132 VETERINARY OBSTETRICS. 
fined to their surface, spread to the depths and to the 
interstitial connective tissue. 
Symptoms.—Disease sets in suddenly, with pain and 
the other symptoms of mastitis. Swelling commences 
in the interior of the udder, but spreads as far as the 
skin, which is warm and reddened. Secretion of milk 
diminishes, or entirely stops, the milk is curdled, later 
becomes yellowish from pus, or red from bleeding; 
finally it may become more and more puriform, and 
contain curdled material, which blocks the milk ducts, 
Following these symptoms there is fever, inappetence, 
excessive thirst, and depression. Either resolution 
sets in, or the disease goes on to abscess formation. If 
the former, after four or five days, sometimes later, 
symptoms gradually begin to recede, while the secre- 
tion more and more becomes normal. In some cases 
there is no permanent disturbance left, though, as a 
rule, the affected section does not completely recover 
its functional activity until the next period of lactation, 
Abscesses, however, frequently form, and permanent 
thickening and milk fistule are not infrequent results 
of the process. Hard swellings also sometimes result. 
These suppurative processes may at times lead to 
pyzmia or septicaemia. 
Causes.—Infectious materials entering through the 
mammary ducts, syphons, catheters, and other instru- 
ments bearing infection, etc. 
Treatment.—Prevent infection, or combat it if 
already existing. Care in using instruments. When 
occurring enzootically, segregation of diseased animals, 
and disinfection of stables, etc. Frequent milking of 
