DALLAS - Charles Denson's face brightens as a speckled Australian shepherd named Bart cuddles next to him while he rests in his hospital bed. "You've got a pretty coat," the 51-year-old heart patient says while stroking Bart's soft fur.

New research indicates that hospitals that use such pet therapy sessions aren't barking up the wrong tree.

Cole, a nurse at the University of California Los Angeles Medical Center who led the study, and her colleagues studied 76 heart failure patients — average age 57 — who got either a visit from a volunteer, a volunteer plus a dog, or no visit.

The scientists meticulously measured patients' physiological responses before, during and after the visits. Anxiety as measured by a standard rating scale dropped 24 percent for those visited by the dog and volunteer team, but only by 10 percent for those visited by just a volunteer. The scores for the group with no visit remained the same.