Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 14, 1998
Publication Date: N/A
Interpretive Summary: Fowl cholera is an important disease of turkeys caused by Pasteurella multocida. Vaccines are available to control the disease in many situations, but vaccine may failures may occur. One source of failure is that turkeys after having had bordetellosis, caused by Bordetella avium, respond poorly or not at all to live-attenuated vaccine of P. multocida. A study was done to determine whether passive immunization of young turkey against bordetellosis would lessen its severity and these turkeys could then respond better to vaccination against fowl cholera. Turkeys that were passively-immunized developed a mild form of bordetellosis and were protected against fowl cholera by the P. multocida bacterin. However, no differences in bacterin protection against fowl cholera were seen between vaccinated birds which previously had bordetellosis, those that did not have bordetellosis, and those that were passively-immunized against bordetellosis. Survivability was better in birds given 2 doses rather tha 1 dose of bacterin. These findings are important because they show that vaccination against fowl cholera with bacterins is a viable alternative to use of live-attenuated vaccine when turkeys have previously had bordetellosis. Thus, using this information, more effective vaccination strategies can be developed to reduce losses due to fowl cholera when the disease may be complicated by prior experience with bordetellosis.
Technical Abstract: Groups of Beltsville small white turkeys, passively-immunized and not passively-immunized against Bordetella avium, were challenged with live B. avium at 2-days old. Birds not passively-immunized developed severe bordetellosis with early onset, whereas passively-immunized birds developed mild bordetellosis with late onset. Following convalescence, birds with and without exposure to B. avium were vaccinated against fowl cholera usin a water-in-oil bacterin. The birds were given a homologous challenge with serotype A:3 Pasteurella multocida. Although no differences in protection against fowl cholera were seen between vaccinated birds which were previously infected with B. avium and those which were not, survivability was better in birds given 2 doses rather than 1 dose of bacterin.