THE RABBIT PASTEURELLA 



453 



ance and gram-negative. It is pathogenic for mice and swallows, guinea-pigs are 

 only slightly susceptible, fowls and ducks are immune. 



Tretrop was able with difficulty to vaccinate mice against the disease by treating 

 them with cultures attenuated by heat (10 minutes at 58 C.). 



The bacillus of hsemorrhagic septicaemia of ducks and fowls (Rabieaux). This 

 bacillus has all the characteristics of the fowl Pasteurella. It is an oval bacterium, 

 non-motile, pleomorphic, gram-negative and does not grow on potato. It is patho- 

 genic for ducks, fowls, pigeons, rabbits, guinea-pigs and white rats. 



The repeated inoculation of filtered cultures of this bacillus or of cultures heated 

 to 60 C. renders rabbits and guinea-pigs immune to the sub-cutaneous inoculation 

 of living and virulent cultures, infected blood and other material. 



2. PASTEURELLA CUNICULI. 

 (The bacillus of rabbit septicaemia). 



A large number of dissimilar affections due to widely different organisms 

 have been classed together under the head of "rabbit septicaemia," but many 

 of these septicaemias are undoubtedly caused by an organism having all the 

 characteristics of the pasteurella (P. cuniculi) first described by Th. Smith 

 and more fully later by Thoinot and Masselin. 



[C. J. Martin and Rowland have recently found that both plague (B. 

 pestis) and rabbit septicaemia (P. cuniculi) may be encountered among rabbits 

 in the same neighbourhood. " The co-existence of this latter disease [rabbit 

 septicaemia] indicates the need for care in the diagnosis of plague among 

 these rodents, as in the organs the cocco-bacilli of rabbit septicaemia may be 

 microscopically indistinguishable from Bacillus pestis." x ] 



The bacillus described by Eberth and Mandry and isolated by them during an 

 epizootic among rabbits is an oval-shaped motile organism, growing on potato, 

 coagulating milk and producing indol. These characteristics should exclude it 

 from the Pasteurella group which in all other respects it resembles. The bacillus of 

 ferret septicaemia of Eberth and Schimmelsbuch is also wanting in most of the 

 characteristics of a typical pasteurella. 



The bacillus described by Lucet in a " new septicaemia of rabbits " in 1889 should 

 apparently be included with the pasteurella, and also a micro-organism described 

 by Lefebre and Gautier in a septicaemia similar to that of Eberth. 



1. Experimental inoculation. Rabbits and guinea-pigs are equally 

 susceptible to inoculation with the rabbit pasteurella ; all birds are also 

 susceptible. A young broth culture or material 

 (blood, spleen or liver tissue) from an animal 

 recently dead of the disease may be used ; intra- 

 peritoneal inoculation is more rapidly fatal than 

 sub-cutaneous inoculation. 



[Martin and Rowland found rats and guinea- 

 igs to be unaffected by a dose of culture which 

 illed large rabbits in less than 18 hours. ] 



Symptoms appear on an average about 20 

 hours after inoculation. The animal is weak 

 and refuses its food, respiration is quickened, 

 locally there is a swelling at the site of inocula- 



V , -IT, -i FIG. 227. Pasteurella cumcuh. 



tion, diarrhoea supervenes and later the animal on the left a film from sparrow's 



.**?* a fllm from the 



becomes comatose and dies. 



Post mortem, the venous system is engorged 

 with thick, dark-coloured blood, the trunk muscles are of a reddish purple 

 colour, the abdominal cavity contains a large quantity of thick, blood-stained 

 1 Report Medical Officer, Local Government Board, 1910-11, Cd. 5939. 



