DIPHTHERIA OF ANIMALS 355 



and litmus milk acid production is slow and feeble. It is non- 

 pathogenic to guinea-pigs. The fermentation reactions will be 

 found in the Table on p. 348. 



Other Diphtheria -like Bacilli 



As already mentioned, diphtheria-like bacilli are not infrequent 

 in wounds, pathological discharges and secretions ; they are 

 common in the urethra. Some of them may be positive with 

 Neisser's stain. They are always non- virulent. The fermenta- 

 tion reactions of some of these organisms will be found in the 

 table on p. 348. 



Bacillus diphtherias columbarum 



Pigeon diphtheria is an infectious disease of pigeons, charac- 

 terised by the formation of diphtheritic -like membranes on the 

 tongue, fauces, and corners of the mouth ; occurs in extensive 

 epizootics from time to time. Loffler isolated a bacillus to which 

 he gave this name. It is short, with rounded ends, non-motile, 

 does not form spores, and does not stain by Gram's method. On 

 gelatin it forms a whitish growth without liquefaction, on agar a 

 creamy growth, and on potato a thin grey film. Milk is not 

 curdled and is unchanged in reaction. It is pathogenic for the 

 mouse and pigeon, but only slightly so for the fowl and guinea- 

 pig. It is possible to prepare a vaccine, and an anti-serum for 

 the disease. 1 Later research has, however, suggested that this 

 disease may be due to a filter-passer. 2 



Diphtheritic roup of poultry is a different disease, and is stated 

 to be due to a protozoan parasite. 3 Macfadyen and the writer 4 

 found Klebs-Loffler-like organisms to be present in the mouths and 

 throats of healthy pigeons and fowls. These organisms resembled 

 the true Klebs-Loffler bacillus in their cultural reactions, but were 

 quite non-virulent to guinea-pigs (see table, p. 348). 



The so-called diphtheria of calves is produced by an anaerobic 

 streptothrix. 



1 See Ann. de VInst. Pasteur, xv, 1901, p. 952. 



2 Dean and Marshall, Journ. of Path, and Bad., vol. xiii, 1908, p. 29. 



3 See also Gordon Sharp, Lancet, 1900, vol. ii, p. 18. 



4 Trans. Path. Soc. Lond., vol. li, 1900, p. 13, and Brit. Med. Journ., 1900, 

 vol. i, p. 994. 



232 



