnosed with inflammatory and noninflammatory CNS disease. ANIMALS: Client-owned dogs with CNS disease and complete diagnostic evaluation including magnetic resonance imaging and CSF analysis were included. One healthy dog was included as a negative control. METHODS: Cerebrospinal fluid was tested for 6 antigenic targets with a commercially available indirect immunofluorescence assay test kit. RESULTS: There were 32 dogs with neurological disease, 19 diagnosed with inflammatory disease (encephalitis and meningitis), 10 with noninflammatory disease (neoplasia, intervertebral disk disease, degenerative myelopathy, and epilepsy), 2 with no diagnosis, and 1 with neoplasia and meningoencephalitis. Anti-N-methyl-d-aspartate receptor 1 (NMDAR1) antibodies were detected in 3 dogs (3/32; 9.38%). All 3 dogs responded to treatment of meningoencephalomyelitis of unknown etiology (MUE). CONCLUSIONS AND CLINICAL IMPORTANCE: Further evaluation of the prevalence and clinical relevance of CSF and serum antibodies to neuronal cell surface antigens is warranted. Defining antigenic targets associated with encephalitis in dogs might allow diagnostic categorization of MUE antemortem.

Neurological symptoms and mortality associated with Streptococcus gallolyticus subsp. pasteurianus in calves.

Suppurative meningitis-meningoencephalitis (M-ME) is a sporadic disease in neonatal ungulates and only a few studies have reported the involvement of Streptococcus bovis/Streptococcus equinus complex (SBSEC) members in bovine neonatal M-ME. The SBSEC taxonomy was recent revised and previous biotype II/2 was reclassified as S. gallolyticus subsp. pasteurianus (SGP). The aim of this study was to describe a case of fatal neonatal neurological syndrome associated with SGP in calves. Ten calves were monitored because of neurological hyperacute symptoms associate with bilateral hypopyon and death. They were not fed with maternal colostrum; two of them died and were subjected to bacteriological, histopathological and biomolecular analysis as well as antibiotic susceptibility test. Both animals presented lesions mostly concentrated to meninges and brain and had bilateral hypopyon. Nine strains isolated in purity from brain, ocular humors and colon were identified as S. bovis group by using the API Strep system and as S. gallolyticus by using the 16S rRNA sequence. Two of these strains where subjected to WGS analysis that confirmed the sub-species identification and the clonality of the two SGP strains. The strains were found resistant to OT, SXT, MTZ and EN and susceptible to AMP, AMC, KZ and CN. We hypothesized that the syndrome observed could be due to the lack of maternal colostrum feeding. A timely and precise diagnosis could have likely prevented the death of the calves and, since the zoonotic potential of SBSECs members is known, accurate and rapid identification is required.

Suspected neurological toxicity after oral application of fluralaner (Bravecto®) in a Kooikerhondje dog.

BACKGROUND: Although the new isoxazoline drug fluralaner (Bravecto®) is generally well tolerated in dogs, adverse drug reactions involving neurological dysfunction occurred in individual dogs. However, most of these cases are documented inadequately and none of them is reported and discussed in the literature. As isoxazoline drugs target neuronal chloride channels with a clear preference for invertebrates, they are considered to have a good safety profile. However, pharmacodynamic effects in the nervous system of vertebrates cannot be ruled out completely. CASE PRESENTATION: A seven-month-old female Kooikerhondje dog was treated with Bravecto® at the recommended dose. About 24 h after administration, the dog exhibited signs of neurological toxicity, including generalized ataxia, myoclonic jerks, tremor of head and body, muscle twitching and oral dysphagia. All symptoms were transient and the dog fully recovered without any treatment after 10 h. CONCLUSION: This case report describes transient occurrence of neurological dysfunction after administration of Bravecto®. It may help to better classify adverse drug reactions after application of isoxazoline drugs and documents a good prognosis even after occurrence of severe neurological dysfunction in the present case.

Central nervous system diseases of cattle in Georgia, 2001-2017.

In a review of 159 archived bovine autopsy cases submitted to the Georgia Veterinary Diagnostic Laboratory System from 2001 to 2017, we evaluated histologic lesions and other laboratory test results in cases diagnosed with central nervous system (CNS) disease to determine the most common disorders and the rate of definitive morphologic and etiologic diagnosis within the population. The most common breed was Aberdeen Angus or Angus (31%), and female animals comprised 60% of the overall submissions. Gross anatomic changes were described in 33% of cases that had histologic lesions. Suppurative meningoencephalitis was the most common diagnosis (28% of cases overall) and was frequently associated with bacterial sepsis. Lymphocytic meningoencephalitis without an identified etiology was diagnosed in 17% of cases. Polioencephalomalacia was the most commonly identified noninfectious diagnosis (17%). Hydrocephalus was the most common CNS comorbidity and potential congenital defect. Identification of specific agents was sporadic, and infectious disease testing was largely dependent on fluorescent antibody testing, almost all of which were negative. Our findings indicate the common differential diagnoses for cattle with neurologic signs in the southeastern United States, as well the need for a well-defined, methodical diagnostic approach, including autopsy, histology, and appropriate additional laboratory testing.

Schwannosis in Three Foals and a Calf.

Proliferation of ectopic Schwann cells within the central nervous system (CNS) parenchyma (schwannosis) in early life is most commonly associated with human neurofibromatosis type-2 and has been unrecognized in domestic animals. Three foals and a calf, 5 to 11 weeks old, with progressive neurological signs from birth were studied. Histologically, at multiple levels of the spinal cord, all animals had bilateral plaques of proliferative spindle cells, predominantly affecting the white matter adjacent to dorsal and ventral nerve roots and variably extending into the gray matter. Proliferating cells had strong intracytoplasmic immunoreactivity for the Schwann cell markers myelin protein zero and periaxin, highlighting the formation of peripheral nervous system (PNS) myelin within the spinal cord. In all cases, foci of disorganized neural tissue (glioneuronal hamartomas) were present, which in 2 cases formed a mass effect that resulted in syringohydromyelia. Neonatal presentation suggests a congenital maldevelopment of the nervous system, with spontaneous invasion of PNS-derived Schwann cells into the CNS.

Immune-Mediated Central Nervous System Disease-Current Knowledge and Recommendations.

Immune-mediated inflammation is responsible for about 25% of central nervous system disease in dogs. The disease can affect all ages and breeds, but young to middle-aged small breed dogs are over-represented for most forms. Diagnosis consists of advanced imaging (MRI), cerebrospinal fluid analysis, and infectious disease testing, but biopsy is required for definitive diagnosis and classification of the disease into one of the many subtypes. Treatment consists of immunosuppressive medication with the goal being to control and/or improve clinical signs. Current literature shows that prognosis is variable.