🫁 Pulmonary Hypertension in Dogs and Cats: A 2025 Vet Guide to High Lung Pressure 🐶🐱

By Dr Duncan Houston, BVSc

Pulmonary hypertension (PHT) is high blood pressure in the arteries of the lungs. It’s a serious and often secondary condition that puts strain on the right side of the heart. In this detailed 2025 guide, I’ll walk you through everything you need to know about PHT in dogs and cats — from symptoms and diagnosis to treatment and outcomes. 🩺

💡 What Is Pulmonary Hypertension?

PHT is a condition where the blood pressure in the lung arteries is too high. This puts stress on the right side of the heart and can eventually lead to right-sided heart failure. 🫀

🧬 Most cases are caused by other diseases (secondary PHT), though some are idiopathic (primary, with no known cause).

🐾 Who’s Affected?

• 🐶 Dogs are affected far more commonly than cats
• 🧬 Any breed or age can be impacted
• 🎯 Often related to heart or lung disease

📋 What Causes Pulmonary Hypertension?

PHT can result from a variety of conditions. Vets categorize it into six main groups:

1️⃣ Group 1: Pulmonary Arterial Hypertension

• 🔹 Primary (idiopathic)
• 🔹 Heritable (genetic)
• 🔹 Left-to-right heart defects (e.g., PDA, VSD, ASD)

2️⃣ Group 2: Left-Sided Heart Disease

• 🫀 Mitral valve disease
• 🫀 Dilated cardiomyopathy
• 🫀 Left atrial obstruction

3️⃣ Group 3: Respiratory Disease or Hypoxia

• 😤 COPD, bronchial collapse, or tracheal issues
• 🌬️ Pulmonary fibrosis, pneumonia
• 🏔️ High-altitude exposure
• 🛌 Severe sleep apnea

4️⃣ Group 4: Pulmonary Embolism or Thromboembolism

🩸 Clots or fat block vessels in the lungs, often from trauma or implanted heart devices.

5️⃣ Group 5: Parasitic Diseases

• 🪱 Heartworm (Dirofilaria immitis)
• 🪱 Lungworm (Angiostrongylus vasorum)

6️⃣ Group 6: Multifactorial/Other Causes

• 📉 Tumors compressing arteries
• 📊 Multiple disease processes in combination

🔍 What Are the Signs of Pulmonary Hypertension?

Symptoms depend on the severity of the hypertension and any underlying diseases. Mild cases may have no signs at all. 🕵️

🚨 Common Signs:

• 😮‍💨 Shortness of breath (especially during activity)
• 😵 Fainting or collapse (syncope)
• 🥴 Wobbliness or weakness (ataxia)
• 🫁 Bluish gums (cyanosis)
• 📦 Distended abdomen from fluid buildup (right-sided CHF)

🔈 Additional Clues:

• 🔊 Heart murmur
• 📢 Crackles or wheezes on lung auscultation
• 🐾 Coughing (from lung disease, not PHT itself)

🧪 How Is Pulmonary Hypertension Diagnosed?

The best tool is a Doppler echocardiogram (ultrasound of the heart), typically performed by a veterinary cardiologist. This non-invasive test allows visualization of heart and lung pressures. 🫀🔍

❗ Note: Pulmonary hypertension is different from regular (systemic) hypertension and can’t be diagnosed with a standard blood pressure cuff.

💊 How Is It Treated?

⚡ Acute (Sudden) Cases

• 💨 Oxygen therapy (home cages can help)
• 🛌 Strict rest
• 💧 IV fluids and medications to stabilize

🕒 Long-Term Management

• 💊 Sildenafil citrate (Viagra®)
• 💊 Tadalafil (Cialis®)
• 💊 Pimobendan for heart support

🧪 Newer human drugs like bosentan or iloprost are effective but often too expensive for veterinary use.

🏹 Target the Underlying Cause

If secondary to heartworm, heart failure, embolism, or lung disease, addressing those conditions may lower pulmonary pressure. 🎯

💤 Mild Cases

Mild to moderate PHT often doesn’t require treatment unless symptoms appear. 😌

📉 Prognosis: What to Expect

• 🕊️ If diagnosed early and managed, dogs can live for months to years
• 📉 Severe PHT can cause sudden death
• 📊 One study showed 84% survived 6 months after treatment started; 73% survived 1 year

📱 Support with Ask A Vet

Managing pulmonary hypertension requires close care. With the Ask A Vet App, you can:

• 💬 Get 24/7 advice from licensed veterinarians
• 📋 Track medications like sildenafil and oxygen needs
• 📈 Monitor breathing, exercise tolerance, and appetite

Visit AskAVet.com or download the app for tailored support. 🐶📱

🧠 Final Thoughts from Dr Duncan Houston

Pulmonary hypertension is a serious and often hidden condition — but it’s not hopeless. Many dogs and cats do well with proper medication, activity restrictions, and underlying disease management. 🫁🐾

Trust your veterinary team. Monitor symptoms. And rely on Ask A Vet for support in every step of your pet’s journey. ❤️