ON THE DISEASES OF FAHM HORSES. 277 
rules for which are simple and easy enough, but are continually 
transgressed through carelessness, or absurd prejudices. 
Also that excess of labour forms a prolific source of disease 
in both young and old horses, and the vigorous health of young 
ones in particular is often wasted and destroyed from premature 
work, which, if economically managed for a year or two at most, 
might have preserved them in health and activity nearly to the 
full term of the allotted periods of their lives, instead of being 
dissipated in the first six or seven years of their existence. 
And, lastly, that insufficient shelter and exposure to wet and 
cold are very common causes of disease, the effects of which 
are certain to manifest themselves in some way or other on 
horses that have been exposed to their influences, though often¬ 
times obscurely, and at a remote period. Our patients, far 
more than those of Ihe human practitioner, are exposed to the 
influence of physical agents. One-half of the diseases of the 
horse and of cattle are referrible to temperature—many more to 
the changes effected in the atmospheric air by respiration, 
perspiration, and the various excretions, and the greater part of 
the residue may be traced to some unknown, and not sufficiently 
appreciated, atmospheric agency. 
These are the chief points to be considered in this essay ; 
food, labour, and temperature, agents that are continually acting 
on the condition and general health of farm horses, either for 
good or for ill : if properly directed, they produce in them 
strength and capability of enduring labour; but misdirected, 
their beneficial influences are changed from ministers of good 
to insidious or manifest sources of disease. 
Insufficient or improper Food. 
The purpose of food being the supply of materials which, 
when prepared by the process of digestion, shall repair The 
waste of the body, and maintain its growth and temperature, it 
must be evident, if this process is interfered with by the supply 
of articles of food such as will neither suit the powers of diges¬ 
tion or the wants of the system, that disturbances of some kind 
are likely to occur in any or all of the steps of the nutritive pro¬ 
cess, from the reception of the food into the stomach, to its ap¬ 
propriation and assimilation to the living textures. Accordingly 
we will direct our attention, first to the diseases of the stomach, 
which are easily traced to errors in diet, and interference with 
the digestive economy. 
Diseases of the Stomach. —The stomach of the horse is com¬ 
paratively small, holding about three gallons, whilst the ox 
possesses four stomachs, the first of which is larger than that of 
VOL. XXV. P p 
