The city is warning residents in SW Calgary about aggressive coyotes after a pet dog was dragged from a backyard and killed.  This happened on Sunday night at a home bordering Strathcona Ravine.  There’s been a bunch of reports from SW Calgary residents about aggressive encounters with coyotes.  While coyote encounters involving dogs are common, it’s very rare when a pet is injured or killed. Click here for more.  (Photo: Postmedia Archives)