Assistance dogs are specially trained to help people  who are blind, deaf, or physically disabled. From  the time they are adopted by puppy raising families  or trainers until the time they are retired, their lives  are devoted to the serious task of providing security  and independence to a person with a disability. It's  not always a specific breed that makes the best assistance  dog.

Instead, dogs are selected for the temperament  and size that suits them for the job they'll have  to do.  The first assistance dogs were developed in  Germany in the 1920s as guide dogs for veterans who  lost their sight during World War I. There are now  three basic types of assistance dogs:  Guide dogs  Hearing dogs  Service dogs  Next time you see someone with an assistance  dog, feel free to approach the person and say hello.  Maybe you'll want to ask  how long they have had  their dog or what its name  is.  Be sure to say hello to  the person first and remember  not to pet the dog without  permission.  About 20,000 people in  the United States. More than  60 non-profit programs train  and place these dogs nationwide.