What a difference a year makes. Although he’s not quite two, Fergus has seen enough of the world on a leash to know his limits. No more dashing after fun in the form of loose dogs, skateboarders, bikers and joggers.

Life isn’t always fair, if you are a 130-pound dog. The 20-pound terriers of the world might get away with mayhem, but big dogs have to be well-heeled.

While I won’t say he’s as meek as a kitten, I will tell you that Fergus “purrs,” when he’s petted. The sound is disarming, if you aren’t prepared for it.

At about the same time he began to purr, Fergus also began to snore, although it took me a while to realize this because I assumed it was my husband, who has been rumbling in his sleep for years. One night, after I had poked Alan for the third time, he rolled over and said, “It’s not me.”

“You need to learn the difference between a growl and a purr,” Fergus’ breeder told me, when I expressed some concern. Sure enough, when I googled “Rottweiler purr,” I discovered Fergus is not alone. Some people even refer to the trait as the “Rottie rumble.”

Over time we discovered that Fergus varies the sound of his “purr” depending on where and how vigorously we pet him. His deepest, most satisfying tones come as a result of a tummy rub, while he is stretched fully out on his back.

Click here for a sample of Fergus’ vibrato.