Heart disease and heart failure in pets

Heart disease and heart failure are common conditions seen daily in veterinary practice. They most often affect small-breed dogs such as Yorkshire Terriers, Dachshunds, Chihuahuas, and Miniature Pinschers, but cats, large-breed dogs, and even younger animals can also be affected.
Because small dogs tend to live longer, heart disease becomes increasingly prevalent with age.

While degenerative heart conditions cannot be cured, they can often be successfully managed with medication, allowing many pets to live comfortably for years with a good quality of life.

 

Common Heart Conditions in Dogs

1. Mitral Valve Disease (MVD)
The most common heart disease in small breeds (e.g., Cavalier King Charles Spaniels, Dachshunds).
The mitral valve gradually degenerates, allowing blood to flow backward from the left ventricle into the left atrium during contraction. Over time, this causes the heart to enlarge and work harder.

2. Dilated Cardiomyopathy (DCM)
Seen mostly in large breeds such as Dobermans, Boxers, and Great Danes.
The heart muscle becomes weak and stretched, reducing its pumping efficiency.

3. Congenital Defects
Present from birth. Common examples include:

• Patent Ductus Arteriosus (PDA): The ductus arteriosus fails to close after birth, allowing blood to flow from the aorta into the pulmonary artery.
• Pulmonic Stenosis: Narrowing of the pulmonary valve obstructs blood flow.
• Aortic Stenosis: Narrowing of the aortic valve restricts blood leaving the heart.

4. Toxic Causes
Certain substances can damage the heart, including:

• Chocolate (especially dark chocolate)
• Xylitol
• Caffeine
• Some chemotherapeutic drugs and insecticides
• Certain plants

 

Common Heart Conditions in Cats

1. Hypertrophic Cardiomyopathy (HCM)
The most common feline heart disease, particularly in breeds like Maine Coons and Ragdolls.
The heart muscle becomes abnormally thick, reducing its ability to fill properly.

2. Restrictive Cardiomyopathy (RCM)
Less common. The heart muscle becomes stiff and less flexible, restricting normal filling.

3. Congenital Defects
Rare but possible, such as ventricular or atrial septal defects (holes in the heart’s dividing wall).

4. Toxins
Similar to those affecting dogs.

 

General Symptoms of Heart Disease

• Coughing (often worse at night) due to fluid in the lungs
• Exercise intolerance or reduced stamina
• Laboured or rapid breathing (sometimes seen as abdominal breathing)
• Panting at rest
• Fainting or collapse
• Weakness or staggering

Dog-Specific Symptoms

Dogs usually show obvious signs, especially those living closely with their owners:

• Persistent cough (often worse at night or after exercise) – may sound like a throat-clearing “choking” noise, often mistaken for kennel cough.
• Fatigue or collapse – sometimes confused with seizures.
• Difficulty breathing or panting without heat or exertion.
• Enlarged abdomen (fluid buildup) – typically a sign of late-stage disease and often mistaken for bloating.

Cat specific symptoms.

Cats are a lot more subtle, possibly due to their independent way of life or their need to hide their symptoms. 

•  Rapid or laboured breathing. Abdominal breathing more evident in cats.
•  Lethargy – this can be difficult to identify especially in older individuals and low       energy cats.
•  Hiding or avoiding activity – can also be hard to pinpoint.
  
•  Sudden hind leg paralysis (from blood clots) causing pain and distress. This         symptom is more obvious but not a common sign.  

 

 

Diagnosis

Your veterinarian will perform several tests to identify the type and severity of heart disease and to tailor an appropriate treatment plan.

• Auscultation: Detects heart murmurs, arrhythmias, or fluid in the lungs.
• Chest X-rays: Show heart enlargement or pulmonary edema.
• Echocardiography (ultrasound): The gold standard for evaluating valve function, chamber size, and blood flow.
• Electrocardiogram (ECG): Detects irregular rhythms.
• Blood pressure measurement: Important in cats, as hypertension worsens heart disease.

 

Treatment and Management

Heart disease is generally managed, not cured (except for some surgically correctable congenital defects).
Treatment aims to support the heart, reduce symptoms, and delay progression to congestive heart failure (CHF)—a stage where the heart can no longer pump efficiently, leading to fluid buildup in the lungs or abdomen.

 

Medical Management

• Pimobendan: Improves heart muscle strength and reduces strain.
• ACE inhibitors (e.g., enalapril, benazepril): Lower the workload on the heart.
• Furosemide (diuretic): Removes excess fluid.
• Spironolactone: A mild diuretic with heart-protective properties.
• Cough suppressants: Used in certain cases to ease discomfort.

 

Monitoring at Home

Regular monitoring helps detect changes early so medications can be adjusted.
Watch for:

• Breathing rate and effort
• Cough frequency
• Energy and appetite

Routine veterinary rechecks, echocardiograms, and chest X-rays are crucial for ongoing care.

 

Lifestyle and Supportive Care

• Limit exercise to controlled, gentle walks.
• Keeping weight down is an integral part of maintaining heart patients healthy
• Keep pets cool and calm – use fans or air-conditioning on hot days; placing a damp towel over your dog can help reduce body temperature.
• Avoid stress and excitement.
• Nutritional supplements and herbs may offer support but should be used under veterinary guidance:
• Hawthorn (traditional cardiac support herb)
• Garlic, Ginkgo, Ginseng, and Salvia – may enhance medications
• Omega-3 fatty acids, Vitamin E, Selenium, Magnesium, Carnitine, Taurine
• Lifewave Carnosine patch as heart muscle support

Always inform your vet before introducing supplements, as interactions can occur.

·          

 

Prognosis

Prognosis depends on the underlying condition and how early it’s detected.

• Dogs with mild disease can live for many years with good quality of life.
• Even pets with congestive heart failure can often be managed successfully for months to years.
• Early detection, regular monitoring, and good home care greatly improve outcomes.
• In elderly pets, other age-related conditions may influence prognosis.