26 CONTROL SERIES No. 63 



Conclusions 



1. Transmission of pullorum disease did not occur among sexually immature, 

 reacting and non-reacting pullets while in contact for 111 days, as determined 

 by the macroscopic tube agglutination test. 



2. The serum titers of the majority of positive reacting birds decreased 

 during the course of the experiment. 



3. Fluctuation of serum titers was observed in some birds. 



PATHOGENICITY OF S. pullorum IN RELATION TO AVES 

 OTHER THAN CHICKENS 



Pullorum disease has been reported as prevalent throughout the different 

 continents wherever the domestic chicken is maintained. The disease is par- 

 ticularly prevalent in sections where there has been much traffic of poultry and 

 where no progress has been made in its control and eradication. While the 

 domestic chicken is regarded as the optimimi host of this disease, other animals 

 cannot be disregarded as to their relation to the causative agent. Investigators 

 who have concerned themselves with this disease have confined their work largely 

 to chickens. Rettger, Hull, and Sturges (77) reported the organism to be patho- 

 genic for cats, guinea pigs, and highly so for rabbits. They found that rats were 

 not affected. Mulsow (66) found that mature and immature rabbits, kittens, 

 mice, rats, cats, sparrows, squabs (less than 48 hours old) and adult pigeons 

 when fed the organism manifested no symptoms of the disease. Cats fed infected 

 sparrows and rabbits that had died from an infection with 5. pullorum mani- 

 fested no symptoms of the disease. INIice, guinea pigs, rabbits, and sparrows 

 inoculated intraperitoneally would in some cases succumb to the disease. The 

 organism appeared to be highly pathogenic for sparrows. Pigeons and rats were 

 quite resistant to the organism. 



In England, Doyle (27) reported that guinea pigs are susceptible to subcutane- 

 ous and intraperitoneal inocidations, whereas ducks of all ages and by all routes 

 are insusceptible. Rabbits were found to be very susceptible. Instillation of three 

 drops of broth culture into the eye proved fatal. A sheep administered dead and 

 live cultures manifested no symptoms. In Germany, Beck and Eber (4) found 

 rabbits, mice, and canary birds to be susceptible to the disease by artificial 

 exposure. Canary birds were found susceptible to both subcutaneous inocula- 

 tion and feeding of the organism. Guinea pigs fed the organism remained healthy. 



The Rhode Island Agricultural Ex-periment Station (80) reported an experi- 

 ment on the control of blackhead in turkeys in which a heavy mortality occurred 

 that was considered apparently due to bacillary white diarrhea. It was not 

 stated whether the diagnosis was confirmed by bacteriological findings. A 

 natural outbreak of the disease among domestic rabbits was reported by Olney 

 (68). Infertile eggs, incubated for 18 days, were received from a commercial 

 hatchery. The eggs were mixed with the mash. The disease did not manifest 

 itself in the sucklings. A mortality of 125 among 128 rabbits was encountered. 

 S. pullorum was isolated from seven rabbits examined. Hewitt (45) isolated 

 5. pullorum from two turkey poults that had been hatched in an incubator 

 previously occupied by chicks. 



In Switzerland, Galli-Valerio (37) encountered a grave disease among a flock 

 of phea.sants {Phasianus colchicus) which he designated as white diarrhea. Low 

 hatchability and mortality were associated with the malady. The clinical and 

 pathologic-anatomi(;al pictures resembled pullorum disease. The morphological 

 and cultural characteristics of the organism isolated from the dead embryos and 



