The legendary dogs only moved between areas when you did, so you could wait until you were in the same area as one, save, then have multiple tries at catching i

The legendary dogs only moved between areas when you did, so you could wait until you were in the same area as one, save, then have multiple tries at catching it; the main difficulty was in quickly incapacitating it so it wouldn't run away or else capturing it on your first turn without any weakening.