Learn How to Recognize the Early Signs of Heart Disease in Your Dog

Have you ever listened to our dog cough and wondered if it’s just a little tickle or a sign of something far more serious? As loving dog parents, we want the best for our pups. This means we’re constantly on the lookout for trouble, which can sometimes make us a little overly cautious. But when it comes to understanding the early signs of heart disease in dogs, that diligence could save a life.
Early detection allows you and your veterinarian to address the problem sooner, potentially slowing the progression of the disease and giving your best friend many more happy, healthy years by your side.
I understand that the thought of heart disease can be daunting, but knowledge is power! This post will guide you through the information you need to be your dog’s best advocate, including the most common types of heart conditions, early warning signs to watch out for, how heart disease is diagnosed and treated, and most importantly, the proactive steps you can take to support your dog’s heart health and prevent a problem before it starts.
Common Types of Canine Heart Disease
Just like humans, dogs can develop different heart conditions and heart-related illnesses, each with unique challenges and care needs. This ranges from congenital defects that were present at birth to acquired diseases that develop over time (although possibly preventable), negatively impacting the heart’s ability to function correctly.
Here are some of the most common types of heart disease your dog may experience:
Mitral Valve Disease (MVD)
One of the most common heart-related illnesses that dogs may experience is Mitral Valve Disease (MVD), a degenerative condition that affects the heart valve that separates the left atrium and left ventricle (aka the mitral valve). This valve’s job is to prevent blood from flowing backward, keeping blood flow in the body moving as it should. As the valve deteriorates, it may start to leak, allowing blood to flow back into the atrium.
Some small breed dogs are at a higher risk of developing MVD, especially as they get older. This includes Cavalier King Charles Spaniels, Dachshunds, and Chihuahuas.
Dilated Cardiomyopathy (DCM)
Another significant heart condition in dogs that has been gaining attention lately is Dilated Cardiomyopathy (DCM). This occurs when the heart muscle weakens and becomes enlarged, making it difficult for the heart to pump blood effectively.
It has been in the news a lot in recent years as researchers evaluate the potential links between DCM and your dog’s diet. While it was once believed that grain-free diets increased the risk, it was later found that there was no clear link between the two. In fact, many grain-free diets were found to have no link to heart problems at all. New research now focuses less on the absence of grains and more on the ingredients used to replace them.
This condition is more commonly seen in large and giant breed dogs, such as Doberman Pinschers, Boxers, and Irish Wolfhounds.
Congenital Heart Defects
Present from birth, congenital heart defects can range from minor to life-threatening. The term is used to describe abnormalities in the heart’s structure, such as holes in the heart or abnormal blood vessel connections. Early detection is crucial for these conditions as some can be corrected with surgery or other interventions, while others require ongoing management.
Heartworm Disease
Unlike the other conditions on the list, heartworm disease isn’t caused by issues with the heart itself. This parasitic infection occurs when worms live in the heart and lungs, dramatically impacting their ability to function effectively. Heartworm disease is transmitted by mosquitoes.
While it would be nearly impossible to keep your dog mosquito-free throughout their entire life, there are preventative medications that will protect them against heartworms. This is crucial for your dog’s health and well-being, as the worms can cause severe and life-threatening damage to the heart, lungs, and blood vessels, resulting in heart failure and death.
Early Warnings Signs: What to Look or
As I mentioned, recognizing the early signs of heart disease is key for early diagnosis and timely intervention. The sooner your dog receives the necessary veterinary care, the better their prognosis in most cases. Unfortunately, many of these warning signs are subtle and easily overlooked.
Changes in Breathing
One of the most common early warning signs is a change in your dog’s breathing patterns. This could include an increased respiratory rate (tachypnea) or difficulty breathing (dyspnea).
To measure your dog’s respiratory rate, count the breaths they take in one minute while resting. A normal resting respiratory rate for a healthy adult dog is between 10 and 30 breaths per minute. If your dog’s rate is consistently faster than this, especially at rest, it’s a sign that something is medically wrong, and you need to contact your veterinarian.
Difficulty breathing is always a red flag. This can manifest as panting excessively, especially when resting, flared nostrils, or abdominal breathing (where the abdomen moves significantly with every breath). Even if your dog’s difficulty breathing isn’t caused by heart-related issues, it is a medical emergency.
A persistent cough, especially one that sounds wet or hacking, can also be a sign of trouble. A cardiac cough is often worse at night or after any physical activity, as fluid builds up in the lungs, making the issue worse. Of course, not all coughs are connected to heart issues. But if your dog’s cough is persistent and doesn’t go away, you should make an appointment to get to the root of the problem.
Becoming Easily Tired or Lethargic
Have you recently noticed your dog is becoming tired much easier after physical activity? Are they showing less enthusiasm for activities or play that they once enjoyed? As the heart struggles to keep up with the demands of your dog’s body, failing to pump oxygenated blood efficiently, it can decrease their stamina. They may be reluctant to play or even go for walks. In the most severe cases, a dog may faint or collapse after minimal activity.
Changes in Appetite or Weight
Loss of appetite (anorexia) is common among dogs with heart issues, as they may feel nauseous or generally unwell. You may also notice your dog is experiencing weight gain despite not eating as much due to fluid retention. Noticeable swelling of the abdomen, known as abdominal distension, is one of the most evident signs of fluid buildup related to heart failure.
Changes in Behavior
Sudden or uncharacteristic behavior changes are always a sign of trouble. Dogs with heart disease may become restless or anxious, especially at night, due to discomfort or difficulty breathing. They may also hide or withdraw from others, including other pets in the home and even their favorite people. As mentioned, they may also show less interest in their usual routines, like going for their daily walk or playing a favorite game, due to feeling tired and worn down.
Other Subtle Signs of Trouble
In addition to abdominal swelling, as already mentioned, you may notice swelling in the legs (edema) due to fluid accumulation. Pale gums or a blue tinge to the gums are signs of poor oxygenation, which may indicate that the heart isn’t keeping up with pumping oxygenated blood s needed.
Of course, any subtle changes related to your dog’s heart should be taken seriously when discussing heart disease. This includes an unexplainable increased heart rate (not just an increase due to exercise) or an irregular heartbeat.
If you are concerned that something seems “off” or “different,” don’t hesitate to contact your veterinarian. They will be able to discuss those concerns and help you decide if there is a reason to worry or if further testing is needed.
When to See the Vet
The previously mentioned signs should never be ignored. Even the most subtle changes in your dog’s behavior or physical condition could indicate serious underlying heart issues. If you notice any changes to your dog’s breathing, exercise tolerance, appetite, weight, behavior, or any other unusual symptoms, you should schedule an appointment with your veterinarian as soon as possible.
At the appointment, your vet will do several tests to assess your dog’s heart health, including:
- Physical exam: Your vet will listen to the heart for any murmurs or abnormal rhythms. They will also check your dog’s pulse, gum color, and overall condition during the exam.
- Chest X-rays: This will help them visualize the heart’s size and shape and make it possible to detect fluid buildup in the lungs.
- Electrocardiogram (ECG): An ECG measures the heart's electrical activity, helping identify arrhythmias or other electrical abnormalities.
- Echocardiogram: An ultrasound of the heart that provides detailed images of the heart’s structure and function, allowing the vet to assess blood flow and whether the heart’s valves are functioning effectively.
- Blood tests: This will allow your vet to check for a heartworm infection and other indicators of heart or organ problems.
Regular checkups and wellness exams are key to maintaining your dog’s overall health, especially heart health. This allows your vet to detect any potential problems early before they become severe. Proactive screening is essential if you have an at-risk breed, such as small breeds prone to MVD and large breeds susceptible to DCM.
Tips to Prevent Heart Disease and Illness
There is nothing we want more for our dogs than to give them the best possible quality of life, which means keeping them happy and healthy. While we can’t prevent all forms of heart disease, there are steps we can take to significantly reduce the risk of trouble.
Feed a Heart-Healthy Diet
Your dog’s diet plays a very important role in their overall health and well-being. Whether you’re feeding a commercially available food or making your own, you want to ensure it is fully balanced and meets all your dog’s nutritional needs. A canine nutritionist can help you identify any possible risk of deficiencies that could ultimately contribute to health problems (including heart problems).
For dogs at higher risk for developing heart problems, a specialty diet may be recommended by your veterinarian. Generally, these diets are low-sodium and contain high-quality proteins to best support heart function.
Prioritize Physical Activity
You’ve likely been told exercise is the key to a healthy heart for people, and the same is true for your dog! But it’s all about balance. Find ways to encourage your dog to be active but avoid overly strenuous activities that could overstress the heart, especially if your pup is used to a more laid-back and casual lifestyle.
Reduce Stress Levels
High stress levels can lead to health problems, including gastrointestinal problems, a lowered immune system, skin and coat conditions, and, of course, heart problems. Consider taking steps to help your dog live a lower-stress lifestyle. Create a calm, quiet environment at home by setting up a safe space. You can add to the relaxing atmosphere with calming music and pheromone diffusers.
Dogs are creatures of habit. Create and stick to a regular schedule, including mealtimes, play sessions, daily walks, and a nighttime routine. This will ensure your dog knows what to expect, reducing stress and anxiety.
Prioritize Your Dog’s Heart Health for a Long, Happy Life
Early detection and preventative steps are both crucial to keeping your dog’s heart healthy. Familiarize yourself with the subtle signs of trouble to look out for, like changes in breathing, behavior, or overall health, and contact your veterinarian as soon as possible if you have any reason to be concerned.
You may not be able to prevent all heart-related problems, but this, paired with regular wellness exams, will help you catch and address any heart issues early before they can progress into something more severe. By prioritizing your dog’s heart health, you can help them live a long, happy, comfortable life by your side.
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Britt Kascjak is a proud pet mom, sharing her heart (and her home) with her “pack” which includes her husband John, their 2 dogs – Lucifer and Willow – and their 3 cats – Pippen, Jinx, and Theia. She has been active in the animal rescue community for over 15 years, volunteering, fostering and advocating for organizations across Canada and the US. In her free time, she enjoys traveling around the country camping, hiking, and canoeing with her pets.
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