Dilated cardiomyopathy, or DCM, is a disease that affects the heart of dogs. Some dog breeds are predisposed to developing DCM but it can occur in any breed. Veterinary attention is necessary to provide a dog diagnosed with DCM the best prognosis but it's helpful for all dog owners to know more about this disease. Potential causes of DCM, if it can be prevented, and how it is treated, can help to educate dog owners.
What Is DCM in Dogs?
DCM stands for dilated cardiomyopathy and occurs when a dog's heart chambers become enlarged or dilated. A dog has four chambers in its heart and if these chambers become too dilated they will be unable to efficiently pump blood. The chamber walls also become thin and the valves within the heart that control the direction that the blood flows may leak. This can eventually lead to congestive heart failure.
Signs of DCM in Dogs
- Difficulty breathing
- Weight loss
- Loss of appetite
- Increased respiratory rate
- Bloated abdomen
Since it affects an internal organ, DCM is not a disease you can see, but you can look for signs and symptoms of heart issues in your dog. Dilated cardiomyopathy affects how much oxygenated blood flows through the body, so the first signs of the disease may be generalized weakness and lethargy. Difficulty breathing, an increase in your dog's respiratory rate, and coughing may be seen next. Weight loss will occur over time since your dog doesn't have much of an appetite and you may see your dog's belly become bloated due to fluid accumulation. Fainting or collapse can occur if your dog is unable to breathe well enough or if the disease progresses without treatment.
Causes of DCM
- Nutrition- Dogs that are eating grain-free diets with exotic ingredients or home-cooked diets have developed DCM. While the exact cause of DCM in these dogs is still unknown, some dogs will have low taurine levels or are thought to be unable to properly absorb taurine due to the diets they are consuming. Research is ongoing.
- Genetics - Certain dog breeds have an inherited predisposition to developing DCM. A genetic component has been found in these breeds.
- Infection/Toxins - While rare, drugs like doxorubicin, viruses like parvovirus, and infections like Chagas disease can result in DCM in dogs.
Diagnosing DCM in Dogs
If you suspect your dog has DCM or are concerned it may be negatively affected by a grain-free diet it is eating, a visit to your veterinarian is warranted. Your veterinarian will take a full history and perform a physical examination. They will listen to your dog's heart and lungs and if DCM is suspected, X-rays will be recommended to assess the lungs, heart size, and to see if any fluid is accumulating. An echocardiogram, or ultrasound of the heart, will then be needed to see how well the blood is being pumped through the heart, the size of the heart chambers, and to assess the heart valves. Finally, an EKG, or electrocardiogram, will look at the heart's rhythm to see if any arrhythmias are present.
If a nutritional cause is suspected, a dietary change will be recommended, and if an infection is the cause of the DCM, treatment of the underlying disease will be necessary in addition to specific treatment of the heart disease. For genetic causes of DCM, treatment of the heart disease is the only option. Medications, diets, and supplements to support the heart's ability to pump blood, decrease fluid build-up, and manage any arrhythmias that may be present.
How to Prevent DCM
Dogs with a familial history of DCM should not be bred. While this does not guarantee that their offspring won't one day develop this disease, it will decrease the likelihood of it occurring. Additionally, grain-free diets are not recommended due to the link they have with DCM in breeds that are traditionally not affected by this heart problem.
Risk Factors for DCM in Dogs
Certain dog breeds are at a higher risk for developing DCM than others due to genetic factors. These include:
- Cocker spaniels
- Doberman pinschers
- Great danes
- Irish wolfhounds (especially males)
- Portuguese water dogs
In addition to dogs with a genetic predisposition, dogs that are eating grain-free diets or home-cooked diets that have not been formulated by a veterinary nutritionist may also be at a higher risk for developing DCM.
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