140 DISEASES OF SWINE AND OTHER ANIMALS. 



is that the bearded ap])earance or black specks are the commencing!: les- 

 ions of the disease, and that this is followed by thickening- or deposit. 

 Anomalons lesions were found in many cases, in one the entire mass of 

 bowels were found agj>lutinated. In several others were found enormous 

 thickening- or deposit in coat of stomach ; but in all cases, as before men- 

 tioned, there was one lesion always present, a deposit or thickening 

 around the ilio-cjBcal valve where the solitary glands of cfecum are sit- 

 uated. 



The cause. — The exciting cause of this disease is a specific poison in 

 the blood, an infectious, miasmatic ])oison, and the disease cannot be 

 generated by any excess of filth, ])y Avant of care, or any errors in food. 

 The specific poison must be there. The hog, to contract the disease, 

 must be exposed to the sj^ecific miasma arising from another animal suf- 

 fering from the disease. This disease is very contagious, and if it once 

 obtains access to a drove of swine, prompt measures only can prevent 

 its spread to the entire lot. The rapidity of its spread depends ui^on 

 the condition of the drove and the ventilation. Wlien the hogs are 

 allowed an extensive range, and are not crowded together, it will spread 

 slowly ; but where they are cooped up in a contracted pen it -will spread 

 very rapidly. Although, as I have before said, this is the most conta- 

 gious and fatal of any disease that has attacked swine, yet it has one 

 redeeming feature, it is more easy to prevent its access to a drove, as 

 the miasm cannot be carried as long distances by -wind and other meth- 

 ods of conveyance as can the poisons of diphtheria and typhoid fever. 



It may be well for me to exi^lain the statement that filth cannot gene- 

 rate the disease. No amount of filth, no confinement in close quarters, 

 no errors in food can produce the disease, but filth, want of ventilation, 

 and improper food can deprave the system, disorder the stomach and 

 render the animal more liable to the inception of the malady. Hence 

 the disease often obtains access to a drove by means of one or two ani- 

 mals whose systems are disordered, and having once obtained a foot- 

 hold spreads to the healthy ones, the contagious influence being now 

 nearer and stronger. 



Incnhation. — From the few cases where the stage of incubation could 

 be accurately determined, that is, the period of time elapsing from the 

 time of exposure until the outward manifestations of the disease, I 

 would place the period of incubation at fourteen days. I have but two 

 instances to report where the time of exi^osure could be exactly deter- 

 mined. To verify this statement, in each of these cases the exact time 

 of exposure (by arrival of strange hogs suffering from the disease,) and 

 the first outward symjitoms of the disease were noted, and in each case 

 it was fourteen days from time of exposure until the sym]:>toins of dis- 

 ease appeared. [See notes on Homestead (Amana Society) Colony.] 

 We shall speak of the ])redisposing causes when we come to consider 

 the three diseases collectively, as the same causes will promote the 

 spread of either one of them, but in difierent ratio. 



Typhoid fever — Bciinition. — A specific continued fever, attended with 

 great ])rostration of strength, stupor, tympanites, diarrhea, sliowing 

 specifi(5 anatomical lesions, namely, ulceration of the solitary glands of 

 coicum and colon. Tlie disease, when uncomplicated, runs its course 

 in nine days. During the first month of my investigation I made no 

 separate classification of those two diseases— typhus and ty])hoid fever. 

 My course was as folloAVs: From each infected drove ins]3ected, I selec- 

 ted from two to five diseased hogs of various ages and at difierent stages 

 of the disease. After carefully noting the age, history, and morbid symp- 

 toms in each case, the animal was kUled, and exact notes taken of the 



