Feline Respiratory Disease refers to a group of illnesses affecting the upper respiratory system of cats. Common causes include viruses like feline herpesvirus and feline calicivirus, as well as bacteria. Symptoms often include sneezing, nasal discharge, coughing, and difficulty breathing. This disease is highly contagious among cats, especially in crowded environments such as shelters or multi-cat households. Vaccination can help prevent some forms of the disease, but it is still important to monitor affected cats and consult a veterinarian for proper diagnosis and treatment.