138 Enzootic Pneumonia of Pigs, 



swine plague culture, while if the serum treatment has been given 24 hours pre- 

 viously, it also has projective action against the toxins of chicken cholera and 

 swine plague bacteria. The passive imnlunity lasts from 3 to 4 weeks, while active 

 immunity could not be produced even in mice by serum and culture injections. 



Literature. Loffler, Arb. d. G.-A., 1886, 1, 46.— Schutz, A. f. Tk., 1886, 

 XII, 210. — Salmon & Smith, Eur. of Anim. Intl., 188(J-1S94. — Smith, Spec. rep. 

 of the cause of swine-plague, Washington, 1891. — Preisz, Z. f. Tm., 1898, II, 1, 

 u. 1907, XI, 161.— Ligniere.s, Bull., 1900, 389 (Lit.).— Beck & Ko«ke, Arb. d. G.-A., 

 1905, XXII, 181.— Joest, Schweineseuche u. Schweinepest, Jena 1906 (Complete 

 Lit.).— Ostertag & Stadie, Z. f. Infkr., 1907, II, 112, u. 425.— Hutyra, ibid., pp. 281, 

 and III, 235.— Citron, Z. f. Hyg., 1906, XLI, 238.— Uhlenhuth, Xylander, Hubener 

 & Bohtz, Arb. d. G.-A., 1908, XXVII, 1 (Lit.).— Broil, Z. f. Infkrkh, 1908, V, 81 

 (Lit. on immunization). — Gniichtel, Diss. Leipzig 1909 (Lit.). 



Enzootic Pneumonia of Pigs (so-called chronic swine plague of 

 pigs). According to the view of Ostertag, which is also accepted by 

 a great number of other investigators, the classical form of swine plague 

 described above has changed since the middle of the nineties of the last 

 century to a milder form, so that at the present time it occurs mostly 

 as a chronic pneumonia affecting only very young pigs. Among these 

 young animals, however, it occurs widely distributed. According to 

 this conception the disease is generally known as ' ' chronic swine plague 

 of pigs," but in some localities it is also designated as pig disease, pig 

 cough and cement disease (as it occurs frequently in new stables with 

 cement floors). 



The disease causes considerable loss, especially among the improved breeds, 

 and occurs principally in Northern Germany (Eastern and Western Prussia, Silesia, 

 Brandenburg, Pommerania, Sehleswig-Holstein, Hessen-Nassau, etc.). Thus for 

 instance in the abbatoir of Hamburg about 50,000 hogs annually show the ana- 

 tomical lesions of the disease. 



The symptoms of the disease develop sometimes early in the 

 first days of life, more commonly, however, between the second and 

 fourth week after birth. The animals lose their sprightliness and appe- 

 tite, sometimes manifesting also a perverted appetite (eating of manure, 

 filth, etc.). A catarrh of the nose (frequent sneezing and blowing, 

 especially during eating), as well as of the deeper air passages, fre- 

 quently develops. The young animals have a short, sharp spasmodic 

 cough which is especially brought on by rising and eating. The cough 

 sometimes is associated with rattling and choking. At the same time 

 the respiration is more or less accelerated and labored, the animals in 

 the more severe affections lying on the sternum or on the side, or they 

 stand with arched back and legs spread apart. 



Of the other symptoms conjunctivitis, muco-purulent nasal dis- 

 charge, and frequently a peculiar skin eruption may be observed. This 

 is manifested in the form of red spots on the head, on the ears and on 

 the sides of the body, which show a slight exudation and soon become 

 covered with scabs and scales. In other cases vesicles form which 

 after bursting also become covered with scabs, so that finally the dry 

 and exfoliated skin appears covered to a great extent with blackish-brown 

 crust. 



With the advance of these symptoms the affected animals are re- 

 tarded in their development, the appetite being changeable or con- 

 tinually absent. Subacute inflammations appear in the different joints, 

 especially in the knee and elbow joints, as a result of which the animals 

 walk with evident pain and stiffness, and after the appearance of 

 diarrhea and bloating the completely exhausted patients usually die 

 in the course of the second or third month of their lives. 



