76 MASS. EXPERIMENT STATION BULLETIN 315 



2. Pullorum Disease Investigations. Investigations to determine the role 

 which feces from positive reacting birds may play in transmitting pullorum disease 

 have revealed interesting results. Adult birds from a pullorum disease free flock, 

 which were negative to the agglutination test, failed to contract pullorum in- 

 fection when feces from infected birds were added to the litter at frequent inter- 

 vals for a period of approximately one year. However, when non-infected birds 

 were force-fed feces from infected birds evidence of transmission was obtained. 

 While some phases of the complex problem of dissemination of pullorum infec- 

 tion have been studied, the transmissibility of this disease among adult stock 

 requires further study in order that certain types of outbreaks may be prevented. 

 Due to the lack of knowledge concerning this particular subject, poultrymen 

 may not be exercising sufficient care in establishing and maintaining a free flock. 



The ability of 5. pullorum to remain viable on a dry piece of cloth is being 

 studied At the present writing the organism has remained alive for 855 days. 



Investigations mentioned here are still in progress and will be reported in 

 detail elsewhere. 



3. Laboratory Diagnoses. 



(a) Personal calls at the laboratory were recorded 127 times. The number 

 of cases handled was 369. The classification of 1393 specimens follows: — 1279 

 chickens, 30 turkeys, 28 ruffed grouse, 20 ducks, 16 pheasants, 6 canaries, 6 

 cattle, 3 sheep, 3 swine, 1 cat, and 1 mink. The diseases encountered most fre- 

 quently were pullorum disease, parasitism, reproductive system disorders, so- 

 called "range paralysis," tumors, kidney disorders, and proventriculitis. The 

 diagnoses of diseases which are believed to be rather rare in Massachusetts were 

 paratyphoid, fowl cholera, fowl typhoid, intestinal capillariasis, and pullorum 

 disease in turkeys. 



(b) Paratyphoid infections were encountered in chicks, ducks, and canaries. 

 The outbreak in chicks received considerable study, which has not been com- 

 pleted. 



(c) The pullorum disease in turkeys was traceable to hatching eggs in an 

 incubator with eggs from an infected flock of chickens. 



(d) Dispharynx spiralis infestation of ruffed grouse was noted in one young, 

 wild bird. The other grouse were all young birds and came from one small flock. 

 Kidney disorders and "slipped tendons" were prominent in necropsies. 



(e) An acute condition affecting high-producing pullets came to our atten- 

 tion. Sporadic cases have been noted annually for the past few years. The histories 

 of outbreaks in flocks present the following: condition excellent when housed 

 two to four weeks previously, production 30 to 50 percent, feed consumption high, 

 one or two dead birds found on roosts, a few birds depressed and weak on legs, 

 and production drops markedly. Many of the depressed birds improve and 

 resume production in two to four weeks, while others go into a neck molt. Approx- 

 imately 10 percent was the highest mortality reported. Necropsy findings include 

 a slightly enlarged liver with numerous yellowish foci, petechia on abdominal fat, 

 pericardium, and pleura, and slightly enlarged pale kidneys. Aerobic and anaerobic 

 bacteriological examination and transmission trial with liver emulsions and with 

 blood were negative. 



4. Farm and Station Bang Disease. In assisting this project, the laboratory 

 tested 1,545 blood samples by the standard tube agglutination method. 



Experiments on the Vaccination of Baby Chicks Against Infectious Laryn- 

 gotracheitis. (C. S. Gibbs.) Practical poultrymen have frequently asked about 

 the possibility of vaccinating chickens against infectious laryngotracheitis at the 



