EMPYEMA. 53 
CHRONIC PLEURISY. 
An acute pleurisy may become chronic, but there is only slight danger of its 
doing so except in feeble subjects; and as a rule, chronic pleurisy is such from 
the first, the pleural inflammation developing imperceptibly. 
This disease sometimes occurs in dogs, but it is very rare ; moreover, its detec- 
tion is even more difficult than that of acute pleurisy, consequently merely a brief 
consideration is warranted. 
The same influences which excite the acute may give rise to the chronic form; 
but usually the latter fixes itself upon subjects in whom the health is considerably 
impaired ; and the direct causes are then not easily determined. 
Generally the symptoms are very obscure, and only point to the lungs in a 
small proportion of cases. The conditions of the pleura somewhat resemble those 
in acute pleurisy, but the inflammation is of a low or mild type; there is but little 
if any fever; pain is not appreciable, and the breathing scarcely affected except 
on active movements, when it becomes quicker than in health. There may be 
some effusion; while the pleural surfaces are even more inclined to become 
adherent than in the acute form of the disease, and the adhesions cripple to 
some extent the lung, causing the chest wall to permanently flatten or sink in. 
Recovery from this disease is possible, but it is not likely to take place except 
in dogs having strong constitutions and that are very healthfully placed. The 
tule is, once the disease occurs, the health is slowly and steadily undermined. 
The lung being crippled, circulation is implicated, and ultimately the victim worn 
out with resulting complications of all the vital organs. 
Were the symptoms so pronounced that the disease could be clearly made out, 
and there was a large amount of effusion, the proper course to pursue would be 
to tap the chest. But cases of large effusions are extremely rare, while patients 
in whom a positive diagnosis is possible are rarer still; consequently the only 
general line of treatment which can properly be advised here is purely hygienic; 
that is, it consists of good, wholesome food, healthy quarters, and a reasonable 
amount of easy exercise each day. 
EMPYEMA. 
While dogs are not exempt from this disease, it is by far the rarest of chest 
affections, and never likely to occur excepting where the walls have been punctured, 
as by a shot, or the lungs are much diseased, as in tuberculosis. 
It is practically pleurisy in which the effusion of serum has changed to pus, 
and the affected side of the chest become a huge abscess. ‘This fluid must be 
evacuated or recovery cannot take place; and while the disease in man generally 
