Could they have been made by a big dog?

那些有可能是大狗留下的吗？

I was scared of the big dog.

我害怕这条大狗。

I saw a big dog behind you.

我看见你的身后有条狗。

The cat hogged himself to attack a big dog.

那只猫拱起背向一条大狗发起了攻击。

A big dog followed them.

一只巨犬跟在他们后面。