Cost wise for me, it was cheaper to make it myself. There are pics here, everything was edible for the dogs with the exception of the Happy Birthday and balloons.
Twalla Grant's Photos - Martin & Sam's Birthday Party | Facebook
The cakes are small that I found locally/online and with as many dogs as I was having, I would have needed 2.
These people just make the fondant then you make the cake.
Free Dog Cake Recipes; Birthday Cake Fondants For Dogs