The effect of subchronic feeding of 2,2'-oxamidobis[ethyl 3(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], Naugard XL-1 (CAS number 70331-94-1), was studied in beagle dogs. The dose levels of Naugard XL-1 used were 2000, 6300, and 20,000 ppm in the diet. Body weight gain and food consumption, organ weight, hematological, clinical chemical, and urine analysis data, and ophthalmic, gross, and histopathological examinations were used to study possible toxic or pathologic effects. No treatment-related effects were seen in any variable of either male or female animals exposed to Naugard XL-1 at any dose level.