NATURE 



289 



THURSDAY, JULY 28, 1892. 



GROUSE DISEASE AND FOWL ENTERITIS. 



The Etiology and Pathology of Grouse Disease and Fowl 

 Enteritis. By E. Klein, M.D., F.R.S. (London: 

 Macmillan and Co. 1892.) 



IN this book Dr. Klein has given the results of an im- 

 portant series of researches made by him upon ' 

 certain diseases in birds. The malady which has specially 

 occupied his attention is that commonly known as the 

 grouse disease. The book will therefore find a large t 

 and appreciative circle of non-professional readers. To : 

 all interested in the preservation of game it may be com- 

 mended as furnishing for the first time an adequate and 

 satisfactory explanation of the origin and mode of propa- 

 gation of the grouse disease. The book is over and 

 above that a valuable contribution to bacteriology. The 

 very excellent illustrations appended enable one to follow 

 the text with great ease. The birds affected are the red 

 grouse {Lagopus scoticus) of our moors. The disease, 

 when it breaks out in the spring or summer, is usually of 

 a very virulent type. A fatal epidemic then arises which 

 carries off large numbers of the birds, to the despair of 

 the owners and keepers, who find themselves powerless 

 to cope with the malady. It is to this quickly fatal 

 epidemic that the name of the grouse disease is applied. 

 Though much written about and much discussed, the 

 origin of this disease has hitherto remained undiscovered. 

 During the last five years numbers of birds, dead or 

 dying from the disease, were sent to Dr. Klein from 

 moors in England and Scotland. The large amount of 

 material furnished has enabled him to make an exhaus- 

 tive inquiry. 



The result is the most noteworthy account yet pub- 

 lished of the etiology and pathology of the disease. Dr. 

 Klein has proved that it is an acute infectious malady 

 primarily affecting the lungs and liver of the birds. The 

 symptoms and appearances are those of an acute in- 

 fectious pneumonia. Dr. Klein has further discovered 

 the causa causans of the disease in the shape of a minute 

 unicellular organism, belonging to the class of the bacteria. 

 This microbe has its special seat in the lungs and liver. 

 It is a bacillus, and is found filling and blocking up the 

 capillary blood vessels in the diseased areas of the lungs 

 and liver. The organism can be isolated from the diseased 

 tissues and grown on suitable media outside the body. 

 In this way a series of culture of the bacilli were made on 

 various soils — gelatine. Agar, beef broth, &c. The man- 

 ner of growth of the microbe in these culture media is 

 very fully described. The growths obtained were always 

 of the same bacterial species. The pure culture of the 

 bacillus subcutaneously inoculated into healthy animals 

 reproduced the symptoms and appearances of the disease. 

 They proved fatal to mice and guinea pigs, and caused 

 in them a congestion of the lungs and liver. No effect 

 was produced on pigeons and fowls. The most virulent 

 cultures of the microbe were those grown in meat broth 

 to which a piece of coagulated white of &g'g had been 

 added. The most positive results were obtained with the 

 common bunting and yellow-ammer. These birds were 

 NO. I 187, VOL. 46] 



inoculated with a minute drop of a meat-broth culture of 

 the microbe. They succumbed within twenty-four hours. 

 The post-mortem appearances were similar to those found 

 in the grouse, viz., a marked congestion of the lungs and 

 liver. The bacilli were found in large numbers in the 

 lungs. From these experiments Dr. Klein was able to 

 conclude that the grouse disease is due to the microbe 

 isolated by him from the diseased organs of the birds. 

 Unfortunately he has not been able to reproduce the 

 disease in large birds, or to utilize healthy grouse for his 

 experiments. In the latter case the difficulty in obtaining 

 living birds and keeping them in captivity prevented this 

 last and most important proof being furnished. The 

 larger birds experimented with (fowls and pigeons) proved 

 unsusceptible. 



The infection of the birds seems to take place through 

 the respiratory organs. Dr. Klein furnishes a very strik- 

 ing experiment in support of this view. A yellow- 

 ammer, afcer being inoculated with the grouse bacillus, 

 was placed in a cage adjoining to one containing six 

 healthy ammers. These six healthy birds acquired the 

 disease and died. 



The autumnal disease of the grouse is similar to the 

 spring and summer disease, and both are caused by the 

 same microbe. 



The bacilli found in the autumnal disease are, however 

 less virulent than those found in cases during the spring 

 and summer. The buntings and ammers inoculated 

 with the autumn microbe died at a much later period. 

 Mice that had survived inoculation with the autumn 

 microbe did not succumb when inoculated with the more 

 virulent spring microbe. Dr. Klein suggests that cultures 

 of the autumnal microbe might be used as a protective 

 vaccine for the young birds on the moors. It is to be 

 feared that those on whose shoulders this task would fall 

 might prefer the disease to the cure. 



The bacillus is easily killed. A temperature of 60° C. 

 completely destroys its life in five minutes. On the other 

 hand, virulent meat broth cultures heated for twenty 

 minutes to 55^ C, retained their virulence and yielded 

 normal growths when grown in a fresh soil. This more 

 prolonged heating so near the critical temperature for the 

 bacilli (60 C.) did not, as one would have supposed, pro- 

 duce any retardation in their subsequent growth or any 

 attenuation of the organisms. 



Meat broth cultures, in which the bacilli had been 

 destroyed by heat, produced in mice all the symptoms of 

 the disease. This points to the presence in the meat 

 broth of some poisonous chemical product. The matter 

 is referred to very briefly, but we hope Dr. Klein will 

 soon be in a position to tell us more about this interesting 

 and important discovery. 



To prevent the spread of the grouse disease the import- 

 ance of weeding out suspicious birds from the moors is 

 emphasized. The birds killed should be removed and 

 burned. 



Dr. Klein describes in the next place a bacillus which 

 he isolated from garden earth. Guineapigs, rabbits, and 

 mice, when inoculated with this organism, developed an 

 oedema of the subcutaneous and muscular tissues. The 

 organism is aerobic, and grows well in the presence of 

 free oxygen, and on the surface of culture media. It is 

 therefore not identical with Koch's bacillus of malignant 



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