BIRD POX VACCINES AND BACTERINS 



215 



not obtainable. An early report from the owner showed an improvement in 

 egg production and hut a few mild cases of the disease among the treated 

 birds. It was questionable, however, whetlier the increase in production was 

 due to recovery from the disease or from an existing neck moult. No data 

 were available concerning the controls. No conclusion can be drawn from the 

 use of the bacterin in this instance. 



Flock 4. 



A fourth flock of 300 cockerels was injected with an autogenous bacterin 

 composed of Staphylococcus aureus, a Pasteurella aficif/a-like organism, and 

 a bacillus similar to the roup bacillus or i^. cacosmus of Harrison and Streit 

 (2). The infection had practically run its course at the time of the treatment. 

 Two injections were given, the first of 0.5 cc. containing 500,000 organisms, 

 and a second six days later of 1 cc. containing 1,000,000 organisms. Tire dis- 

 ease entirely cleared up during the following three weeks. No difference was 

 noted between the injected and control groups. 



Summary. 



1. Several organisms were isolated from the lesions of avian diphtheria, 

 diphtheritic roup, and pox. They proved to be of no causative significance, 

 but were prominent secondary invaders. A filtrable virus was found to be 

 the common cause of all types of the disease. 



2. Commercial stock powdered pox viruses varied markedly in ability to 

 produce the disease. The need of a method of standardizing the virus and 

 vaccine was indicated. 



3. One, two, and three injections of the powdered pox virus vaccines failed 

 to produce an absolute protection against artificial infection with homologous 

 and heterologous viruses. 



4. Infection by contact occurred in 50 per cent of all cases. 



5. The powdered pox virus vaccine caused a slight improvement in the 

 general condition of diseased birds when administered as a means of bringing 

 about recovery from the infection. 



6. One attack of either or both tj-pes of the disease conferred an immunity 

 of at least fifty days' duration against both types. 



7. Autogenous bacterins, when administered in the early stages of the dis- 

 ease, caused an improvement in the general health of the birds. As avian diph- 

 theria and pox advance in severity the egg production of hens decreases. 

 With the injections of these bacterins, data at hand indicate that the egg 

 production is increased. While all these observations are interesting and 

 point to a certain degree of therapeutic efficiency; the time consumed in the 

 manufacture, standardization, and administration of these bacterins would 

 work against their use as an economic practice. 



Bibliography. 



(1) Smith, Theobald, and Veranus A. Moore: Investigations concerning 



infectious diseases among poultry. U. S. Dept. Agric, Bur. Anim. 

 Indus., Bull. 8, p. 56, 1895. 



(2) Harrison, F. C, and H. Streit: Roup: an experimental study. Onta- 



rio Agric. College Bull. 132, 18-22, 1903. 



(3) Hausser, Albert: Bacteriologische Untersuchungen iiber Gefliigeldiph- 



therie. Centralbl. f. Bakteriol., Parasitenk. u. Infekt. — Krankh., 1908, 

 1 Abt. Orig., Bd. XLVIII, S 535. 



