Special Report on Diseases of the Horse

DISEASES OF THE DIGESTIVE ORGANS.

By CH. B. MICHENER, V. S.

[Revised by John R. Mohler, V. M. D.]

It is not an easy task to write "a plain account of the common diseases, with directions for preventive measures, hygienic care, and the simpler forms of medical treatment," of the digestive organs of the horse. Being limited as to space, the endeavor has been made to give simply an outline--to state the most important facts--leaving many gaps, and continually checking the disposition to write anything like a full description as to cause, prevention, and modes of treatment of diseases.

WATER.

It is generally held, at least in practice, that any water that stock can be induced to drink is sufficiently pure for their use. This practice occasions losses that would startle us if statistics were at hand. Water that is impure from the presence of decomposing organic matter, such as is found in wells and ponds in close proximity to manure heaps and cesspools, is frequently the cause of diarrhea, dysentery, and many other diseases of stock, while water that is impregnated with different poisons and contaminated in very many instances with specific media of contagion produces death.

Considering first the quantity of water required by the horse, it may be stated that when our animals have access to water continually they never drink to excess. Were the horse subjected to ship voyages or any other circumstances where he must depend upon his attendant for the supply of water, it may be roughly stated that he requires a daily average of about 8 gallons of water. This varies somewhat upon the character of his feed; if upon green feed, less water will be needed than when fed upon dry hay and grain.

The time of giving water should be carefully studied. At rest, the horse should receive it at least three times a day; when at work, more frequently. The rule should be to give it in small quantities and often. There is a popular fallacy that if a horse is warm he should not be allowed to drink, many asserting that the first swallow of water "founders" the animal or produces colic. This is erroneous. No matter how warm a horse may be, it is always entirely safe to allow him from six to ten swallows of water. If this is given on going into the stable, he should have at once a pound or two of hay and allowed to rest about an hour before feeding. If water is now offered him it will in many cases be refused, or at least he will drink but sparingly. The danger, then, is not in the "first swallow" of water, but is due to the excessive quantity that the animal will take when warm if he is not restrained.

Ice-cold water should never be given to horses. It may not be necessary to add hot water, but we should be careful in placing water troughs about our barns to have them in such position that the sun may shine upon the water during the winter mornings. Water, even though it is thus cold, seldom produces serious trouble if the horse has not been deprived for a too great length of time.

In reference to the purity of water, Smith, in his "Veterinary Hygiene," classes spring water, deep-well water, and upland surface water as wholesome; stored rain water and surface water from cultivated land as suspicious; river water to which sewage gains access and shallow-well water as dangerous. The water that is used so largely for drinking purposes for stock throughout some States can not but be impure. I refer to those sections where there is an impervious clay subsoil. It is the custom to scoop, or hollow out, a large basin in the pastures. During rains these basins become filled with water. The clay subsoil, being almost impervious, acts as a jug, and there is no escape for the water except by evaporation. Such water is stagnant, but would be kept comparatively fresh by subsequent rains were it not for the fact that much organic matter is carried into it by surface drainage during each succeeding storm. This organic matter soon undergoes decomposition, and, as the result, we find diseases of different kinds much more prevalent where this water is drunk than where the water supply is wholesome. Again, it must not be lost sight of that stagnant surface water is much more certainly contaminated than is running water by one diseased animal of the herd, thus endangering the remainder.

The chief impurities of water may be classified as organic and inorganic. The organic impurities are either animal or vegetable substances. The salts of the metals are the inorganic impurities. Lime causes hardness of water, and occasion will be taken to speak of this when describing intestinal concretions. Salts of lead, iron, and copper are also frequently found in water; they also will be referred to.

About the only examination of water that can be made by the average stock raiser is to observe its taste, color, smell, and clearness. Pure water is clear and is without taste or smell.

Chemical and microscopic examination will frequently be necessary in order to detect the presence of certain poisons, bacteria, etc., and can, of course, be conducted by experts only.

FEEDS AND FEEDING.

In this place one can not attempt anything like a comprehensive discussion of the subject of feeds and feeding, and I must content myself with merely giving a few facts as to the different kinds of feed, preparation, digestibility, proper time of feeding, quality, and quantity. Improper feeding and watering will doubtless account for more than one-half the digestive disorders met with in the horse, and hence the reader can not fail to see how very important it is to have some proper ideas concerning these subjects.

KINDS OF FEED.

In this country horses are fed chiefly upon hay, grass, corn fodder, roots, oats, corn, wheat, and rye. Many think that they could be fed on nothing else. Stewart, in "The Stable Book," gives the following extract from Loudon's Encyclopedia of Agriculture, which is of interest at this point:

In some sterile countries they [horses] are forced to subsist on dried fish, and even on vegetable mold; in Arabia, on milk, flesh balls, eggs, broth. In India horses are variously fed. The native grasses are judged very nutritious. Few, perhaps no, oats are grown; barley is rare, and not commonly given to horses. In Bengal a vetch, something like the tare, is used. On the western side of India a sort of pigeon pea, called gram (Cicer arietinum), forms the ordinary food, with grass while in season, and hay all the year round. Indian corn or rice is seldom given. In the West Indies maize, guinea corn, sugar-corn tops, and sometimes molasses are given. In the Mahratta country salt, pepper, and other spices are made into balls, with flour and butter, and these are supposed to produce animation and to fine the coat. Broth made from sheep's head is sometimes given. In France, Spain, and Italy, besides the grasses, the leaves of limes, vines, the tops of acacia, and the seeds of the carob tree are given to horses.

We can not, however, leave aside entirely here a consideration of the digestibility of feeds; and by this we mean the readiness with which they undergo those changes in the digestive canal that fit them for absorption and deposition as integral parts of the animal economy.

The age and health of the animal will, of course, modify the digestibility of feeds, as will also the manner and time of harvesting, preserving, and preparing.

In the horse digestion takes place principally in the intestines, and here, as in all other animals and with all feeds, it is found that a certain part only of the provender is digested; another portion is undigested. This proportion of digested and undigested feed must claim passing notice at least, for if the horse receives too much feed, or bulky feed containing much indigestible waste, a large portion of it must pass out unused, entailing not only the loss of this unused feed, but also calling for an unnecessary expenditure of vital force on the part of the digestive organs of the horse. It is thus that, in fact, too much feed may make an animal poor.

In selecting feed for the horse we should remember the anatomical arrangement of the digestive organs, as well as the physiological functions performed by each one of them. Feeds must be wholesome, clean, and sweet, the hours of feeding regular, the mode of preparation found by practical experience to be the best must be adhered to, and cleanliness in preparation and administration must be observed.

The length of time occupied by stomach digestion in the horse varies with the different feeds. Hay and straw pass out of the stomach more rapidly than oats. It would seem to follow, then, that oats should be given after hay, for if reversed the hay would cause the oats to be sent onward into the intestines before being fully acted upon by the stomach, and as a result produce indigestion. Experience confirms this. There is another good reason why hay should be given first, particularly if the horse is very hungry or if exhausted from overwork, namely, it requires more time in mastication (insuring proper admixture of saliva) and can not be bolted, as are the grains. In either instance water must not be given soon after feeding, as it washes or sluices the feed from the stomach before it is fitted for intestinal digestion.

The stomach begins to empty itself very soon after the commencement of feeding, and continues rapidly while eating. Afterwards the passage is slower, and several hours are required before the stomach is entirely empty. The nature of the work required of the horse must guide us in the selection of his feed. Rapid or severe labor can not be performed on a full stomach. For such labor feed must be given in small quantity and about two hours before going to work. Even horses intended for slow work must never be engorged with bulky, innutritious feed immediately before going to labor. The small stomach of the horse would seem to lead us to the conclusion that he should be fed in small quantities and often, which, in reality, should be done. The disproportion between the size of the stomach and the quantity of water drunk tells us plainly that the horse should always be watered before feeding. One of the common errors of feeding, and the one that produces more digestive disorders than any other, is to feed too soon after a hard day's work. This must never be done. If a horse is completely jaded, it will be found beneficial to give him an alcoholic stimulant on going into the stable. A small quantity of hay may then be given, but his grain should be withheld for one or two hours. These same remarks will apply with equal force to the horse that for any reason has been fasting for a long time. After a fast, feed less than the horse would eat, for if allowed too much the stomach becomes engorged, its walls paralyzed, and "colic" is almost sure to follow. The horse should be fed three or four times a day. It will not do to feed him entirely upon concentrated feed. Bulky feed must be given to detain the grains in their passage through the intestinal tract; bulk also favors distention, and thus mechanically aids absorption. For horses that do slow work the greater part of the time, chopped or cut hay fed with crushed oats, ground corn, etc., is the best manner of feeding, as it gives the required bulk, saves time, and half the labor of feeding.