Hypomyelination associated with bovine viral diarrhea virus type 2 infection in a longhorn calf.
A newborn Longhorn heifer calf presented with generalized tremors, muscle fasciculations, ataxia, and nystagmus. At necropsy, no gross central nervous system lesions were observed. Histologically, the brain and spinal cord had mild to moderate diffuse microgliosis and astrocytosis, minimal nonsuppurative encephalitis, and decreased myelin staining. Ultrastructural examination revealed thinning and absence of myelin sheaths. Various cell types were immunohistochemically positive for bovine viral diarrhea virus (BVDV). Noncytopathogenic BVDV was isolated from the brain and identified as BVDV type 2 by phylogenetic analysis. BVDV-induced hypomyelination is rare and analogous to lesions in neonates infected with border disease and classical swine fever viruses. 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.
Porter
B F
BF
Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA. bporter@cvm.tamu.edu
Ridpath
J F
JF
Calise
D V
DV
Payne
H R
HR
Janke
J J
JJ
Baxter
D G
DG
Edwards
J F
JF
D000818:Animals; D000831:Animals, Newborn; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000150:complications / Q000151:congenital* / Q000473:pathology; D002417:Cattle; D030242:Diarrhea Virus 2, Bovine Viral / Q000302:isolation & purification*; D017809:Fatal Outcome; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D009186:Myelin Sheath / Q000473:pathology*