Pericardial Effusion In Dogs

The pericardium is a double-layered, fibro serous structure that separates the heart from the remaining mediastinal structures. The 2 pericardial layers are separated by a pericardial cavity that is filled with a lubricating serous fluid that provides lubrication and minimizes the friction generated by the heart as it contracts.

Pericardium provides mechanical protection for the heart while also having a considerable hemodynamic effect on the atria and ventricles. The pericardium is not that mandatory for normal cardiac function - however, affected pericardium presenting clinically as chronic or acute/recurrent pericarditis, pericardial constriction, cardiac tamponade, and pericardial effusion can be life-threatening and can be challenging to manage.

The etiology of most the pericardial diseases remains idiopathic or it is often varied and complex to determine.

Thankfully, most of the dogs are not severely affected. This condition is rare in dogs, accounting for less than 2% of all congenital heart defects. Most dogs live have few or no symptoms and many have normal life spans.

General symptoms of the pericardial disease:

• Signs of Congestive Heart Failure (CHF) may be present.
• Sudden onset, Retrosternal, and Pleuritic Chest Pain.
• Exercise Intolerance
• Increased Respiratory Rate
• Cyanosis
• Intermittent Cough / Rapid tiring or Fatigue.
• Fluid accumulation in the lungs (pleural effusion), within the lungs (pulmonary edema), and abdomen (ascites) / abdominal swelling.
• Increased Breathing Rate

Treatment is not required for acute cases of dogs that are asymptomatic and those that have a good quality of life. Long-term management of pericardial conditions depends on the underlying cause.

Surgery in dogs is riskier and rarely done with conditions that aren’t life-threatening though surgery is routine in humans with pericardial conditions. You may go for frequent check-ups to assess if the problem is getting worse.

Pericardiocentesis: Also called pericardial tap, this procedure is done to pull out fluid from the pericardial sac using a catheter and a syringe. Sedatives and local anesthesia might be used during this process to keep your pet comfortable. After the fluid is removed, a short course of a diuretic may be recommended to clear if any fluid has accumulated in the dog’s belly. The success rate of pericardiocentesis is high and almost 70% of dogs that undergo this procedure have no negative reports.

Partial or Subtotal Pericardiectomy: Performed by a thoracoscopy, this surgical procedure is done to remove pericardium and allow fluid to drain into the thoracic cavity. Moreover, neoplasia present in the pericardium will also be removed.

If malignant or infectious causes are diagnosed, therapy will be aimed at managing that disease.

Talk to Your Veterinarians and understand your pet’s treatment options.

• Pain can be so subtle in dogs - access your dog’s pain and watch out for any abnormal behavior.
• Don’t forget even sick dogs need a few low-stress activities and a lot of rest.
• Work with your vet to find the optimal dietary plan for your dog.
• Home remedies such as herbs, diet, and exercise will depend on your dog’s age and stage of the disease they are in.

Prevention of pericardial diseases is not possible as there is a variety of reasons. There is also a hereditary angle in certain cases. Dogs with pericardial diseases including first-degree relatives (littermates and parents) should not be bred so as to avoid passing the condition on to the next generation.

Screening of highly affected breeds prior to breeding is strongly recommended.

Golden Retriever, Saluki, German Shepherd, Boxer, Bulldog, Boston Terrier, French Bulldog, Afghan Hound, Weimaraner.

There is no sex predisposition.

1. Causes:

• Idiopathic (85-90%)
• Bacterial/Viral Infections
• Systemic Illnesses, including Neoplasia
• Autoimmune Disease (5%)
• Connective Tissue Disease
• Renal Failure
• Previous Cardiac Surgery/ Previous Myocardial Infarction
• Trauma
• Aortic Gissection
• Radiation
• Usage of certain drugs

2. Types:

Chronic Pericarditis: This is a long-lasting, inflammation of the pericardium that develops over time and causes permanent thickening and scarring of the pericardium. Chronic type is rare and it is usually preceded by acute pericarditis.

Acute Pericarditis: Acute type is the most frequent among the pericardial syndromes with multifactorial aetiology. Acute pericarditis is of two types:

1. Infectious Causes: Viral causes, Bacterial causes, and Fungal Infections (rare).
2. Non-infectious Causes: Metabolic Diseases (such as myxedema, Uremia); connective tissue disease (such as rheumatoid arthritis, Behçet’s disease, and systemic lupus erythematosus).

• Recurrent Pericarditis: One of the most troublesome complications after an episode of acute pericarditis is recurrent pericarditis in which pericarditis relapses after discontinuation of treatment. This usually happens in dogs with systemic autoimmune disorders. Recurrence typically occurs in about one-third of acute cases.
• Constrictive Pericarditis: Pericardial constriction can be defined as a syndrome due to the compression of the heart caused by inelastic, thickened, and fused pericardial membranes that limit ventricular filling during diastole. This type of pericarditis is very rare in dogs.
• Cardiac Tamponade: This clinical syndrome is caused by reduced ventricular filling and consequent hemodynamic compromise. This may be acute or subacute.
• Pericardial Effusion: The increased fluid accumulation within the pericardial sac forms a pericardial effusion, which may be purulent, serous, or hemorrhagic, depending on etiology. When the pericardial effusion is large or the rate of accumulation is too rapid, this fluid accumulation may become hemodynamically significant, as the fluid can extrinsically constrict the cardiac chambers restricting diastolic filling and causing cardiac tamponade syndrome.

3. Morbidity:

Incessant/ acute pericarditis last for > 4 to 6 weeks but < 12 weeks.

Chronic Pericarditis is episodes that typically last more than 3 months.

Recurrent pericarditis is defined as an episode of pericarditis that occurs after a symptom-free interval of an acute episode.

4. Mortality:

In general, pericardial diseases are serious and lead to life-threatening complications without proper treatment. Luckily, pericardial diseases are rare in dogs and the mortality rate is less than 2%.

5. Diagnosis:

• A complete blood count (CBC), and chemistry profile.
• X-ray
• Cardiac Biomarker Blood Test - NTproBNP.
• ECG (electrocardiograph) / echocardiogram
• Abdominal Ultrasound

6. Differential Diagnosis:

• Angina
• Pneumonia
• Costochondritis
• Acute MI
• Pleurisy
• Bony pain

The overall prognosis of infectious/ acute/ idiopathic pericarditis prognosis is excellent, with most dogs experiencing a complete recovery after appropriate treatment.

Constrictive pericarditis is extremely rare after acute or idiopathic pericardial diseases, occurring in less than1% of cases. In up to 30% of acute pericardial dogs, recurrent pericarditis can occur and this is spot on in cases that are not treated with colchicines.

The most feared acute complication following pericardial disease is cardiac tamponade and it is more frequently encountered in association with infectious causes of pericarditis and malignancy.

For chronic constrictive pericarditis, the only possible cure is the surgical removal of the pericardium. Surgery is successful in 85% of chronic dogs.

The typical approach for this condition is no treatment is needed until symptoms are noted.

Treatment for pericardial diseases varies according to the presence of other heart abnormalities and the extent of the defects.

For young, otherwise healthy dogs with a life-threatening defect, surgery may be effective but this will depend on the recommendation of a veterinarian.

Dietary management of pericardial diseases in dogs.

• Sodium or salt should be limited to help reduce fluid accumulation.
• Foods that tend to be high in salt should be cut off. snack foods (crackers, chips, pretzels, etc.), pizza, bread, cheese, other dairy products, etc.
• In diets elevated in protein (>100 grams per 1000 calories) at least 30% meat-based protein (on a dry matter basis) is recommended.
• Spicy foods, Greasy, fried foods, and Allergens (gluten, soy, and dairy) should be avoided.
• Omega-3 fatty acids (fish oils).
• Vitamin E, B-Vitamins, co-enzyme Q10, carnitine, and Magnesium supplements.
• Generally, all ingredients should be fresh, easily digested, highly palatable with a good smell, and should be highly bioavailable.

The prognosis for pericardial disease in dogs depends on its severity and how early it was treated. The survival rate for dogs that undergo surgical repair for idiopathic pericardial diseases is good.

Obviously, recurrence of pericardial diseases is not possible after surgical procedures. Many dogs can live normal lives if they are without any other complications. Dogs with mild symptoms can be managed with medications.