DEPARTMENT OF SURGERY. 
129 
begins mildly, and, in fact, is often unnoticed until the thorax 
is filled with fluid ; pain, if any, is very slight ; fever is very 
low and seldom noticed, even if the thermometer is used by the 
owner or attendant. The thorax, slowly filled by the effusion, 
accommodates itself to the condition, and out little inconven¬ 
ience is experienced therefrom until the cavity is almost filled. 
When the effusion comes on slowly and gradually the patient 
may lie down, and if it be an animal that can have unilateral 
hydrothorax, it will lie upon the side affected to relieve the 
pressure upon the mediastinum. Most of these cases are 
brought to the veterinarian on account of dyspnoea following 
the slightest exercise and general debility, and upon making 
a careful physical examination the condition and symptoms 
presented point to asthenic pleurisy with effusion ; this then 
can be verified by making a tentative puncture. The treat¬ 
ment in such cases is the same as already mentioned under 
hydrothorax. 
3. Hemothorax .—Blood-stained effusions may result from 
simple pleurisy, but more commonly from tubercular, carcino¬ 
matous or some other like condition. Bloody effusions may come 
from wounds to the thorax or its viscera, or from within by the 
rupture of an aneurism, sanguineous cancer or a hematoma. 
Blood in the pleural cavity resulting from extravasation should 
be allowed to remain in it to be reabsorbed, but if this does not 
suffice it must be removed by tapping. If the effusion is 
ichorous it may require additional surgical interference. It 
should be remembered, however, that the thoracic cavity of the 
horse cannot be opened (sic) ; other animals in which the 
pleural sacs do not communicate the surgeon can resort to major 
operations of the thorax and its viscera. 
4. Moi bid Growths of the Pleura .—The pleura of domestic 
animals is not free from sarcomatous, carcinomatous, actinomy¬ 
cotic or tubercular invasions. Growths of the first two varieties 
are comparatively rare, but those of the second are more com¬ 
mon. They may cause effusion by impeding circulation 
(dropsy ); if septic material escape into the cavity it soon be¬ 
comes putrid and causes septic infection. Blood may also 
escape from highly vascular formations. The diagnosis in such 
cases is impossible without a tentacular puncture, and the course 
of treatment adopted should be governed by the information 
gained therefrom. 
5. Hydatids of the Pleura .—Hydatids of the pleura of do¬ 
mestic animals are not often diagnosed during life. When the 
