Cat Circulatory System

The hardest worker in your cat's body is the heart. It is a top-of-the-line, four-chambered model (just like the human heart) that actually consists of two pumps.The right side of the heart receives the blue blood (depleted of oxygen) that hasalready dropped off its cargo of oxygen and nutrients and has returned with wasteproducts, such as carbon dioxide, by way of the veins. This blue blood is pumped through the lungs to receive fresh oxygen and to remove the carbon dioxide. The blood then returns to the left side of the heart and is pumped out through the arteries to the trillions of cells in your pet's body.

The normal heart beats about 120 times per minute in a resting cat. You can feel the heart beat by placing the palm of your hand against your pet's chest, near the left elbow. You may hear the "lub-dup" of the normal heart valves closing by placing your ear there. Panting, breathing, and purring may make it difficult for you to hear even with a stethoscope,which you can purchase at a medical supply store. The heart receives its oxygenby way of two branching coronary arteries that are about the width of a piece of spaghetti. Fortunately, cats do not have heart attacks (sudden blocking of the coronary arteries), but after eight years of age they often develop a problem with the heart valves (flaps that control the passage of blood through the heart's chambers):The valves do not close properly, and the heart must work harder to pump theblood. It may even fail unless treated with digitalis-like drugs. Your veterinarian(or even you, by using your stethoscope) will detect a heart murmur when thevalves are closing improperly. A "zsa" sound may be heard between the "lub-dup"of the regular heartbeat: "lub-zsa-dup." The regurgitation of blood around "sick"valves is responsible for the "zsa" sound. Not all heart murmurs are serious prob-lems. Your veterinarian is the best judge. Cardiomyopathy (a disorder of the heart'smuscle tissue) is another typical cat problem.

The pulse and capillary refill time will give you some indication of how wellthe heart and blood vessels are working to maintain your pet's blood pressure. When you press a finger against your pet'sgum and then lift it away, the white area should return to the normal pink color inone second. This indicates that the capillaries are refilling with blood.

- Place your palm over your cat's left chest wall.
- Hold this position for fifteen seconds and count the number of beats felt in that time.
- Multiply the number by four. For example 30 beats in 15 seconds seconds 30 x
4 = 120 beats per minute.

A normal cat heart rate should fall in the range between 80 and 175.