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Pleural Effusion in Cats

Pleural effusion is abnormal fluid in a cat’s chest.

Pleural effusion is the abnormal accumulation of fluid in a cat's chest cavity between the lungs and the lining of the chest (pleura).

Causes of Pleural Effusion in Cats

Fluid builds up in the chest either when there is too much of it being produced or when not enough is absorbed or drained by the body. The primary conditions that lead to pleural effusion in cats include:

  • High blood pressure
  • Build-up of lymph in the chest (chylothorax)
  • Cancer
  • Congestive heart failure
  • Chest trauma
  • Infection
  • Heartworm disease
  • Intestinal disease
  • Kidney disease
  • Liver disease
  • Pancreatitis
  • Over-hydration (Usually the result of IV fluids given for another condition. Often due to underlying heart disease or protein imbalances, the body can't handle the extra fluid)
  • Lung lobe torsion
  • Clotting disorder or warfarin poisoning

Signs of Pleural Effusion in Cats

When a cat is suffering from pleural effusion, the liquid present in the chest cavity prevents the lungs from fully inflating. A cat with this condition might show some or all of the following signs:

  • Panting
  • Labored breathing
  • Fast breathing
  • Sitting or lying in strange positions to ease breathing
  • Exercise intolerance
  • Decreased or absent appetite
  • Lethargy
  • Bluish tint to gums and/or skin

Diagnosis of Pleural Effusion in Cats

A veterinarian will take a thorough history of signs from a cat's owner when diagnosing pleural effusion. Then he or she will do a complete physical exam. The doctor might hear crackles or wheezing in the chest when listening with a stethoscope or be unable to hear the heart well.

An x-ray is helpful in diagnosing pleural effusion because the abnormal fluid can be seen in the chest cavity. A thoracic (chest) ultrasound can also help.

Once fluid is identified in the chest cavity, the cause must be determined. Testing that can help with diagnosis includes blood work, urinalysis, x-ray, ultrasound, and evaluation of fluid collected from the chest with a needle.

Treatment of Pleural Effusion in Cats

The first order of treatment for a cat with pleural effusion is to help ease the breathing by removing some liquid. This can be done through a needle with a chest tap. After that, treatment is individualized depending on the cause and may include:

  • Placement of a chest tube
  • Oxygen therapy
  • Pain medications
  • Antibiotics, antifungals, or anti-parasitics
  • Heart medications
  • Surgery to repair trauma, remove tumors, or create a shunt

All causes of pleural effusion in cats are serious, and many carry a guarded to poor long-term prognosis.

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Chylothorax in Cats

Heart Disease in Cats

Heartworm Disease in Cats

Saddle Thrombus: Aortic Blood Clots in Cats

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