DEPARTMENT OF VETERINARY SCIENCE AND 

 ANIMAL PATHOLOGY 



CONTROL OF BACILLARY WHITE DIARRHOEA 

 1925-1926 



By p. E. BRANSFIELD 



During the 1925-1926 season the Massachusetts Agricultural Experiment 

 Station, through its Department of Veterinary Science and Animal Pathol- 

 ogy, has continued its work in the control and eradication of bacillary white 

 diarrhoea of poultry in the State. The attempt this year has again been to 

 establish disease free flocks from which chicks and hatching eggs may be 

 obtained. The macroscopic agglutination test has been used as the con- 

 trolling agent. This test is by no means perfect, but it is as reliable as a 

 biologic test can be and at the present time is the best method known for 

 controlling the disease. The Massachusetts Association of Certified Poultry 

 Breeders has continued its good work in improving the poultry industry in 

 the State, and this department has cooperated to this end. 



The problem presented by the bacillary white diarrhoea situation in this 

 State was thoroughly discussed last year in Control Bulletin No. 31, and only 

 a brief statement need be given here. The disease is caused by a micro- 

 organism known as Sahtionella pullora. These microorganisms become local- 

 ized in the ovaries of the hen and are transmitted through the egg yolk to 

 the chick. The problem in the control of the disease is to detect the hen 

 carriers whose ovarian tissue is diseased or which harbors the organism, by 

 means of the agglutination test. All positive and doubtful reactors should 

 be removed from the breeding flock and disposed of. As an additional pre- 

 cautionary measure the premises should be disinfected after the reactors 

 have been removed. 



The methods and control measures used this year have been the same as 

 those of previous years. They were fully described in Control Bulletin No. 31 

 of this Station, and therefore are not repeated here. 



Service Rendered under the Poultry Disease Elimination Law for the 

 Season ending July 31, 1926. 



During the 1925-1926 season, 67,919 birds, 3,815 of which were males, have 

 been tested by the macroscopic agglutintition test for bacillary white diar- 

 rhoea. The following tables show the geographical distribution according to 

 breeds, location of reactors, amount of infection among various breeds, and 

 tlie number of flocks having certain limits of infection. 



