Understanding heart failure in dogs
Heart failure in dogs is a condition where the heart can no longer pump blood as efficiently as the body needs. This does not mean the heart has stopped working, but that it is struggling to keep up with the demands placed on it.
How a normal heart pumps blood around the body:
Heart failure usually develops as a result of underlying heart disease. With appropriate treatment and monitoring, many dogs can live comfortably for months or even years after diagnosis.
What causes heart failure in dogs?
The most common causes of heart failure in dogs include:
- Mitral valve disease – particularly common in small and medium breeds
- Dilated cardiomyopathy (DCM) – more common in large and giant breeds
- Congenital heart defects present from birth
- Long-standing heart rhythm abnormalities
Over time, these conditions place increasing strain on the heart, eventually reducing its ability to circulate blood effectively.
What happens in heart failure?
As the heart weakens, pressure builds up in the circulation. This can cause fluid to leak into the lungs or abdomen, leading to breathing difficulties and reduced exercise tolerance.
The body attempts to compensate by activating hormonal systems that temporarily support circulation. While helpful in the short term, these changes eventually worsen heart disease. Many heart medications are designed to counteract these harmful effects.
Common signs of heart failure in dogs
Signs of heart failure may develop gradually and can be mistaken for normal ageing. Common symptoms include:
- Coughing, especially at night or after activity
- Reduced stamina or reluctance to exercise
- Increased breathing rate or effort
- Lethargy or weakness
- Abdominal swelling due to fluid accumulation
- Collapse or fainting in advanced cases
Any of these signs warrant veterinary assessment.
How heart failure is treated
Heart failure cannot usually be cured, but it can often be managed very effectively with medication. Treatment plans are tailored to the individual dog and adjusted over time based on response and disease progression.
Management typically involves a combination of medications that:
- Help the heart pump more effectively
- Reduce fluid build-up
- Limit harmful hormonal effects on the heart
Common medications used in dogs with heart failure
Pimobendan (Vetmedin, Cardisure)
Pimobendan is one of the most important medications used in dogs with heart failure. It increases the strength of heart contractions while also relaxing blood vessels, making it easier for the heart to pump blood around the body.
It is commonly prescribed for dogs with mitral valve disease and dilated cardiomyopathy, and is often introduced before overt heart failure develops.
Pimobendan is available under different brand names. Vetmedin is the original branded product with extensive clinical evidence. Licensed alternatives such as Cardisure contain the same active ingredient and must meet the same regulatory standards.
Diuretics (furosemide, Furosoral, Upcard)
Diuretics are used to remove excess fluid from the body. In heart failure, fluid can build up in the lungs or abdomen, making breathing difficult and reducing comfort.
Commonly used diuretics in dogs include:
- Furosemide – a fast-acting diuretic widely used in heart failure management
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Furosoral - an alternative version of furosemide.
- Upcard – a tablet containing torsemide that may be easier to administer in some dogs and can be useful in cases that stop responding to furosemide.
ACE inhibitors and related medications (benazepril, spironolactone)
ACE inhibitors and related medications help counteract hormonal changes that worsen heart disease over time. These hormones initially support circulation but ultimately increase strain on the heart.
Common medications in this group include:
- Benazepril – an ACE inhibitor used to reduce cardiac workload
- Prilactone – a spironolactone-based medication providing additional heart protection
These medications are often used alongside pimobendan and diuretics as part of a comprehensive treatment plan.
Living with a dog with heart failure
With appropriate treatment and monitoring, many dogs with heart failure can enjoy a good quality of life. Regular veterinary check-ups allow medications to be adjusted as the condition changes.
Owners play a key role by:
- Giving medication consistently
- Monitoring resting breathing rate
- Watching for changes in appetite, energy, or coughing
- Seeking veterinary advice promptly if symptoms worsen
Tracking resting respiratory rate at home
Monitoring your dog’s resting respiratory rate is one of the simplest and most reliable ways to spot early changes in heart disease.
