134 Enzootic Pneumonia of Young Animals. 



Occurrence. Enzootic pneumonia of young animals occurs 

 in all countries in wliicli young animals are bred in large num- 

 bers and it has been ol)served particularly in Holland, Germany, 

 Denmark, France, Belgium, England, Italy, Switzerland, Eus- 

 sia, Hungary and America. Most commonly affected are calves, 

 lambs, young pigs, less commonly kids, and rarely foals. The 

 animals are, as a rule, affected during the first weeks of their 

 lives, but even up to the sixth montli and later. 



The disease has become of greater economic significance 

 since it recurs annually again and again in spring and becomes 

 more extensive as a barn enzootic, causing numerous deaths and 

 retarding the development of those animals which survive. 



Strose & Heine demonstrated contagions pneumonia in 1 to 1%% of all 



young hogs slaughtered in the stockyards of Hanover (Simader claims, however, 



that the?e were cases of pulmonary atelectasis). Grips, Glage & Nieberle saw 

 pneumonia in about 50,000 young hogs in Hamburg. 



Etiology. There is no uniformity in the etiology of the dis- 

 ease. The bacillus bipolaris septicus (see Vol. I) or its varie- 

 ties (bacillus vitulisepticus, ovisepticus, suisepticus, equisep- 

 ticus) are frequently the cause of the disease. Galtier's pneu- 

 mobacillus septicus is probably identical with the former or- 

 ganisms. 



Virulency. The experiments of Poels have shown that the inocula- 

 tion of cultures of bacilkis vitulisepticus into the lungs or the serous 

 cavities of rabbits kills the animals Avithin fifteen to thirty-five hours; 

 calves within twenty to sixty-six hours. Intrapulmonary infection is 

 followed by a serofibrinous pleurisy, occasionally accompanied by lobu- 

 lar pneumonia. Rabbits, guinea-pigs and mice die from septicemia 

 after subcutaneous injection or feeding. Hogs, when artificially in- 

 fected, sicken under symptoms similar to those of swine plague ; other 

 animals, occasionally even guinea-pigs (Jensen), develop suppuration 

 at the place of injection. Dogs are resistant. The experiments of Gal- 

 tier with his pneumobacillus septicus were positive in intrapulmonary, 

 intratracheal, nasal, intraperitoneal, intraocular and sulicutaneous injec- 

 tions in calves, lambs, kids and hogs. Semmer, however, did not suc- 

 ceed in spreading the disease to healthy calves by the nasal, intratracheal 

 and intrapulmonary injection of pulmonary juice. Bacteria, which 

 were not fully described, were cultivated from the afiPected lungs, but 

 did not prove effective in Greve's case; some other animals could not l)e 

 infected. Similar were the (negative) results of Hartl & Reisinger in 

 inoculating small laboratory animals with a pleomorphous bacterium 

 similar to the bacillus bipolaris. After subcutaneous injections of this 

 bacillus domestic animals susceptible to the disease did not usually 

 become affected, though rabliits sometimes succumbed to a pneumonia 

 (Stohr). The same observations have been made with reference to the 

 bacillus suisepticus (Smith, Kitt) or to the bacillus bovisepticus 

 (Marek). 



Several investigators found other bacteria, aside from the 

 bacillus bipolaris as the cause of enzootic pneumonia in young 

 animals. Poels, J. Miiller and Schreiber observed an enzootic 

 pneumonia in calves and young pigs, caused by a bacterium of 



