Make paw prints from construction paper, or using sidewalk chalk, and have them going up the driveway. Make a doghouse out of a large cardboard box. Put it in front of the open door, and have the guests crawl through to the house.
Make dog faces on filled, helium balloons. Use construction paper for the ears, and let them float through the party room.
Use a washable black marker to draw a dog face on your guests as they arrive. Make signs that say things like "Beware of dogs", "Cat free zone", and "Wipe your paws", hang them around the party room.
Play dog music. Some good choices are "Who let the dogs out", "Hound Dog" and "BINGO".
Cut dog bones from construction paper. Write the guests names on them and use them as place cards.
Serve food in new, clean dog bowls. Personalize them with the children's name using paint or permanent marker.
Serve sandwiches cut out with a bone shaped cookie cutter. Make sugar cookies in the shape of dog bones.
> Make a dog birthday cake by baking a round cake, and four cupcakes. Frost them all the same color. The large cake is the paw pad, and the cupcakes are toes, when arranged around the top half of the cake.
If you don't want to make a big cake, make paw print cup cakes. Ice the cupcakes, and then use a Junior Mint as the paw pad, and brown M & M's as the toes.