Degree Type

Dissertation

Date of Award

1981

Degree Name

Doctor of Philosophy

Department

Veterinary Pathology

Abstract

Epizootics of porcine proliferative enteritis (intestinal adenomatosis) were studied on 44 farms during a two year period (1978-1980). The disease occurred throughout the year in swine past weaning age. It occurred primarily in conventionally housed 18-45 kg feeder pigs and in confinement housed bred gilts, sows, and boars. The 34 affected feeder pigs examined usually had chronic intermittent diarrhea and became emaciated. The 24 adult pigs examined had blood in their feces one to three days before death;At necropsy, the 58 affected pigs had thickening of the wall of the ileum and distal jejunum. Feeder pigs also had pseudomembranes in their intestinal lumina while adult pigs often had clotted blood. The microscopic lesions in all age groups were proliferation of crypt epithelial cells, crypt elongation, inflammation of the lamina propria, and loss of villi. Affected crypt epithelial cells had variable numbers of curved, argyrophilic Campylobacter sp.-like organisms within their apical cytoplasm;Homogenized mucosal scrapings (crude inoculum) prepared from the intestine of pigs with naturally occurring proliferative enteritis were given to 22 10-week-old Caesarean-derived and colostrum-deprived (CD-CD) pigs. Fifteen of the 22 pigs developed gross and/or microscopic lesions of proliferative enteritis. Campylobacter sp.-like organisms were in the apical cytoplasm of affected crypt epithelial cells. Campylobacter sputorum subspecies mucosalis (CSM) was isolated from the ileal mucosa in 7 pigs;Sixteen 10-week-old CD-CD pigs were given cultures of CSM, S. choleraesuis, or both. Nine of ten pigs given cultures of both CSM and S. choleraesuis had fibrinous gastroenteritis, and two of these pigs which survived until the termination of the experiment (5 weeks) had proliferative ileal mucosal lesions. Pigs (4) given cultures of S. choleraesuis did not develop proliferative lesions. One of five pigs given cultures of CSM developed lesions of proliferative enteritis;Thirty-three 10-week-old specific-pathogen-free pigs were randomly placed into three treatment groups. Eleven pigs were given crude inoculum, eleven were given cultures of CSM, and eleven served as uninfected controls. One pig from each treatment group was killed 4, 7, 10, 14, 18, 21, 24, 28, 31, 36, and 38 days post inoculation in order to study lesion development of proliferative enteritis. Development of proliferative lesions in the intestinal mucosa was similar in pigs given either crude inocula or cultures of CSM.

DOI

https://doi.org/10.31274/rtd-180813-4685

Publisher

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

Copyright Owner

Larry Gene Lomax

Language

en

Proquest ID

AAI8128835

File Format

application/pdf

File Size

209 pages

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