Our 7-month old dachshund/terrier puppy used to sleep about 10 hours/night, but in the past month, he's gone from waking about 8:00 to waking at 6:00 AM, then 5:30, which quickly became 5:00 AM, and now 4:30 AM. He won't go back to sleep, and I am exhausted. I can't just stick him in his crate because he will bark and yip and wake the other 4 members of the house. Any suggestions?