ANNUAL REPORT, 1938 95 



reacting flocks (100 percent tested), representing 432,919 birds, were identified 

 in 11 counties. The flocks tested for three or more consecutive years revealed 

 the lowest average percentage (0.07) of infection. Poultrymen are encouraged to 

 buy only from flocks officially recognized as free from the disease. 



Concerning fowl other than chickens, reacting birds were detected onl}* among 

 the turkeys. 



During the past year this department has continued to cooperate in making 

 available to the Massachusetts Department of Agriculture testing results which 

 are used for official recognition and classification of pullorum tested flocks. 



2. Diagnostic Service. The amount of material available for examination 

 continued to show an increase. Personal delivery of specimens occurred in 352 

 of the 560 cases handled, which included 2,617 specimens. The classification of 

 the specimens is as follows: 2,359 chickens, 172 turkeys, 19 canine feces, 15 

 pigeons, 9 rabbits, 8 pheasants, 5 bovine feces, 3 canaries, 3 canine skin scrapings, 

 2 each of bovine liver, canine, fox, goat feces, laryngotracheitis vaccine, mink, 

 quail, ruffed grouse, and sheep, and 1 each of bovine placenta, canine tumor, 

 feline parasites, fish roundworms, swine, and woodchuck. The diseases encount- 

 ered most frequently were coccidiosis, pullorum disease, tumors, fowl paralysis, 

 and avian encephalomyelitis (epidemic tremor). Presumably rare but important 

 diseases were noted as follows: fowl cholera 3, fowl typhoid 2, paratyphoid in- 

 fection 2, and avian tuberculosis 1. Each of these outbreaks represents a hitherto 

 unknown focus of infection. 



3. Mortality Studies of Cottontail and White Hare Rabbits Imported into 

 Massachusetts. During the past year this department, in cooperation with the 

 Massachusetts Department of Conservation, investigated mortalities among 

 cottontail arid white hare rabbits which were imported into Massachusetts. 

 The cottontail rabbits were imported from Arkansas, Kansas, Missouri, Okla- 

 homa, and Texas and the white hare rabbits, from Maine and Canada. Fifty 

 consignments of dead rabbits were submitted to the laboratory from December 

 to April inclusive. Among 2,415 cottontail rabbits imported, 213 were dead 

 on arrival. The majority of specimens submitted were unfit for satisfactory 

 examination. Coccidial oocysts were frequently observed in cecal contents. 

 The following ectoparasites and endoparasites were detected: Odontopsyllus 

 multispinosus, Spilopsyllus simplex, Haemaphysalia leporis-palustris, Ixodes 

 dentatus, Taenia pisiformis, Cittotaenia variabilis, Trichuris leporis, and Obelis- 

 coides cuniculi. No evidence of Pasteurella tularense infection was obtained from 

 the gross pathology or animal inoculation. Papillomatosis was observed in several 

 specimens. The majority of cottontail rabbits appeared to be in good state of 

 nutrition. 



Among 329 white hare rabbits imported, 15 were dead on arrival. In the 

 specimens submitted to the laboratory two species of parasites {Protostrongylus 

 leporis and Obeliscoides cuniculi) were encountered. 



Appreciation is extended to members of the Zoological Division, Bureau of 

 Animal Industry, United States Department of Agriculture, for identifying the 

 parasites mentioned in this report. 



4. Infectious Bronchitis Immunization. Infectious bronchitis is a virus 

 disease which is of great economic concern to the poultry industry. The greatest 

 loss suffered from the disease when present in mature birds is reduced egg pro- 

 duction. 



During the past year an outbreak of infectious bronchitis was investigated 

 from the viewpoint of control by means of immunization with vaccine prepared 

 from infected birds taken from the affected flock. 



