IO 
Colorado Experiment Station. 
swollen brisket is merely a symptom of a general dropsy, and a 
weakened heart and surgical manipulation of it can be of no value. 
We must either strengthen the heart or lessen its work. 
PREVENTION. 
Since the disease is far more prevalent in cattle shipped ir. 
from low altitudes than in natives, it would seem only wise that im¬ 
portations be somewhat curtailed or, if practiced, that the animals 
be brought more gradually to the extreme altitudes. For instance, 
hold them for a few months or seasons, at a moderate elevation, say 
seven or eight thousand feet. This practice is not likely to prevent 
all cases as is evidenced by reading the history of case eight, but 
would probably be worth while. 
Since extreme exertion on first arrival at the higher level 
seems to play a part, more care should be taken in the handling of 
the animals during the first weeks to see that they are not subjected 
to long hard drives. Realizing that these animals are usually wild, 
we are aware of the difficulty in complying with this suggestion. 
The practice of buying pure bred bulls from low altitudes, 
while praiseworthy in its intent, seems to be responsible for some 
of the difficulty. Not only do the bulls themselves in many in¬ 
stances die of the disease after some months’ residence under the 
new conditions, but their calves appear to be much more susceptible 
than calves sired by native bulls. In order to reduce this source of 
trouble it is recommended that bulls be purchased from altitudes 
more nearly approaching that at which they are to be used. We 
believe that this practice, if followed, would do much toward elim¬ 
inating the disease. Finally, it may become necessary to abandon 
some of the higher ranges, especially during cold and wet summers. 
Since the disease has not been seen in sheep it may be possible to 
range these animals at the higher levels where the cattle do not 
thrive. 
CAUSE. 
Whatever may be the real cause of the malady, it would seem 
from our work thus far, that the matter of barometric pressure as 
influenced by the altitude is the deciding factor in the disease. 
About November io, 1913, two two-year-old steers (cases 5 and 6), 
affected with the disease, as evidenced by a profuse diarrhoea and 
marked swelling of the brisket, were shipped from Jefferson, the 
altitude of which is nine thousand five hundred feet, to Denver (al¬ 
titude five thousand two hundred and eighty feet). They were kept 
in the stockyards at the latter place for a little over two weeks 
when the diarrhoea was checked and the swelling of the brisket 
had entirely disappeared. On November 28th, they arrived at the 
