TORONTO (Reuters) - A Canadian couple has launched a business offering worried parents or concerned employers private drug-detection services that will search homes and offices for everything from marijuana to heroin. Russ Rathy of Pense, Saskatchewan, started the home-based business, Crusader Resources, along with his wife, after buying a young German shepherd trained to sniff out drugs. The dog, named Alis Vicona, cost C$20,000 ($16,000) and can detect drugs or the residue of drugs in buildings or on clothing, even after 30 days. "If you suspect your kids of drug use, this is one way to make sure there's no...