Hypoalbuminemia is defined as an abnormally low level of albumin in the blood. Albumin is the most abundant protein produced by the liver, and it serves a critical physiological function known as "oncotic pressure." Essentially, albumin acts like a sponge that holds water inside the blood vessels. In a healthy animal, the kidney filters keep this large protein in the bloodstream. However, in cases of Glomerulonephritis or severe Chronic Kidney Disease (CKD), the glomerular filters become damaged and "leaky." This allows albumin to escape into the urine, a condition called Proteinuria or Protein-Losing Nephropathy (PLN). As albumin is lost, the blood loses its ability to hold onto fluid. The water leaks out of the vessels and into the body tissues or cavities. This results in edema (swelling of the limbs), ascites (fluid in the abdomen), or pleural effusion (fluid in the chest), which can impair breathing. For the CKD cat, this loss of protein also contributes to severe muscle wasting and weight loss, necessitating aggressive management of the protein loss (often using ACE inhibitors) to seal the leaky filters.
Disclaimer: This content is for educational purposes only and does not constitute veterinary medical advice. Always consult with your primary care veterinarian or a veterinary internal medicine specialist regarding your cat’s specific condition.