Isolation of transmissible Gastroenteritis virus, pseudorabies virus, and porcine enterovirus from pharyngeal swabs taken from market-weight-swine

Pharyngeal swab samples were collected at a central Iowa abattoir from 6,010 market-weight slaughter hogs from September 1, 1979 to August 31, 1980. The swab samples were examined for cytopathic viruses by inoculation of monolayer cultures of continuous line of swine testicular cells. Of the 6,010 swab samples tested, transmissible gastroenteritis virus was isolated from 91 (1,51%), pseudorabies virus was isolated from 431 (7.17%), and porcine enterovirus was isolated from 21 (0.35%). Although all 3 viruses were identified throughout the year, transmissible gastroenteritis and pseudorabies viruses were found more frequently during the winter and early spring. In contrast, porcine enterovirus was detected more frequently during the spring and summer.