from the looks of the nail prints the nails seem to be alot longer then what you would find on a non domesticated animal. the track is deffinately of a domestic dog from the size of the track it would be a large dog maybe labrador or an other breed similar in size. you might look around the area where the track was found and see if you can see anyones dogs in the area. 10 out of 10 that track belongs to a large local dog in your area.