Kitty Dukakis says she feels healthier but plans to use common sense to protect her health as she resumes campaigning for her husband, Democratic presidential nominee Michael Dukakis.

Before leaving her hospital room Thursday, Mrs. Dukakis received a telephone call from her husband and wished him a happy 55th birthday. They had planned to campaign together in Waterbury, Conn., Thursday before she was hospitalized Monday night with a temperature of 102 degrees.Mrs. Dukakis was treated for a bacterial and viral infection at the University of Minnesota Hospital.

"I feel much better," Mrs. Dukakis said as she left the hospital. "I'm looking forward to resuming campaigning . . . I'm going to do what I can, but I'm going to use common sense as well."

Her press secretary, Paul Costello, said Mrs. Dukakis was to meet her husband in Chicago late Friday and that she would keep a limited schedule Saturday, with appearances tentatively scheduled in Texas and Colorado.

If possible, Mrs. Dukakis will resume a full schedule with her husband on the West Coast Sunday and Monday for the final two days of the campaign, Costello said.