Pneumonia in Cats

Pneumonia is an infection of the lungs and is classified according to cause: viral, bacterial, fungal, parasitic, or inhalation.

Pneumonia can follow one of the feline viral respiratory illnesses, when the cat's natural defenses are weakened by the primary infection. This allows secondary bacterial invaders to gain a foothold. Individuals most likely to develop pneumonia are kittens, old cats, cats who are malnourished or immunosuppressed, and cats with long-standing respiratory diseases such as chronic bronchitis.

Aspiration of foreign material during vomiting (perhaps while the cat is under anesthesia) and the unskilled administration of medications or supplemental feedings account for occasional cases. Tuberculosis and systemic fungus infections are infrequent causes of pneumonia. These illnesses are discussed in chapter 3, Infectious Diseases.

The general symptoms of pneumonia include high fever, rapid breathing, splinting, cough, fast pulse, and rattling and bubbling in the chest. When the disease is severe enough to cause an oxygen deficiency, you will notice a blue cast to the mucous membranes of the mouth. The diagnosis is confirmed by laboratory tests and a chest X-ray.

Treatment: Pneumonia is a serious illness requiring urgent veterinary attention. Until veterinary help is available, move your cat to warm, dry quarters and humidify the air. Give her plenty of water. Do not use cough medications, because coughing in a cat with pneumonia helps to clear the airways.

Pneumonia usually responds to an antibiotic selected specifically for the causative agent. Your veterinarian can select the proper antibiotic. A nebulizer may be used as the best method of getting antibiotics into the cat's lungs. Your cat may need to be hospitalized for fluids and oxygen therapy.

Cats with severe respiratory infections may not want to eat because they can't smell the food. Strong-smelling food, such as canned tuna, may help to stimulate appetite. Gently warming the food will also make it more aromatic.

Pleural Effusion

The most common cause of difficult breathing in cats is pleural effusion-fluid accumulation in the pleural space surrounding the lungs. The fluid compresses the lungs and keeps them from filling with air. This condition is much more common in cats than it is in other animals. The reason is that cats suffer from two diseases that produce pleural effusion: feline infectious peritonitis and feline leukemia. Other causes of pleural effusion include cancers, congestive heart failure, and liver disease.

Infections in the pleural space follow puncture wounds of the chest, often acquired in fights with other animals, including other cats. The infection leads to pus formation in the lungs, a condition called empyema or pyothorax.

Bleeding into the chest cavity and lungs often follows chest trauma. A severe blow to the abdomen can rupture a cat's diaphragm, allowing the abdominal organs to enter the chest cavity and compress the lungs. This is a diaphragmatic hernia. These cats can show evidence of shock.

Depending on the cause, cats can show acute distress or more gradual, chronic signs of pleural effusion. However, in all cases, the cat will have difficulty breathing. Cats often sit or stand with elbows out, chest fully expanded, and head and neck extended to draw in more air. The animal may be unable to lie down. The least effort produces sudden distress or collapse. Breathing is open-mouthed, and the lips, gums, and tongue may look pale or appear blue or gray. The blue-gray color, called cyanosis, is due to insufficient oxygen in the blood. Depending on the cause of the fluid accumulation, other signs of illness may include weight loss, fever, anemia, and signs of heart or liver disease.

Treatment: When fluid builds rapidly in the chest, urgent veterinary attention is required to prevent respiratory failure and sudden death. The fluid will need to be drained. The cat should be hospitalized for care and further diagnosis. A chest drain may need to be placed, antibiotics and pain medications are usually required, and surgery may be necessary. An oxygen cage may be required until the cat is stabilized.

This article is excerpted from “Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.