Notetaker gw211/7/2022 ![]() ![]() ![]() The diarrhea outbreak presented some non-regular characteristics observed in bovine coronavirus (BCoV) enteric infections in dairy calves. This study, through some etiological and epidemiological characteristics of an outbreak of neonatal diarrhea, has the aim to alert to the possibility of pathogenic microorganism spread in a dairy heifer calf rearing unit. Diarrhea is the main and most frequent consequence of enteric infections in newborn calves. However, aspects related to the health profile of the heifer calves that arrive in the rearing unit as well as about biosecurity practices and microbiological challenges have not yet been evaluated in this rearing system in a tropical country. This is the first documented case of hypomyelination in a calf specifically attributed to BVDV type 2 and the first description of the ultrastructural appearance of BVDV-induced hypomyelination.ĭairy calf rearing unit and infectious diseases: diarrhea outbreak by bovine coronavirus as a model for the dispersion of pathogenic microorganisms.Īlfieri, Amauri Alcindo Ribeiro, Juliane de Carvalho Balbo, Luciana Lorenzetti, Elis Alfieri, Alice Fernandesĭairy calf rearing unit is a management system that is only recently being implemented by some milk producer's cooperatives in southern Brazil. BVDV-induced hypomyelination is rare and analogous to lesions in neonates infected with border disease and classical swine fever viruses. Noncytopathogenic BVDV was isolated from the brain and identified as BVDV type 2 by phylogenetic analysis. Various cell types were immunohistochemically positive for bovine viral diarrhea virus (BVDV). ![]() Ultrastructural examination revealed thinning and absence of myelin sheaths. Histologically, the brain and spinal cord had mild to moderate diffuse microgliosis and astrocytosis, minimal nonsuppurative encephalitis, and decreased myelin staining. At necropsy, no gross central nervous system lesions were observed. Porter, B F Ridpath, J F Calise, D V Payne, H R Janke, J J Baxter, D G Edwards, J FĪ newborn Longhorn heifer calf presented with generalized tremors, muscle fasciculations, ataxia, and nystagmus. Hypomyelination associated with bovine viral diarrhea virus type 2 infection in a longhorn calf. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow- calf operations. Other factors including both the environment and management practices influence disease severity or outcomes. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. dairy, half of the deaths among unweaned calves was attributed to diarrhea. In the report of the 2007 National Animal Health Monitoring System for U.S. PMID:208735Īn overview of calf diarrhea - infectious etiology, diagnosis, and interventionĬalf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. However, those two techniques must be used simultaneously for a better detection of a greatest possible number of cases. For the detection of the Nebraska viruses, the fluorescent antibody techniques were more sensitive than the electron microscopy. Four bovine virus diarrhea viruses, two infectious bovine rhinotracheitis viruses and two enteroviruses have also been isolated in the preceding 107 Nebraska positive specimens. An association of rotaviruses and coronaviruses was found in 58 cases (54%) whilst the coronaviruses and the rotavirus were found singly in 34 cases (53%) and in 15 cases (14%) respectively. The Nebraska viruses have been demonstrated in 107 (80%) out of 134 field case specimens. The presence of Nebraska viruses (rotavirus and coronavirus) has been demonstrated by using the electron microscope and the fluorescent antibody techniques while the presence of other viruses has been detected by the observation of a cytopathic effect on monolayer cells of calf testis. Marsolais, G Assaf, R Montpetit, C Marois, Pĭuring this study, 134 samples have been examined for the detection of the viruses associated with neonatal calf diarrhea. Diagnosis of viral agents associated with neonatal calf diarrhea. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |