Back in the early 80's (What's the Statute of Limitaions on taking a swamp rabbit?)we would get one about every two or three trips hunting in the Ohio River bottoms near Harrison County...You could tell when the dogs would pick up a swamp rabbit because they were runners and fast..It's hard to explain (except to Beagle men) but the "Race" started quicker and you would actually lose the sound of the dogs for a few minutes..It just took them longer to bring them back around..The first time I heard it I looked at my cousin and said "Deer?"...He listened for a minute and said "Nope..Swamp Rabbit."
My Dad would hunt with his cousin in the Green River bottoms in Kentucky and they always bagged a few...They are Big....Dad brought one home uncleaned to show me when I was a kid...He had it in a kitchen garbage bag held at hip level and touching the ground and tried to get me to guess what was in it..I said "It has to be a fox.." He laughed and pulled out one big old rabbit...In Kentucky they are called "Blue Bellies" due to the sort of bluish tint on their belly fur..(Or maybe that was Kentuckians letting folks know what they thought of Blue uniforms.)