"The cat's pajamas" is just like your ones.
Other animal-related ones:
I could eat a horse.
Knee-high to a grasshopper.
As black as a cow's belly (a Welsh one, which only works if all cattle are Welsh Blacks).
Hung like a horse (or donkey).
Dog's (or pig's) breakfast.
One swallow doesn't make a summer.
Fine weather for ducks.
A dog's life.
Strong as an ox (or horse).
(From "I'm Sorry I Haven't a Clue"): gnat's crochet.
All this talk of dogs reminds me of a joke. "Look at that dog -- I wish I could do that!" "Give him a peanut and he'll let you..."