 Now, although infection is fairly common in felines, most cats do not get sick. Young cats are at the highest risk. Symptoms include fever, loss of appetite, lethargy, also diarrhea, and weight loss. Pneumonia, liver disease, and infection of the central nervous system are more devastating possibilities. Many affected cats do not survive. However, infection involving just the eyes often can be managed successfully. And as known, women who are pregnant should not be changing the litter box.