98 DISEASES OF THE HORSE. 



material is required, which cannot be produced without inflam- 

 mation, as we shall presently see. 



The Causes of inflammation are various, and yet they all act 

 by violently exciting particular parts. Thus an external blow 

 or a sudden alternation of temperature may produce inflammation 

 in different parts, but, in both cases, the immediate effect is 

 great excitement of the injured part : in one instance, we may 

 have an external abscess, and in the other inflammation of the 

 throat or lungs. 



Inflammations near the surflice of the body are generally 

 produced either by violence from witliout, as in wounds, bruises, 

 and falls, or from over-exertion, as in strains. 



Internal inflammations may proceed from various causes. 

 Over-exertion of any organ, as of the lungs, in breathing, or the 

 bowels from physic. The exposure to cold, particularly for 

 some time, or the alternation from cold to heat, may produce 

 inflammation of the throat and windpipe, or the lungs. The 

 circulation of the exposed part is first lessened, then by re action 

 greatly increased, so as to produce inflammation ; great exertion 

 may produce inflammation either of the lungs or the bowels 

 (both parts being thereby greatly excited), according to the sus- 

 ceptibility of the part. This susceptibility is called pre-disjwsition. 

 All organs are rarely equally perfect; one part is generally weaker 

 than another, and therefore more predisposed to disease ; and. 

 thus the same cause may produce different diseases in different 

 horses, verifying the old pi*overb, " The weakest goes to the 

 wall." One fertile cause of inflammation is a redundancy of 

 blood in the system ; but this cause may produce in one horse 

 inflammation of the lungs, in another inflammation of the liver, 

 in a third that of the brain, according to the susceptibility of the 

 particular viscus in each horse. Inflammation of the lungs is, 

 however, more likely to occur from this cause, inasmuch as all 

 the blood in the body passes through these organs, and only a 

 portion of it through other parts. 



The season of the year, too, has much to do in the production 

 of different inflammatory complaints : thus, diseases of the liver, 

 and the bowels, are more frequent in hot weather ; and those of 

 the air passages, when the atmosphere is damp, cold, or change- 

 able. This is owing to the prevalence, at these seasons of the 

 year, of the particular causes of these different diseases. In the 

 human subject, inflammation is considered of two kinds, the 

 phlegmonous and the erysipelatous. In the horse, our attention 

 is principally confined to the former ; we can scarcely say that 

 he is liable to erysipelas, at any rate only to that eruptive 

 affection of the skin, denominated Erythema. Inflammation 

 has various terminations, such as Resolution, Adhesion, Suppura- 

 tion, and Ulceration, all of which are often the natural processes 

 of nature to repair the effects of an injury. The three last 



