GO 
LOUIS P. COOK. 
membrane of both ventricles should be removed. This bilateral 
paralysis can be determined only by operating on the left side 
first. Failure to obtain full relief from the dyspnoea by this oper¬ 
ation indicates that the muscles of the right side are also para¬ 
lyzed. The second operation on the right ventricle can then be 
performed in about six weeks after the first operation. If this 
bilateral laryngeal paralysis were not so extremely rare, it would 
be advisable to operate on both ventricles at once. The writer has 
repeatedly done this, and the double operation caused no more in¬ 
convenience to the animal than the single one would, and that is 
practically none in most cases. Strange to say, little soreness 
results and the patients seldom miss a meal after the operation. 
They swallow food and water without apparent pain or difficulty. 
In the fall of 1909 the writer first called the attention of the 
veterinary profession to the fact that the dyspnoea in roaring 
could be permanently relieved by the mere obliteration of the 
lateral ventricle of the affected side, and that this could be done 
without dividing any of the cartilages of the larynx. His method 
of operating at that time necessitated the casting of the patient, 
but he soon found that the removal of the lining of the ventricle 
could be more easily done with the patient on its feet. At the 
Cincinnati Veterinary College about 40 dissecting subjects, a 
number of which were “ roarers,” have since been operated on 
by the writer, and in no case did the ventricle fail to close up, a 
fact that was determined on post-mortem examination later. Our 
experience shows that it takes from* two to four weeks for this to 
take place. All “ roarers ” operated on proved absolutely cured 
on tests made a month after operation- and since. 
Of course, this operation is useful only iji laryngeal paralysis. 
It will not relieve the dyspnoea of pulmonary emphysema, etc. 
The operation is indicated only in uncomplicated cases of laryn¬ 
geal paralysis. However, in the event of error in diagnosis, the 
operation can do no harm to the animal. In cases where this ex¬ 
tremely simple operation is indicated it guarantees a positive cure 
within five or six weeks’ time. 
