Dilated cardiomyopathy (DCM) - Enlarged Heart

Quite a few breeds are affected by a heart condition known as Dilated Cardiomyopathy (DLM) which in layman's terms is a disease that eventually sees a dog developing an enlarged heart. The condition affects the heart's function which is then seriously impacted causing it to pump and contract inefficiently. As a result, the chambers of a dog's heart eventually become larger and heart valves may even begin to leak which can then cause a dog to suffer from congestive heart failure.

Causes of Dilated Cardiomyopathy

Sadly, it’s not known why some dogs are prone to developing the disease, but research suggests that some breeds may suffer from Dilated Cardiomyopathy as a result of certain nutritional deficiencies namely carnitine and taurine. Another finding is that the condition appears to affect male dogs more so than it does females, with larger breeds being more susceptible to developing the condition than others too. The breeds most affected by Dilated Cardiomyopathy are as follows:

• Dobermann Pinscher
• Boxer
• Scottish Deerhound
• Great Dane
• Saint Bernard
• Irish Wolfhound
• Afghan Hound
• Cocker Spaniel

However, similar systems to those displayed in Dilated Cardiomyopathy can develop as a result of a dog having been exposed to toxins or when they have suffered from some form of heart infection. In short, the same systems can manifest themselves as a result of an identifiable heart condition.

Symptoms to Watch Out For

Unfortunately, it is very hard to see there may be something wrong with a dog at the onset of the condition because they are no obvious signs to begin with. However, a few dogs may show a reluctance to be walked or exercised which could be an early sign of there being something wrong, but normally the earliest a vet might suspect a dog is suffering the onset of Dilated Cardiomyopathy would be if they hear a heart murmur or some other abnormal heart rhythm when carrying out a routine examination of a dog.

The Dilated Cardiomyopathy is progressive disease which, in short, means that it gradually gets worse and as a result a dog's heart has to work that much harder because its ability to pump blood through the chambers decreases over time. This in turn results in a dog's blood pressure rising in the veins found behind their heart. When this happens it is common for a dog's lungs to build up with fluid causing congestion. These fluids often build up around their lungs and in their abdomens too, more especially when the right side of a dog's heart is affected by the condition. The result of this fluid build-up is heart failure.

Signs a dog may be suffering from DCM include the following:

• A reluctance to be walked
• Tiring very quickly
• Increased panting
• Coughing
• Heavy breathing
• Weakness
• Fainting
• Sudden death

Some dogs suffering from the condition may also have swollen and enlarged stomachs due to the build-up of fluids found in them. Sudden death typically occurs when a dog's heart rhythm is severely affected by the condition.

Advanced Signs of Something Being Wrong

As the disease progresses, affected dogs become more distressed and find it that much harder to breath and get comfortable. The advanced systems of DCM include the following:

• Laboured breathing
• Difficulty and a reluctance to lie down
• Unable to get comfortable
• A bad cough that appears to be getting worse
• Loss of appetite•

Although it is easy to think the onset of heart failure is rapid, the disease, as previously mentioned, progresses slowly often with no obvious signs of there being anything wrong with a dog in its early stages. In some cases, a dog's heart may have been impacted by the condition for years before it finally gives out.

Diagnosing the Problem

Vets usually pick up the fact a dog may be suffering the onset of Dilated Cardiomyopathy when they are giving them an annual physical examination. However, to confirm a diagnosis, they would need to carry out specific tests which would also determine just how far the condition has progressed. The problem is that a vet cannot determine to what extent a dog's heart has been affected by simply listening to its function alone. As such, more tests are needed which includes a specific, yet simple BNP blood test which measures the amount of a certain hormone and what levels are found in the blood. The hormone is peptide"" which is only released by a dog's heart when it is having to work overtime just to keep blood pumping through it.

A vet may also want to take some X-rays of a dog's heart in order to determine whether the chambers have become enlarged and to see if there's any build-up of fluid in a dog's lungs. On top of this an EKG would show whether a dog's heart rate has increased at all which could be a clear indication of them suffering from Dilated Cardiomyopathy. However, to make absolute certain that a dog is suffering from DCM, a vet would need to carry out an echocardiogram (heart ultrasound) which establishes the size of a dog's heart and whether or not it can function efficiently. A diseased heart would have enlarged chambers. It’s worth noting this same test can be carried out earlier in dogs known to be more susceptible to DCM to determine the early onset of the disease.

Treating Dilated Cardiomyopathy

When treating DCM, the end goal is to improve a dog's heart function and to treat any symptoms associated with congestive heart failure. The most common treatment sees vets using certain drugs to control a dog’s heart function. ACE inhibitors are often given to affected dogs which help slow the progression of the disease which in turn reduces the risk of a dog suffering heart failure.

As previously mentioned, DCM is a progressive disease as such as the condition gets worse, a vet would prescribe different drugs with an end goal being to improve a dog's heart function whether it's to slow it down or to control the amount of fluid that builds up in a dog's hearts and lungs. A vet might also recommend giving an affected dog certain drugs that help dilate their blood vessels. With today's advancement in veterinary medicine, there are specific drugs that help regulate a dog's heart beat which as a result means their hearts can function and pump blood more efficiently.

What About Side Effects?

Whenever a dog suffers from DCM and a vet prescribes specific drugs, they have to be carefully monitored for any side effects which could include the following:

• Diarrhoea
• Vomiting
• A reduced appetite
• Lethargy
• Depression
• Low blood pressure

A dog suffering from Dilated Cardiomyopathy would need to be given specific medication for the remainder of their lives which means that doses often have to be increased over time to stay on top of this progressive disease.

Alternative Therapies

Diet can play an important role in how the condition progresses and certain alternative therapies have been shown to be beneficial which include adding certain herbal and other supplements to an affected dog's diet. The herbs and supplements known to be helpful include the following:

• Hawthorne berries
• Cayenne
• Acetyl L-carnitine
• Taurine (an amino acid)
• Arginine
• D-ribose
• Omega-3 fatty acids

Many vets recommend feeding a fresh food diet to a dog suffering from Dilated Cardiomyopathy and to dogs known to be susceptible to the condition which can help reduce the risk considerably. However, it’s essential to discuss changing a dog’s diet with a vet before attempting to do so and to follow their recommendations once they have been diagnosed as suffering from DCM.

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