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Dogs with Heart Murmurs

Spatter, our Dalmatian, is only 10 weeks old. She's alert and playful, has a good appetite and generally seems to be coming along quite well. It was a shock when our veterinarian said she had a heart murmur. He wants to check her again in a week and said not to worry. Do you think Spatter has a serious problem?

I wish I could give you a definite answer, but at this point it's hard to tell if Spatter's murmur is serious or not. Your veterinarian was listening for clues when he put his stethoscope to Spatter's chest. He will use what he learns about the location and loudness of the murmur and about Spatter's activity levels and weight gain to help evaluate the severity of the problem. Murmurs are audible vibrations produced by abnormal blood flow through an area of the heart. For example, if your puppy is anemic due to worms, the viscosity or texture of the blood changes and a murmur can be heard as the blood moves through the heart. Removing the worms from the intestines removes the problem -- and the murmur. The purpose of next week's visit probably is to check if the murmur is changing. The fact that your veterinarian is not very concerned at this point leads me to believe that he suspects a functional murmur. If this is the case, the stethoscope picks up a soft sound that can be caused by excitement, anemia, or fever. If he wormed Spatter or treated her for an infection, he may find that the murmur has disappeared by next week's checkup. So far, I've reviewed fairly minor heart murmurs. There are some murmurs caused by serious problems -- a malformed valve or heart muscle wall that did not close properly at birth or patent ductus arteriosus (PDA). The latter is a grave condition in which a small blood vessel, which helps blood bypass the heart in an unborn pup, fails to close off completely at birth. This causes oxygen-rich blood to try to return back through the heart again instead of flowing out to the body. Surgery can correct the problem but at some risk. Such life-threatening heart murmurs occur in puppies that were the runts of their litters or who have had problems since birth. Usually they stop growing and begin to lose weight. The heart murmurs produced are quite loud. I hope next week's checkup finds nothing serious and that Spatter continues to grow and thrive.