Oh my dear ~<3 I feel for you, losing a pet is not an easy thing! But keep your eyes peeled! If I can find my snake in my house, I'm certain you can find your hamster! Just be sure you find it before your dog does....
Anywho, I give you all my luck, and if you do get a mouse, I'd love to hear about it!
Mice are such lovely little creatures, all small and fluffy and...anyway, back to you!