sleuthhound

Not even the very keenest of the law's sleuthhounds were able to avoid such mistakes.

I suppose it will be a long race, for these Norman sleuthhounds are sure of scent, and will not be easily shaken off!

This explains why the dog has sometimes been called a sleuthhound; that is, a dog set upon a sleuth, or trail.

“Hearken now to the tale of the sleuthhound,” the latter continued, setting down his hat, cane and gloves upon the sideboard and thrusting his hands into his trousers pockets.

From that instant, all pretenses were abandoned, Robert was a sleuthhound on a keen scent.