8 CONTROL SERIES No. 58 



which contain eggs from infected flocks. 



The spread of infection is not limited to the incubator, but may also occur 

 while chicks are in shipping boxes and after they are placed in the brooder. 

 Non-infected chicks may contract the disease by picking at droppings from 

 infected chicks. 



In feeding eggs to chicks, one should safeguard against infective eggs. 

 Only eggs from non-infected flocks should be fed. 



Grain sacks may play a role in spreading the disease. At this laboratory 

 it was observed that a grain sack artificially contaminated with S. pullorum 

 and used for holding mash was responsible for infecting 2 out of 25 chicks 

 which received this mash for three weeks. No mortality was observed. The 

 organism was recovered from one of the two reactors. Used grain sacks 

 which are refilled with feed by feed stores may be a disease hazard. Sacks 

 that have been properly and thoroughly sterilized may be used again with 

 safety. 



During the last few years, attention has been directed toward fowl other 

 than chickens to determine what role they play in pullorum disease dissemina- 

 tion. A few isolated cases of pullorum infection in turkeys, pigeons, pheas- 

 ants, sparrows, and bull-finch have been reported. In most cases, the source 

 of infection was traceable to chickens. In this State during the last four 

 years, such fowl hav^ been tested whenever possible and four reactors were 

 detected — one guinea hen and three turkeys. The three turkeys were necrop- 

 sied and S. pullorum was not isolated. 



Prevention and Eradication 



Prevention. — Prevention of the disease is of interest to those who own a 

 non-infected flock and to those Mho are contemplating the purchase of stock 

 in the form of eggs, chicks, and adult birds. To assure prevention of the 

 disease, the following measures should be observed: — 



1. The entire flock should be tested annually. 



2. New stock should be introduced or purchased only from non-infected 

 flocks. 



3. Birds returning from shows or contests should be tested, and not ad- 

 mitted to any flock until pronounced free of the disease. 



4. If custom hatching is a necessary business procedure, it should be of- 

 fered only to those who supply eggs from non-infected flocks. 



5. If eggs have to be hatched away from the premises, one should ascertain 

 definitely that the eggs are not being exposed to infection. 



6. Infertile eggs from infected and untested sources should not be fed. 



7. Offal from dressed birds should be burned. 



8. Proper sanitary measures should be observed at all times. 

 Eradication. — The best means of eradicating the disease from a flock is 



through intensive testing of the entire flock, provided the breeding value of 

 the birds warrants the expenditure. It may require two or more tests within 

 the same season to determine that all of the infected birds have been de- 

 tected. The success of intensive testing depends upon follow-up measures 

 such as prompt disposal of reactors for meat, followed by thorough cleaning 

 and proper disinfection of pens, houses, and equipment. While the infection 

 is being eliminated from the premises and after the flock is regarded as free 

 of the disease, the measures listed under prevention should be observed in 

 order that the flock may not become re-infected. 



