Chapter 38 Diseases of the Cardiovascular System
Clinical cardiac disease in reptiles may be primary or secondary to metabolic or nutritional problems. This type of disease has been poorly reported in the past, possibly because no one has looked for it.
Although the anatomy of the heart (two atria and one ventricle) suggests a singular circulatory system, the function of the heart actually provides a dual system similar to other animals. The heart rate depends on a number of variables: body temperature, body size, metabolic rate, respiratory rate, and sensory stimulation. The heart functions most effectively within the preferred optimal temperature zone. The heart rate tends to increase during active respiration and decrease during apnea. Monitoring of the cardiac activity is possible in snakes using electrocardiographic equipment already in the hospital.
Another difference in the cardiovascular system is the presence of nucleated red cells. The hemoglobin in these cells is similar to that in mammalian cells; however, the oxygen affinity of the hemoglobin tends to decrease with the age of the animal. It is important for the veterinarian and the technician to understand the anatomy and physiology of the cardiovascular system and how it relates to the development of disease to diagnose cardiovascular diseases in the snake.
Dietary deficiencies can affect the function of the cardiovascular system. Hypocalcemia, vitamin E deficiency, and excessive amounts of vitamin D3 and calcium can all affect the cardiovascular system.