The Dog Days of Heart Failure

This post demonstrates that my post ideas can develop from the most surprising scenarios.   I might be in the midst of an innocent conversation with people I barely know, or reading something totally unrelated to heart failure, and I will learn an interesting fact about the heart.

A few months ago, a friend invited me to an awards ceremony at her Federal agency.  I was honored to see her receive an award because I know how hard she works to address legal issues at her agency with empathy and foresight.  Her approach to the practice of law in a Federal agency mirrors what I tried to implement for years:  Respect the client’s talents, understand the client’s environment and help the devise tangible, practical solutions to the client's issues.
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The awards ceremony included a luncheon.  I was able to meet other employees who received awards as well as their family members.  I was so impressed not just by the caliber of the employees, but by how welcoming and courteous they were.  I was especially impressed by a young woman who was employed in the Hawaiian office of the agency, and her sister, who was a veterinarian. 

The veterinarian sister and I had a lovely chat during lunch.  I explained that I was retired.  She was incredulous, because I guess I look young for a retiree.  So I eventually explained that I retired because of a heart issue.  I discussed the trauma of blacking out on a treadmill, and then mentioned that the condition progressed to where I would become dizzy or black out in some very ordinary situations.  I told her that I received a pacemaker implant, and then retired, only to be diagnosed with more severe heart issues.

She looked at me and said:  “So you have AV heart block?”  I was stunned.  Do you know how many people I run into outside my doctors’ offices who even know what that term means?  I can count them on one hand leaving about 4 fingers left to count.  I gave her a dumbfounded look and said:  “How do you even know that term?”  Well, the answer would be that she is a doctor to dogs, and just like we have found with horse and fish (see previous posts), animals can have heart issues.  She told me that Doberman Pinschers and Cocker Spaniels are two breeds that are prone to AV Block.  As the result of our casual, and even astonishing, conversation, I decided to do some research on dogs with AV Block and dilated cardiomyopathy. 

First, let’s talk about Mobitz Type 2 conduction disorder, also known as heart block, in dogs.  The website wagwalking.com (isn’t that a great name!) says: 

• Your dog’s heart is similar to your own, having four chambers, which are the two atria on top and two ventricles on the bottom. When the upper heart chambers are not communicating well with the lower chambers, the body (left ventricle) and lungs (right ventricle) are not getting enough blood, this is a condition called heart block (AV block). There are four kinds of heart block, which are first degree, second degree (Mobitz type I), second degree (Mobitz type II), and third degree (complete heart block). A normal heart rate can fluctuate from 60 to 175 beats per minute, but in second degree Mobitz type II, your dog’s heart can skip beats and become slower than 50 beats per minute at times. Unlike type I, this disorder is almost exclusively caused by an underlying disease or disorder, and affects older dogs (over eight years) most often. The causes of type II heart block vary, but heart infection or inflammation are the most commonly found conditions.

As we learned with humans, if there is a heart block this means that the natural pacemaker may not be working properly.  This led me to question whether it is possible to implant a pacemaker in a dog who has heart block issues.  The answer is yes.  According to a story on the CBS website dated October 8, 2010: 

• A few thousand dogs have gotten the lifesaving implants over the past two decades. The numbers have risen from 100 to 200 implants a year in the 1990s to the current 300 to 500 a year, said David Sisson, an Oregon State University professor of cardiovascular medicine.  Sisson, who did his first canine pacemaker implant in the mid-1980s, calls the trend "a certain amount of payback" considering that the small devices arose from research in the 1940s in which man's best friend played a key role as test subject.

What if a dog’s heart enlarges and the veterinarian makes a diagnosis of dilated cardiomyopathy.   Is the DCM the result of the same causes that impact humans?  According to the Vetmed web page of Washington State University:

• In contrast to people, heart muscle dysfunction in dogs and cats is almost never the result of chronic coronary artery disease ("heart attacks").   But as is the case with humans, the following symptoms can occur with dogs:  blood pressure can increase in the veins behind one or both sides of the heart. Lung (pulmonary) congestion and fluid accumulation (edema) often develop behind the left ventricle/atrium.  Fluid also may accumulate in the abdomen (ascites) or around the lungs (pleural effusion) if the right side of the heart is also diseased.  When congestion, edema and/or effusions occur, heart failure is present.   Other symptoms can include weakness and fainting episodes.

According to the website for Pet Coach, the following breeds are most likely to have dilated cardiomyopathy:  Great Danes, Doberman Pinschers, Irish Wolfhounds, Boxers, Newfoundlands, St. Bernards, Boxers, Dalmatians, Portuguese Water Dogs and Cocker Spaniels.  DCM dogs typically take drugs such as the diuretic Furosemide (Lasix) and an Ace Inhibitor – just like me!

Are dogs with DCM as sensitive to shortness of breath as their human counterparts?  According to the PetWave website:  “As the dog’s condition progresses, it will have increasing difficulty breathing; this is called “dyspnea.”  Affected animals may breathe shallowly and rapidly, which is known as “tachypnea,” or being “tachypnic.”  Dogs in heart failure often have breathing problems even when they are asleep or resting, as their body tries to get enough oxygen into its blood supply to support its vital organs and tissues.” 

What about exercise?  According to the website vcahospitals.com, the answer is the same as it is for humans like me:  “In general, dogs with both asymptomatic and symptomatic DCM should be allowed to exercise at their normal level if they want to, but the duration of sustained strenuous activities such as ball retrieval, swimming, Frisbee etc. should be limited, especially in really hot or cold weather. Some exercise is good for you and your dog and part of what helps your dog enjoy life.”

If you see a dog panting uncontrollably during these hot and humid summer days, have some sympathy because you perhaps have stumbled across a dog with heart failure.  I know that I find it a bit more challenging to walk distances and to walk up inclines and stairs when my heart pump has to factor in humidity and heat.  But at least I can adapt my wardrobe and make sure that my a good portion of my restricted fluid intake occurs at the times I will be outside in the hot summer weather.  These actions may help me moderate the impact of the heat and humidity.  But think about man’s best friend.  His or her coat of fur, other than normal grooming, is pretty constant year round.  Also, I doubt that you have seen a dog carrying a water bottle as an accessory.

My research also led me to wonder:  Does the old adage “the dog days of summer” have some connection to dogs with DCM?  Not if you believe the information on the National Geographic website.  They report that this adage: “doesn’t have to do with dogs lying around in the heat—the phrase comes from ancient Greek beliefs about a star. ***  Instead, it turns out, the dog days refer to the dog star, Sirius, and its position in the heavens.  To the Greeks and Romans, the dog days occurred around the day when Sirius appeared to rise just before the sun, in late July. They referred to these days as the hottest time of the year, a period that could bring fever, or even catastrophe.”

I suspect that when Sirius rises just before the sun, dogs with DCM just like humans with DCM suffer much from the impact of heat on their poor hearts. 

My research also led me to find mythological support for the old saying that a dog is man’s best friend.  The website earthsky.org related this heart-warming tale from India: 

• In India, Sirius is sometimes known as Svana, the dog of Prince Yudhistira. The prince and his four brothers, along with Svana, set out on a long and arduous journey to find the kingdom of heaven. However, one by one the brothers all abandoned the search until only Yudhistira and his dog, Svana, were left. At long last they came to the gates of heaven. The gatekeeper, Indra, welcomed the prince but denied Svana entrance. Yudhistira was aghast and told Indra that he could not forsake his good and faithful servant and friend. His brothers, Yudhistira said, had abandoned the journey to heaven to follow their hearts’ desires. But Svana, who had given his heart freely, chose to follow none but Yudhistira. The prince said that, without his dog, he would forsake even heaven. This is what Indra had wanted to hear, and then he welcomed both the prince and the dog through the gates of heaven.

Can we find support for this myth in real life as well?  Well as sometimes happens when I am writing a blog post, I will stumble across a story that relates to the post I am working on.  In this case, the story appeared on a Saturday morning segment of the Today show relating to heart disease and dogs, 

As is the case with “heart disease” in humans, covers a wide variety of heart issues like degenerative disease of heart valves, disease of heart muscles, etc.  The story revealed that veterinarians in Colorado are using cutting edge technology and imaging to treat dogs with heart disease.  The dog profiled for Today had begun to experience shortness of breath, lethargy and fatigue.  The doctors repaired a hole in the dog’s heart, and the dog regained energy and vitality.

Is there a chance that doctors can learn from the treatment of dogs and then transfer the knowledge to humans?  The doctor interviewed for this segment said yes.  The procedures are easier to do in dogs, as there is less paperwork and oversight required.  This provides an environment to experiment and find what works for canines, and then see if it can be applied it to humans.

Like the Prince and Svana of Indian mythology, we benefit from our loyalty to each other even in the worst of times.  I hope when we make it to the gates of heaven, we also will be rewarded for our faith and courage in uniting to deal with this awful chronic disease, and be welcomed through the gates of heaven to enjoy eternity together!