Production of red blood cells (RBCs) takes place in the bone marrow. For development and maturation of red blood cells to take place, bone marrow requires an adequate supply of a hormone called erythropoietin (EPO), a glycoprotein hormone that controls the production of red blood cells. Erythropoietin is produced by the kidneys. In chronic kidney disease (CKD), the kidney cannot produce an adequate amount of erythropoietin, resulting in bone marrow failure. Lack of RBC production will ultimately lead to anemia in cats that are suffering from chronic kidney failure. Middle-aged to older cats are most commonly affected by chronic kidney failure, but the condition may also occur in young cats.
Symptoms and Types
As anemia in this case is principally related to chronic kidney disease, the symptoms are mixed, and relate to both CKD and anemia. Following are a few of the symptoms related to anemia in the presence of CKD:
- Weight loss
- Apathy (state of indifference)
- Cold intolerance
- Changes in behavior
- Tachypnea (rapid breathing)
- Tachycardia (rapid heartbeat)
- Syncope (fainting)
Following are some of the causes behind chronic kidney failure and anemia:
Chronic kidney disease can occur as:
- Congenital (pups born with the problem)
- Acquired form (in later life)
- Iron deficiency
- Blood loss through alimentary tract (the entire canal from the mouth to the anus)
- Disease that causes disruption of RBCs
You will need to give a thorough history of your pet's health, including a background history of symptoms. After taking a complete history, your veterinarian will conduct a complete physical examination on your cat. Laboratory tests will include a complete blood profile, a chemical blood profile, a complete blood count, and a urinalysis. The results of these tests will provide valuable information for the diagnosis of the cause of the kidney failure and the extent of anemia related to it. Your veterinarian will be particularly interested in knowing the level of erythropoietin in the blood. Specific tests may be used to diagnose the underlying cause of the chronic kidney disease and resulting anemia. An examination of the bone marrow examination may be conducted to evaluate the structure and functions of bone marrow. X-ray and ultrasound imaging will show any abnormal structure of the kidneys that is typical in chronic kidney disease. Ultrasound may reveal smaller than normal or irregular-shaped kidneys, both characteristic of chronic kidney disease.
Supportive therapy will be started immediately to meet your cat’s energy demands. Treatment involves treating the symptoms related to chronic kidney failure and anemia, and replacement of deficient erythropoietin. In case of severe anemia, a whole blood transfusion will be performed. Iron will also be added to the supportive therapy in cases with low levels of iron in the blood. Erythropoietin replacement usually provides both rapid and long-term correction of anemia related to chronic kidney failure.
Living and Management
It must be remembered that in most cases of chronic kidney failure, long-term treatment and management is required. Regular evaluations will be required to follow your cat’s progress and to avoid further complications. Your veterinarian will schedule follow-up visits for once a month until your cat’s condition has stabilized. During these visits your veterinarian will record your cat’s blood pressure and adjust the dosage of various drugs being given to your cat. The treatment of chronic kidney disease and anemia is not without side effects, you will need to consult with your veterinarian throughout the process in order to ensure proper management of your cat’s health.
Correction of anemia through erythropoietin replacement therapy will improve the overall health of your cat, including improved appetite and activity level. Your cat will be more playful, gain more weight, and also in better position to cope with cold intolerance. Despite these short-term benefits, unfortunately, the long-term prognosis of patients with chronic kidney failure is usually poor.