Changing frequency of arteriosclerosis in mammals and birds at the Philadelphia Zoological Garden; review of autopsy records.

From 1901 through 1932 arteriosclerosis was found in less than 3 per cent of autopsies on mammals and birds at the Philadelphia Zoological Garden, but thereafter its frequency has increased to about 20 per cent. This study has attempted to identify factors that may be associated with this change in frequency. A CONSIDERABLE volume of clinical and experimental evidence supports the opinion that the frequency of arterio-sclerosis in human populations is determined to a large degree by the level of dietary fats.1-7 However, other studies suggest instead that the development of this disease reflects the interaction of several factors some of which, at least, are not related to fat intake.8"-1 The observations to be reported here support the latter view, insofar as it may apply to captive wild mammals and birds.