Nov. i8, i9i8 Further Studies on Brisket Disease 413 



These six cases were fed the high-altitude South Park hay in order to 

 determine whether the feed was a factor. The first two animals died 

 without eating enough of the hay to determine its effect, but the other 

 four improved and finally recovered on it. Therefore, we are led to 

 believe that the change of altitude and not the change in feed is the 

 essential factor in the recovery of animals from this disease on being 

 shipped to the lower levels. 



SUMMARY 



Our observations tend to shov/ that normal animals living in a high 

 altitude have a heavier heart than those living near sea level; that 

 animals affected with brisket disease had dilated, flabby, and heavy 

 hearts; that they have a high percentage of red corpuscles; that they 

 show generalized edema and enlarged and sclerosed livers, such as one 

 would expect in cardiac weakness; that they usually recover when 

 shipped to lower altitudes, but seldom do if they remain at the higher 

 levels ; and that the feed is not a factor ; that animals from low altitudes 

 are more often affected than natives; that calves sired by bulls from 

 low altitudes are more likely to be affected than those sired by native 

 bulls; that the higher the altitude the more prevalent is the disease. 



We therefore have no hesitancy in concluding that the malady is due 

 to failure of acclimatization at high altitudes. The remedy lies not in 

 drugs, but in breeding a hardier strain of cattle which can accustom 

 themselves to the rigorous conditions incident to an existence at these 

 extreme altitudes. 



