IMMUNIZATION OF ANIMALS 459 



[M'Gowan's bacillus of distemper.] 



[M'Gowan 1 lias recently brought forward evidence to show that " Dis- 

 temper " is due to a gram-negative, non-spore-bearing slightly motile bacillus. 



[ The organism was recovered from a large number of more or less diseased 

 animals of different species : in all the primary focus of the disease was the 

 respiratory tract. The dogs and cats from which the organism was isolated 

 showed the symptoms commonly associated with " distemper." 



[The organism measures when taken from the tissues from 0'5-2'3/x long by 

 about 0'4-0'5/A broad. It grows on all the ordinary media both aerobically 

 and anaerobically and does not liquefy gelatin. 



[ It forms neither acid nor gas in a peptone-salt medium containing any of 

 the following carbohydrates : lactose, saccharose, salicin, mannite, dulcite, 

 maltose, galactose, raffinose, glucose, inulin, inosite, adonite. On the other 

 hand, the solutions become markedly alkaline after a few days. 



[Litmus milk is turned alkaline and not coagulated. 



" On potato the growth is characteristic, the appearance being that of a 

 buff-coloured, or yellow to copper-brown, raised, moist, heavy growth. The 

 brownish colour is perceptible in 24 hours and is very evident in 48 hours " 

 (M'Gowan). 



[On intra-peritoneal inoculation the organism was pathogenic to a large 

 variety of animal species including dogs and cats, and there is evidence " that 

 the organism in pure culture can produce in healthy dogs, when applied to 

 their nasal mucous membrane, the clinical symptoms of "distemper."] 



9. IMMUNIZATION WITH THE POLYVALENT VACCINES 

 OF LIGNIERES. 



Starting with the idea that an animal may be infected with several varieties of 

 pasteurella, Lignieres recommends the use of polyvalent vaccines. The vaccine 

 is prepared by mixing cultures of the sheep, ox, dog, horse, pig, and fowl varieties. 

 In order to avoid any changes in virulence, only cultures which have been grown on 

 agar in the laboratory for at least a year and have been re-sown every other day 

 are used. To prepare the vaccines, these cultures are sown in flat- bottomed flasks 

 containing a shallow layer of broth and incubated at 42-43 C. for 5 days for the 

 first vaccine and for 2 days for the second. 



The dose of each vaccine varies from O'125-l c.c. according to the size of the 

 animal, and the two inoculations are given sub-cutaneously at intervals of 12 days 

 or a fortnight. The resulting immunity lasts, on an average, 12 months. 



Polyvalent serum. 



Lignieres and Spitz prepared a polyvalent serum which was both prophylactic 

 and curative. 



Mixed cultures of the six varieties of the pasteurella which have been kept on 

 agar for a year, and sown as described above, are injected into horses in repeated 

 small doses (5-20 c.c.) at intervals of a few days first under the skin then into the 

 veins. After each inoculation the animals show a sharp reaction lasting 2 or 3 days. 



The serum so obtained is prophylactic and curative but has no antitoxic properties. 

 In doses of 40-60 c.c. it gives the best results in the treatment of the equine pas- 

 teurellosis, and in doses of 5-10 c.c. if given at the onset of the disease it is [said 

 to be] very efficacious in the treatment of distemper in dogs. 



Journal of Pathology and Bacteriology, xv. p. 372. 



