Pseudo Membranous ( Croupous ) Enteritis in Birds. 227 



pigeons, linnets, rabbits and mice, but not to hens, Guinea-pigs, 

 rats or dogs. Chickens, however, suifer from an acute diphther- 

 itic affection caused b}' a nearl}^ alhed bacilhis, and it remains to 

 be seen whether the varying pathogenesis ma}' not be due to the 

 habit of long-continued growth in a particular genus and an ac- 

 quired unfitness for growing in the other. The pathogenesis is 

 also different from the bacillus of diphtheria of man, and the two 

 diseases are not usually inter-communicable, in spite of the fact 

 that in rare instances infection has appeared to have taken place 

 from man to birds. 



In pigeons and fowls the upper parts of the air passages and 

 digestive tract are mainly involved, the tongue, fauces, corners 

 of the mouth, nares, larynx, and conjunctiva. The bowels suffer 

 less frequently and mostly concurrently v^ith the mouth, nose 

 and throat. Tlie mucosa is deeply congested and in part covered 

 b}' a 3'ellowish exudate which ma}^ accumulate in masses, and 

 dry into a firm substance. The disease affects particularly high 

 bred birds, kept in close warm houses, and is often imported by 

 prize animals returned from a show. There may be dullness, 

 listlessness, sunken head, trailing wings and tail, erect plumage, 

 diarrhoea, and, if the nose and throat are affected, a modification 

 of the voice as in roup. Death may occur from asphyxia from 

 the second to the fourth day near the beginning of an outbreak 

 or the illness may last twenty days, after the more susceptible 

 birds have been killed off. 



In investigating a series of outbreaks of roup in chickens in 

 America, Dr. V. A. Moore found a non-motile bacillus allied to 

 the colon bacillus which proved much more deadly to rabbits and 

 guinea pigs than to chickens, and which was not found in the 

 blood nor internal organs but only in the local lesions where 

 inoculated. The disease tended to assume a chronic type in 

 place of the acute form as seen in Europe. Three inoculated 

 chickens escaped the disease altogether. It would appear there- 

 fore that we have here a disease distinct from that described by 

 lyoeffier, or that there was an absence of some unknown predis- 

 posing or contributing conditions that were present in the 

 European outbreaks. In both diseases however infection is an 

 undoubted factor and similar measures of prevention and even of 

 treatment may be followed. 



