Evaluation of two avirulent vaccines for preventing experimental fowl cholera in turkeys, and use of one vaccine in the field.

The Clemson University (CU) strain of live cholera vaccine administered in water (LCVW) was effective in immunizing turkeys against the pulmonary, arthritic, and cranial forms of fowl cholera. The Missouri strain of LCVW immunized turkeys against the pulmonary and septicemic forms of fowl cholera. Pasteurella multocida was isolated from the orifice of the auditory tube of 5% of the turkeys vaccinated with the CU strain 2 weeks postvaccination, but not 4 weeks after challenge. Mortality was not increased by administering the CU strain of LCVW at 5, 10, 20, and 40 x the standard dose of 4 x 10(8) P. multocida. A low concentration of Rofenaid (providing 0.01% potentiated sulfadimethoxine) had no perceptible effect on the development of immunity with the CU vaccine.