🫀 Vet Guide to Congestive Heart Failure in Dogs and Cats: Symptoms, Diagnosis & Care in 2025 🐾

By Dr Duncan Houston, BVSc

Congestive heart failure (CHF) is a life-threatening condition in pets where the heart can no longer effectively pump blood, causing fluid to accumulate in the lungs, chest, or abdomen. With earlier detection and advances in veterinary care, managing CHF has improved—but understanding the signs and acting quickly remains vital. In this 2025 guide, we explore what CHF is, why it happens, symptoms to recognize, how it's diagnosed, and how to care for a pet living with heart failure. 🩺🐶🐱

What Is Congestive Heart Failure? 🧠

CHF is the accumulation of fluid in specific body areas due to failing heart function. This fluid buildup is influenced by which side of the heart is affected:

• 💔 Left-sided CHF: Fluid accumulates in the lungs (pulmonary edema) or chest cavity (pleural effusion)
• ❤️ Right-sided CHF: Fluid builds in the abdomen (ascites) or chest cavity, occasionally in limbs or skin

CHF results from high pressure in veins and capillaries that drain into the heart. Think of it like a garden hose: too much pressure, and fluid leaks out—flooding the surrounding area. 🪣

What Causes CHF in Pets? 🩻

CHF only occurs when the heart disease is severe enough to elevate internal pressure. Common causes include:

• 🔁 Mitral or tricuspid valve disease – leaking valves overload heart chambers
• 📉 Cardiomyopathies: Dilated (dogs) or hypertrophic (cats)
• 🫀 Pericardial disease: Restricts heart expansion (affects right side)
• 🐛 Heartworm disease: Can block blood flow, affecting right side
• 🧬 Congenital heart defects: e.g., patent ductus arteriosus, septal defects

Note: Diseases that obstruct blood outflow (like pulmonic or aortic stenosis) typically do not cause CHF. 🧪

Signs of Congestive Heart Failure 📋

Left-Sided CHF (Most Common in Dogs & Cats)

• 😮 Difficulty breathing (dyspnea)
• 📈 Rapid respiratory rate, especially at rest or during sleep
• 🥵 Exercise intolerance
• 🐈 Sudden open-mouth breathing or collapse (more common in cats)
• 🗣️ Coughing – though not always a reliable CHF sign

Right-Sided CHF

• 📦 Abdominal swelling (ascites)
• 🛌 Restless sleep, may sit up to breathe better
• 🍽️ Decreased appetite due to abdominal pressure
• 💨 Pleural effusion (fluid in chest) – causes difficulty breathing

Monitoring your pet’s breathing rate during sleep is one of the best ways to catch CHF early or detect worsening symptoms. 🔍

How Veterinarians Diagnose CHF 🧪

1. Physical Exam

• 🩺 Murmurs, elevated heart rate, and abnormal breathing sounds
• 🐱 Cats may have low body temperature if in advanced CHF

2. Imaging

• 🩻 Chest X-rays: Detect enlarged heart and fluid in lungs or chest cavity
• 🖥️ Echocardiogram: Confirms heart structure/function (performed by specialists)

3. Blood Tests

• 🧬 Evaluate kidney function and monitor medication safety

CHF diagnosis involves both identifying fluid accumulation and confirming severe heart disease. 🧠

Treatment of Congestive Heart Failure 💊

1. Treat Underlying Cause (If Possible)

• 🔧 Surgery to close PDA or repair valves (expensive, limited availability)

2. Diuretics – Mainstay of CHF Management

• 💧 Furosemide or Torsemide: Loop diuretics that remove excess fluid
• 📉 Reduce vein pressure and lung/abdominal fluid buildup

3. Additional Medications

• 💗 Pimobendan: Improves heart contractility and output
• 🧪 ACE inhibitors: Lower blood pressure and reduce strain
• 💊 Spironolactone & Thiazide diuretics: Used in combination therapy

4. Fluid Tapping (Right-Sided CHF)

• 💉 Manual removal of abdominal fluid via catheter
• ⏱️ May be required every 1–2 weeks
• 🧘 Improves comfort and breathing dramatically

Monitoring CHF at Home 📈

Daily or weekly checks of your pet’s resting respiratory rate (RRR) while sleeping are vital:

• 📏 Normal RRR: Less than 30 breaths/minute at rest
• ⚠️ Consistently above 35 → contact your vet

💡 Tip: Use a smartphone timer to count chest rises for 15 seconds, then multiply by 4. Keep a log. 📓

Veterinary Monitoring Includes:

• 🧪 Routine blood tests for kidney/liver function and electrolytes
• 🩻 Follow-up x-rays or ultrasound if symptoms worsen

Prognosis for Pets with CHF 🧾

CHF is a progressive condition—but with treatment, pets can enjoy quality time. Prognosis depends on the underlying disease and response to therapy:

Dogs (Mitral Valve Disease)

• ⏳ 50% live 8–10 months
• ⏳ 20% live 18–24 months

Cats (Hypertrophic Cardiomyopathy)

• ⏳ 50% succumb within 7–10 months

Some pets live far longer than average with dedicated care, early detection, and proper medication. 💖

Final Thoughts from Dr Duncan Houston 👨‍⚕️

Congestive heart failure is not the end—it’s a condition that, when treated properly, can allow pets to enjoy many more happy months or years. By recognizing symptoms early, keeping a close eye on respiratory rate, and sticking to your vet’s plan, you become your pet’s most powerful ally.

Need guidance or a second opinion on CHF care? Visit Ask A Vet or download the Ask A Vet app to speak with a licensed veterinarian anytime. 🐾📱