overlooked and that the examiner is in a position to arrive at an opinion that is as accurate as is possible for him. Of course, an experienced eye can see, and a trained hand can feel, slight alterations or variations from the normal that are not perceptible to the unskilled observer. A thorough knowledge of the conditions that exist in health is of the highest importance, because it is only by a knowledge of what is right that one can surely detect a wrong condition. A knowledge of anatomy, or of the structure of the body, and of physiology, or the functions and activities of the body, lie at the bottom of accuracy of diagnosis. It is important to remember that animals of different races or families deport themselves differently under the influence of the same disease or pathological process. The sensitive and highly organized thoroughbred resists cerebral depression more than does the lymphatic draft horse. Hence a degree of fever that does not produce marked dullness in a thoroughbred may cause the most abject dejection in a coarsely bred, heavy draft horse. This and similar facts are of vast importance in the diagnosis of disease and in the recognition of its significance.

The order of examination, as given hereafter, is one that has proved to be comparatively easy of application and sufficiently thorough for the purpose of the readers of this work, and is recommended by several writers.

HISTORY.

It is important to know, first of all, something of the origin and development of the disease; therefore the cause should be looked for. The cause of a disease is important, not only in connection with diagnosis, but also in connection with treatment. The character of feed that the horse has had, the use to which he has been put, and the kind of care he has received should all be closely inquired into. It may be found by this investigation that the horse has been fed on damaged feed, such as brewers' grains or moldy silage, and this may be sufficient to explain the profound depression and weakness that are characteristic of forage poisoning. If it is learned that the horse has been kept in the stable without exercise for several days and upon full rations, and that he became suddenly lame in his back and hind legs, and finally fell to the ground from what appeared to be partial paralysis, this knowledge, taken in connection with a few evident symptoms, will be enough to establish a diagnosis of azoturia (excess of nitrogen in the urine). If it is learned that the horse has been recently shipped in the cars or has been through a dealer's stable, we have knowledge of significance in connection with the causation of a possible febrile disease, which is, under these conditions, likely to prove to be influenza, or edematous pneumonia.

It is also important to know whether the particular horse under examination is the only one in the stable, or on the premises, that is similarly afflicted. If it is found that several horses are afflicted much in the same way, we have evidence of a common cause of disease which may prove to be of an infectious nature.

Another item of importance in connection with the history of the case relates to the treatment that the horse may have had before he is examined. It sometimes happens that medicine given in excessive quantities produces symptoms resembling those of disease, so it is important that the examiner be fully informed as to the medication that has been employed.

ATTITUDE AND GENERAL CONDITION.

Before beginning the special examination, attention should be paid to the attitude and general condition of the animal. Sometimes horses assume positions that are characteristic of a certain disease. For example, in tetanus (lockjaw) the muscles of the face, neck, and shoulders are stiff and rigid, as well as the muscles of the jaw. This condition produces a peculiar attitude, that once seen is subsequently recognized as rather characteristic of the disease. A horse with tetanus stands with his muscles tense and his legs in a somewhat bracing position, as though he were gathered to repel a shock. The neck is stiff and hard, the head is slightly extended upon it, and the face is drawn, and the nostrils are dilated. The tail is usually held up a little, and when pressed down against the thighs it springs back to its previous position. In inflammation of the throat, as in pharyngolaryngitis, the head is extended upon the neck and the angle between the jaw and the lower border of the neck is opened as far as possible to relieve the pressure that otherwise would fall upon the throat. In dumminess, or immobility, the hanging position of the head and the stupid expression are rather characteristic. In pleurisy, peritonitis, and some other painful diseases of the internal organs, the rigid position of the body denotes an effort of the animal to avoid pressure upon and to protect the inflamed sensitive region.

The horse may be down in the stall and unable to rise. This condition may result from paraplegia (paralysis), from azoturia, from forage poisoning, from tetanus, or from painful conditions of the bones or feet, such as osteoporosis or founder. Lying down at unusual times or in unusual positions may indicate disease. The first symptom of colic may be a desire on the part of the horse to lie down at an unusual or inappropriate time or place. Sometimes disinclination to lie down is an indication of disease. When there is difficulty in breathing, the horse knows that he can manage himself better upon his feet than upon his breast or his side. It happens, therefore, that in nearly all serious diseases of the respiratory tract he stands persistently, day and night, until recovery has commenced and breathing is easier, or until the animal falls from sheer exhaustion. If there is stiffness and soreness of the muscles, as in rheumatism, inflammation of the muscles from overwork, or of the bones in osteoporosis, or of the feet in founder, or if the muscles are stiff and beyond control of the animal, as in tetanus, a standing position is maintained, because the horse seems to realize that when he lies down he will be unable to rise.

Abnormal attitudes are assumed in painful diseases of the digestive organs (colic). A horse with colic may sit upon his haunches, like a dog, or may stand upon his hind feet and rest upon his knees in front, or he may endeavor to balance himself upon his back, with all four feet in the air. These positions are assumed because they give relief from pain by lessening pressure or tension upon the sensitive structures.

Under the general condition of the animal it is necessary to observe the condition or state of nutrition, the conformation, so far as it may indicate the constitution, and the temperament. By observing the condition of nutrition one may be able to determine to a certain extent the effect that the disease has already had upon the animal and to estimate the amount of strength that remains and that will be available for the repair of the diseased tissues. A good condition of nutrition is shown by the rotundity of the body, the pliability and softness of the skin, and the tone of the hair. If the subcutaneous fat has disappeared and the muscles are wasted, allowing the bony prominences to stand out; if the skin is tight and inelastic and the coat dry and harsh, we have evidence of a low state of nutrition. This may have resulted from a severe and long-continued disease or from lack of proper feed and care. When an animal is emaciated—that is, becomes thin—there is first a loss of fat and later the muscles shrink. By observing the amount of shrinkage in the muscles one has some indication as to the duration of the unfavorable conditions under which the animal has lived.

By constitution we understand the innate ability of the animal to withstand disease or unfavorable conditions of life. The