AIll-PASSAGES OF HOliSES. 
343 
complicated with diseases of the lungs and pleura, accompanied by 
tubercles; more especially with hepatic disease, and with chronic 
inflammation of the mucous surface of the stomach and intestines— 
the large bowels particularly. No invariable or certain form of the 
disease is presented in any of the consecutive and complicated 
states, its duration, progression, and termination, being its princi¬ 
pal characters, which are modified by the strength of the constitu¬ 
tion and the severity of the attack. 
Characters of Bronchitis on Dissection .—When the respiratory 
passages are examined of a horse that has died from any cause, and 
at the same time has been suffering from bronchitis in a recent and 
slight degree, a blush or trifling redness of some part of the mucous 
surface will be discovered, and this usually at the lower end of the 
windpipe and the first portions of the bronchi: but when the inflam¬ 
matory action has been severe, the redness is found in a greater 
number of the tubes, and also in the subdivisions of them. Some¬ 
times the redness is limited to the tubes of one lobe alone. The in¬ 
flammatory blush occasionally appears as a fine injection of the 
mucous membrane, and seems to extend to the sub-cellular struc¬ 
ture, and generally presents a moderate degree of tumefaction. In 
some cases the bloodvessels are not visible, but a considerable num¬ 
ber of points or spots of a red colour, congregated and encircling 
each other, are observed. Occasionally a general inflammatory ac¬ 
tion is presented. The redness of the mucous surface declines as 
it proceeds from the large to the smaller tubes in some instances; 
and in others this disposition of inflammatory colouring is reversed. 
Sometimes it appears in bands, patches, or circumscribed phlegma- 
siae, and the mucous surface between them is white and free. The 
mucous tunic is of a dark-bluish colour or brownish hue in chronic 
inflammation. In some cases of the chronic form, and possessing 
obstinate symptoms and a puriform sputa, on dissection the mucous 
membrane has exhibited a surface pale and free from redness 
throughout, which is a very remarkable fact. Perhaps in such cases 
there may have been inflammatory action; but, in my opinion, co¬ 
pious secretions, and of a purulent character, are sometimes dis¬ 
charged from mucous surfaces, or gain this appearance by retention 
in the tubes, from a relaxed state of their capillary vessels. Pro¬ 
bably there was a large determination of blood in order to keep up 
the discharge, and on the cessation of this the entire vascularity 
may have disappeared. Besides these changes, and especially in 
the chronic form of bronchitis, thickening, dilatation, softening, ul¬ 
ceration, &c. are presented on dissection. 
Diagnosis .—The chief characters by which we are enabled to 
distinguish the existence of bronchitis are, in the cough, the sputa, 
and tlie physical signs. Inflammation of the mucous surface in the 
