88 
ACTINOMYCOSIS. 
following:—As a protection against anthrax certain farmers in his 
practice were in the habit of thoroughly steaming all cattle food before 
giving it to the animals. Although in other parts of the same district 
actinomycosis, especially of the parotid region, was extremely common, 
the farms on which this practice was observed remained entirely 
free of it. 
ihe pharyngeal mucous membrane is probably the commonest point of 
entry of the actinomyces fungus, and the primary swellings almost always 
affect the pharyngeal walls, though infection may occasionally occur 
through the skin. One certainly sees cases of infection in that part of 
the neck which oftenest rubs against the manger. Actinomycotic 
abscesses of the parotid gland dis¬ 
charge infective pus on the edge of 
the manger, and the tiny splinters 
of wood always present there pene¬ 
trate the skin and implant the 
fungi in any fresh animal placed 
in the same stall. This mode of 
infection is, however, rare. The 
disease varies greatly in frequency 
in given districts and in different 
years. On one farm almost every 
animal may be affected, whilst on 
another in the immediate neigh¬ 
bourhood the disease may be practi¬ 
cally unknown. In certain years 
the disease appears almost epi¬ 
zootic, in others it is strictly 
, . sporadic. The reasons remain 
obscure, but are possibly connected with the condition in which the fodder 
is harvested. 
The symptoms consist of a small, insensitive, sharply defined, and 
somewhat hard tumour, from which a cord-like thickening extends into 
tne depths. The swelling gradually becomes larger, fluctuation appears, 
and i the skin is without pigment, the yellow-coloured contents may 
show through. Incision liberates a thick, muco-purulent fluid, in which 
caie ul examination discovers the above-mentioned yellow grains. If not 
opened the tumour breaks spontaneously. Cicatricial contraction very 
se dom brings about healing. As a rule, the growth proceeds, sooner or 
later producing, according to its position, functional disturbance, difficulty 
in swallowing dyspnoea, and finally, in consequence of advancing ex¬ 
haustion, death. The swellings in the parotid region occasionally attain 
a great size, sometimes becoming as large as a child’s head, but such 
Fig. 53.—Actinomycosis of the parotid gland 
in an ox, from a photo by Esser. 
