370 KEPOKT OF THE COMMISSIONER OF AGRICULTURE. 



2. SYMPTOMS. 



1 have visited tbirty-two different lierds, and examined a large num- 

 ber of diseased animals, but have very little to add to my former report. 

 ^J^ho essential differences observed are as follows : During the vrinter and 

 in the spring bleeding from the nose, difficulty of breathing, and symp- 

 toms of respiratory disorders in general seem to be more, and symptoms 

 of gastric disorders less frequent than in the summer and in the fall. 



3. PEoaNOSis. . 



Though always unfavorable, the same, as a rule, is not quite so hope 

 less in the ^vinter and spi'ing as in the summer and early autumn, ]>rob- 

 ably because in the former seasons the seat of the morbid process is 

 limited more frequently to the respiratory organs and to the pulmonal 

 tissue, and is not found so often in the intestinal canal. Still the dift'er- 

 ence, partially due no doubt to some other causes or conditions, to be 

 explained liuther below, is not a very great one, especially if it is taken 

 into consideration that swine plague is always more fatal to very young 

 pigs than to older animals or full-grown hogs ; and that more pigs ai-e 

 born in the spring than at any other season of the year. Consequently, 

 the average age of the pigs diseased with swine plague is much less in 

 the summer than in the winter. 



4. MORBID CHANGES. 



Since December 15 numerous examinations (thirty-one is the exact 

 number) have been made, but no new morbid changes not met with be- 

 fore have been discovered, and the combinations in which the various 

 morbid changes presented themselves did not essentially differ fi?om 

 those alreadyrecorded in my first report. It will, therefore, be sufficient, 

 in order to avoid unnecessary repetition, and to give at the same time a 

 complete description of the various combinations of morbid changes 

 Tfhich have come under my observation, to describe only those few cases 

 which presented such variations as may possibly serve to throw more 

 light upon the nature of the morbid process, by pouiting out some of 

 the probable causes of the great diversity of morbid changes found ui 

 different animals. Swine, just as well as other domesticated ^nimals, 

 and perhaps even more than other animals, on account of being omniv- 

 orous, and having therefore more opportunity to pick up worm-brood, 

 are subject to being inhabited and preyed upon by various species of 

 parasitic Avorms or entozoa, especially at certain seasons of the year. 

 These worms, of course, occur just as well in those animals that are 

 afflicted with swine plague as in those that have never been exposed to 

 any infection; consequently they are found quite often on 2>ost mortem 

 exajuinations. 



As mentioned in my first report, some species of entozoa — Strongyliis 

 imradoxus (in the bronchial tubes), Tricoeephalus crenatus (in the 

 cecum), and a few others — were found in thirteen animals, or at least 

 25 per cent, of the post mortem examinations made last summer and fall, 

 prior to December 1 ; but no entozoa whatever could be found, notwith- 

 standing I searched for them in nearly every examination made since 

 December 15. The absence of worms or entozoa in 75 per cent, of the 

 whole number of animals dissected prior to December 1, and their en- 

 tire absence -m every animal examined after death since Decem.ber 15, 

 proves conclusively, if anything, that the morbid changes characteristic 



