Degree Type

Dissertation

Date of Award

1989

Degree Name

Doctor of Philosophy

Department

Veterinary Pathology

First Advisor

Norman F. Cheville

Second Advisor

John P. Kluge

Abstract

Acute bovine viral diarrhea (BVD) was induced in eight healthy calves by intranasal inoculation with noncytopathic (n = 4) or cytopathic (n = 4) BVD virus. Calves were examined postmortem five or 12 days post-inoculation. The most frequent gross lesion was proximal colonic mural edema. Consistent microscopic findings were acute to subacute tracheitis, mild enterocolitis with edema, petechial hemorrhages of mesenteric lymph nodes with mild follicular lymphoid depletion, and paracortical lymphoid hyperplasia. At necropsy, virus was recovered from six calves and neutralizing antibodies to BVD virus were detected in the other two calves. Immunohistochemical analysis of lymphoid tissues demonstrated a small, widely scattered population of mononuclear cells expressing BVD viral antigen;Cattle with induced mucosal disease (n = 3), spontaneous mucosal disease (n = 6) and spontaneous chronic BVD (n = 4) were examined postmortem. Consistent microscopic findings were lymphocytic depletion of lymphoid tissues, degeneration of myenteric ganglion cells and mild adrenalitis. Intracytoplasmic BVD viral antigen was detected in myenteric ganglia and endocrine glandular cells. Noncytopathic virus was isolated from all cattle and cytopathic virus was isolated from 12 of 13 cattle. Of five cattle examined serologically, none completely neutralized the homologous noncytopathic virus and four of five cattle had neutralizing antibodies to their cytopathic viruses.

DOI

https://doi.org/10.31274/rtd-180813-9001

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Catherine Louise Wilhelmsen

Language

en

Proquest ID

AAI9003580

File Format

application/pdf

File Size

120 pages

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