886 
J. V. LADDEY. 
ORIGINAL ARTICLES. 
THE X-RAY AS AN AID IN THE DIAGNOSIS OF 
TUBERCULOSIS IN CATTLE. 
By J. V. Laddey, D. V. S., Arlington, N. J. 
Paper read before the New Jersey Veterinary Medical Association, at Trenton, 
January 9, 1902. 
The very slow, and in some respects often impractical way 
of examining cattle for tuberculosis by means of the tuber¬ 
culin test, has led me to experiment with the X-ray as to the 
feasibility of detecting the disease in the living animal. I ar¬ 
rived at satisfactory results. The infiltrated calcareous matter, 
which it seems exists already in the early stages of tubercular 
lesions, prevents the X-ray from passing through the lesions, 
thus causing a shadow or opacity. After the successful fluoro¬ 
scopic test, I decided first to have radiographs made, to ascertain 
whether it would be practical to go to the trouble of experiment¬ 
ing on the living animal. Being compelled to take expense 
into consideration, I chose specimens, not with a view to obtain 
impressive pictures, but to put 
the idea to a severe test. Ac¬ 
cordingly I selected lesions with 
small tubercles in the early stages, 
as in Plates No. 3 and 4, arguing 
that if disadvantageous specimens 
showed satisfactory results, the 
better developed cases would be 
less penetrable to the rays, and 
therefore more evident. It is 
obvious from the photographs 
that if an enlarged tubercular 
mediastinal gland were to be 
radiographed, its shadow would 
be as dense as that thrown by 
compact bone tissue. 
PHOTOGRAPH NO. 1. 
Portion of Pleura with Tubercles, spread 
on cardboard. 
