24 Colorado Experiment Station. 
feet) all recovered without other treatment, although it seems rea¬ 
sonable to believe that they would have died had they not been 
shipped. 
It appears to be caused by an exhaustion of the heart muscle 
associated with a varying degree of dilatation and hypertrophy and 
this being brought about by exertion before acclimatization at high 
altitudes, or in the case of calves, inherited cardiac weakness. 
Medical treatment has so far proven of little avail, but where 
possible shipping the affected animals to a lower altitude is recom¬ 
mended. 
Preventive measures include the use of bulls that have been 
raised at altitudes of eight thousand feet or more, with a view to 
building up a hardier strain of cattle, also the curtailment of in¬ 
discriminate shipping of low altitude cattle to high altitudes. 
