94 PRINCIPLES AND PRACTICE OF MILK HYGIENE 
Diagnosis of Tuberculosis of the Udder.—For a time after 
the disease has been established in the udder, the tubercles are 
not large enough to be discovered by palpation and the milk 
retains its normal appearance, but during this initial stage 
of the disease symptoms are usually present in other organs 
which enable one to discover the presence of the disease by 
physical examination. In 119 cows affected with tuberculosis 
of the udder, Lungwitz ?! found tuberculosis in other organs 
in every one. The observations of Rick and of Joest and 
Kracht, already quoted, show that the disease is usually gener- 
alized when the udder becomes infected. 
Tuberculosis of the udder runs a slow, insidious course. 
The perceptible changes in the udder which indicate its presence 
are firm nodules, which are neither hot nor painful, or a rather 
diffuse painless induration without local increase of tempera- 
ture, in one or more quarters. Later, abscesses may form and 
rupture (mixed infection); atrophy may also occur. The 
posterior quarters are most commonly affected. The supra- 
mammary lymph glands may be enlarged, while the udder is of 
normal appearance, but in these cases the udder is usually also 
infected. In rare cases, the disease runs an acute course, the 
udder showing the symptoms of acute inflammation. 
In contrast with what occurs in other forms of udder disease, 
the milk remains of normal appearance for eight to ten weeks, 
although it may be highly virulent. Fimally, it becomes thin 
and transparent like water, assumes a yellowish color and con- 
tains small clots or flakes. When it is permitted to stand, a 
pus-like sediment is deposited with a yellow, transparent fluid 
resembling serum above it. The acidity is reduced one-half 
(Raudnitz), or the reaction is even sometimes alkaline (Oster- 
tag). In advanced cases, the secretion of milk ceases and only 
a purulent fluid in moderate amount can be obtained from the 
affected quarter. 
Diagnosis of Open Tuberculosis ——(a) Pulmonary Tubercu- 
losis.—The most characteristic symptom is a chronic cough, at 
21 Leblanc, Diseases of Mammary Gland (Nunn’s transla- 
tion). 
