an educated guess
i believe the whiskers are designed to protect the mouth, ears and eyes from being bit and scratched while capturing prey..if you look close they are concentrated most along the lip line..around the nose..above the eyes and there are even two on each side that sit before the ear. If a canine was to catch per say a squirrel that would be of course biting back if possible..the whiskers could alert before the damage was done that could later prove fatal to the predator..by being in perfect little lines along the muzzle they provide the best cover..like a protective screen where random placement might not.