INFLAMMATION. 145 



factors in the production of inflammation because they are the 

 most frequent offenders. Infection usuaHy produce inflam- 

 matory disturbances through the action of chemic substances 

 elaborated by the infecting micro-organisms, as metaboHc pro- 

 ducts. The infection may be local and produce localized in- 

 flammation as in a superficial abscess and in coccidiosis. The 

 elaborated chemic substances may be absorbed from the local- 

 ized infection and produce inflammation elsewhere in the body. 

 Infection may be general and produce conditions similar to in- 

 flammation in practically all the tissues of the bodv as in gen- 

 eralized anthrax. However, the term inflammation is usually 

 confined to local disturbances. The extent of irritation pro- 

 duced by any infecting organism is dependent upon the virul- 

 ency of the given organism and the resistance of the infected 

 animal. Thus, infection with Streptococcus pvogenes ecpii niav 

 produce pyemia in one animal and onlv a local abscess in an- 

 other. Again, some bacteria, as the anthrax bacilli, may pro- 

 duce septicaemia in one animal and localized inflammation in 

 another. A concise etiological classification of inflammation 

 produced by living organisms is impossible l)ecause of variations 

 both in the virulency of the organisms and in the resistance of 

 the tissxies. Animal parasites are of considera1:)le consecpicnce 

 in the production of inflammation. Thev may produce inflam- 

 mation by mechanical interference, as the Echinorychus gigas 

 which inserts its barbed proboscis into the intestinal mucosa 

 thus injuring the tissue as well as opening an avenue for the 

 entrance of various bacteria. The Trichina spiralis bv perfor- 

 ating the intestinal wall and by burrowing in the muscular 

 tissue produces sufficient irritation to establish inflammation, 

 the results of which are evidenced on microscopic examina- 

 tion of a lesion. It has been suggested that tlie etiological 

 factor of rabies is an animal parasite; the round-celled infil- 

 tration of the ganglionic nerve cells and perivascular spaces 

 having marked characteristics of the lesions of inflammation. 

 Psorospermosis, a condition resulting from psorospermic in- 

 festation, is inflammatory in its character. 



In a o-eneral way infective inflammations mav be discussed 

 as non-suppurative and suppurative. 



The non-suppurative infective inflammations are those in- 

 flammatory disturbances in which there is no purulent fluid or 

 pus produced. .A.s examples the following may be cited — septic 

 infection succeeding nail pricks in horses feet ; blackleg in 

 calves caused by the Bacillus anthracis symptomaticus. (Sar- 



