DISEASES OF SWINE AND OTHER ANIMALS. Bysi i 
in good condition, and naturally strong and vigorous, the mortality some- 
times may not exceed 25 per cent., but may, on an average, reach 40 to 
50 per cent. The prognosis is comparatively favorable only in those few 
eases in which the morbid process is not very violent; in which the seat 
of the disease is confined to the respiratory organs and to the skin; in 
which any thumping or pumping motion of the flanks is absent; and 
in which the patient is, naturally, a strong, vigorous animal, not too 
young and in a good ‘condition 3 ; further, in which but a ‘few, not 
more than two or three, animals are kept in the same pen or sty, and 
receive nothing but, clean uncontaminated food and pure water for ‘ar ink- 
ing, and in which a frequent and thorough cleaning of the sty or pen 
prevents any consumption of excrements. 
The duration of the disease varies according to the violence and the 
seat of the morbid process, the age and the constitution of the patient, 
and the treatment and keeping in general. Where the morbid process 
is violent, where its principal seat is in one of the most vital organs— 
in the heart, for instance—where a large number of animals are kept 
together in one sty or pen, where sties and pens are very dirty, or where 
the sick animals are very young, the disease frequently ‘becomes fatal in 
a day or two, and sometimes even within twenty-four hours. On the 
other hand, where the morbid process is not very violent or extensive, 
where the ‘heart, for instance, is not seriously alfected, and where the 
patients are natur ally strong and vigorous, and w ell kept in every 
respect, it usually takes from one to ‘three weeks to cause death. If 
the termination is not a fatal one, the convalescence, at any rate, re- 
quires an equal and probably a much longer time. A perfect recovery 
seldom occurs; in most cases some lasting disorders—morbid changes 
which can be repaired but slowly or not at all—remain behind, and inter- 
fere more or less with the growth and fattening of the animal. 
From a pecuniary standpoint, it makes but little difference to the 
owner whether a pig affected with this plague recovers or dies, because 
those which do survive usually make very poor returns for the food 
consumed, unless the attack has been a very mild one. 
4, MORBID CHANGES. 
The morbid process, although everywhere essentially the same (see 
chapter on Contagion, Causes, and Nature of Morbid Process), can have 
its seat in many “different or gans or parts of the body, and ‘produces, 
therefore, a great variety of morbid changes. The disease, in conse- 
quence, very often presents a somewhat different aspect in different 
animals. In some cases the principal seat of the morbid process is in 
one organ or set of organs (organs of respiration and circulation, for 
instance), and in others in entirely different parts (intestinal canal and 
organs of digestion, &c.) Death, therefore, has very often a different 
cause in different cases; in some cases it results froma cessation of the 
functions of the heart, the lungs, &c., and in others it is in consequence 
of the inability of entirely different organs to perform their functions, 
—of the digestive apparatus, for instance. 
But few morbid changes have ever been found entirely absent at any 
of the fifty-three post- -mortem examinations made since August 2, and 
may, therefore, be considered as a constant occurrence. All others have 
been found absent a larger or eller number of times. These constant 
morbid changes consist— 
1. In a more or less perfect hepatization of a larger or smaller portion 
of the lungs, or a more or less extensive accumulation of bloed, blood- 
22 AGR 
