Vacuolização neuronal e degeneração espinocerebelar em filhote de Rottweiler / Neuronal vacuolation and spinocerebellar degeneration in a Rottweiller puppy

Background: Spinocerebellar degenerations and neuronal vacuolations are alterations characterized by the formation of vacuoles in the nervous tissue, commonly called status spongiosus. This condition occurs in young Rottweiler dogs causing a disease called Neuronal Vacuolation and Spinocerebellar Degeneration. Clinically, it presents with ataxia of the pelvic limbs, which evolves to generalized ataxia, tetraparesis, and laryngeal paralysis. Histologically, spongiform and vacuolar alterations of the neuropil and neurons are highlighted. This reports a case of neuronal vacuolation and spinocerebellar degeneration in a Rottweiler puppy. Case: Necropsy was performed on the cadaver of a 5-month-old Rottweiler bitch that had been presenting with ataxia for approximately 1 month, in addition to dyspnea, pulmonary crepitations, and microphthalmia. Macroscopic evaluation revealed pale ocular and oral mucosae; marked gastric dilatation and abdominal distension; pulmonary hemorrhage and edema; hepatosplenomegaly; fatty degeneration of the liver; and congestion of meningeal blood vessels. Microscopically, histological evaluation of the spinal cord showed an increase in gray matter cellularity with marked presence of oligodendrocytes and microglia cells; moderate to severe multifocal intracytoplasmic micro- and macrovacuoles with displacement of the neurons' nuclei to the periphery of the cell; central chromatolysis of the neurons adjacent to neurons affected by vacuolation; and mild multifocal necrosis associated with mild multifocal neuronophagia. The white matter exhibited discrete digestion chambers, in addition to marked diffuse congestion of the leptomeninges. In the cerebellum, neurons in the nerve nuclei (emboliform, globose, and fastigial) showed moderate multifocal vacuoles in the cytoplasm, whereas adjacent neurons showed central chromatolysis, necrosis, and mild neuronophagia. Additional histological findings included lymphoid hyperplasia, fatty degeneration of the liver, pulmonary edema, and pulmonary hemorrhage. Discussion: Spongiform and degenerative encephalopathies are diseases recognized worldwide, mainly in cattle and sheep. However, the identification of these changes in new species has led to the need for further investigations. In dogs, the first reports occurred in 1995 and 1997 in Rottweiler animals. This disease affects young dogs, and although its pathogenesis is not completely known, it is believed to be associated with a genetic mutation in the RAB3GAP1 gene. Clinically, it is associated with clinical neurological manifestations, including progressive ataxia of the pelvic limbs, changes in spinal reflex, disordered proprioceptive reactions, laryngeal paralysis, as well as behavioral and gait alterations. In the clinical evaluation, leukoencephalomyelopathy and neuroaxonal dystrophy should be diseases considered as possible differential diagnoses, as they present with similar alterations. However, in histological evaluation, the exclusion of both is basically due to the absence of neuronal vacuolization. Unfortunately, the definitive diagnosis is only made post mortem, through a histopathological evaluation of the nervous tissue. Because it is a disease whose pathogenesis is little known and which shows signs of having a genetic character, histopathological examination for diagnostic purposes in young animals with neurological signs is of great importance.

Listeria innocua and serotypes of Listeria monocytogenes isolated from clinical cases in small ruminants in the northwest of Uruguay / Listeria innocua e serotipos do Listeria monocytogenes isoladas dos casos clínicos em pequenos ruminantes no noroeste do Uruguai

Listeriosis is an infectious disease caused by bacteria of the genus Listeria, the neurological form being more common in ruminants. There are many reports of listeriosis in small ruminants in the region that includes Brazil, Argentina and Uruguay. However, these diagnoses were mainly based on histological lesions in the central nervous system (CNS) without the isolation and characterization of the involved Listeria strains. The aim of this study was to report sheep and goats listeriosis cases from 2016 to 2021 in northwestern Uruguay. The diagnosis was made according to lesions observed at histopathology, plus Listeria isolation in CNS, identifying it at specie and serotype level. Nine animals (n=9) of three outbreaks and five sporadic cases of listeriosis were studied. Sheep was the species with more cases in relation to goats, and adults were the category most affected. Cases occurred in spring and less frequently in winter. All presented neurological clinical signs and the lesions in the CNS were consistent with suppurative meningoencephalitis and micro-abscesses in the brainstem. In eight of nine CNS samples, Listeria strains were isolated (seven L. monocytogenes and one L. innocua). All the L. monocytogenes isolates carried the inlA gene; serotyping showed that four strains belonged to serotype 1/2b, two isolates belonged to serotype 4b, and one to serotype 1/2a. Considering that listeriosis is a common disease in this region and the fact that isolates are scarcely recovered from small ruminants, it would be important to emphasize the need for Listeria isolation to better characterize the strains that affect animals. Not only to improve knowledge about the epidemiology of disease but also with the objective of developing serotype specific vaccines for animal use.

Listeriose uma doença bacteriana causada pelo gênero Listeria, a forma nervosa é a mais comum em ruminantes. No Brasil, Argentina e Uruguai há vários relatos de listeriose em pequenos ruminantes com diagnóstico baseado na histopatologia do sistema nervoso central (SNC), sem o isolamento e a caracterização do agente. O objetivo deste trabalho foi relatar uma série de casos diagnosticados em ovinos e caprinos no período 2016-2021 no noroeste do Uruguai. O diagnóstico foi feito basado nas lesões observadas na histopatologia, e caracterização das cepas de Listeria recuperadas do SNC quanto à espécie e sorotipo. Nove animais (n=9) do três surtos e cinco casos isolados de listeriose foram estudados. Os ovinos foram a espécie com o maior número de casos em relação aos caprinos, sendo os animais adultos a categoria mais afetada em ambas espécies. A doença ocorreu principalmente na primavera com alguns casos observados no inverno. Todos os casos apresentavam sinais clínicos nervosos e as lesões no SNC caracterizavam-se por meningoencefalite supurativa com presença de microabscessos no tronco encefálico. Em oito de nove amostras do SNC foram isoladas cepas de Listeria (sete L. monocytogenes e uma L. innocua). Todos os isolados de L. monocytogenes continham o gene inlA; a sorotipagem apresentou quatro cepas do serotipo 1/2b, duas cepas serotipo 4b e uma cepa 1/2a. Levando em consideração que nesta região a listeriose é uma doença frequente e que existem poucos isolados recuperados de casos clínicos em pequeño ruminantes, torna-se relevante o isolamento deste agente para caracterização das cepas que afetam os animais. Não só para melhorar o conhecimento sobre a epidemiologia da doença, mas também com o objetivo de desenvolver vacinas sorotipo-especificas para uso animal.

Antiparkinsoniano para tratamento de sequelas neurológicas causadas pela cinomose / Antiparkinsonian for treatment of neurological sequels caused by canine distemper

Background: Canine distemper (CD) is a highly contagious viral disease caused by the canine distemper virus (CDV). In dogs, CDV infection is characterized by the presentation of systemic and/or neurological signs with viral persistence in some organs, including the central nervous system (CNS). Neurological damages resulting from CD are a defiance for veterinarians, due to occasioned clinical sequels that influence the patient quality of life. The treatment of sequelae should seek to promote the resolution or decrease of the deleterious effects that impede the patient independence. Thus, the present report aims to describe the action of antiparkinsonian medication (levodopa associated with carbidopa) administered to 3 dogs who presented neurological sequels resulting from the canine distemper. Cases: Dog 1. A 9-month-old male mixed breed; Dog 2. A 6-month-old male Shih Tzu. Dog 3. A 8-years-old bitch mixed breed. All animals were referred for neurological care because presented neurological damages after distemper involvement. Only the Dog 2 was vaccinated to CD. Dog 1 (mixed male) had severe myoclonus, lack of proprioception, decreased of muscle tonus and paralysis in both pelvic limbs, associated with a marked thoracolumbar kyphosis. Dog 2 (a puppy Shih Tzu male) presented myoclonus in PL, proprioceptive loss in thoracic and pelvic limbs, absence of withdrawal reflex in thoracic and pelvic limbs, decrease in muscle tonus in pelvic limb and increase in thoracic limb. Dog 3 (adult unneutered bitch) presented intense myoclonus, absence of proprioception, decrease in muscle tonus and paresis of pelvic limb. All patients were treated with antiparkinsonian medication (levodopa 250 mg associated with carbidopa 25 mg) with following dosages: Dog 1 received a commercially available tablet, orally once a day for 30 days, while Dogs 2 and 3 had doses calculated by extrapolation allometric. For the Dog 2 it was prescribed 0.25 mg of levodopa and 0.025 mg of carbidopa daily for 30 days. Dog 3 was treated with 1 mg of levodopa and 0.1 mg of carbidopa patient day for the same period. Thirty days after starting the treatment, the 3 patients were evaluated again, and showed improvement of the motor signs, and the treatment was maintained. At the next return (30 days): Dog 1 showed significant improvement, however, Dog 2 started to present epileptic seizures and nystagmus that were treated with levetiracetam, while the Dog 3 not returned. As Dog 1 had a better prognosis, treatment was maintained for 1 year, with the frequency being changed from 24 h x 24 h to 48 h x 48 h after 30 days and 72x72 h after another 30 days. Unfortunately, Dog 2 had a worsening of epileptic condition and died, while Dog 3 died by road-kill. Discussion: The cases reported are uncommon, because not exist information about the use of antiparksonian to treatment of neurological damages occasioned by canine distemper. Although there are emerging therapies, such as the use of mesenchymal stem cells, that can reduce these sequels, the access is still restricted to a few professionals. Thus, the use of medications for demyelinating diseases, as antiparkinsonian, may be an alternative. In fact, the three reported patients showed recovery of the motor and sensorial damages observed, which corroborates with the possibility of a new treatment using antiparkinsonian or other drugs to demyelinating diseases.

Compressive lesions in the central nervous system of buffaloes / Lesões compressivas no sistema nervoso central de bubalinos

This study describes, through a retrospective study, the epidemiological and clinical-pathological findings of compression in the central nervous system (CNS) of buffaloes. The study includes observations made in 15 animals from 1998 to 2021 by reviewing the clinical records of animals with compressive injuries of the CNS treated at the Veterinary Hospital of the Veterinary Medicine Institute of the Federal University of Pará. The animals treated with clinical signs compatible with CNS compressive lesions were subjected to general and specific clinical examinations of the nervous system. Blood samples were collected from four animals for complete blood counts, and cerebrospinal fluid (CSF) samples were collected from three animals for physical evaluation. Thirteen animals were necropsied. The age range of the affected animals ranged from four months to 11 years of age, with a greater frequency over age 12 months (80%, 13/15). The most affected vertebral segment was between T3 and L3 (60%, 9/15), followed by brain injury (20%, 3/15), the L4-S2 segment (13.3%, 2/15) and the C1-C5 segment (6.7%, 1/15). The clinical findings varied according to the location of the lesion. The necropsy findings revealed paraypophyseal abscess in the brainstem and vertebral body, subarachnoid hematoma, lymphoma and vertebral fractures. The performance of a thorough clinical examination of the CNS combined with the necropsy findings was important to characterize the clinical picture and to locate the cause and the affected CNS segments in the buffaloes studied. It is important to include CNS compressive lesions among the neurological diseases of buffaloes.

Esse trabalho descreve, através de estudo retrospectivo, os achados epidemiológicos e clínico-patológicos de compressão no sistema nervoso central (SNC) de bubalinos. O estudo compreendeu as observações realizadas em 15 animais, durante os anos de 1998 a 2021, por meio da revisão dos arquivos de fichas clínicas de animais com lesões compressivas no SNC atendidos pelo Hospital Veterinário do Instituto de Medicina Veterinária da Universidade Federal do Pará. Os animais atendidos com sinais clínicos compatíveis com lesões compressivas no SNC foram submetidos a exames clínicos geral e específico do sistema nervoso. Foram coletadas amostras de sangue de quatro animais para realização de hemograma e amostras de líquido cefalorraquidiano (LCR) de três animais para avaliação física. Foram necropsiados 13 animais. A faixa etária dos animais acometidos variou de quatro meses a 11 anos de idade, com maior frequência na faixa acima de 12 meses (80%, 13/15). O segmento vertebral mais acometido foi entre T3-L3 (60%, 9/15), seguida por lesão no encéfalo (20%, 3/15), pelo segmento L4-S2 (13,3%, 2/15) e pelo segmento C1-C5 (6,7%, 1/15). Os achados clínicos variaram de acordo com a localização da lesão. Os achados de necropsia revelaram abscesso parahipofisário, no tronco encefálico e no corpo da vértebra, hematoma subaracnoidea, linfoma e fraturas vertebrais. A realização de um minucioso exame clínico do SNC associado aos achados de necropsia foram importantes para caracterizar o quadro clínico e localizar a causa e os seguimentos acometidos do SNC nos búfalos estudados. Torna-se importante incluir as lesões compressivas do SNC entre as enfermidades neurológicas dos bubalinos.

Compressive lesions in the central nervous system of cattle: a retrospective study of 50 cases in the Amazon biome / Lesões compressivas no sistema nervoso central de bovinos: um estudo retrospectivo de 50 casos no bioma amazônico

The present study gathered epidemiological and clinical-pathological information about cattle with compressive lesions in the central nervous system (CNS). The retrospective study included observations made in 50 cattle from 1998 to 2021 by reviewing the clinical records of animals with compressive lesions in the CNS treated at the Veterinary Hospital of the Veterinary Medicine Institute of the Federal University of Pará. The animals had clinical signs and were subjected to general and specific clinical examination of the nervous system. Blood samples were collected from 13 animals for complete blood counts, and cerebrospinal fluid (CSF) samples were collected from four animals for physical evaluation. Twenty-nine cattle underwent necropsy. The most affected sites were the T3-L3 (46%, 23/50), C1-C5 (22%, 11/50), C6-T2 (14%, 7/50), sacrococcygeal vertebrae, (4%, 2/50), L4-S2 (2%, 1/50), brain (8%, 4/50) and cerebellum (4%, 2/50). The age of the affected cattle ranged from 20 days to 16 years, with a higher occurrence in animals younger than 12 months (56%, 28/50). More Females were affected (58%, 29/50) than males (42%, 21/50). The clinical signs varied according to the location of the lesion and were mainly represented by ataxia, paresis or paralysis of the limbs, inability to stand and walk, postural changes, hyperesthesia in the extremities, and loss of skin sensitivity at the location of the lesion. The necropsy findings revealed changes such as abscesses in the vertebral body; intervertebral space in the medullary canal, pituitary and cerebellum; granuloma in the arch of the vertebra; fractures of the body of the vertebrae; subarachnoid haematoma; congenital bone alteration causing spinal cord compression; and spondylitis. Detailed anamnesis and clinical examination of the CNS, associated with necropsy findings, were important to determine the cause of the disease, correlate with the clinical picture and locate the affected segments of the CNS in the cattle. It is important to include these diseases in the list of differential diagnoses in cattle with nervous symptoms.

O presente trabalho reúne informações epidemiológicas e clínicopatológicas de bovinos com lesões compressivas no sistema nervoso central (SNC). O estudo retrospectivo compreendeu as observações realizadas em 50 bovinos durante os anos de 1998 a 2021, por meio da revisão dos arquivos de fichas clínicas de animais com lesões compressivas no SNC atendidos pelo Hospital Veterinário do Instituto de Medicina Veterinária da Universidade Federal do Pará. Os animais atendidos com sinais clínicos foram submetidos a exame clínico geral e específico do sistema nervoso. Foram coletadas amostras de sangue de 13 animais para realização de hemograma e amostras de líquido cefalorraquidiano de quatro animais para avaliação física. Foram submetidos à necropsia 29 bovinos. Os locais mais acometidos foram as vértebras T3-L3 (46%, 23/50), C1-C5 (22%, 11/50), C6-T2 (14%, 7/50), sacrococcígea (4%, 2/50) e L4-S2 (2%, 1/50); cérebro (8%, 4/50) e cerebelo (4%, 2/50). A idade dos bovinos afetados variou de 20 dias a 16 anos, com maior ocorrência em animais com menos de 12 meses (56%, 28/50). As fêmeas foram mais acometidas (58%, 29/50) do que os machos (42%, 21/50). Os sinais clínicos variaram de acordo com a localização da lesão e foram representados principalmente por ataxia, paresia ou paralisia dos membros, incapacidade de se levantar e de ficar em estação, alterações posturais, hiperestesia nas extremidades, além de perda da sensibilidade cutânea relacionada com a localização da lesão. Os achados de necropsia revelaram alterações como abscessos no corpo vertebral, no espaço intervertebral, no canal medular, para-hipofisário e no cerebelo; granuloma no arco da vértebra, fraturas do corpo das vértebras; hematoma subaracnoide; alteração óssea congênita causando compressão medular e espondilite. Anamnese detalhada e exame clínico do SNC, associados aos achados de necropsia foram importantes para determinar a causa da doença, correlacionar com o quadro clínico e localizar os segmentos acometidos do SNC dos bovinos. Torna-se importante incluir estas enfermidades na lista de diagnósticos diferenciais em bovinos que apresentem sintomatologia nervosa.

4-hydroxy-2-nonenal as a marker of the oxidative stress in brains of dogs with canine distemper / 4-hidroxi-2-nonenal como marcador de estresse oxidativo no cérebro de cães com cinomose

Canine Distemper is a disease caused by Canine morbillivirus (CM), a pantropic virus that can affect the central nervous system (CNS), causing demyelination. However, the pathogenesis of this lesion remains to be clarified. Brain samples of 14 naturally infected dogs by CM were analyzed to evaluate the presence of oxidative stress and demyelination. RT-PCR assay was performed to confirm a diagnosis of canine distemper in the brain, immunohistochemistry anti-CM was used to localize the viral proteins in the tissue, and anti-4-hydroxy-2-nonenal (4-HNE) was a marker of a product of lipid peroxidation. The results showed the presence of viral proteins in the demyelinated area with the presence of 4-HNE. Our results suggest that the CM virus infection causes oxidative stress leading to lipid peroxidation, which causes tissue damage and demyelination. In conclusion, oxidative stress plays a significant role in canine distemper pathogenesis in the CNS.(AU)

A cinomose canina é uma doença causada pelo Morbilivírus canino (CM), um vírus pantrópico que pode afetar o sistema nervoso central (SNC), causando desmielinização. No entanto, a patogênese dessa lesão não está totalmente esclarecida. RT-PCR e imuno-histoquímica foram realizadas para confirmação do diagnóstico de cinomose em amostras de encéfalo de 14 cães naturalmente infectados. Após confirmação, foi realizada uma avaliação do estresse oxidativo por imuno-histoquímica com uso de anti-4-hidroxi-nonenal (4HNE) como marcador de produtos resultantes da peroxidação lipídica. Os resultados sugerem que a infecção pelo CM causa estresse oxidativo no tecido, levando a peroxidação lipídica, a qual causa danos ao tecido, culminando com desmielinização. Conclui-se que o estresse oxidativo tem papel importante na patogênese da cinomose canina no sistema nervoso central.(AU)

Assessment of melatonin-alpha adrenergic receptor complexes by molecular docking analysis / Avaliação dos complexos melatonina-receptores alfa-adrenérgicos por análises de docagem molecular

The pineal melatonin (N-acetyl-5-methoxytryptamine) is a molecule associated in a way or another with probably all physiological systems, aiming to fulfil its functional integrative roles in central nervous system activity, sleep and wakefulness cycles, energy metabolism and thermoregulation, immune, reproductive, endocrine, cardiovascular, respiratory and excretory systems. Within this context, the present study aimed to assess in silico the formation of complexes between ligand melatonin and other potential receptor proteins by molecular docking analyses. The main steps established in this experimental procedure were: a) search and selection of the 3D structure of the melatonin from DrugBank; b) search and selection of 3D structures of other target receptor proteins using STRING, protein BLAST and database PDB; and c) formation of the complexes between melatonin and receptors selected using AutoDock4.0 server by molecular docking analyses. High reliability score and significant similarity were only identified between type 1B melatonin and alpha-2A adrenergic receptor. Thus, molecular docking assays were carried out using ligand melatonin and crystallographic structures of the alpha-2A adrenergic receptor coupled to an antagonist (ID PDB 6kux) and a partial agonist (ID PDB 6kuy) available in the database PDB. Binding energy values of -6.79 and -6.98 kcal/mol and structural stability by non-covalent intermolecular interactions were predicted during the formation of complexes between melatonin and alpha-2A adrenergic receptor 6kux and 6kuy, respectively. In this way, the findings described in current study may indicate strong interactions between melatonin and adrenoceptors, suggesting its possible partial agonist effect on the activation of the alfa-2A adrenergic receptor.(AU)

A melatonina pineal (N-acetil-5-metoxitriptamina) é uma molécula associada de um modo ou outro com provavelmente todos os sistemas fisiológicos, visando cumprir seus papéis funcionais integradores na atividade do sistema nervoso central, ciclos de sono e vigília, metabolismo energético e termorregulação, sistemas imunológico, reprodutivo, endócrino, cardiovascular, respiratório e excretor. Assim, o presente estudo objetivou avaliar in silico a formação de complexos entre o ligante melatonina e outras proteínas potenciais receptoras por meio de análises de docagem molecular. As principais etapas estabelecidas neste procedimento experimental foram: a) busca e seleção da estrutura 3D da melatonina a partir do banco de dados DrugBank; b) busca e seleção de estruturas 3D de outras proteínas receptoras-alvo utilizando STRING, proteína BLAST e o banco de dados PDB; e c) avaliação da formação dos complexos entre melatonina e receptores selecionados a partir do servidor AutoDock4.0 para análises de docagem molecular. Alto escore de confiabilidade e similaridade significativa foram identificados apenas entre a melatonina do tipo 1B e o receptor alfa-2A adrenérgico. Valores de energia de ligação de -6,79 e -6,98 kcal/mol e estabilidade estrutural pela presença de interações intermoleculares não covalentes foram preditos durante a formação de complexos entre o ligante melatonina e os receptores adrenérgico alfa-2A 6kux e 6kuy, respectivamente. Dessa forma, os achados descritos no presente estudo podem indicar fortes interações entre melatonina e adrenoceptores, sugerindo seu possível efeito agonista parcial na ativação do receptor alfa-2A adrenérgico.(AU)

Antimicrobial resistance profile of Staphylococcus spp. isolates in cattle herds from Western Amazon / Perfil de resistência antimicrobiana de Staphylococcus spp. isolados em rebanhos leiteiros da Amazônia Ocidental

Staphylococcus is one of the most frequent etiological agents of bovine mastitis, causing economic losses to milk farming. This study aimed to describe the milk production and management practices in 15 herds located in three microregions of the State of Rondônia and to identify the antimicrobial resistance profile of 97 isolates of the genus Staphylococcus from these herds. The isolates were subjected to antimicrobial susceptibility tests using the agar diffusion method. Twenty-nine S. aureus isolates were selected to determine their minimum inhibitory concentration (MIC). In the farms studied, the breeding system was semi-intensive, with the Girolando breed being predominant. Milking was performed predominantly using a mechanical milking system (86.7%), twice a day (66.7%), in the presence of the calf (53.8%). The average number of lactating cows in the farms was 24, with an average milk production of 204.9 L d-1 and a milk productivity of 10.2 L animal-1 d-1. The use of antimicrobials for the treatment and prevention of bovine mastitis was reported for all properties, and therapy for dry cows was adopted in 80% of the herds. The percent susceptibility to antimicrobials ranged from 85.5% to 100% for S. aureus, 22.2% to 88.9% for coagulase-positive staphylococci (CPS), and 69.2% to 100% for coagulase-negative staphylococci (CNS), with the highest resistance frequencies for penicillin, ampicillin, and tetracycline. Among the S. aureus isolates, 100% susceptibility to oxacillin, cefalexin, and gentamicin was observed, and among the CNS isolates, 100% susceptibility to gentamicin was observed. None of the antimicrobials tested showed 100% in vitro effectiveness for CPS. CPS and CNS presented lower percentages of susceptibility to penicillin, ampicillin, and tetracycline than the S. aureus isolates. Twelve resistance patterns were detected, six of which were multiresistance patterns. The most prevalent resistance patterns were penicillin and ampicillin (PEN-AMP) and penicillin, ampicillin, and tetracycline (PEN-AMP-TET). Results of the MIC assay revealed that all 29 S. aureus isolates were susceptible to cephalothin, cefoxitin, tetracycline, and erythromycin, whereas 25 (86.2%) were susceptible to penicillin.(AU)

O gênero Staphylococcus destaca-se como um dos agentes etiológicos mais frequentes da mastite bovina, causando prejuízos econômicos à pecuária de leite. Este estudo teve o objetivo de descrever a produção de leite e práticas de manejo de 15 rebanhos localizados em três microrregiões do Estado de Rondônia, e identificar o perfil de resistência aos antimicrobianos de 97 isolados do gênero Staphylococcus provenientes destes rebanhos. Os isolados foram submetidos a testes de suscetibilidade a antimicrobianos, utilizandose a técnica de difusão em ágar. Foram selecionados 29 isolados de Staphylococcus aureus (S. aureus) para determinação da concentração inibitória mínima (CIM). Nas propriedades estudadas, o sistema de criação era semi-intensivo, com predomínio da raça Girolando. A ordenha era realizada predominantemente em sistema de ordenha mecânica (86,7%), duas vezes ao dia (66,7%) e com a presença do bezerro (53,8%). A média do número de vacas em lactação das propriedades era de 24 animais, com média de produção de leite de 204,9 L d-1 e produtividade de leite de 10,2 L animal-1 d-1. O uso de antimicrobianos para o tratamento e prevenção da mastite bovina foi relatado em todas as propriedades, sendo adotada a terapia da vaca seca em 80% dos rebanhos. A percentagem de susceptibilidade aos antimicrobianos variou de 85,5 a 100% para S. aureus, 22,2 a 88,9% para Staphylococcus coagulase positivos (SCP) e 69,2 a 100% para Staphylococcus coagulase negativos (SCN), sendo as maiores frequências de resistência para penicilina, ampicilina e tetraciclina. Entre os isolados de S. aureus foi observada 100% de susceptibilidade aos antimicrobianos oxacilina, cefalexina e gentamicina, e entre os isolados de SCN, 100% de susceptibilidade à gentamicina. Nenhum dos antimicrobianos testados apresentou 100% de efetividade in vitro para SCP. SCP e SCN apresentaram menores percentagens de susceptibilidade à penicilina, ampicilina e tetraciclina do que os isolados de S. aureus. Foram observados 12 padrões de resistência, sendo seis padrões de multirresistência. Os padrões de resistência mais prevalentes foram resistência à penicilina e ampicilina (PEN-AMP) e à penicilina, ampicilina e tetraciclina (PEN-AMP-TET). A determinação da CIM dos 29 isolados de S. aureus mostraram que todos foram susceptíveis à cefalotina, cefoxitina, tetraciclina e eritromicina, e 25 (86,2%) foram susceptíveis à penicilina.(AU)

Listeriosis outbreak in sheep raised in feedlots in the Southern Region of Rio Grande do Sul state, Brazil

Background: A listeriosis outbreak in a sheep fattening feedlot in the Southern Region of Rio Grande do Sul State, Brazilis described. This disease is caused by Listeria monocytogenes and represents a risk to public health since it affects notonly ruminants but also humans. This agent is widely spread in the environment, such as in the soil and water. It is alsofound in decaying vegetable matter and the feces and fluids of domestic animals. The aim of this study was to describe alisteriosis outbreak in sheep raised in feedlots, its epidemiology, and to establish the importance of this disease in this typeof sheep management system, evaluate the possible sources of infection, and suggest ways to control it.Cases: Sheep were kept in a 2-sector shed, one with east solar orientation and the other with west solar orientation, thelatter with free access to domestic birds. Sheep were fed silage and concentrate. Seven sheep were affected, 5 died and 2recovered. Clinically, the sheep displayed loss of balance, excessive drooling, and tremors; one exhibited circling, headdeviation, apathy, nystagmus, lateral recumbency, paddling, and labored breathing. At necropsy, macroscopic lesions werenot found, and histologically several micro-abscesses and perivascular cuffs with lymphocytes, macrophages, and neutrophils were present in the brain stem. Listeria monocytogenes suspected colonies were observed in the microbiologicalculture, and the bacteria was identified by biochemical analysis. The immunohistochemistry test in brain stem sectionswas positive for the antibody BD DifcoTM Listeria O Antiserum Poly Serotypes 1 and 4.Discussion: A listeriosis outbreak in a feedlot sheep was confirmed through epidemiological findings, histological lesions,bacterial culture, and immunohistochemistry analysis. This infection is frequent...

Listeriosis outbreak in sheep raised in feedlots in the Southern Region of Rio Grande do Sul state, Brazil

Background: A listeriosis outbreak in a sheep fattening feedlot in the Southern Region of Rio Grande do Sul State, Brazilis described. This disease is caused by Listeria monocytogenes and represents a risk to public health since it affects notonly ruminants but also humans. This agent is widely spread in the environment, such as in the soil and water. It is alsofound in decaying vegetable matter and the feces and fluids of domestic animals. The aim of this study was to describe alisteriosis outbreak in sheep raised in feedlots, its epidemiology, and to establish the importance of this disease in this typeof sheep management system, evaluate the possible sources of infection, and suggest ways to control it.Cases: Sheep were kept in a 2-sector shed, one with east solar orientation and the other with west solar orientation, thelatter with free access to domestic birds. Sheep were fed silage and concentrate. Seven sheep were affected, 5 died and 2recovered. Clinically, the sheep displayed loss of balance, excessive drooling, and tremors; one exhibited circling, headdeviation, apathy, nystagmus, lateral recumbency, paddling, and labored breathing. At necropsy, macroscopic lesions werenot found, and histologically several micro-abscesses and perivascular cuffs with lymphocytes, macrophages, and neutrophils were present in the brain stem. Listeria monocytogenes suspected colonies were observed in the microbiologicalculture, and the bacteria was identified by biochemical analysis. The immunohistochemistry test in brain stem sectionswas positive for the antibody BD DifcoTM Listeria O Antiserum Poly Serotypes 1 and 4.Discussion: A listeriosis outbreak in a feedlot sheep was confirmed through epidemiological findings, histological lesions,bacterial culture, and immunohistochemistry analysis. This infection is frequent...(AU)

Meningioma intracraniano em cão - tratamento com radioterapia / Intracranial meningioma in a dog - treatment with radiotherapy

Background: The most common primary brain neoplasm is meningioma. Dolichocephalic breeds are predisposed and there is no sexual predilection. Clinical signs depend on the location and size of the tumor and have a progressive course. Primary treatement includes surgery, radiotherapy or both. This study aimed to describe the treatment of a dog with suspected intracranial meningioma with definitive radiotherapy, which resulted in significant clinical improvement and prolonged survival. Case: A 9-year-old Shetland Shepherd bitch was diagnosed with a head tilt to the left side that progressed over a few weeks. She previously received corticosteroid therapy, which resulted a clinical improvement that worsened after treatment was discontinued. Computed tomography revealed an extra-axial brain mass in the caudal fossa, lateralized to the right, welldelimited, and measuring approximately 1.5 × 1.4 × 1.7 cm, suggestive of intracranial meningioma. The patient was treated with radiotherapy using Cobalt-60 equipment, with 18 daily fractions of 2.5 Gy at a total dose of 45 Gy using parallel and opposite technique fields. A new tomography performed 30 days after treatment showed a remission of 85% of the initial brain mass measuring approximately 0.9 × 1.0 × 0.5 cm, as well as complete resolution of the clinical signs initially presented. After 14 months, the patient presented with signs of lethargy and ataxia and was medicated with hydroxyurea at a dose of 50 mg/kg 3 times a week and corticosteroid therapy. However, the patient's neurological condition deteriorated, and she was subjected to reirradiation using the same protocol used previously, which resulted in clinical improvement and a 54% reduction in tumor volume on magnetic resonance. As a late side effect, only permanent alopecia in the irradiated region was observed. The patient died of disease 330 days after the second course of radiotherapy, with a total survival time of 1087 days. Discussion: Meningiomas are extra-axial neoplasms of the central nervous system that grow inside the dura mater. The literature shows that meningiomas are more common in dolichocephalic races with a mean age of 9 years, which supports our findings. Meningiomas most commonly affect the cortical thalamus and cerebellopontine region in dogs, which are normally associated with vestibular symptoms, as seen in this case. Diencephalic damage can result in vestibular signals since the thalamus functions as a relay station for vestibular afferent stimuli that are relayed to the cerebral cortex. In addition to the vestibular syndrome, common clinical signs associated with meningiomas in dogs include seizures, behavioral changes, and walking in circles, which are frequently misinterpreted due to tumor-induced side effects, such as cerebral edema, obstructive hydrocephalus, and cerebral hernia. Advanced imaging techniques should be used to diagnose intracranial neoplasms. In this case, computed tomography was critical for diagnosis and treatment planning. Meningioma treatment may comprise palliative measures, surgery, and radiotherapy. Radiotherapy as a single treatment can improve the quality of life with a decrease in clinical signs and a median survival time of approximately 250-536 days, as reported in the literature. Hydroxyurea can be a therapeutic option in inoperable cases and for patients with clinical limitations to undergo successive anesthesia during radiotherapy. Its most serious side effect is progressive myelosuppression. It can cause temporary partial tumor remission and improvement in clinical signs. As previously stated, radiotherapy can be an effective primary treatment option for treating intracranial meningiomas in dogs, with significant improvement in neurological clinical signs and mild side effects.

Meningoencephalitis caused by Bovine alphaherpesvirus 5 in Pernambuco, Brazil / [Meningoencefalite causada pelo Bovine alphaherpesvirus 5 em Pernambuco, Brasil]

Objetivou-se descrever a ocorrência do Bovine alphaherpesvirus 5 (BoHV5) como causa de meningoencefalite não supurativa em bovinos do estado de Pernambuco, Brasil. Para tanto, 32 amostras de sistema nervoso embebidas em parafina foram obtidas de animais acometidos por doenças neurológicas atendidos na Clínica de Bovinos de Garanhuns da Universidade Federal Rural de Pernambuco (CBG-UFRPE), entre 2012 e 2016. As amostras foram analisadas quanto à presença do gene da glicoproteína C do BoHV5 por reação em cadeia da polimerase (PCR). Dois animais (6,25%) tiveram resultado positivo à PCR, e sua análise de sequenciamento indicou 100% de similaridade para o BoHV5. Os resultados histopatológicos desses dois animais revelaram lesões multifocais de meningoencefalite não supurativa associada à polioencefalomalácia, presença de corpúsculos de inclusão basofílicos, infiltração de células de Gitter e presença de manguitos perivasculares. A PCR se mostra uma importante ferramenta para diferenciação das infecções por BoHV5 de outras enfermidades neurológicas de bovinos, especialmente a raiva.(AU)

Crotalaria spectabilis poisoning in a horse

Plant poisoning is an important cause of death in horses and cattle in Brazil. Crotalaria spp. has stood out in this scenario due to its toxic potential caused by monocrotaline, a pyrrolizidine alkaloid found throughout the plant, mainly in seeds. Here is reported a case of Crotalaria spectabilis poisoning a horse. A horse consumed oats contaminated with Crotalaria spectabilis seed and presented clinical signs of toxicosis characterized by jaundice, progressive weight loss, hemoglobinuria, subcutaneous edema in the pectoral region and neurological symptoms typical of hepatic encephalopathy. In the serum evaluation, there was an increase in the activity of the enzymes alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and aspartate transaminase (AST), urea, creatinine and creatine phosphokinase (CPK). At necropsy, the main macroscopic findings were opaque and congested liver with capsular irregularity and accentuated the lobular pattern, trachea with foamy and pinkish fluid and congested and edematous pulmonary lobes. The main histopathological findings were hepatic fibrosis, periportal ductal hyperplasia, centrilobular necrosis, megalocytosis and binucleated hepatocytes. The brain parenchyma showed perivascular edema and Alzheimer type II astrocytes. Crotalaria spp. is among the main plants that cause acute or chronic mortality after exposure to the toxic compound in horses and farm animals.(AU)

Crotalaria spectabilis poisoning in a horse

Plant poisoning is an important cause of death in horses and cattle in Brazil. Crotalaria spp. has stood out in this scenario due to its toxic potential caused by monocrotaline, a pyrrolizidine alkaloid found throughout the plant, mainly in seeds. Here is reported a case of Crotalaria spectabilis poisoning a horse. A horse consumed oats contaminated with Crotalaria spectabilis seed and presented clinical signs of toxicosis characterized by jaundice, progressive weight loss, hemoglobinuria, subcutaneous edema in the pectoral region and neurological symptoms typical of hepatic encephalopathy. In the serum evaluation, there was an increase in the activity of the enzymes alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and aspartate transaminase (AST), urea, creatinine and creatine phosphokinase (CPK). At necropsy, the main macroscopic findings were opaque and congested liver with capsular irregularity and accentuated the lobular pattern, trachea with foamy and pinkish fluid and congested and edematous pulmonary lobes. The main histopathological findings were hepatic fibrosis, periportal ductal hyperplasia, centrilobular necrosis, megalocytosis and binucleated hepatocytes. The brain parenchyma showed perivascular edema and Alzheimer type II astrocytes. Crotalaria spp. is among the main plants that cause acute or chronic mortality after exposure to the toxic compound in horses and farm animals.

Síndrome do mau ajustamento neonatal em potros: foco em neuroesteróides / Foal mal adjustment syndrome: focus on neurosteroids

O processo de transição do feto para a vida extra-uterina é considerado um período crítico que requer complexas adaptações fisiológicas do potro neonato. Eventos estressores de origem hipóxicoisquêmicas no periparto podem desencadear um quadro de encefalopatia neonatal equina, também conhecida como síndrome do mau ajustamento neonatal. O diagnóstico é feito baseado na avaliação clínica e na anamnese e avaliação do histórico da gestação. Casos leves a moderados tem prognóstico favorável. É imprescindível o entendimento da endocrinologia da gestação, do papel dos neuroesteróides no desenvolvimento do sistema nervoso fetal para que o estabelecimento precoce da terapia adequada seja realizado de maneira bem sucedida. Assim, o objetivo do presente é abordar os principais aspectos clínicos e fisiopatológicos da Síndrome do Mau Ajustamento Neonatal em neonatos equinos, com foco especial no papel dos neuroesteróides durante a maturação cerebral do feto no terço final da gestação e na transição para a vida extra-uterina.

The transition from fetus to extrauterine life is considered a critical period that requires complex physiological adaptations on the part of the newborn foal. Peripartum hypoxic-ischemic stressors can result in equine neonatal encephalopathy, also known to as neonatal maladjustment syndrome. The diagnosis is made based on clinical examination, anamnesis, and a review of the mare’s pregnancy history. Cases that are mild to moderate in severity have a favorable prognosis. It is critical to understand the endocrinology of pregnancy and the role of neurosteroids in the development of the fetal nervous system in order to successfully initiate appropriate therapy early. Thus, the purpose of this article is to discuss the major clinical and pathophysiological aspects of neonatal maladjustment syndrome in equine neonates, with a particular emphasis on the role of neurosteroids during fetal brain maturation in the final third of pregnancy and during the transition to extrauterine life.

Central nervous system infiltration in acute lymphoblastic leukemia in a dog

Background: Acute lymphoblastic leukemia (ALL) is a malignant neoplasia in which there is proliferation of lymphoid progenitor cells in the bone marrow, blood, and extramedullary sites. This disorder has a fast and progressive development; in dogs, cases of infiltration of ALL cells in the central nervous system (CNS) are uncommon and rare. Diagnosis can be achieved with the help of the clinical history and physical, radiographic, hematological, myelographic, and cerebrospinal fluid (CSF) tests in patients with or without neurological clinical signs. The present report aims to describe a case of ALL and the presence of lymphoblasts in the CSF of a dog with neurological clinical signs. Case: An 8-year-old Lhasa Apso dog was examined at the Veterinary Hospital of Universidade Federal do Paraná, Curitiba campus. At the physical examination, the animal exhibited apathy and paralysis of pelvic limbs, which progressed to tetraplegia. Abdominal palpation revealed presence of hepatosplenomegaly and absence of lymphadenomegaly. No alterations were observed in radiographs of the cervical, thoracic or lumbar spine. A complete blood count revealed presence of non-regenerative anemia (hematocrit = 22%), extreme lymphocytosis (185,229 cells/µL), lymphoblasts at a level of 72% (133,364 cells/µL), and thrombocytopenia (66,000 platelets/µL). The biochemical tests revealed increased alkaline phosphatase (859 IU/L). The levels of alanine aminotransferase, creatinine, urea, total protein, albumin, and globulin were normal. The diagnosis of ALL was achieved with the help of a myelogram. The myelogram findings included 39% of mature lymphocytes and 59% of lymphoblasts exhibiting large size, spherical shape, poorly delimited borders, with a high nucleus/cytoplasm ratio, marked cytoplasmic basophilia, and 2 to 3 evident nucleoli; metarubricytes (1%) and promyelocytes (0.6%) were also observed. The CSF contained an increased number of nucleated cells (27 cells/µL) comprising lymphocytes (43%), macrophages (33%), and segmented neutrophils (24%). Of the 11.6 lymphocytes per µL of CSF, 8.1 were lymphoblasts, which indicates infiltration of ALL cells in the CNS. The animal died one day after collection of bone barrow and CSF. Discussion: Relevant alterations observed in this case included the neurological signs caused by the infiltration of neoplastic cells in the CNS, severe leukocytosis and lymphocytosis, with large amounts of lymphoblasts in the blood and predominance of lymphoblasts in the bone marrow, which are alterations typically found in ALL. The animal also exhibited non-regenerative anemia and thrombocytopenia, which were secondary to infiltration of leukemic cells in the bone marrow. The CSF exhibited pleocytosis (27 cells/ µL), and 30% of the cells observed were lymphoblasts. Lymphoblast infiltration in the CNS of leukemic dogs is rare, and other studies have reported absence of neurological signs or neurological signs different from those observed in the present study. CSF analysis in indicated in cases of leukemia to assess leukemic cell infiltration in the CNS. In the case reported here, the plasma level of alkaline phosphatase was increased (859 IU/L) as a consequence of hepatomegaly and hepatic cholestasis. ALL is a very aggressive, proliferative neoplasia, and the resulting lymphoblasts infiltrated the CNS of the animal. In cases of ALL, performing complete blood count, myelogram, and CSF analysis is indicated whether the patients exhibit neurological signs or not.(AU)

In vitro efficacy of iodine in the pre and post dipping against coagulase negative Staphylococcus isolated in milk of cows with subclinical mastitis / Eficácia in vitro do iodo no pré e pós dipping frente a Staphylococcus coagulase negativa isolados em leite de vacas com mastite subclínica

The efficiency of the disinfectants used in the milking management is fundamental to the success in the dairy activity, being a critical point to the control of mastitis. The objective was to evaluate the in vitro efficacy of iodine used in pre and post-dipping against coagulase negative Staphylococcus (CNS). Thus, 53 CNS isolates were studied for the action of the 1.0% disinfectant and their serial dilutions of 0.5%, 0.375% and 0.25%, in addition to two commercial presentations of iodine in concentrations of 0.5% and 0.25%. The rate of CNS inhibition achieved by iodine at 0.375%, 0.5% and 1.0% for 60 seconds, was 60.4%. In 30 seconds, iodine at 0.5% and 1.0% showed a microbial inhibition rate of 52.8% and 56.6%, respectively. The other protocols tested were less efficient. It is concluded that the greatest in vitro disinfectant activity for CNS was demonstrated by iodine at 0.375%, 0.5% and 1.0%, for 60 seconds. Microbial susceptibility tests should be carried out periodically, as well as health education practices and corrective training on the property, in order to ensure udder health and mastitis control.(AU)

A eficiência dos desinfetantes empregados no manejo de ordenha é fundamental no sucesso na atividade leiteira, sendo um ponto crítico ao controle da mastite. Objetivou-se avaliar a eficácia in vitro do iodo utilizado no pré e pós-dipping frente à Staphylococcus coagulase negativa (SCN). Foram estudados 53 isolados de SCN quanto à ação do desinfetante a 1,0% e suas diluições seriadas de 0,5%, 0,375% e 0,25%, além de duas apresentações comerciais nas concentrações de 0,5% e 0,25%. A taxa de inibição de SCN alcançada pelo iodo a 0,375%, 0,5% e 1,0% durante 60 segundos, foi de 60,4%. Em 30 segundos, o iodo a 0,5% e 1,0% apresentaram taxa de inibição microbiana de 52,8% e 56,6%, respectivamente. Os demais protocolos testados foram menos eficientes. Conclui-se que a maior atividade desinfetante in vitro para SCN foi demonstrada pelo iodo a 0,375%, 0,5% e 1,0%, durante 60 segundos. Testes de susceptibilidade microbiana devem ser realizados periodicamente, assim como práticas de educação em saúde e treinamentos corretivos na propriedade, visando garantir a saúde do úbere e o controle da mastite.(AU)

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)

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)

Influence of euthanasia, the intensity of inflammatory lesion and viral load in the laboratory diagnosis of rabies in cattle

ABSTRACT: This research reports the use of different diagnostic tests in cattle, naturally infected by Rabies lyssavirus (RABV), and correlates the positivity of the tests with the clinical moment of euthanasia, the intensity of the inflammatory lesion and viral load. It also highlights the possibility of euthanasia in early stages of the disease as a way to improve animal welfare. For that, samples of 34 bovine brains were collected for analysis, preserved in 10% buffered formaline and refrigerated with subsequent freezing. The samples were subjected to direct immunofluorescence antibody technique (DFAT) tests, viral isolation in cell culture (VICC), histopathology with hematoxylin and eosin staining (HE), immunohistochemistry (IHC), Shorr stainied neural tissue smears (DSS), Reverse transcription polymerase chain reaction (RT-PCR) and polymerase chain reaction by quantitative reverse transcriptase (qRT-PCR). The areas used for analysis were the cerebellum, parietal telencephalon and thalamus. Samples with Negri bodies (NBs) or immunostaining in at least one of the analyzed areas were considered positive. For the study of the intensity of histological lesions, the lesions were classified into grades 0, 1, 2 and 3 and the positivity of the test in the presence or absence of NBs in one of the three areas analyzed. To verify the influence of the disease clinical evolution, 4-four groups of analysis were created according to the animals clinical status at moment of the euthanasia, being: M1 = animal euthanized while standing, M2 = euthanized when in sternal recumbence, M3 = euthanized when in lateral recumbence, M4 = animal with natural death. Of the 34 brains evaluated, IHC was positive in 100% of cases, DFAT was positive in 97.05% of them, and in this negative sample the presence of RABV was confirmed by VICC. NBs ere seen in 88.23% of the cases, and the DSS test was positive in 82.35% of them. All diagnostic techniques showed positive cases in all groups analyzed. Each case was positive in at least two diagnostic methods. All cases that contained NBs were positive for rabies in the other tests. In this study, it was observed that the variables analyzed (intensity of injury and clinical evolution at the moment of euthanasia) had an influence only on HE and DSS techniques, which are based on NB research to form the diagnosis, but did not interfere with the effectiveness of the diagnosis performed by detecting the viral antigen performed by DFAT and IHC. All isolated RABV samples included in the present study have a genetic lineage characteristic of hematophagous bats Desmodus rotundus. The evaluation of qRT-PCR showed that the amount of virus did not interfere in the positivity of the tests. This work shows that IHC and DFAT are safe diagnostic techniques. They are capable of detecting RABV even in euthanized animals in the early stages of clinical evolution with mild intensities of histological lesions.

RESUMO: Esta pesquisa relata a utilização de diferentes testes de diagnóstico em bovinos, naturalmente infectados pelo Rabies lyssavirus (RABV), e correlaciona a positividade dos testes com o momento clínico da eutanásia, a intensidade da lesão inflamatória, e a carga viral. Salienta também a possibilidade da eutanásia em estágios precoces da doença como forma de melhorar o bem-estar animal. Para isso amostras de 34 encéfalos bovinos foram coletados para análise, conservadas em formol tamponado 10% e sob refrigeração com posterior congelamento. As amostras foram submetidas aos testes de imunofluorescência direta (IFD), isolamento viral em cultivo de células (IVCC), histopatologia com coloração de hematoxilina e eosina (HE), imuno-histoquímica (IHQ), esfregaço direto com coloração de Shorr (EDS), reação da polimerase em cadeia por transcriptase reversa (RT-PCR) e reação da polimerase em cadeia por transcriptase reversa quantitativo (qRT-PCR). As áreas utilizadas para análise foram o cerebelo, telencéfalo parietal e tálamo. Foram consideradas positivas as amostras que apresentaram Corpúsculo de Negri (CNs) ou imuno-marcação em ao menos uma das áreas analisadas. Para o estudo da intensidade das lesões histológicas, as lesões foram classificadas em graus 0, 1, 2 e 3 e a positividade do teste na presença ou ausência de CN em uma das três áreas analisadas. Para verificar a influência da evolução clínica da doença foram criados 4 grupos de análise conforme o estado clínico do animal no momento da eutanásia, sendo: M1 = animal eutanasiado em estação, M2 = eutanasiado em decúbito esternal, M3 = eutanasiado em decúbito lateral, M4 = animal com morte natural. Dos 34 encéfalos avaliados a IHQ foi positiva em 100% dos casos, a IFD foi positiva em 97,05%, sendo que na amostra negativa a presença de RABV foi confirmada por IVCC. A histologia com HE, através da visualização das CNs, foi positiva em 88,23 % dos casos, e o teste de EDS, foi positivo em 82,35%. Todas as técnicas de diagnóstico apresentaram casos positivos em todos os grupos analisados. Cada caso foi positivo em, pelo menos, dois métodos de diagnóstico. Todos os casos que continham CN foram positivos para raiva nos demais testes. Nesse estudo observou-se que as variáveis analisadas intensidade de lesão e evolução clínica no momento da eutanásia tiveram influência somente nas técnicas de HE e EDS, que se baseiam na pesquisa do CN para formação do diagnóstico, mas não interferiram na eficácia do diagnóstico realizado através da detecção do antígeno viral realizado por IFD e IHQ. Todas as amostras RABV isoladas incluídas no presente estudo apresentam linhagem genética característica de morcegos hematófagos Desmodus rotundus. A avaliação de qRT-PCR demostrou que a quantidade de vírus não interferiu na positividade dos testes. Esse trabalho mostra que a IHQ e a IFD são técnicas seguras de diagnóstico e que mesmo em animais eutanasiados em estágios iniciais de evolução clínica com intensidades leve de lesões histológicas, são capazes de detectar o RABV.