The pathogenesis of turkey rhinotracheitis virus in turkey poults inoculated with the virus alone or together with two strains of bacteria.

Turkey rhinotracheitis virus (TRTV) was recovered in large amounts from the upper respiratory tract of young turkey poults for about 5 days after experimental eyedrop inoculation with either a virulent or an attenuated strain. Thereafter, small amounts of virus were isolated, but only for up to 14 days after inoculation. Virulent TRTV could be recovered infrequently from the internal organs or the intestinal tract but only if bacteria (Bordetella avium and a Pasteurella-like organism) were administered contemporaneously. The results of transmission studies were in agreement with the virus isolation results since they showed that virus could be transmitted from inoculated poults to TRTV-free poults placed in direct contact with them only during the first 9 days after inoculation. Whether inoculated alone or together with TRTV, B. avium colonised the upper respiratory tract to the same degree but apparently did not invade. In contrast, the Pasteurella-like organism did not colonise when inoculated alone but could be recovered from the respiratory tract when administered simultaneously with either a virulent or an attenuated strain of TRTV.