<human>: Can you provide a brief rundown of the text in within 3 sentences?

Story on my dog: almost 3 y/o mostly-Westie mixed breed.  Male.  Fixed.  Very few behavior issues aside from barking at the TV and canine passers-by.  

Sunday night, my dog SPRINTS across the living room and kitchen to just below the dishwasher, the same way he chases squirrels or rabbits in the yard.  He will not leave this one corner of the dishwasher.  I immediately get suspicious, and sure enough, find some mouse droppings. I go to Target for some pet-safe traps.

I get home and he has a new obsession - the floor vent in our bedroom.  I have never seen him so intent on a thing for so long -- the only way he has left it alone since becoming fixated is by being physically picked up and taken out of the room.  He barks, he wines, he SHAKES.  I tried his Thundershirt - no help. I've tried the pet corrector that we use for TV barking - nothing.  I stayed with him in a different room and still hardly slept Monday night (he would get up and scratch and whine at the bedroom door).  He seemed a bit more calm when I got home from work yesterday, but quickly went back to the vent. 

We finally took him to my parent's house for the night so we could sleep. He's been fine over there - they've offered to keep him another night if we need, but it can take weeks to get rid of a mouse problem, depending on how many we might have.   I realize this is exactly what he is bred for, but it's driving me nuts. Any advice on calming him down?
<bot>: We have a mouse (or mice).  We have a terrier.  He is OBSESSED with where he thinks the mouse is and will not shut up.