96 Fowl Cholera. 



application is indicated only in flocks already infected or in 

 those which are threatened by infection. (Experiments to 

 change innnnnity through subsequent inoculation of virulent 

 material into an active form have thus far been unsuccessful.) 



Through a procedure similar to that of Kitt & Mayr, Schreiber 

 succeeded in preparing a blood serum of which .5 cc. protected a pigeon 

 against a virus which was fatal in 24 hours. The dose of this serum 

 is for geese or ducks 1 cc, for smaller birds .5 cc. Hartel obtained a 

 serum by treating an ass with living liouillon cultures (intravenous) 

 of which .5 cc. protected a pigeon against a dose of virus of which 

 1-10,000 part was fatal. 



Jess & Piorkowski inject fresh horse serum containing alexin under 

 the skin of fowl before the use of the immune serum in order that the 

 antibodies contained in the horse serum may find a sufficient quantity 

 of alexins in the tissue fluids. The single dose is .5 to 4 cc. of imnmne 

 serum, depending on the size of the bird, and 1 to 8 cc. of normal serum. 

 The mixture is supposed to effect also a curative action when applied 

 not later than 6 hours after the infection has taken place. Mosler found 

 the mixture also more effective in mice than the immune serum alone. 

 The experiments made in Prussia are, however, contradictory (Rae- 

 biger). 



Klett & Braun immunize horses with 4-day old bouillon cultures 

 of the fowl cholera bacteria which have attained the highest degree of 

 virulence by passage through the bodies of sparrows. The treatment 

 commences with a dose of .25 cc. of culture subcutaneously and intra- 

 venously, which ({uantity of culture is gradually increased to 20 cc. and 

 is later injected directly into the circulation. Horses thus prepared 

 produce an immune serum of which 0.0015 to 0.005 cc. will protect 

 gray mice for a period of aliout 3 weeks against the fatal action of a 

 loopful of a 4-day old bouillon culture. The results obtained in practice 

 met the expectations leased on the laboratory experiments, and the sera 

 sometimes appear to have a curative action in animals already affected. 



In consideration of the close etiological relation of swine plague 

 and chicken cholera Schreiber employed for the inoculation of fowl a 

 serum (septizidin) which affords protection against the former disease, 

 and some other authors (Hartenstein, Graffunder, Schmidt and others) 

 also o])tained with it satisfactory results. The official reports, however, 

 of Prussia and Saxony are mostly unfavorable. Finally, Lignieres' 

 polyvalent serum may also come into consideration. 



The "Hoehst Farbwerke" prepare a polyvalent serum (Galloserin) with 

 which Kovacs, Sioke & Szabu and others obtained quite satisfactory results in ex- 

 posed as well as already affected birds. Eaebiger made comparative experiments with 

 the various vaccines on the market and found that pigeons inoculated with Hochst 

 serum or with septizidin withstood the infection in 66%, while those injected with 

 Gans' (Frankfurter) and Piorkowski 's (Berlin) sera died. The serum of Klett- 

 Braun ])roved effective in lalioratory experiments and also once in practice. Del- 

 fino found Lignieres' vaccine effective in rabbit experiments. 



Technique of vaccination. Pasteur originally inoculated into the point of 

 the wing, later the inoculation was made under the skin of the breast or into the 

 breast muscle. According to the suggestion of Jess it is more satisfactory when 

 made under the skin of the neck. An assistant secures the bird with both liands 

 on the rump while the operating veterinarian raises a fold of the skin of the neck 

 with his left hand. The dose to be inoculated is indicated specially for each 

 preparation. 



III. Immunization with Aggressins. Weil employs, according to 

 the procedure of Bail, a pleural exudate produced by injections of 



