“Each evening
They come back.
They howl like dogs.
They are prowling about the city.
They roam about for food.
They growl if they do not get their fill.”
Just like verses 6-7 of this psalm, the howling dogs are back prowling the city. This time they are looking for food. They growl until they filled. Thus the common term of enemies is they are like a pack of growling dogs.