Dear Sadie,
We are considering adopting a dog but he only has three legs.  How will he get around and what
special care needs might he have?
Signed, Hopping in Hampton

Dear Hopping,
Miss Sadie is touched that you are considering adopting a special needs dog.  It takes a special heart
to make room for one of us who is missing a part or
two. We happen to have a foster in the house
right now who has a bad front leg.  He’s still got the leg, but it cannot bear much weight.  We call him
“Flash” if
that is any indication of what you can expect.

This boy runs everywhere, I guess because he cannot balance right to stand.  Why just today he got
up at six, had his breakfast and did not slow down once
until 9 tonight.  So don’t worry about your dog
being unable to do the things that other dogs do as he or she will find a way.  There are a few things
to keep
in mind though.

•        Your pet may be more prone to arthritis and joint soreness as she or he ages, so it is especially
important to be sensitive to signs of pain. Remember
that the whole body and especially the shoulder and hip joints are compensating for a missing limb.
•        Make sure your dog's nails are trimmed regularly, as long nails can significantly inhibit mobility.
•        Other ailments are more probable as well, like cracked or sore pads.
•        It's important to consult with a veterinarian, because there are supplements that may ease or
treat ailments specific to three legged pets.
(These tips courtesy of “Cassie’s Club: The Place for Three Legged Dogs and the People Who Love

Here is another site with very good information to help prepare you:

Most of all, let your three-legged dog be a dog.  It is better to hop on three legs than limp on four.