Terry Gurley, 57, was walking her Akita Shepard mix near her apartment complex Friday when authorities believe the 325 pound bear scared the dog.
The bear attacked her near a garbage can and left the woman with four puncture wounds.
Officials set traps for the bear and plan to euthanize it, which normally happens to bears that come into congested areas.
Officials say bears are common in the area because Longwood is close to the Wekiva River. The largest single population of black bears is near Longwood in the Ocala National Forest, according to the newspaper.
The Florida Fish and Wildlife Conservation Commission received more than 2,000 bear-related calls in 2010, mostly about bear sightings.