Please note that the oil was eaten and not applied topically (does anybody EAT massage oil?)
When the study was repeated using different strains of rats and also in dogs, there were no detectable histopathological changes in these tissues. It appears that F344 rats have a genetic susceptibility to mineral white oil that hasn’t been found elsewhere (refer below for the human story). Even though the rats showed the above changes, they did not exhibit clinical toxicity (ie had no symptoms of sickness).