CONTAClIOrS PNKUMONIA. 1 89 



The symptoms of contagious pneumonia are by no means so 

 constant or so uniform as has been suggested by certain authors. 

 Among those regarded as most important some are susceptible of 

 modifications in their expression and intensity, which are apt to deceive 

 the practitioner who only looks for typical cases. As in the simple 

 form, three periods may be distinguished : (i) onset and increase ; (2) 

 hepatisation ; and (3) resolution, gangrene or suppuration. 



The onset is usual!}- sudden, and too well marked to be overlooked. 

 A few patients remain fairly bright and livel}', and continue to take part 

 of their food ; but the majority are dull and depressed, hang back from 

 the manger, and do not touch anything. The}- show rigors, trembling 

 fits, and signs of sore throat, bronchitis, or slight colic. In the play of 

 symptoms now commencing two signs, however, o\-ershadow all others, 

 the acceleration of breathing and the fe\er. With rare exceptions the 

 flank mo\'ement is already \-ery rapid, and attracts attention. The 

 respirations are from 20 to 30 per minute ; sometimes inspiration is 

 fairly free, sometimes \-er}- shallow. The temperature rapidl}- rises to 

 a high point, often marking 40°, 40*5'^, or even 41'^ C. (104'^ F. to 

 105*8° F.), before the animals are noticed to be ill. I twice noted the 

 latter figure on first examining animals which onl}- the e^■ening before 

 had appeared health}- both in regard to work and feeding. Where 

 patients ha%-e been observed from the outset the temperature has often 

 risen 3° C. in twent}'-four hours. 



The conjuncti\-a is usuall\- reddish, sometimes of a yellowish tint, the 



the lung rhieflv in consequenre of being associated with the streptococcus of strangles. 

 At the moment when the " bacille typhiqiie" affects the organism, the streptococcus of 

 strangles (which is widely distributed) is often to be found in the upper air-passages, 

 without, however, having produced any manifest indications of its existence. Thanks to 

 the depression of the svstem produced by the " cocco-bacille,'" the streptococcus multiplies 

 in the lungs, forms caseous centres around the bronchi, and then gradually invades the paren- 

 chyma of the lung and more or less completely the entire organism. 



Inoculation of healthy animals with attenuated " bacilles typhjijiies" should render them 

 proof not only against the abdominal form of influenza, but also against pneumonia of the 

 same character. Hence the use of vaccination as a prophylactic measure in affected stables. 

 Sick horses should be simultaneously treated with injections of protective strangles serum 

 and of "serum antityphiqiier 



Experience has not yet pronounced on these laboratory suggestions. The first test, of 

 the protective method with the vaccine of " Pasteurellose equine," however, was made in the 

 stables of the Compagnie Generale des Voitures de Paris. The result was as follows : 



" From the 4th October, 1897, to the 12th May, 1898, 5007 horses were bought. All the 

 odd numbers were twice vaccinated, whilst the even numbers were left as controls. Up to 

 the 31st October, 1898, two hundred and fifty-four horses had died from chest diseases, one 

 hundred and fifty-eight which had not been vaccinated, — that is to say, a loss of 601 per 

 cent.; and ninety-six which had been twice vaccinated, that is a loss of 403 per cent. Seven, 

 horses were killed bv the use of insufficientlv attenuated vaccine." 



