10 year old Carin Terrier exhibiting odd behavior

[tmeyer91]

We adopted a 10 year old Carin Terrier  He was abandoned in front of our local SPCA. He has had a couple of hernia surgeries and has a heart murmur which we give enamapril.  Other than the expense of those procedures he has been a pretty relaxed dog. He does his cute growl and bitting motion when he wants to go on a walk. I work from home and he has slept most of the day. However, lately he has displayed oddly obsessive digging behavior. It started with him periodically "digging" at the carpet with his paws and sniffing the carpet. Lately he has become obsessive about his bed. He seems to have no off switch and drags his bed around the apartment. It is completely separated and he drags the cushion around.  He does this through the night sometimes.

We have a vet appointment on Monday but we are not sure if this is something wrong or nothing. We did give Hydroxyzine for itching but we stopped once the behavior began after about a week. Other than that we have no other ideas what could be causing this behavior.

Anyone have any similar stories with older terriers?