To begin with, it helps to have a little background on dog allergy. Contrary to popular belief, dogs' fur is actually not much of an allergen on its own. Rather, the skin cells (called dander), dust and pollen that collect in the fur are what can trigger allergic reactions. Some people are allergic to dander, while others are allergic to dogs' saliva, or even their urine. If you're allergic to dog urine, as long as the dog urinates outdoors, it's not usually much of a problem; but if you're allergic to saliva, one lick may be enough to trigger a severe reaction.
Therefore being "allergic to dogs" is actually a very general term. Before you consider adopting a dog, find out if your allergy is to pet dander, saliva or urine. If you're allergic to saliva and your doctor approves of you adding a canine family member, you can ask your local rescue groups to keep an eye out for an adult dog that doesn't lick people. You need a mature pooch, because you'll be able to tell exactly what the dog's licking behavior is—unlike with a puppy whose behavior has yet to become permanent. Make sure to wash your hands after playing with or petting your dog, especially if your hands come in contact with toys that have been in your dog's mouth.
While no dog is 100 percent nonallergenic, if you're allergic to dander, you may be able to tolerate a so-called "low-dander" dog. Several breeds are known as low-dander dogs. These types of dogs have coats that are more like hair than fur, and they tend not to shed much. They also usually require a lot of brushing and grooming, due to their constantly growing hair.Get Adopt-a-Pet.com's list of low-dander breeds