The key responsibility of all red blood cells (erythrocytes) is to transport oxygen to the tissues, where cellular metabolism takes place. The oxygen molecules affix themselves to haemoglobin, which are iron-containing proteins found within red blood cells. Haemoglobin plays the role of carrier molecule, transporting oxygen from the lungs to all the body tissues, all the while giving red blood cells their characteristic crimson tinge. During the respiration process, oxygen is used up in order to produce energy for the body, with carbon dioxide being eliminated as a waste product. The carbon dioxide is then transported by the red blood cells away from the tissues straight to the lungs, where it’s breathed out. Anaemia occurs when the number of red blood cells in the body drops considerably, resulting in a deficit in oxygenated blood. This causes tiredness and loss of energy. On the other hand, excessive amounts of red blood cells, a condition called polycythemia, causes blood to thicken and hinder the heart’s ability to deliver oxygen to the body tissues. An animal’s metabolism is primed to defend both haemoglobin and the red blood cells from harm. Disease is caused when the creation and production of haemoglobin and red blood cells are interfered with.
The overall number of red blood cells in healthy animals stays constant throughout, therefore maintaining the body’s oxygen-carrying capacity. With a limited duration of life, the creation and destruction of mature red blood cells has to be balanced properly to avoid ill health.
The stem cells in the bone marrow are the first step in the creation of red blood cells, culminating in the discharge of mature red blood cells into the circulatory system of the body. Every blood cell within the bone marrow starts its life as a stem cell. These stem cells then break up to form undeveloped red blood cells, white blood cells, and platelet-creating cell. These undeveloped cells undergo further cellular division and subsequent maturity, until they turn into mature red and white blood cells, and platelets.
The rate at which blood cells are produced is dependent on the needs of the body. A hormone called erythropoietin, which is manufactured in the kidneys, is responsible for triggering the development of red blood cells in the bone marrow. An increase in production of erythropoietin signifies that there is a deficit of oxygen in the body, a condition known as hypoxia. In most animals, the kidney acts like the antennae organ; analysing how much oxygen the tissues are getting and also producing erythropoietin. If the kidneys constantly fail in their functions, anaemia sets in. The key roles of erythropoietin are to decide whether to raise the number of stem cells being used in production of red blood cells; to reduce the red blood cells’ maturity period; or to trigger the timely release of red blood cells. There are other factors that influence red blood cell production, such as the provision of iron and vitamins, and inter-cellular interactions between substances that help in their development. Some diseases are the express consequence of abnormal red blood cell metabolism. One such condition is known as haemolytic anaemia, which is caused by a genetic enzyme deficiency that diminishes the life span of red blood cells.
It is critical to understand that a reduction in red blood cell count in the body doesn’t constitute a specific diagnosis; it’s just a sign of disease. Anaemia may be a result of loss of blood, haemolysis (red blood cell destruction), or a drop in production. When excessive blood-loss anaemia occurs, death is brought about by the loss of total blood quantity, and not necessarily by lack of red blood cells and oxygen. Haemolysis could result from poisons, infections, birth deformities, drugs, or antibodies that kill red blood cells. Most dogs that suffer from severe haemolysis do so as a result of immune-mediated haemolytic anaemia, where an antibody attacks the dog’s own red blood cells.
Certain factors that may hinder the creation of red blood cells are bone marrow failure or a tumour, kidney failure, poisons or drugs, sever long-term disease, or rogue antibodies. The diagnosis and handling of the situation is dependent on the causal reason for the anaemia.