YOU SAID:

My dog has eaten his food

INTO JAPANESE

私の犬が食べ物を食べてしまいました

BACK INTO ENGLISH

my dog ate the food

INTO JAPANESE

私の犬が食べ物を食べました

BACK INTO ENGLISH

my dog ate food

INTO JAPANESE

私の犬は食べ物を食べました

BACK INTO ENGLISH

my dog ate food