278 ON THE DISEASES OF FARM HORSES. 
the horse. This affords us a very important lesson at the 
commencement, that whilst the ox is so constructed as to 
consume large quantities of fodder at a meal, the horse, on the 
contrary, requires a more moderate quantity of a more nutritive 
nature, and to be fed oftener. To insure perfect digestion of 
the food, it requires to be first masticated with the teeth, and 
moistened with the salivary secretion in the mouth, which flows 
during this process in considerable quantities. According to 
Professor Spooner, the saliva flows during the time of feeding 
at the rate of two gallons per hour.* In the stomach, the food is 
further acted on in healthy digestion by the gastric juice, when 
it is converted into a soft pulpy mass called chyme , which passes 
as fast as it is formed into the intestinal canal. This part of 
the digestive process is very active in the horse ; but it is some¬ 
times interfered with, in consequence of devouring his food in 
too rapid a manner, without being either properly masticated, 
or mixed with the salivary secretion. This circumstance occa¬ 
sionally happens when the animal has been fatigued with hard 
work, and restricted from food for an improper length of time. 
In these cases indigestion takes place, which is a very serious 
affair, for the life of the animal is in considerable danger. 
Fermentation of the food and disengagement of the gases 
quickly ensue, and as the horse can neither belch up the air, nor 
vomit up the food, distention of the coats of the stomach takes 
place, occasioning violent agonizing pains, spasm, and all the 
symptoms recognised in aggravated cases of colic, for which it 
is frequently mistaken. This alarming disease is recognised by 
veterinary surgeons as acute indigestion. 
It should be understood that digestion, although always in 
part chemical, is controlled by a superior superintending influ¬ 
ence—the vital power ; and no sooner does this power fail, or 
the chemical agencies or decompositions become too strong for 
it, than we have fermentation of the food, and precisely the same 
changes in the stomach as would occur out of it, when kept in 
a moist state at similar temperature. The fermentable nature 
of the food, and the peculiar construction of the horse’s stomach, 
which prevents vomition, and his occasional detention from 
food and water during the long hours of labour, are circum¬ 
stances which account for the great liability of farm horses to 
this disease. 
The stomach of the horse is liable to another dangerous 
disease, arising from a false and injurious system of dieting. 
* “ In injuries where the salivary or parotid ducts had been opened, he,” 
(Mr. Spooner), “ had observed no flow of saliva took place, except when the 
animal was feeding; and it then discharged itself in a stream, by weight, measure, 
and time, at the rate of two gallons per hour .”—Proceedings Veterinary Medical 
Association, 1837-8, p. 102. 
