CHAPTER VIII

The Meaning of Disease

Any departure from a normal condition is disease. The body, composed of different organs and parts, is in a healthy state when each of these performs its natural functions. Thus the normal mind is concerned with normal mental acts; any disturbances of the brain or spinal cords is immediately manifested in the action of the animal; likewise frequently a disturbance elsewhere may later have its effect on the mental system.

Disease may result from some external cause like from a wound, from food causing poison or derangement of the digestive system, from water introducing impurities, from parasites that disturb normal functions, disorganize tissue or produce toxines, or from other abnormal conditions--all of which interfere with the normal functions of one or more organs, regions, or parts.

In most cases the disturbances are readily recognized. Swellings, bruises and wounds are located at a glance. When blood passes from nose, ears or intestines, a key to the trouble is at hand. Coughs have their story. And vomiting, diarrhœa, convulsions, spasms, abnormal breathing or temperature each indicates at what points an abnormal condition is evident.

=Disease, Both General and Local.=--Some diseases lead to disturbance throughout the entire body. For instance, pus may accumulate at some point from which it finds its way into the blood, in the end reaching to other parts of the body that in time also become affected.

Those diseases, with which fever is associated, are general in nature. The nerve centers are influenced, the body heat is increased and a weakened condition prevails. Back of this are the disease poisons--chemical poisons or germ poisons.

When the temperature of the body, as a result of fever, rises too high certain life principles are changed and death immediately follows. A temperature of 106° or 107° is very high, and, therefore, very dangerous. In treating disease the temperature is watched, that the course of the fever may be followed. Treating a fever, then, is helpful and a natural part of the treatment of the disease itself. The basis of the curative process rests upon the principle of proper circulation and the excretion of the impure substances.

CAUSES OF DISEASE

In the first place most diseases arise from mismanagement. The very principles at the bottom of good health receive no consideration and little thought. On some farms it is seldom that a case of disease is heard of; on others, stock are under treatment at all times. Where order prevails, where cleanliness is appreciated, where disease-producing conditions are never allowed to accumulate or even gain an introduction, health is the rule and disease the exception. When the latter appears, it is due to some outside influence that gave it admission.

The greatest mischief in handling farm stock comes from improper food, filthy or impure drinking water, bad ventilation of stables, overwork, or lack of exercise and poor sanitary conditions.

Disease, therefore, is largely due to causes within control of the owner of the farm stock. True, one source of trouble is due to mechanical causes: horses get nail punctures, legs and necks and head are cut in fences, blows bring bruises. But whose fault? Certainly not the animal. Old boards with nails ought not to be left in all sorts of places, fences should be protected, and stable fixtures, gates and harnesses should be in such order that only in rare cases will injury result.

=Disease from Chemical Causes.=--Poisonous materials and poisonous plants cause death to thousands of animals annually. Of great importance to the stock interests is the rapid destruction of these harmful products. Fortunately in the older sections these are about eliminated now, and we are also understanding more about the molds that lead to bad results when moldy forage is given as feed to farm animals. In time disease will be considerably lessened when only clean, wholesome food finds its way into the mangers and feed racks--then disease will depart and more rapid gains will come.

=Heredity Plays a Part.=--Despite caution and care, health is often disturbed because of hereditary influences. Thanks to science, we know now that many of the old bugbears of the past, and once so entrenched, have become dislodged, and their true import set right before the owner. Tuberculosis, for instance, once so dreaded in both man and beast, is now known not to be handed down from parent to progeny; it is a germ disease, pure and simple, and gets its start just as many other ailments--through breath, or drink, or feed. There are hereditary troubles, however, that continue down through many generations. The narrow hock of the horse invites curb diseases; the narrow chest is a good breeding ground for tuberculosis germs; straight pasterns are bad for the feet; poor conformation is not consistent with efficiency or easy functional activity.

These examples clearly show that form and type and physical characteristics have roles to play in animal economy and in health to which the wise stockman will give heed.

=Germs and Parasites.=--In addition to the above causes of disease, another class is before us ready to inflict its injury at all times. Indeed, it is a class of the greatest importance. I refer now to parasites, bacteria, and germs, which cause more loss to live stock than all others combined. Think of hog cholera, a germ disease; of tuberculosis, a germ disease; of stomach worms, parasites; of staggers, a mold disease; of abortion, a germ disease; and hundreds of like nature, all due to parasites and germs, disease agents that disturb and destroy the delicate organs or exposed regions, as the case may be, regardless of age, value, or breed.

Of course, remedies and treatment are being worked out to meet these individual diseases as they occur. Nevertheless, the best treatment is prevention. It is far better to prevent than to cure; and that is the line of action especially for this class. Indeed, it is far easier to understand the simple laws of prevention than the complicated curative processes. Especially is this true since germs are known and isolated, and their rapid destruction with air, sunlight, and disinfectants understood and available.

ORIGIN OF DISEASE

Enough has now been said to indicate that disease originates as a reaction between the cause of it and the body. Withhold food, and starvation--the disease--follows. Withhold fresh air and oxygen, and the tissue breaks down; disease results as a reaction from the normal use of air and the demands of the body for oxygen. Allow bacteria admission to the body and settlement in the tissues or organs most agreeable to each particular one, and these will grow, multiply, and, unless overcome by the natural resistance of the body, will conquer and destroy, causing sooner or later death and decay.

=Immunity Sought by Inoculation.=--Many diseases that now yield to no curative treatment are being met by inoculation. By this method the body is reinforced by serum injections, that disease germs and infections may be warded off, or in case of attack, be so fortified against the disease germs as to destroy them or render them inactive.

=Some Animals More Resistant to Disease.=--An infectious and contagious disease may affect a herd or flock, destroying few or many. Some may never be affected and yet be subjected to exposure and contagion; such are immune and resist this particular disease. Others may suffer a mild attack, but throw it off with no disastrous consequence; such are strong and their organs ably fortified against any injurious inroad by the disease. On the other hand the majority in a flock or herd is not so able to throw off the disease for the reason of being predisposed by nature to such attacks; their very susceptibility invites attack, and if the infection is intensely virulent the affected body will most likely yield and death follow.

THE COURSE OF DISEASE

Each disease possesses its own peculiar characteristics, which are more or less conspicuous in each individual case. Then, too, some diseases develop quickly and end quickly. Others run a course of several weeks; and still others several months or even years. The first class is acute, the second chronic. In both kinds nature is at work endeavoring always to effect a cure; and, unless other complications arise, the result of improper food, bad sanitary quarters, bad air, or conditions not conducive to health, recovery will, in most cases, result. The great drawback to rapid recovery comes from the outside influences that counteract the curative processes of the body itself. Good nursing, good air, proper food, are back of rapid recovery.

Most diseases have been carefully studied, and their course of development has been mapped out. Our veterinarians know, in a general way, how fever acts in live stock. If an animal is inoculated with Texas fever germs, the veterinarian knows the course of the disease beforehand. In a general way, he knows when the fever will begin, how long it will last, when it will be at its highest point, and when it will disappear. He knows all of this, even before he makes the inoculation. Yet no disease invariably runs the same course in different individuals. In fact, the virulence of bacteria have much to do with the course; mild cases occur usually when the germ is weak, and severe cases when the germs are very virulent. This explains why some attacks of measles or Texas fever or hog cholera are more fatal than other attacks in other places, or at other seasons of the year.

=Typical Courses the Rule.=--It is in rare cases only that a regular course is not followed by most diseases. Take an infectious disease. The period of incubation comes first; this follows up the infection. During this period, no change in the animal is observed. He seems well, acts well, and does his work well. Nevertheless, all the time, during this period of infection, the germs are developing, multiplying, gaining headway, and so entrenching themselves that illness and disorder will soon follow. The period of infection varies in different animals and in different diseases. It may take two or three weeks for development, or as few as two or three days.

Following the period of infection comes the period of eruption. At this stage the typical characteristics are observed. At the next step the disease reaches its height with the animal under its complete dominion. But only temporarily. If properly nursed and treated, with most diseases, the animal will pass through the period and recover.

The final stage is the period of improvement. The battle that has been waged between the body and the disease is now about ended. The disease germs have been routed and the body has been victorious. All that now remains is the clearing away of the débris. In this case it is scattered throughout the body system. The damage that has been done is to be repaired and left, if possible, as near to the original condition, as the nature of the disease will allow. The period of improvement will vary in different diseases and in different animals. Recovery may occur in a few days, in some cases, and in others weeks and months will be required. A change of feed or pasture or work is usually necessary if the most rapid recovery would be had. In some cases, nothing other than absolute rest will suffice.

THE TERMINATION OF DISEASES

After the disease has run its course, the body usually returns to its former normal condition. There seems to be a limit to what the disease can do. A healthy body may be attacked, but, in the end, disease retires, having used itself up. There are diseases, however, that leave their marks in many ways. And these become permanent marks. With many of these all of us are acquainted. Smallpox is one. The pits over the face record the fierce battle that was fought. The same is true of wasted tissues, with scars that conspicuously mark the track along which blood poison has traveled. The shrunken hoof of the foundered horse tells the adverse termination of that disease.

While recovery may be more or less complete, the effect is to seriously injure the worth and value of the individual. There is a long list of this kind.

Other diseases act differently in another way. They progress slowly, are not noticeable at first, but in the end are incurable. Take glanders as a typical case. It quietly and silently develops, often taking months or years in reaching the stage of eruption or before it becomes apparent. During all this time, and even after the disease is recognizable, the animal goes on about his duties with no apparent trouble. The disease, however, is progressing all the time; in the end it conquers its victim, the final stages are reached, and the animal dies.

The stock raiser is concerned with different diseases in so far as they mean slow or rapid recovery, and particularly if they be contagious or not. His entire herd will be impaired if glanders is introduced into it. One tuberculosis cow will convey the disease to all susceptible individuals in the herd to which she belongs, especially if stabled in a tight barn during the winter seasons when little or no ventilation is intentionally provided.