If a dog's heart is beating really hard and he hasn't just finished a long run or play session, it could be just one of the symptoms of a potential heart problem. These conditions can be difficult to diagnose since dogs don't tend to show pain or other medical problems until the heart condition has progressed. Be sure to get your dog regular veterinary checkups and watch for some common symptoms to help diagnose and treat your dog as soon as possible.
Breathing issues and coughing
One potential symptom of a heart problem is if the dog's heart is beating fast and he is panting when he has not been exercising. The panting may indicate difficulty with breathing.
When heart problems are more advanced, breathing may be more difficult when the dog is lying down. In more severe cases, you may notice your dog stretching his neck out and bracing his feet wide in an effort to breathe.
A cough that persists for more than a few days may also indicate a heart problem. This could be due to an enlarged heart irritating the dog's airways or the dog's effort to clear fluid accumulation in the lungs.
Behavior changes with heart problems
Dogs with heart problems often become more lethargic than they used to be. You may notice your dog sleeps more and plays less than he used to and that he gets tired more quickly during walks or play. He may isolate himself and lose his appetite.
Another potential symptom is if your dog suddenly begins to walk strangely and unsteadily, or becomes disoriented. You are most likely to see this during exercise.
Weight and body changes
Weight loss is another common symptom. In puppies with a heart condition, such as a heart murmur, you may notice stunted growth. If a heart condition such as pericardial effusion is ongoing, muscle wasting may occur.
Heart problems may also cause fluid to accumulate in the body. While fluid in the lungs isn't visible, fluid can also back up in the abdomen. This can cause a swollen abdomen and the swelling can even appear in your dog's legs.
Another potential symptom is blue or pale gums and tongue. This is caused by a lack of oxygen and circulation due to the heart not working properly.
Possible acute symptoms
Dogs with heart problems may faint or collapse due to a lack of blood flow and oxygen to the brain. This may happen during exercise or while coughing. Although it is rare, dogs can experience heart attacks and die suddenly.
Some potential heart problems
If your dog's heart is beating really hard for no apparent reason or you notice any of the other symptoms of heart problems, contact your veterinarian. Some of these symptoms are common to other conditions, so your vet will need to examine your dog and do testing such as x-rays or an echocardiogram to diagnose the issue.
Some heart problems that dogs may experience include congestive heart failure, which occurs when the heart cannot pump blood adequately, and pericardial effusion, which is a build-up of fluid in the pericardial sac around the heart. Heart murmurs are also a concern but are usually more easily diagnosed as they are audible during a physical exam. Some puppies will outgrow heart murmurs with no residual health problems. In other cases, the murmur may be the result of a birth defect or the problem may develop as the dog ages.
Dogs may also contract heartworm parasites that fill the heart. This condition is preventable with heartworm medications. However, once a dog is infected, he will require extensive treatment with a series of injections of the drug melarsomine and complete rest.