THE 1NTRA-DERMAL TEST FOR TUBERCULOSIS. 
By Fred W. Porter, D.V.M., Tampa, Fla. 
It has recently been my privilege to apply the intra-dennal 
test for tuberculous cattle, for the first time officially, in the state 
of Florida. The opportunity also served to compare the intra- 
dermal test with the subcutaneous temperature test, under our 
local conditions. My test was used within a day or two of six 
weeks after the temperature test had been given. 
Some years ago, 1906 to 1908, acting under an ordinance of 
the city of Tampa, I tested by the old method some 3,500 head of 
dairy cattle, supplying milk and dairy products to this city. I 
did not then consider that test as good, owing to its being subject 
to so many variations; still my results were fairly satisfactory, as 
I was enabled to reduce the per cent, of reactors from 50 per 
cent, to about 9 per cent. From 1908 up to a few months ago 
nothing was done. Consequently conditions had gotten back to 
about their original standing. 
In this locality our dairy cattle are never stabled except at 
the time of milking; this usually occurs between 11 and 2 o'clock 
midday and at the same hours at night. This means, that in order 
to use the temperature reactions, the cattle must be kept under 
abnormal conditions for from 48 to 72 hours. This of itself will 
produce a rise in temperature. Then, during the late winter, 
spring and early summer months we have the virulent tick to con¬ 
tend with, and even our native, immune cattle will very often 
carry an abnormal temperature at this season, so that true, tuber¬ 
culin reading cannot be had. Again, a high milker, in the full 
period of lactation, will very often carry a temperature of 104 
degrees F. during a few hours of one of our hot afternoons. Late 
pregnancy or approaching parturition also makes it inadvisable 
to use the thermal test. None of these conditions affect the intra- 
dermal test. 
My opportunity came when I was called upon to retest sixty 
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