I don't like the citronella collars as the citronella spray keeps correcting the dog after the year stop. Sounds like a "teenage" dog that uses much more mental stimulation. Teach the dogs tricks with it's meals. GomtomLeerburg.com and read about marker training. When you take a break from working, work him for just five to ten minutes. Do that several times a day. And probably some good games of "2 toys" would help. Outside have two like toys and teach him to bring back the one you threw to get you too thow the other one.
dogbyte Cathy, Rossi ( the Dutch shepherd) and Gunny (the Czech/DDR GSD) with Zoey, Chance,Xara,Gracie, and Jaden snuggled deep within my heart