DISEASES OF THE A Ill-PASSAGES OF HORSES. 401 
influence. Ehrmann calls it synochus catarrhalis, catarrhal fever 
of the mixed kind, which, in my opinion, is descriptive of the real 
nature of the disease. Medical men in the other profession com¬ 
monly speak of it as epidemic catarrh, or the catarrhal epidemic; 
and some veterinary surgeons, and veterinary authors too, have 
used the same term, although it is exclusively referrible to the 
human subject. 
But enough of this. Catarrhal Fever in the horse is one of the 
frequent complications with asthenic bronchitis; indeed, it is one 
of its most general associates. The ready and easy procession, 
by extension of the inflammatory action over the mucous surface 
from the nasal passages throughout the trachea and bronchia to the 
minutest subdivisions of the latter, must be apparent to every one 
in the profession. When the mucous surface is inflamed, the sub¬ 
mucous cellular tissue is generally more or less implicated in the 
morbid action, and the adjacent structures are frequently involved 
at the same time ; the consequences and terminations of which are 
chiefly depending upon the vital power and state of vascular ac¬ 
tion. When the disease terminates favourably, it is by change to 
the sthenic state: thus it is indispensable to restoration of the 
animal to health that the asthenic inflammation should change to 
the true or sthenic form. 
The mucous membrane, when asthenically inflamed, secretes a 
large quantity of a puriform fluid, frequently discoloured by the 
commixture of a portion of blood, and very often of a foetid smell, 
depending upon the state of vital influence and resistance of the 
tissues. The membranous tissue frequently undergoes softening, 
followed by a loss of substance, and ulceration succeeds. The dis¬ 
charge becomes exceedingly offensive, and discoloured; the pros¬ 
tration of strength rapidly increases; the vital cohesion of the tis¬ 
sues diminishes; absorption of the morbid matter into the circula¬ 
tion takes place; depositions of pus in circumscribed chambers of 
the cellular tissue, w'eak and yielding in their walls, numerously 
form, superficially or deep-seated, varying in extent from the size 
of a pea to that of an egg, an orange, or a cricket-ball. Sero- 
lymphatic accumulations in the cellular areolae proceed in all the 
pendent parts of the body, enlarging the extremities, the muzzle, , 
and face, and the under surface of the abdomen and prepuce, to an 
extreme size. The nostrils and bronchi are nearly closed by accu¬ 
mulation of foetid sputa, rendering the respiration difficult and roar¬ 
ing, and the blood is imperfectly changed in the lungs. 
Depression is attendant upon vital arfd structural impairment. 
Ihogressive and rapid changes of the sensihlc properties of the cir¬ 
culating fluid aiul the various tissues, itJ the vital cohesion of the 
OIK' and in the erasis of llie other, tnkes [ilace, and, at length, the 
