Today, our Huntersville veterinary team explains a bit about ECGs for dogs and cats, when your vet will order one, and how to understand the results so that you can informed decisions regarding your pet's health care.
What is a cat or dog ECG?
An ECG, or as it is sometimes called an EKG, stands for electrocardiogram. This is a test that is used to monitor the heart. Little sensors are attached to the skin and they monitor electrical activity to give a representation of what the heart is doing. This is a non-invasive way of observing the heart in pets and people.
What information does an ECG give your veterinarian about your pet?
An ECG tells your vet several things about your pet's heart. It gives the rate and the rhythm of the heartbeat along with an understanding of the electrical impulses that are going through each section of the heart.
A typical ECG will consist of a pattern where it will be a small bump that rises up called the P wave, then a large spike upward called the QRS complex, and then another small bump called the T wave.
The P wave represents the atria contracting. The QRS complex is where the ventricles depolarize (The large contraction of the heart that is the typical heartbeat). And The T wave in the ventricles is repolarizing.
The important data your vet will be looking for is that the shape of the wave is correct and the distance between the various parts of the wave. Often the concerns are the information provided by the PR interval and the QRS complex interval. These tell how fast the heart is taking in blood and how fast it is pumping it.
The next major information is to look at the peaks of the QRS complex (the big spike) and measure the distance between them. If they are a constant distance between the spikes you have a regular heartbeat (normal dog or cat ECG) if the distance between spikes varies your pet has an irregular heartbeat.
Last but not least you can read how many QRS complexes there are and calculate how many there are over a time interval and you will have the heart rate.
When an ECG is done, you can see that the rate and rhythm of cats and dogs can vary between pets. So, what is a normal dog ECG or cat ECG? Your veterinarian will be sure to provide you with the expected values for your animal companion.
Is having an ECG test safe for pets?
Yes, ECG tests are safe. ECG is a non-invasive diagnostic test that passively monitors the heart.
When would a vet recommend a dog or cat ECG?
Some examples of when a vet may order an ECG test are:
Abnormal Cardiovascular Physical Exam
Cardiac murmurs, gallop sounds, and arrhythmias are just a few of the obvious physical exam abnormalities that call for an echocardiogram. This is frequently an indication of diastolic dysfunction in dogs and cats, and an echocardiogram is always recommended. The intracardiac or extracardiac disease can cause arrhythmias. An echocardiogram can help rule out primary cardiomyopathy and/or infiltrative cardiac disease, which could be the cause of the arrhythmia. The echocardiogram also aids in determining the best anti-arrhythmic therapy for each patient.
Breed Screening
Many dogs and cat breeds are genetically predisposed to heart disease. Auscultation by a board-certified cardiologist is sometimes recommended to rule out the presence of a murmur. If a murmur is detected, an echocardiogram is recommended for a complete evaluation. However, in some breeds, an echocardiogram is always recommended to screen for heart disease.
Thoracic Radiographic Changes
On radiographs, cardiomegaly can be caused by cardiac enlargement, pericardial fat accumulation, and/or patient variability. An echocardiogram is the most specific tool for determining the size of each cardiac chamber and is extremely helpful in determining the cause of radiographic cardiomegaly. For congestive heart failure and pulmonary hypertension, the echocardiogram is highly specific and sensitive.
Feline Echocardiography
Cats are particularly difficult as cardiology patients to treat because they can have severe cardiomyopathy despite the absence of physical exam abnormalities, radiographic changes, and/or clinical signs. In many cases, an echocardiogram is the only diagnostic test that is both specific and sensitive for heart disease in cats. Because purebred cats have a higher incidence of heart disease, echocardiographic evaluation is frequently high yield in these patients. If this test reveals that the patient has suspected heart disease, an echocardiogram is recommended to confirm the presence of heart disease and determine the patient's therapeutic needs.
Pre-Anesthetic Evaluation
Before placing a dog or cat under anesthesia, it can be helpful to obtain a complete understanding of the patient’s cardiovascular status.
How much is an ECG for a dog or cat?
The cost of your pet's ECG will depend on a variety of factors ranging from the size of your pet to where your veterinarian is located. Because prices vary so widely across North American the only way to get an accurate estimate of the cost of your pet's ECG is to speak to your veterinary hospital to request an estimate.
Most veterinary clinics are happy to provide clients with a breakdown of fees related to any service they provide, and your team of veterinary professionals will be able to answer any questions you may have about your pet's health or any testing that has been recommended.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.