Barking dogs seldom bite.
吠犬不咬人。（意指：对于发出恐吓，或惯于大声吼叫的人，勿须当真。）

Every dog has his day.
凡人皆有得意日。（风水轮流转。）

Dog does not eat dog.
同类不相残；同室不操戈。

a cat-and-dog life
争争吵吵的日子

Give a dog a bad name and hang him.
人言可畏。

go to the dogs
每况愈下 ；堕落

hang-dog look
愁眉苦脸

Love me, love my dog.
爱屋及乌。

He is a lucky dog.
他是个幸运儿。

lead a dog's life
过着猪狗不如生活

not have a dog's chance
毫无机会

top dog
当权派；头儿

a lazy dog
懒汉

a dirty dog
下流坯

as/like a dog with two tails
高兴得跟什么似的

be (old) dog at
对…有经验；对…很内行

Beware of a silent dog and still water.
提防不吠的狗,小心静止的水。

come like a dog at a whistle
一呼即来    

It is ill to waken sleeping dogs.
别惹事生非。/别惹麻烦。

Hungry dogs will eat dirty puddings.
急不暇择, 饥不择食。

dog it
拈轻怕重，逃避工作

put on the dog
装模作样；装出斯文、有钱或有文化的样子

a dog in the manger
占马槽的狗；占着茅坑不拉屎的人

help a lame¹ dog over a stile
助人于危难之中；雪中送炭

He who has mind to beat his dog will easily find a stick.
欲加之罪，何患无辞。