How is an echocardiogram performed? — When is it needed and how are the results interpreted?

HeartQ&AMeongsiljang Veterinary Advisory Board

Based on veterinary textbooks, we’ll explain the principles, actual procedure, and essential indications for echocardiography in dogs and cats. We’ve also summarized everything you need to know about pre-exam preparation and costs.

What is an echocardiogram?

A scene of a puppy undergoing an echocardiogram

An echocardiogram is a noninvasive, high-resolution imaging test that uses ultrasound to visualize the heart’s structure, motion, and blood flow in real time. What’s truly important is that it’s the standard test for quickly and safely assessing heart disease. If you hear a murmur on auscultation, notice rapid breathing, or see sudden collapse, an X-ray alone isn’t enough. An echocardiogram is needed for an accurate diagnosis.

When should the test be performed?

Veterinary internal medicine textbooks categorize the indications for echocardiography based on two main criteria: medical history and physical examination. Rather than vaguely suspecting “something is wrong with the heart,” we recommend testing if any of the following signs are present. In the medical history, look for signals such as fainting, exercise intolerance, or a positive test for heartworm. During the physical exam, check for findings like heart murmurs, gallop rhythms, arrhythmias, or rapid breathing.

Fainting/Collapse: Loss of consciousness with no clear cause

Exercise Intolerance: Tiring more easily than usual and panting

Heart Murmur: Detection of murmurs or gallop rhythms during auscultation

Arrhythmia: Irregular heartbeat, or a heart rate that is too fast or too slow

Rapid Breathing/Coughing: Increased respiratory rate even at rest

Positive Heartworm Test: Assessment of cardiac involvement after confirming infection

Do not delay and get tested immediately in these situations

If your pet’s breathing becomes noticeably rapid (tachypnea) at rest, their tongue or gums turn blue (cyanosis), or they suddenly collapse and lose consciousness, this is an emergency. Breeds such as Maine Coons and Ragdolls in cats, and King Charles Spaniels, Dachshunds, and Maltese in dogs, are at higher risk for hereditary heart disease, so an echocardiogram is needed immediately if symptoms appear.

How is the test actually performed?

Echocardiograms are performed with your pet lying on their side. A small area of chest fur is shaved, gel is applied, and the veterinarian scans the heart from multiple angles using a probe.

Duration: Typically 20–40 minutes

Anesthesia: Usually unnecessary (mild sedation may be used if cooperation is poor)

Pain: None — no radiation involved, unlike X-rays

Assessment items: Atrial and ventricular size, valve condition, blood flow velocity and direction, and contractile function

Most pets tolerate the procedure calmly while lying down, and results are available on the same day.

The process of performing an echocardiogram on a cat

Echocardiogram vs. other cardiac tests

Item	Echocardiography	Chest X-ray	ECG
Cardiac structure assessment	True	False	False
Cardiac function measurement	True	False	False
Arrhythmia diagnosis	False	False	True
Pulmonary congestion check	False	True	False
Anesthesia required	Not required	Not required	Not required
Test time	20–40 minutes	5–10 minutes	5–10 minutes

The three tests are complementary and are often performed together when heart disease is suspected.

What owners should prepare before the test

While an echocardiogram doesn’t require special fasting, your pet needs to be calm for us to capture clear images.

Day-of Condition: Keep travel quiet to avoid overexcitement or panting.

Meals: Fasting is generally not required (unless sedation is planned, in which case fast for 4–6 hours).

Records to Bring: Previous X-rays and blood test results.

Notes for the Vet: When symptoms first appeared and what situations seem to worsen them.

Your veterinarian will combine these medical records with the imaging to ensure an accurate diagnosis. Since we don’t rely on images alone, please share your detailed observations.

The owner holding their dog while waiting for the examination

How are the results interpreted after the test?

Right after the exam, the veterinarian will explain how measurements from each part of the heart—such as left atrial size, left ventricular wall thickness, and contractility—compare to normal reference ranges. In dogs, mitral valve insufficiency and dilated cardiomyopathy are common, while hypertrophic cardiomyopathy (HCM) is the most frequent condition in cats. Depending on the results, your vet will recommend monitoring, medication, or further tests like an electrocardiogram (ECG) or blood BNP testing. If you’d like to learn more about managing heart disease, check out our Early Signs of Heart Disease in Dogs Guide.

Breeds and situations requiring regular screening

Even in the absence of symptoms, regular echocardiograms are recommended in certain cases. For Maine Coons and Ragdolls, which may carry the MYBPC3 gene mutation, we recommend starting annual screenings between 1 and 3 years of age if the cat is intended for breeding, followed by re-screening at ages 5 and 8. For breeds at high risk of heart disease—such as Cavalier King Charles Spaniels, Dachshunds, and Maltese (high risk for mitral valve disease), and Doberman Pinschers and Boxers (high risk for dilated cardiomyopathy)—it is advisable to consult your veterinarian about when to begin screening and the appropriate frequency, even during the asymptomatic phase. Pre-breeding health checks are also essential for any dog or cat planned for breeding.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently asked questions

How much does an echocardiogram cost?

Costs vary widely depending on the clinic, location, and scope of testing, so we can’t provide an exact figure. The final price will depend on whether sedation is needed and whether a color Doppler ultrasound is included, so it’s best to contact the clinic directly before your visit for the most accurate estimate.

Is it really possible to perform the test without anesthesia?

Most pets can undergo the examination lying on their side without anesthesia. However, if a pet is extremely anxious or has unstable breathing, we may use mild sedation for safety.

Is it really necessary to shave your pet’s fur?

Ultrasound waves cannot pass through air, so thick fur can blur the images. To ensure a clear view, we shave a small area on each side of the chest—about the size of a palm—and apply ultrasound gel. The fur will grow back within a few weeks.

Does a heart murmur always mean heart disease?

Not necessarily. Heart murmurs can sometimes be heard in healthy pets, much like physiological noise. However, an echocardiogram is needed to accurately determine the cause of the murmur. It’s safest to consider a murmur as a sign that further examination is necessary.

How often should I receive it?

Even healthy dogs may benefit from routine cardiac check-ups, depending on their age and breed. For breeds at higher risk of heart disease, it’s a good idea to consult your veterinarian about when to begin screening. If your dog has already been diagnosed with a heart condition, regular follow-up exams should be performed according to the schedule set by your veterinarian.

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References

[1] Textbook of Cardiovascular Medicine in Dogs and Cats, Echocardiography Chapter

[2] Small Animal Critical Care Medicine, 3rd Ed, Box 43.1 Indications for Echocardiography

[3] Feline Emergency and Critical Care Medicine, 2nd Ed, Focused Cardiac Ultrasound

[4] Clinical Medicine of the Dog and Cat, 4th Ed, Point-of-care Ultrasound