Pulmonary Hypertension in Dogs: Vet’s 2025 Guide to High Lung Pressure, Causes & Care 🐶❤️🩺 

By Dr. Duncan Houston BVSc

Hello—I’m Dr Duncan Houston BVSc, veterinarian and Ask A Vet founder. Pulmonary hypertension (PH) is high blood pressure in the lung vessels. It's uncommon but serious, and often linked to underlying diseases. In this vet‑approved guide, I explain:

• What PH is and how it affects the heart and lungs
• Common signs you might notice
• Primary vs secondary PH and typical causes
• How vets diagnose PH
• Medical treatments and lifestyle strategies
• Monitoring, prognosis, and Ask A Vet tracking tools

1. What Is Pulmonary Hypertension?

PH develops when blood pressure in the lung vessels is abnormally high. That pressure strains the right side of the heart, reducing oxygen flow and potentially leading to right-sided heart failure.

2. Signs & Symptoms

• Exercise intolerance or weakness
• Coughing, rapid or labored breathing
• Fainting episodes (syncope)
• Distended abdomen (ascites), cyanotic gums
• Lethargy, weight loss, sudden collapse

3. Causes: Primary vs Secondary PH

Primary (idiopathic) PH is rare. Most cases are secondary to other conditions :

• Heartworm disease—worms blocking vessels
• Left-sided heart disease—e.g. valve disease, cardiomyopathy
• Pulmonary disease—chronic bronchitis, fibrosis, hypoxemia
• Blood clots/tumors—pulmonary thromboembolism
• Other causes: congenital shunts, parasites (Angiostrongylus), multifactorial

4. Diagnosing PH

• Physical exam: loud heart sounds, ascites, cyanosis
• X‑rays: enlarged pulmonary arteries, right heart changes
• Echocardiography: gold standard—measures pulmonary pressures and heart structure
• ECG: may show right-sided enlargement
• Biomarkers: NT‑proBNP and troponin may help assess severity

5. Treatment & Care

• Treat underlying conditions: heartworm therapy, diuretics for heart failure, anticoagulants for clots, inhalers/anti‑inflammatories for lung disease
• Vasodilators: sildenafil (Viagra), tadalafil, pimobendan improve blood flow 
• Supportive care: oxygen therapy, low-stress rest, weight management

6. Monitoring & Prognosis

Monitoring is based on clinical signs, re‑echocardiograms, and radiographs. Without treatment, prognosis is poor. With sildenafil, median survival improved to ~3 months, with some living up to 2 years. Prognosis varies by cause, disease severity, and response to therapy.

7. Ask A Vet: How We Help You

• Log breathing effort, exercise tolerance, weight & appetite
• Track medication schedules, dosage changes, side effects
• Set reminders for echo/radiograph rechecks
• Receive alerts for signs of worsening (cough, fainting, ascites)

📌 Final Thoughts from a Vet

Pulmonary hypertension is a serious and potentially life-threatening condition—but early detection, treating underlying disease, and targeted therapies can significantly improve your dog’s comfort and lifespan. With Ask A Vet’s monitoring and reminders, you’ll stay proactive and responsive to changes. Together, we’ll support your pup’s journey with clarity, confidence, and care. 🐾❤️