A lot of people want to adopt or foster an animal but arent suited for it. When fostering puppies it can be a very difficult thing to do, most of the times they are very skittish from being in traumitizing expireneces, they arent potty trained, and unless your going to commit to adopting, you should never get attached.
"A cute Dog 4" by Chen Vision is licensed under CC BY-NC 2.0
You also need to consider having to spend a lot of time and money tending to dog, as well as being able to have close acess to a vet.