How safe are Rottweilers? The American Kennel Club describes Rottweilers as calm, confident and courageous dogs especially suited as a companion, guardian and general all purpose dog. Many owners will tell you their Rottweilers are not aggressive, in some cases calling them gentle giants. But dog experts will tell you owner education and dog training is critical to making these animals safe pets. Rottweilers were first bred in Germany, and researchers say they became popular in the U.S. in the 1990's as more people sought them for protection.