The dog who played Toto was actually a female named Terry. According to her autobiography, I Toto, by Willard Carroll, Terry was born in 1933. Her first home in Pasadena was unhappy, thus she ended up with trainer Carl Spitz, a German immigrant. Spitz trained many dog actors.

Terry once knocked Clark Gable's false teeth out with her enthusiastic greeting. She appeared in Bright Eyes with Shirley Temple before being cast in her most famous role as Toto. Terry made several other movies before retiring to Carl Spitz's school where she died sometime around the end of World War II. She was buried in the backyard of Carl Spitz's Hollywood Dog Training School which was plowed over to build the Ventura Freeway in 1958. Gone but still with us.

More Info: en.wikipedia.org