360 
JOHN M. PARKER 
gus, and so mechanically preventing regurgitation of food 
or gas from the stomach. Persistent oestrum or heat, with 
barrenness, especially when there is a harsh, unthrifty condi¬ 
tion of the coat and a general loss of condition, must be 
looked upon with suspicion. Tubercular arthritis is also 
common in dairy cattle. 
The most common form of tuberculosis, however, is where 
there is an almost characteristic chronic cough ; on exertion 
the breathing becomes hurried and more labored, and is usu¬ 
ally accompanied or followed by the cough. Auscultation 
and percussion show a more or less diseased condition of the 
lungs. There is usually more or less marked tumefaction of 
one or more of the superficial lymphatic glands. There is 
often scouring, the buttocks being in a dirty state. The tem¬ 
perature may or may not be altered, and the pulse but little 
affected. 
The only positive diagnostic symptom is the finding of 
the bacilli in either the nasal or vaginal discharges, pharyn¬ 
geal mucus or the milk. The microscopical examination of 
the nasal discharge, when present, usually yields the best re¬ 
sults. The only other methods in use as aids to diagnosis 
are the inoculation of the suspected animal with Koch’s 
tuberculin and the inoculation of rabbits or guinea-pigs with 
either discharge or milk. 
The first of these methods (Koch’s tuberculin) has been 
extensively used and highly recommended by both European 
and American investigators for diagnostic purposes, and while 
it has not yet been recognized as an infallible diagnostic agent, 
the results have been sufficiently encouraging to warrant fur¬ 
ther trial and investigation. 
The second of these methods, the inoculation of rabbits 
or guinea-pigs with the milk or the discharge from a sus¬ 
pected animal, will probably never be brought into general 
use by the ordinary practitioner. In a suspicious case, how¬ 
ever, it is often of the greatest value as an aid to diagnosis. 
Aetiology. — As you are aware, the immediate cause of 
bovine tuberculosis is the same as in the human family (viz., 
Koch’s bacilli). The bacilli do not always present the same 
