Fluid in the Chest in Dogs

Many problems with respiratory function can result from fluid buildup in your dog’s chest. Examples of complications can include lack of room for lungs to expand, which causes restricted breathing, or lung collapse. On occasion, pleural effusion is found at a regular check up. Most often the issue is diagnosed at a time of respiratory distress. If you start to notice laboured breathing in your dog, or if your dog is having trouble keeping up his normal activity level, a veterinary visit is advised without delay.

Fluid in the chest in dogs is known in veterinary terms as pleural effusion. It's expected that there is a very small amount of fluid in the pleural space; but if there is a problem with drainage or an excess of production, the accumulation of fluid can cause a crisis situation for your pet.

Fluid in the chest is a somewhat common reason for abnormal respiratory function in dogs. Often resulting from an underlying condition, pleural effusion can cause the following symptoms:

Early pleural effusion meaning only a small amount of fluid has begun to accumulate:

• Showing a low tolerance to activity and exercise
• Lethargy and lower energy level than usual

Increasing pleural effusion as respiratory affliction is proliferating:

• Rapid breathing (tachypnea)
• Difficulty breathing (dyspnea)
• Extension of neck as if trying to reach air
• Sitting or lying in an unusual position in an attempt to ease breathing
• Blue or pale gums, lips, or tongue (cyanosis) due to lack of oxygen in the blood
• Low body temperature (hypothermia)
• Shock

Depending on the underlying cause of the fluid accumulation, you may see fever, weight loss, mental dullness, depression, pale gums, or other symptoms that accompany the disorder.

Types

The types of fluid in the chest in dogs are classified in the following ways:

• Hydrothorax - (noninflammatory transudate) due to increased hydrostatic pressure, brought on by an elevated cell and protein content or decreased oncotic pressure, brought on by low albumin in the blood.
• Chylothorax - milky lymphatic fluid and chylomicrons containing a high concentrate of triglycerides accumulate.
• Hemothorax - blood accumulates in the pleural cavity.
• Pyothorax - accumulation of fluid due to an infection or growth.

Fluid in the chest in dogs is a relatively common complication. There are a plethora of reasons that can lead to the accumulation of fluids; some of which are listed below:

• Hydrothorax - liver disease, malnutrition, malabsorption, right-sided heart failure, burns, chronic hemorrhaging, protein-losing nephropathy (kidney disease), protein-losing enteropathy (intestinal disease).
• Chylothorax - cancer, chronic vomiting, diaphragmatic hernia, twisted lung lobe, blood clot in chest veins, congenital defects.
• Hemothorax - trauma, lymphoma, pulmonary and chest wall tumors.
• Pyothorax - penetrating wounds, infection,  pulmonary thromboembolism, heartworm, pneumonia, esophageal disease, complications from an underlying condition such as lupus or rheumatoid arthritis.

The veterinarian will begin the process of diagnosis after requesting a brief history from you in regards to your pet’s recent behavior and apparent health. Be sure to be as accurate and complete as possible in relaying information to the veterinarian. There are many diagnostic procedures used to identify this condition, and any information you can initially provide is extremely helpful.

Chances are, the veterinarian will hear muffled sounds in the lungs through the use of a stethoscope. Palpation of the abdomen may show pain is present. She may then decide to perform additional tests in order to pinpoint the cause of the problem.

A chest x-ray can reveal an accumulation of fluid in the thoracic cavity, and may show possible lung collapse, or evidence of heart disease or the growth of a tumour. Fluid may be obtained from the chest with the use of a needle, which is necessary when proceeding to identify the type of fluid in the chest. Draining the fluid away also forms part of the treatment plan. An ultrasound of the chest, and often including the abdomen, will be done to show the condition of the lungs and other organs. An ultrasound is also helpful when determining where the needle should be placed for removal of fluid.

A complete blood count, chemistry profile, and fungal titers test may be done, as well as a heartworm test. Results may show abnormalities in glucose, albumin or liver enzyme levels, for example. Urinalysis may show proteinuria. A coagulation profile may be done as well. Information from all of the completed tests will be used to determine the type and cause of the fluid buildup.

In order to resolve the issue of fluid in the chest, the cause, whether it be sudden or due to an underlying disease, must be determined. As an example, cancer will be additionally treated with chemotherapy and radiation after the fluid in the chest has been drained. Another example would be the need to treat and eliminate an infection through the use of antibiotics.

To start treatment for pleural effusion, the veterinarian will provide oxygen therapy in order to make your dog more comfortable. The chest will be drained by the insertion of a needle, along with suction through the placement of a chest drain. This may need to be in place for a few days.

Intravenous fluids may be required if your pet is dehydrated. At times, a surgical exploratory thoracotomy may be necessary to investigate the cause of the fluid buildup. A thoracotomy may be necessary for draining, or to perform a correctional procedure. Radiographs will be part of the treatment because it will be important to monitor how the chosen therapy is working.

The prognosis of recovery will range from good to poor, depending on the cause and whether a serious underlying disease is found. If surgery was part of the treatment, your dog might remain in the hospital for 3 to 5 days, and the chest tube will need to remain in place until the fluid accumulation problem is under control.

When released from the hospital, your pet may require additional pain medication and/or antibiotics. Follow up appointments are an important part of the treatment for pleural effusion; radiographs and ultrasounds are often repeated to ensure that recovery is continuing.

The veterinarian will recommend any dietary changes required(such as a low fat, low sodium diet), and will advise you on exercise restrictions and for how long leash only outings are mandatory.