Submitted to: International Virtual Conference on Infectious Diseases of Animals
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/1997
Publication Date: N/A
Technical Abstract: Thirty-six conventional pigs were weaned at 2 weeks of age and separated into 4 treatment groups (A through D with 9 pigs/group). Treatment groups B and D were then infected with porcine reproductive and respiratory syndrome virus (PRRSV), whereas groups A and C remained uninfected. Two weeks later, one pig from each group was necropsied to assess gross lung involvement, and then the remaining group-D PRRSV-infected pigs and the group-C uninfected pigs were challenged at 4 weeks of age with transmissible gastroenteritis virus (TGEV) to determine if prior infection with PRRSV increased the severity of TGEV challenge. One hundred percent morbidity but no mortality occurred in pigs following challenge. Clinically, pigs of both groups C and D were similar in terms of onset and severity of diarrhea. The serum antibody response and the amount and duration of TGEV shedding after challenge was similar for both groups. Only a few pigs in each group had a transient fever post-challenge and both group-C and group-D pigs began to recover and to gain weight at or near the end of the first week post-challenge. We conclude that the clinical course of TGEV was not affected by infection of pigs with TGEV 2 weeks after they had been infected with PRRSV. Subtle differences in the severity of the enteric illness caused by TGEV could be accounted for because the PRRSV-infected pigs were in the immediate recovery phase of a mild respiratory infection.