Cats still are exposed to organisms that are carried through the air or brought in on a cat owner's shoes or clothing. Even the most housebound cat ventures outdoors at some time and can be exposed to diseases and worms through contact with other animal's feces.

  Some cats can be infected with a disease called toxoplasmosis, which occasionally can be spread to humans through cat litter boxes and cause serious problems in unborn babies. However, these problems can be controlled. The only way a woman can get toxoplasmosis from a cat is through direct contact with its feces, which most people try to avoid anyway! A few simple precautions are all that's needed to prevent exposure to this parasite during pregnancy. The expectant mother should avoid contact with the litter box and assigns daily cleaning to a friend or other family member.

  "If you have been exposed to toxoplasmosis and produced an antibody, you're pretty well protected," says Dr. John Botti, director of maternal-fetal medicine at Penn State University College of Medicine.