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.
All in all the question of prognosis cannot always be judiciously
decided at a first visit, and for the sake of his own reputation, it is
well that the practitioner should give only a qualified opinion at first
until he can certify himself as to the probable outcome of the disease.