YOU SAID:
I can't believe you eat the dog's food.
INTO JAPANESE
あなたが犬の餌を食べるなんて信じられない。
BACK INTO ENGLISH
I can't believe you eat dog food.
INTO JAPANESE
あなたがドッグフードを食べるなんて信じられない。
BACK INTO ENGLISH
I can't believe you eat dog food.
That didn't even make that much sense in English.