[sidebar]2. Give your pet heartworm medication once a month. One bite is all it takes for a mosquito to transmit heartworms that can clog the heart and lead to heart failure. For dogs, a monthly oral or topical medication can prevent infection. The test used to diagnose heartworm in cats is not always reliable, so I recommend that all felines—even if they stay indoors—be put on preventive medications too. 3. Ask your vet to check for heart murmurs. Cats with murmurs often have shortened life spans, so once diagnosed, they’ll need an echocardiogram to determine the severity, along with medications to help prevent heart failure or life-threatening clots. For small-breed dogs, I’m not as alarmed by a heart murmur, but it’s still important to take proper precautions because murmurs in smaller dogs are often caused by chronic valvular heart disease. If you have a large or giant breed dog with a heart murmur (like a Great Dane), it could be dilated cardiomyopathy (DCM), a fatal type of heart disease. Regardless, check with your vet if your pet has a murmur, as frequent heart workups (with a physical exam, chest x-ray, and echo) are a must! More from Prevention: The Natural Way To Pet Wellness