The proper treatment for feline heart disease depends on the type of condition involved. Generally speaking, the therapeutic options include supportive care, activity restriction, dietary management and selection from a number of medications, each of which has its own pros and cons in managing heart disease in cats. New treatments and treatment protocols are constantly being developed, and a veterinarian is the only one who can assess a given cat and come up with the best therapeutic plan for that patient.
Treating Heart Disease in Cats
Most affected cats will benefit from minimization of stress, oxygen supplementation if they are having respiratory difficulty, and a nice warm, safe, quiet living environment. The treating veterinarian may recommend a sodium-restricted diet and activity restriction as well. Hospitalization is usually necessary at least initially to stabilize cats that have reached the point of having clinical signs of heart disease.
One of the more dangerous consequences of heart disease is accumulation of fluid in and around the lungs, referred to as pulmonary edema, pleural effusion or ascites. Once these conditions develop, cats typically are approaching congestive heart failure. In acute cases where a cat is in severe respiratory distress, a procedure called thoracocentesis can be used to pull fluid out of the thoracic cavity through a needle inserted directly into the chest. A medication known as furosemide is frequently prescribed to cats having extreme difficulty breathing due to this fluid build up, although it should not be used in very high doses long-term as cats seem especially sensitive to developing dehydration and renal complications from this drug. In cases where the symptoms are severe, the medication typically is given intramuscularly rather than intravenously to avoid excess stress to the cat, and then is transitioned to oral administration once the clinical signs are controlled. Application of nitroglycerin ointment topically is also often used to help stabilize critical cats on the theory that it might reduce pleural effusion and pulmonary edema due to its vasodilation properties. Some reports suggest that nitroglycerin may have benefits for long-term management of these conditions in cats.
Vasodilators such as enalapril (which is called an ACE-inhibitor) are available to help conserve the strength of the heart and reduce “wear and tear” by lowering blood pressure through dilation of the blood vessels. Enalapril has also been shown to reduce enlargement of the left side of the heart in cats that are suffering from hypertrophic cardiomyopathy. Beta blockers, particularly atenolol but there are others, are quite effective in lowering heart rate and controlling arrhythmias. Calcium channel blockers such as diltiazem can be prescribed to increase elasticity of the heart, promote vasodilation and enhance ventricular relaxation. Diltiazam is generally less effective than the beta blocker drugs in reducing heart rate, although it has some effect. Diltiazem or atenolol are presently the hallmarks of long-term treatment for cats with HCM. Long-term therapy also usually includes use of an anticoagulant such as aspirin or warfarin to help reduce the serious risk of thromboembolism that accompanies feline heart disease.
It is critically important for owners to recognize that there are no cookie-cutter approaches to heart disease in cats. Each animal is an individual requiring individualized assessment, treatment, monitoring and follow-up care. Each of the available drugs carries risks and benefits, and there can be severe complications from adverse drug interactions that your veterinarian will want to watch for.