Chronic kidney disease (CKD) is a common and progressive condition in felines, affecting their quality of life. One of the prevalent complications of CKD is anaemia (low red blood cell levels), impacting 30–65% of cats with this condition.
Understanding Anaemia of CKD
Anaemia of CKD is primarily non-regenerative, meaning the body struggles to produce enough new red blood cells (RBCs). This deficiency is mainly due to a lack of erythropoietin (EPO), a hormone produced by the kidneys that stimulates RBC production. In CKD, the damaged kidneys are unable to produce adequate amounts of EPO. Additionally, CKD can lead to gastrointestinal blood loss, reduced RBC survival, and iron deficiency, all contributing to the anaemia.
Diagnosis and Monitoring
Anaemia is often identified during routine blood tests showing a low packed cell volume (PCV) or haematocrit. A PCV persistently below 20% may require intervention with erythrocyte-stimulating agents (ESAs). Monitoring serum iron levels, ferritin, and total iron-binding capacity can also be considered to ensure that iron deficiency isn’t worsening the anaemia.
Treatment Approaches
- Erythropoietin-stimulating agents (ESAs): The primary treatment for CKD-related anaemia is the use of ESAs, which stimulate RBC production. Two common ESAs used in veterinary medicine are recombinant human epoetin alfa (EA) and darbepoetin alfa (DA). DA is preferred as it has a lower risk of adverse reactions, particularly pure red cell aplasia (PRCA), a condition where the body produces antibodies against EPO.
- Iron supplementation: Cats undergoing ESA therapy should also receive iron supplementation, as it enhances the effectiveness of ESA treatment. This can be administered orally (e.g., ferrous sulfate) or through intramuscular injections (e.g., iron dextran).
- Blood transfusions: While not commonly used for chronic anaemia in CKD, blood transfusions could be considered in severe cases where the cat’s oxygen-carrying capacity is critically low.
Monitoring Treatment Effectiveness
Once ESA therapy begins, frequent monitoring is essential. PCV, reticulocyte counts, and blood pressure should be checked weekly until the target PCV (around 25%) is reached. After achieving the target PCV, the dosage of ESAs can be tapered, and monitoring can be reduced to every 1–3 months.
Potential Complications
- Hypertension: ESA therapy can lead to hypertension in some cats, so blood pressure should be regularly monitored.
- PRCA: Although rare, especially with DA, cats receiving long-term ESA treatment can develop PRCA, which requires discontinuation of ESA therapy and supportive care.
Further Reading:
Take a moment to read our other blog posts about other important management aspects of CKD:
Managing Diet and Mineral Balance in Cats with Chronic Kidney Disease
Maintaining hydration in cats with CKD
Managing proteinuria
Managing inappetence, nausea and vomiting