Dilated Cardiomyopathy in Cats

The defective cardiovascular organ causes the feline to have poor circulation, noted by cold paws, and reluctance to engage in physical activity. The feline may also appear weak and have a poor body condition as it ages. Dilated cardiomyopathy was once linked to a dietary deficiency in the amino acid, taurine. However, due to cat food manufacturers adding this essential ingredient into their products, DCM is rarely caused by taurine deficiency. Today, unless the feline is fed a naturally sourced diet, DCM occurs for idiopathic (unknown) reasons. Dilated cardiomyopathy possess a threat for blood clots, stroke and heart failure in cats, therefore treatment must be sought by a veterinary professional.

Dilated cardiomyopathy (DCM) in cats is a heart disease of the ventricular muscle, which prevents the organ from moving blood out of the bottom of the heart at full capacity. To understand feline dilated cardiomyopathy, a basic understanding of heart anatomy is required. The feline’s heart has four chambers, just like the human heart, with two right and left aortas atop two right and left ventricles. The chambers separate oxygenated blood from un-oxygenated blood, pushing the blood from the heart to be used throughout the body. In the case of dilated cardiomyopathy, the ventricular chambers are dilated. The enlarged ventricle chamber is large in size compared to the other portions of the heart and upon contraction, the compression is weak, resulting in a partial blood pump.

The symptoms caused by dilated cardiomyopathy in cats is related to the decreased blood flow in the body. DCM is noted by a weak pulse, murmur of the heart, and irregular lung sounds, which can also be heard with the help of a stethoscope. At home, cat owners may be able to detect the symptoms of dilated cardiomyopathy in their cat if it displays the following clinical signs: 

• No interest in food 
• Lethargy
• Distended belly
• Pain
• Sudden paralysis 
• Intolerance to exercise 
• Coughing 
• Shortness of breath

Dilated cardiomyopathy in cats is usually caused by idiopathic, or unknown, reasons. The heart condition tends to affect male felines more than females, and it usually appears between two and twenty years of age. Historically, feline dilated cardiomyopathy was linked to a deficiency in the essential amino acid, taurine. After discovering this connection, cat food manufacturers began adding the amino acid into their cat food products and the percentage of cats present with DCM greatly decreased. A feline with dilated cardiomyopathy could still have a deficiency in taurine if she is fed a vegetarian diet or has an underlying absorption-related health condition. 

Felines presented to the veterinary clinic are usually in distress, which requires stabilization before most diagnostic tests can be performed. The veterinarian may first place the feline on oxygen and fluid therapy before returning to talk to you about the symptoms you have noticed at home. The doctor will review the feline’s medical history, talk to the owner about her current diet and medications, then move on to complete the following diagnostic exams: 

• Radiography: x-ray of the chest and abdomen 
• Fluid aspirate biopsy 
• Blood chemistry profile: assess the levels of circulating taurine and electrolytes, and evaluate the liver and kidneys. 
• Electrocardiogram (ECG) 
• Echocardiogram, also known as a heart ultrasound

Dilated cardiomyopathy in cats is treated with therapeutic diuretic, angiotensin converting enzyme inhibitor drugs in severe cases, but additional medications may be needed depending on the specific case. In the case of a taurine deficiency, the veterinarian will prescribe supplements to readily supply the body with the missing essential amino acid. You may also be advised to feed your cat a specialized diet, low in sodium, to aid in cardiovascular recovery. 

Cats with dilated cardiomyopathy are usually asked by the veterinarian to return for a re-evaluation approximately seven to fourteen days after hospital discharge. The doctor will likely repeat the ECG exam and take additional x-rays of the chest to visualize the heart. These tests are usually paired with blood work to obtain a full evaluation of the cat’s most recent condition. Cat owners should expect to have the same test repeated every two to three months for the first year and follow check-up visits for the remainder of the cat’s life, as requested by the veterinarian. 

The prognosis for felines with dilated cardiomyopathy is variable, depending on the underlying cause. Taurine deficiencies are reversible and if treated promptly; most felines live a long life. However, DCM that does not have an identified cause will greatly shorten the feline’s life span.