Tracheal Wash in Cats

A tracheal wash is performed by passing a sterile fluid into the upper airways of the lung, and then recovering that fluid along with tissue samples “washed” out with the fluid for analysis to determine underlying pathological conditions that may be causing illness in your cat. 

There are two types of tracheal washes: transoral and transtracheal. The procedure used for transoral tracheal washes involves passing a tube through the mouth, into the trachea and then inserting fluid which is then pumped back up along with tissue cells for analysis. This is more commonly used in cats than the alternative trans-tracheal wash, which involves a catheter being placed through the skin into the trachea and fluid inserted and recovered via this pathway. 

This procedure is used to assess the cause of a respiratory disorder. Samples of lung tissue cells can identify bacteria, fungus, foreign organisms such as protozoans, and even cancerous cells present in the lungs, and is an extremely useful diagnostic test your veterinarian may use when your cat is experiencing respiratory disorder. 

During a tracheal wash your veterinarian will anesthetize you cat and will insert a sterile tube, usually through the mouth, and into the upper airways of the lungs. A second tube is then inserted into the first and sterile fluid, usually a small amount of 4-6 ml, is then instilled into the smaller tube. Usually the patient will then cough and fluid and material will be withdrawn from the tube using a syringe and collected for analysis. The tracheal tube may then be connected to oxygen, and maintained until your cat recovers, at which time the tracheal tube can be removed. Samples of fluid and cells from the lung are submitted for testing by microscopic review and cultures. These tests will reveal the presence of fungus, bacteria, cancerous cells and foreign organisms present in the lungs. 

Transoral Tracheal Wash

This procedure is the most commonly used in cats. Prior to a transoral wash your cat will be put under sedation and light intravenous anesthetic for a short period of time. A relatively large tube is inserted through the mouth into the trachea (windpipe). A smaller tube is inserted into the large tube and into your cat's upper airways. A small amount (4-6 ml) of sterile fluid is trickled into the small tube and down into the airways of the lungs. This fluid is then sucked back out of the lungs using a syringe and collected for analysis of the fluid and any cells that may have washed out with the fluid. Some fluid will remain in the lungs, this fluid will absorb back into the tissues and is not usually problematic for your cat.

Transtracheal Wash

More commonly used in larger animals, a transtracheal wash involves passing a catheter through the skin into the windpipe to perform the tracheal wash. Your pet may be lightly sedated and a local anesthetic used to numb skin. The area for insertion will be clipped and cleaned antiseptically. A needle will be passed through the skin into the animal's airway between the cartilage rings and the trachea and then a catheter inserted. Sterile fluid is then inserted and aspirated through this passage. 

Tracheal washes are very valuable diagnostic tools in cats experiencing chronic breathing problems. They produce excellent cellular samples from the lungs for analysis. In acute cases, other diagnostic tools including radiographs, blood tests, and urine tests may be adequate to identify pathology. 

It is common after a tracheal wash for your cat to have a cough due to irritation from the endotracheal tube, and until any remaining fluid is absorbed by the lung tissues. This cough usually resolves itself shortly and is not of concern. 

If a transtracheal wash was performed there may be some leakage where the needle was inserted through the skin and air may accumulate under the skin (subcutaneous emphysema). When you pet your cat there will be a crackling sound due to the trapped air. This usually resolves itself, if it persists or causes respiratory distress, follow up as soon as possible with your veterinarian. 

If your cat coughs up blood or has a severe cough after tracheal wash this is not normal and veterinary care should be sought immediately.

The cost of a tracheal wash procedure in cats is approximately $200-$300 including sedation and anesthesia.

Because cats requiring tracheal wash are already experiencing respiratory problems, there is a risk of their condition becoming complicated by this procedure. 

Excessive fluid can be aspirated, which can cause respiratory distress or cause your cat to stop breathing. This risk is small and when the procedure is performed by a qualified veterinarian who controls the airway and with oxygen present to mitigate respiratory issues, it is unlikely to occur.

The procedure does require sedation and anesthesia; there is always a risk of respiratory issues or allergic reaction with anesthetic. Again, the presence of oxygen and respiratory assistance such as positive pressure ventilation can mitigate this concern.

Most commonly used to diagnosis chronic breathing problems in cats such as asthma, tracheal washes can be avoided by mitigating the chances of your cat experiencing a chronic asthma-type condition. Exposure to allergens, contaminants, and secondhand smoke can increase your cat’s lihood of developing asthma. Keeping your home free of smoke and dust that aggravates asthma can be beneficial to your family and your cat. Some parasites and protozoan organisms can also cause respiratory distress. Monitoring your cat for signs of infection with parasites, fungus or bacteria, and providing treatment before breathing problems occur, can eliminate the need of investigation of lung tissues acquired through tracheal wash.