Overview of Pleural Effusion in Cats
Pleural effusion is an abnormal accumulation of fluid in the pleural space, which is the cavity between the lungs and the thoracic wall. Normally, a small amount of fluid is present in the pleural space which serves to lubricate the surfaces and prevent friction as the lung expands and deflates. A disturbance in the production or removal of this fluid may cause excessive fluid to accumulate. This can interfere with the function of the lungs and lead to the restriction of lung expansion and ventilation. When this occurs the lung lobes may collapse. Severe accumulations are usually life-threatening.
Below is an overview of pleural effusion in cats followed by in-depth information on the diagnosis and treatment of this condition.
Pleural effusion is a symptom of many diseases, but is rarely a disease itself. Diagnostic tests are needed to determine the underlying cause, and subsequent treatment recommendations are based on these findings. The type of abnormal fluid accumulated can help determine the underlying cause of the fluid. The fluid is usually categorized based on its protein level and the types and numbers of cells present.
Some of the diseases or conditions in which pleural fluid may accumulate include:
What to Watch For
Diagnosis of Pleural Effusion in Cats
Diagnostic tests are needed to exclude other diseases that may cause similar signs and to determine the underlying cause of the effusion. Diagnostic tests that your veterinarian may wish to perform include:
Treatment Pleural Effusion in Cats
The treatment of pleural effusion ultimately will depend upon the underlying cause. Initial treatments may vary depending on the likelihood of the specific diseases based on your pet’s physical examination and history. Treatment may include:
Home Care and Prevention
Optimal treatment for a pet with pleural effusion requires a combination of home and professional veterinary care. Follow-up can be critical. Be aware of your pet’s general activity, exercise capacity and interest in the family activities.
Keep a record of your pet’s appetite, ability to breathe comfortably (or not), and note the presence of any symptoms such as coughing or severe tiring.
Never withhold water, even if your pet urinates more than normal, unless specifically instructed to do so. Difficult breathing is an emergency. See your veterinarian as soon as possible.
Administer prescribed medication as directed and be certain to alert your veterinarian if you are experiencing problems treating your pet. Take your medications with you to your recheck examinations to show your veterinarian. Dosing is critical for heart medication.
Regular examinations that include an interview about your pet’s clinical symptoms and quality of life should be scheduled. Be prepared to answer questions regarding your pet’s activity, appetite, ability to sleep comfortably, breathing rate and effort, presence or frequency of coughing, exercise tolerance and overall quality of life.
During re-evaluations, a chest X-ray may be performed to evaluate the lungs for fluid. Measurement of arterial blood pressure may also be done periodically. Blood tests to examine kidney function and blood electrolytes are routinely recommended. A blood digoxin test should be done periodically if that drug is being administered and an electrocardiogram is recommended if there is a heart arrhythmia.
In general, pleural effusion cannot be prevented. Once your pet has been diagnosed with pleural fluid you should prevent excessive physical activity or excitement, avoid high heat/humidity and avoid high salt (sodium) foods or treats.
In-depth Information on Pleural Effusion in Cats
There are dozens of reasons for coughing, difficulty or labored breathing and fatigue. The conditions that are most likely to cause these signs are diseases of the airways and lung, abnormalities of the heart and blood vessels, and accumulation of air in the chest cavity (pleural space). Examples of such diseases include:
When severe, the accumulation of fluid around the lungs (pleural effusion) will cause your pet to have difficulty breathing. The condition can become life threatening. Though dramatic, the symptoms of difficulty breathing (dyspnea) are not specific for only one condition. There are numerous causes of pleural effusion and it is imperative that your veterinarian determine the cause in order to institute appropriate and specific therapy.
However, initial treatment of pleural effusion in all cases where the animal is having difficulty breathing, is directed at removing the fluid in order to allow the lungs to re-expand and to improve ventilation (air intake).
Diagnostic tests are needed to recognize pleural effusion and exclude other diseases that may cause similar symptoms. A complete medical history will be taken which will likely include the following questions:
Your veterinarian will perform a thorough physical examination. The number of diagnostic tests that are necessary depends on the duration of signs, the extent of the illness, and what your veterinarian finds on the physical examination. The physical examination should include observation of respiration, auscultation of the heart and lungs, and determination of the color of mucous membranes. Your veterinarian will handle your cat with care during the examination so as to reduce stress. If your cat is having a great deal of difficulty breathing, emergency treatment will be necessary.
Your veterinarian may recommend additional diagnostic tests to ensure optimal medical care. These are selected on a case-by-case basis if indicated from the examination, prior test results or lack of response. Examples may include:
Consultations with appropriate specialists may be recommended depending on the findings of these tests.
The principles of therapy for pleural effusion are dependent upon the underlying cause. Goals in therapy may include improving heart function, preventing fluid accumulation, preventing further deterioration of the heart muscle and antagonizing chemicals and hormones produced in excessive quantities in pleural effusion. Congenital heart defects should be referred to a specialist for management. The initial therapy should be aimed at the diagnosis and treatment of the underlying cause.
Emergency management of animals with pleural effusion may include:
Further therapy will be dependent upon the underlying cause.