Talk about a mixed and confusing metaphor/idiom, that depending on its connotation maligns two large categories of animals with a mere two words. BIRD DOG. So, whether you apply one definition which is "to control closely with unceasing vigilance" or another, "to steal or attempt to steal another person's date," they are an affront to those sentient beings. I am kind of confused as to who is doing the BIRDING and who is doing the DOGGING.
However, from a bird's perspective, the worst connotation is for sure a literal one, "a dog used or trained to retrieve game birds after they have been shot."
Les Shulman Ex-Mex/AthAg/Birds Ed.