456 



glands. The usual form, however, is chronic in nature and char- 

 acterized by catarrhal pneumonia in which the lungs show areas 

 in different stages of progress of the disease. All stages of pneu- 

 monia may be seen with areas of necrosis. These necrotic cen- 

 ters may be liquid or caseous and may be small or large, some- 

 times involving centers of several cubic inches. There is usually 

 a fibrinous pleurisy with or without adhesions. The lungs have 

 a mottled appearance and the bronchial and mediastinal lymph 

 gland may be hemorrhagic or necrotic. 



Swine plague is frequently confused with cholera and often 

 veterinarians fail to get good results from the use of anti hog 

 cholera serum because they have ncTt correctly interpreted the 

 symptoms and lesions seen in animals suffering from swine 

 plague. It has been demonstrated that cholera serum has no 

 effect upon the animals infested with the B. Suisepticus. Fre- 

 quently cholera and swine plague exist in the same animal or 

 herd, and in most of these cases the iise of serum does little good. 

 The symptoms of swine plague occurring in the chronic form are 

 those of pneumonia with a short, dry, spasmodic cough. Dysp- 

 noea is usually well marked, especially if the animal is forced to 

 run a short distance. Thumping or spasmodic abdominal res- 

 piration is characteristic of the cases. The temperature is about 

 104° F., appetite poor, quite rapid emaciation until the animal 

 dies from exhaustion in from 30 to 50 days. 



The diagnosis is a very important factor in successfully hand- 

 ling hogs affected by this disease. 



In the treatment of swine plague a new field has opened. Cholera 

 serum has no effect either as an immunizing or curative agent. 



Hemorrhagic septicemia vaccine for swine is giving good results 

 in herds where swine plague occurs uncomplicated with cholera. 

 If there is cholera, serum should be given ; if there is swine 

 plague, vaccine should be given ; if- the two diseases occur to- 

 gether, both serum and vaccine should be given. Hogs may be 

 immunized against swine plague by the injection of one or two 

 doses of hemorrhagic septicemia vaccine for swine, and cases 

 where the destruction of lung tissue is not too extensive may be 

 cured by three or four injections. 



Swine plague vaccine is prepared according to an original for- 

 mula perfected several years ago. The basis for tliis formula is 

 taken from the vaccine used by the B. A. I. in combating hemor- 

 rhagic septicemia in buffalo, in Yellowstone National Park. The 

 formula was prepared after the examination of many lung speci- 

 mens to determine the variety of organisms usually accompany- 

 ing the B. Suisepticus. Hemorrhagic septicemia vaccine for swine 

 is a polyvalent or mixed vaccine based upon the association of 

 pathogenic organisms most frequently found in swine plague. 



The above note is quoted from a trade journal issued by the 

 Jensen Salsbery Laboratories in Kansas City, wdiich have been 

 furnishing the division of animal industry with samples for ex- 

 perimental purposes. — Editor. 



