YOU SAID:

The dog went to bark at my sisters dogs friends dog

INTO JAPANESE

犬は私の姉の犬の友達の犬に吠え始めました

BACK INTO ENGLISH

The dog started barking at my sister's dog friend's dog.

INTO JAPANESE

その犬は妹の犬の友達の犬に向かって吠え始めました。

BACK INTO ENGLISH

The dog started barking at my sister's dog friend's dog.