dogs bark, cats meow

all bark and no bite

Full of big talk but lacking action, power, or substance; pretentious.

bark up the wrong tree

To take the wrong approach to a situation; to follow a false lead; to attempt to solve a problem using mistaken assumptions about its true nature.

buy a dog and bark oneself

To do something that one has hired someone else to do.

call off the dogs

To ease up on after inflicting great punishment.

cat's meow

A self-satisfied person.

dog my cats

Used as a mild oath, or as an expression of astonishment

go to the dogs

To decline or deteriorate shockingly.

herd cats

To attempt to control the uncontrollable; to attempt to manage a great many unruly factors or people to a single end.