respiratory system feline respiratory disease complex (frdc): signs of infection



Respiratory infections of cats are caused by numerous organisms.

The most common are several different viruses and a bacteriumlike organism (see chart) that infect the tissues of the nasal cavity, respiratory passages and lungs, eyes, and sometimes the mouth. These respiratory infections can range from mild to very severe illnesses. All are contagious from cat to cat, some more extremely so than others. They are often spread by licking and grooming between cats and sharing food and water dishes. Some are also spread by sneezing and coughing although this may occur only over short distances. They are probably the most frequently seen infectious diseases of cats. The important thing for you as a cat owner to know is not how to distinguish among the various respiratory infections (veterinarians often can’t without refined laboratory tests), but how to prevent them, how to recognize that an infection is present, and how to determine when veterinary care is necessary.


The most common signs of feline respiratory disease complex are sneezing, fever, watery to sticky puslike discharges from the nose and eyes, lack of appetite, and listlessness. Sometimes drooling is seen, and in these instances raw areas (ulcers) can often be found on the tongue or hard palate. Some very mild infections are marked only by evidence of a mild eye irritation (conjunctivitis) accompanied by a small amount of watery eye discharge and no other signs. In severe cases the eyes can be swollen and crusted shut from discharges, the nasal passages clogged, the nose raw, and the cat most uncooperative with any efforts to give aid.

Whether a respiratory infection is mild, moderate, or severe is dependent upon many factors—among them, the age of the cat, his or her general health, the acquired resistance from previous exposure or vaccination, and the strain of the infective organism.