Electric to garage stopped working (detached)

I have a detached garage which is approx. 15 yrs old. There is a breaker box in the garage. The electric was run from the beaker box in the house, buried to the garage. A few months ago all the electric to the garage stopped. I believe there is a break (possibly caused by my dog digging under the deck) Any idea how I can find and repair this? I really don't want to have to get out in winter and manually open the garage, and I am TIRED of needing a flashlight to find anything out there... Thank you