There are a lot of reasons to foster dogs.
The main one, of course, is because you value dogs and want to help them go on to good, lasting homes. But even though we all work toward that ultimate goal, there are a lot of different roles that foster homes can play in getting there. Some hold animals for set periods of time so that they can meet quarantine requirements for out-of-state transport. Some take sick or very young animals out of the stressful shelter environment so that they can be nursed back to health, or reared to an adoptable age, in a supportive home.
Our role as foster parents is more like... running a finishing school, with a dash of matchmaker thrown in toward the end.
The dogs we foster are mainly adults and adolescents from the rural South. Most of them grew up as strays or "yard dogs" and have little or no experience living indoors with people. Nessie had no idea how to walk on a leash when she arrived; Pepper was terrified of stairs and glass doors. Gremlin had never had any dog toys and, once she grasped the basic concept, mistakenly eviscerated one of the dog beds thinking it was a stuffed animal. The dogs we get are good dogs -- they're friendly, people-oriented, of sound temperament -- but they aren't potty trained, they don't have any manners, and they don't know any commands. They'd be happy to do what's expected of them, they just don't know what that is.
From that background, they get plunged into the heart of a major city -- a highly artificial environment filled with strange new noises, smells, and sights. The sidewalks are crowded with other dogs and people of every description: all ages and genders, all colors, many wearing unusual clothes or walking with unusual gaits, some high or drunk or mentally ill. SEPTA buses and police sirens go blaring by at all hours. There's not much grass, there's a lot of concrete, and all in all, it's an extraordinarily alien place for a dog to find itself in.
And yet adopters expect a dog to be able to handle itself calmly in this environment. They want dogs that don't bolt when a fire truck roars past, that don't growl when strange dogs rush up to greet them, that can behave politely to kids and friendly-but-clueless strangers who reach out to pat their heads without warning. They want a dog that won't make messes in their home, can Sit and Stay and Down on command, and maybe knows a couple of cute tricks to show guests on top of that.
Some of these expectations are realistic, some probably aren't. A dog who met all of them would pass its Canine Good Citizen test with flying colors -- and that's a level of training that is difficult to accomplish in the limited time we have with foster dogs. But it gives us something to aim for. At the very least, we can start them on the right path to get there, and we can give adopters some pointers to keep them on track (and, if necessary, gently adjust their expectations a little bit in the meantime). So the biggest part of our work, by far, is equipping dogs with the skills they need to navigate this strange new world.
Once the dog seems ready, we start working on the matchmaker phase. Not all dogs are suited for all people, and vice versa; the ideal home will be a match of compatible personalities, lifestyles, and activity levels. For the most part, this just involves observing the dog and making the relevant information available to prospective adopters, who can then figure out for themselves whether it seems like a good fit.
None of this is difficult, but it does take time... and time is the one thing that dogs in rescue can least afford. The flood of unwanted dogs and puppies is never-ending. Even in those lucky communities where animals do not have to be routinely euthanized for space, the sheer stress of being in the kennel environment for weeks or months on end can severely damage dogs' psyches, rendering them unadoptable. Accordingly, there is enormous pressure to place foster pups quickly so that more can be saved.
Our living situation doesn't lend itself to high volume or quick turnover, though, so instead I try to compensate by giving our foster dogs the most thorough education I can manage. One at a time is all we can do... but that one gets a lot of work. And in the end, if all goes well, that pup will be the belle of the ball.