For the more precise points in diagnosis, including chemical, physical, electrical and instrumental methods, etc., the reader is referred to the special diseases.
PROGNOSIS.
Definition. Demands on the veterinarian, the question of economy. Basis of Prognosis. Cause of the illness, internal or external, vital or nonvital organ, enzootic, fatigue, infection, in one or two symmetrical vital organs, regular or irregular in its course, persistence, relapse, complications, effect of treatment, appetite, temperature, pulse, breathing, youth, age, debility, previous disease, breeding, climate, season.
Prognosis is a more complicated question for the veterinarian than for the physician. The latter must pronounce on the malady, whether it is likely to follow a regular or irregular course, whether it will last short or long, whether it will be curable or incurable, and if curable whether recovery would be complete or partial. For the veterinarian there is in addition the question of economy. The veterinary patient is, as a rule, of value, only if he can be rendered sound, and a partial recovery may be even worse than a fatal result, since the subject remains as a ruinous charge on his owner. The veterinarian must pronounce on the prompt and perfect curability of the case, on the outlay that will be requisite for treatment, on the depreciation which will be entailed on the patient, and whether, in certain lesions that do not harm the carcass, it would not be more judicious to butcher the subject. The physician is expected to do the best he can for life and health, and even a very imperfect recovery brings him a mead of gratitude. The veterinarian on the other hand must be an expert not only on disease, but on animal values, and if his treatment, however skillful it may be, results only in the prolonging of the life of an useless animal, the owner may charge him with imposing upon him an unnecessary outlay. The soundest judgment and highest skill are often necessary to secure the interests of an employer in such circumstances. In certain cases the recommendation to destroy is of much more value to the employer than the most skillful, and partially effective, curative treatment. On this basis, the reputation of a skillful man may be securely built. He can deceive no one if his prediction of recovery is not justified, while if he advises destruction and the patient recovers, he is at once discredited.
To give a sound prognosis the practitioner must have a thorough knowledge of pathology, he must have acute powers of observation, and he must be quick to appreciate every point that makes for or against the patient in the particular case.
The causes of the trouble must be carefully considered. Are they transient or permanent? Are they removable or irremovable? Are they external or internal? As a rule an internal cause is the more redoubtable. Some lesions are necessarily fatal, as a needle penetrating the heart or an attack of rabies or milk sickness. Is the cause an enzootic one? If so can the patient be removed from the locality? Is it a fatigue fever or an infectious one? Is it a simple inflammation or an infecting one? The latter are usually much more grave. In case of contagious disease, can its propogation be prevented? Is it of a fatal or non-fatal type? Is it situated in a tissue favorable to a fatal extension, (anthrax in lung) or in one unfavorable (anthrax in the tip of the tail)? Disease in a single vital organ like the heart is necessarily much more grave than in one of a symmetrical pair (kidneys, lungs) one of which can carry on the functions. The regular progress of the disease and especially an uninterrupted improvement, following on a critical perspiration or urination, is a good prognostic sign, whereas unevenness of temperature, pulse and respiration, with temporary aggravations of the general symptoms, should demand a less hopeful prognosis. The persistence of the malady is also an unfavorable indication. A relapse after partial recovery is a serious indication unless due to some obvious and easily removable cause, and unless the former convalescent condition is speedily restored on its removal. A complication is a serious indication whether it consists in an embolism, or new centre of the same disease, or the supervention of a second disease upon the first. The system has just so much more to contend with and the very supervention of the second focus or malady argues a special susceptibility, debility, or lessened power of resistance.
The prompt success or entire insuccess of treatment proves valuable.
The preservation of appetite, the slow, uniform descent of the temperature, and the improvement of pulse and breathing are among the most valuable indications.
Something may be deduced from the condition of the patient. If very young or old, debilitated by overwork, bad or insufficient food, previous disease, or any other cause, the prognosis is less hopeful, as it is also as a rule, during gestation, in the parturient state, or if abortion ensues. A hereditary predisposition to the malady in question is equally unfortunate.
Climate may be an important factor. Thus liver diseases are far more to be dreaded in a damp tropical or semi-tropical region, and rheumatism and catarrhal affections in winter and in cold northern localities. Acclimatization should also be considered. The bovine animal, raised on the Gulf Coast is likely to make a good recovery from Southern Cattle Fever while the northern beast would almost certainly die.