As fit as a butchers dog
In the dog house
it's a dogs life
Cat on a hot tin roof Means you are acting very jumpy or jittery
To let the cat out of the bag to reveal something, often a secret
Cat got your tongue? meaning you are being very silent or maybe lost for words.
Let sleeping dogs lie Meaning Leave things alone, especially is they can cause trouble
A doggie bag A restaurant container for leftovers.
Gone to the dogs.. the quality has significantly decreased