Could it be he's just bored and making his own fun? I'd personally crack down hard on his freedom until he stops being a goober head, all dogs have their moments but there are some things you just can't tolerate for safety reasons. I allow Delgado to only play with one cat because that particular cat is smart and feisty enough to say enough when he's had enough but I still keep an eye on the play and stop when needed.
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010