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 consists of two pumps. The right side of the heart receives the blue blood (depleted of oxygen) that has already dropped off its cargo of oxygen and nutrients and has returned with waste products, such as carbon dioxide, by way of the veins. This blue blood is pumped through the lungs to receive fresh oxygen and remove 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 heartbeat 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 oxygen by 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 the blood. 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 the valves 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 the sick and valves is responsible for the Zsa and sound. Not all heart murmurs are serious problems. Your veterinarian is the best judge. Cardiomyopathy (a disorder of the heart’s muscle tissue) is another typical cat problem.
The pulse and capillary refill time will give you some indication of how well the heart and blood vessels are working to maintain your pet’s blood pressure. When you press a finger against your pet’s gum and then lift it away, the white area should return to the normal pink color in one 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, 30 x 4 = 120 beats per minute.
- A normal cat’s heart rate should fall in the range between 80 and 175.
See more: Cat Chest Injuries