Have dog hair all over their clothes but either don’t notice or don’t care.
Carpet or place rugs over hardwood floors so their dog won’t slide all over the room.
Allow the dog to have the majority of the couch while they scrunch up in a corner.
Their dog eats better than they do.
Doggie toys litter the living room.
Two kinds of dog lovers with this one: either talk to their dog in baby talk or adult speak, as if the dog completely understands everything they say (I suspect they usually do).
Sincerely believe dogs are furry angels sent here to guide us lowly humans.