Fowl cholera immunization in turkeys. II. Use of experimental epornitic method to study vaccine efficacy in flocks of turkeys.
Groups of turkeys were challenged with Pasteurella multocida (P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of P. multocida organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.
Studies on Pasteurellosis. V. Two Immunogenic Types of Pasteurella multocida Associated with Fowl Cholera
13. Jowett, W. Blackhead-infections entero-hepatitis or typhylo-hepatitis. A disease of young turkeys. J. Comp. Path. and Therap., 24, 1911, 289. 14. Kendall, S. R. Some factors influencing resistance to Histomoniasis in turkeys. Brit. Vet. J., 113, 1957, 435. 15. Kuprowski, M. Zur Pathogenese und Morphologie der Moniliasis der Hfihnerv6gel. Deutsch. Tierirztl. Wochenschr., 67, 1960, 185. 16. Malewitz, T. D., Runnells R. A., and Calhoun, M. L. The pathology of experimentally produced Histomoniasis in turkeys. Am. J. Vet. Res., 19, 1958, 181. 17. McGuire, W. C., and Morehouse, N. F. Blood induced blackhead. J. Par., 44, 1958, 292. 18. Pallaske, G. Zur Histopathologie der enzootischen BlinddarmLeberentziindung (Blackhead) der Truthihner. Tierartzl. Umschau, 4, 1949, 298. 19. Smith, T. An infectious disease among turkeys caused by protozoa (infectious enterohepatitis). Bur. An. Ind., U.S.D.A., Bul., 8, 1895. 20. Tyzzer, E. E. The flagellate character and reclassification of the parasite producing "blackhead" in turkeys.-Histomonas (gen. nov.) meleagridis (Smith). J. Parasit., 6, 1920, 124. 21. Tyzzer, E. E. Studies on Histomoniasis, or "blackhead" infection in the chicken and the turkey. Proc. Am. Acad. Arts and Sciences, (9, 1934, 189.
Bacterins and Drugs for the Control of Experimental Fowl Cholera
FOWL cholera, caused by the bacteria Pasteurella multoctda, is one of the oldest poultry diseases studied. In fact, in 1880 Pasteur grew this organism in pure culture and used it in some of his fundamental experiments in the attenuation of bacteria. Much research has been done on controlling this disease by immunization, but no real progress was shown until 1958.6 Certainly the major problem with this disease in flocks has been its chronic nature. Recent11 work in Russia showed that the organism is difficult to kill under natural environmental conditions. The organism survived 2-4 months in fowl carcasses left out-of-doors in the winter at -25?C to 2?C temperatures. In buried carcasses it survived for 5 months. In spring at temperatures of -13.5 to +22?C, it survived 3-4 months in the heart, liver, and spleen, and 2-21/2 months in the intestines. In summer, at 8-29?C, it survived for 25 days in exposed carcasses and for 3 months in buried carcasses. Research in South Dakota4 has indicated that most outbreaks were acute. Epizootiological studies suggested older birds as the carriers and most probable source of infection in young birds. The researchers were unable to immunize birds with a chick embryo vaccine inactivated with formalin. They found that oxytetracycline (Terramycin; Pfizer) was the most effective of the antibiotics they tested against experimental fowl cholera infections.