DOGS AND CATS · OWNER EDUCATION
Heart Disease
Heart conditions can involve valves, heart muscle, electrical rhythm or fluid-related complications; dog and cat warning signs are not identical.
THE SHORT VERSION
Understanding supports better veterinary conversations.
Heart disease describes several different conditions rather than one diagnosis. Dogs commonly develop certain valve disorders, while cats may develop heart-muscle disease; electrical rhythm problems can occur in either species.
What is this condition?
Heart disease describes several different conditions rather than one diagnosis. Dogs commonly develop certain valve disorders, while cats may develop heart-muscle disease; electrical rhythm problems can occur in either species.
Which animals can be affected?
Risk factors, examination findings and management can differ between species and individual patients.
Why can it happen?
- Valve degeneration, heart-muscle disease, congenital abnormalities or rhythm disorders.
- High blood pressure, endocrine disease or other conditions can affect heart function.
- Age, breed and individual history change risk.
What might an owner notice?
- Coughing, reduced exercise tolerance, fainting or abnormal breathing.
- Cats may show subtle lethargy, rapid breathing or sudden weakness without a cough.
- Severe cases can involve fluid accumulation, collapse or painful blood clots.
How is the problem investigated?
- Physical examination, chest radiographs, electrocardiogram and blood pressure when indicated.
- Echocardiography to evaluate heart structure, valves and function.
- Laboratory testing and specialist consultation depending on the clinical question.
What might treatment involve?
- Medication and activity guidance selected for the specific heart condition.
- Emergency oxygen or hospital care when breathing is compromised.
- Monitoring of symptoms, heart structure, rhythm and other organs when recommended.
This is an overview, not a prescription or a recommendation for a specific individual animal.
What can owners do at home?
- Track resting breathing, appetite, energy and prescribed medication use.
- Know the clinic’s emergency instructions for respiratory distress or collapse.
- Keep follow-up imaging and laboratory appointments.
Avoid actions that could make care less safe.
- Do not force exercise or give human heart medications.
- Do not delay care for open-mouth breathing, blue gums or sudden limb weakness.
- Do not give human medications, leftover prescriptions or supplements without veterinary approval.
- Do not stop, increase, decrease or double prescribed medication without contacting your veterinary team.
- Do not delay assessment if symptoms are worsening, the animal stops eating or an emergency sign appears.
What can the longer-term outlook involve?
Heart-disease prognosis depends on the exact diagnosis, severity, presence of congestive failure or rhythm problems, and the animal’s response to treatment.
Can risk be reduced?
- Keep recommended wellness and heartworm prevention appointments.
- Discuss murmurs, breed-associated concerns and abnormal breathing promptly.
When should you arrange care?
- Call for new cough, reduced stamina, fainting or changes in resting breathing.
Seek emergency veterinary care if you notice:
SEEK EMERGENCY VETERINARY CARE- Difficulty breathing, open-mouth breathing in a cat, blue or pale gums, collapse or sudden severe painful weakness of a limb.
Sources behind this guide
American Animal Hospital Association veterinary guidelinesPrimary veterinary or veterinary-university guidance ↗Cornell University: hypertrophic cardiomyopathy in catsPrimary veterinary or veterinary-university guidance ↗Content last reviewed: August 23, 2026. Review status: veterinary-informed; independent veterinarian review not yet completed.