Karen B. London, PhD, is a Certified Applied Animal Behaviorist and Certified Professional Dog Trainer whose clinical work over the last 17 years has focused on the evaluation and treatment of serious behavioral problems in dogs, especially aggression. Karen has been writing the behavior column for The Bark since 2012 and wrote The Bark’s training column and various other articles for eight years before that. She is an adjunct professor in the Department of Biological Sciences at Northern Arizona University, and teaches a tropical field biology course in Costa Rica. Karen writes an animal column, The London Zoo, which appear in The Arizona Daily Sun and is the author of five books on canine training and behavior. She is working on her next book, which she expects to be published in 2017.