A little house where your dog lives.
Snoopy sleeps on top of his and flies it against the Germans during World War I.
Jim Bakker's dog had a ritzy, air-conditioned doghouse provided by God. (We should not blame Jim Bakker's dog for this.)
When a guy gets in trouble with his girlfriend, he is said to be "in the doghouse."
When I was a little kid, I wanted to camp out in the doghouse so I could be with my dog all the time.