AMPUTATION OF THE PENIS. 
399 
elastic ligature is also recommended. Warts and other benignant 
tumours with broad bases may, unless very large, be destroyed by 
irritants such as chromic, nitric, or sulphuric acids; the larger, and 
particularly those suspected to be malignant, are better excised. Malig¬ 
nant growths on the penis may necessitate amputation, to save the 
animal or to render it capable of work for some time. 
AMPUTATION OF THE PENIS. 
The greater part of the penis consists of the corpora cavernosa, which, 
together with the urethra and blood-vessels, are surrounded by the firm fibrous 
tunica albuginea. At the lower border of the penis lies the urethra in a 
furrow, surrounded by the corpus spongiosum, cavernous bodies and muscles. 
The arteria and vena dorsalis penis form the large blood-vessels. In dogs the 
os penis must also be considered in operating. 
In amputation of the penis, three factors are to be reckoned with, 
viz.:— 
(1) The bleeding. 
(2) The after-contraction of the urethra. 
(3) The pain. 
Amputation may be rendered necessary, as described, by the presence 
of tumours, by paralysis, and by inflammation and necrosis of the penis. 
The following methods have been proposed :— 
(1) Ligation. This gives the greatest security against bleeding, is, 
however, very painful, and requires particular care to preserve the 
urethra. To prevent its occlusion from pressure of the ligature, the 
urethra must previously be dissected out, or a metal tube thrust into it 
to keep it open. The elastic ligature is particularly valuable, and will 
be considered later. Hertwig recommends the castrating loop. By daily 
tightening the cord, the penis is cut through in from six to eight days. 
When the ligature has to be applied high up the prepuce must previously 
be laid open. 
Ligation is, of course, useless in dogs over the region of the os penis. 
(2) The actual cautery. To prevent bleeding, a knife-shaped cautery 
has been recommended. Its application is very painful, but the pain 
may be avoided by narcosis. The urethra is exposed, and the penis cut 
through with the cautery. In order to fix it conveniently, two ligatures 
are passed around it, and the division made between them ; particular 
care is required in severing the dorsal vessels. Nocard recommends the 
galvano-cautery for small animals, though, as it is a very expensive piece 
of apparatus, it is not always to be found even in large cliniques. 
(3) Simple section. It has often been remarked that even in large 
animals simple section produces no dangerous bleeding. Some operators 
