Chihuahua: The Movie.

Sondra Wellington (Anya Benton) is bossy, controlling, and extremely unpleasant. But everything changes when a special friend from Sondra's past transforms her into Bella -- her assistant's loveable little Chihuahua. While Sondra lives as Bella, her real body is in a coma. In order to gain access to the hospital, Sondra must prove that she has what it takes to be a therapy dog. As she learns the tricks of the trade, she becomes more connected with the people around her and realizes her past mistakes. It appears that Sondra is finally ready to turn over a new leaf in her own life --that is, if she ever gets the chance.