As someone else said, it would easier on the dog (and you) if you just leave him for short periods first instead of being with you 24/7 then suddenly being left 4 or 5 hours a day............

Maybe on the days you are not working you can start leaving him for short periods and building up - even tho he still has to stay for 4 hrs on his own when you are working, he needs to get used to you coming in and out and not being there all the time then suddenly disappearing for 4 hrs............. Maybe leave him several times a day for short periods when you are not working.

Hope it works out for you, you have to be the strong one unfortunately cause the dog will be picking up on your anxiety!!!

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Proud owner of Rocky the Yorkie, born July 2008, who came to live with us at 8 weeks old
and
Ellie the Yorkie, born February 2012, who came to live with us at almost 8 weeks