230 PROGNOSIS AND TREATMENT OF SHOULDER ABSCESS. 
possible that infective materials may set up inflammatory changes and 
swelling in the lymph glands directly, and thus render them more liable 
to bruising. 
In many of Moller’s cases the disease has started in the prepectoral 
glands, and shown the character of a lymphadenitis chronica suppurativa. 
The process either arises from the common mastoido-humeralis muscle, 
and is of the nature of a myositis apostematosa, or the underlying 
lymph glands are the primary seat of disease, and in such cases it should 
be described as lymphadenitis suppurativa; while from this, the inflam¬ 
mation extending to the muscles produces a myositis chronica fibrosa. 
Other growths, however, occur here ; thus in a grey horse Moller saw a 
melano-sarcoma, which had been mistaken for abscess on the shoulder, 
and Gunther reports a similar case. The slow development of melano- 
sarcoma, however, sufficiently differentiates it from the condition now in 
question. The disease is usually chronic, especially when not treated. 
Resorption of the pus may even occur, but is very rare. 
Prognosis is favourable where treatment is early adopted. When 
delaved, imflammation becomes chronic, firm masses of connective tissue 
are produced, and when these have existed for months complete extirpa¬ 
tion, which is always difficult, is the only remedy ; otherwise the swelling 
is again bruised by the collar and becomes inflamed, leading to further 
formation of fibrous tissue. Whatever the cause, the earlier the abscess 
is opened and drained, the more rapid and thorough is resolution. 
Extirpation of the glands is the only means of dealing with chronic 
lymphadenitis. 
Treatment. Formerly blisters were recommended as the first applica¬ 
tion, and the abscess was punctured in eight to ten days. Stockfleth 
inserted the actual cautery into the cavity of the abscess after dividing 
the skin. Others allow the abscess to mature. Block has lately recom¬ 
mended the following compound: Ungt. cantharid. off., 30 parts ; tinct. 
cantharid. and tinct. euphorb., of each 15 parts (evaporated to half their 
bulk); ol. croton, 1*20; hydrarg. biniod., 4; fresh butter, 30. After 
clipping the hair and applying the ointment, Block holds a red-hot iron 
a short distance from the skin so as to heat it. The animal is then 
fastened up for three days. The best treatment is to immediately open 
the abscess and evacuate the contents. The abscess sometimes lies as 
much as 4 inches below the surface, but this should not prevent opera¬ 
tion. By thrusting the knife towards the centre of the swelling dangerous 
bleeding is avoided and the abscess opened with certainty, though the 
knife must not pass beyond this point on account of endangering large 
vessels. 
As in other such operations, the hair is removed, the skin cleansed, the 
position of the swelling determined by palpation, and the horse twitched. 
