Kidney Failure in Cats

15 min read




Cancer of the kidney is extremely rare in cats. If seen, it typically takes the form of secondary invasion of metastatic cancer originating in a distant tissue. In cats with leukemia disorders, the kidneys can be infiltrated with neoplastic leukemic cells which can severely compromise renal function. There is also a form of leukemia in cats that targets the kidneys and crowds out normal kidney cells.


External Toxins (Poisonings)


One of the most devastating external toxins that causes kidney failure in cats is antifreeze that contains ethylene glycol. It doesn't take much of this sweet tasting liquid to prompt crystals to form in the delicate tubules of the kidney's filtration systems. Other renal toxins include Vitamin D, thallium, turpentine, heavy metals such as lead and mercury, even parts of a Easter Lily. There is also evidence that raisins/grapes can be nephrotoxic to cats.




Endotoxins are chemicals produced within the animal that are toxic. The most common type is that group of poisons formed by certain types of bacteria. Clostridia organisms are famous for causing tetanus. Many bacteria produce toxins from their normal metabolic waste products.  In others, when they die off they leave behind toxins that can have damaging effects on delicate body tissues such as kidney structures and heart valve tissues. 


Endotoxins can have systemic effects as well and play a role in triggering shock in an animal where blood pressure declines, heart output diminishes and body tissues become starved for oxygen and nutrients. The resulting shock can leave irreversible damage in any organ of the body, including the kidneys.




Some types of medications can be nephrotoxic such as acetaminophen (analgesic), amphotericin B (antifungal), adriamycin (doxorubicin) in cats, kanamycin (antibiotic), neomycin (antibiotic), polymyxin B (antibiotic), cisplatin (a cancer drug), penicillamine (chelating agent/immune modulator), Cyclosporine (immunosuppressive), amikacin (antibiotic), and radiographic contrast agents. 


Autoimmune Diseases


Systemic Lupus Erythematosis  (SLE), also known as the great imitator, can be difficult to diagnose since it can manifest as a disease of the skin/mucous membranes/nails, kidney and/or joints. As a consequence of the animal's adverse and abnormal immune response to its own body tissues and proteins, many organ sites can be affected, including the kidneys.


As the kidneys filter the circulating blood the abnormal immune molecules are trapped in the glomeruli and blood vessels, causing the kidney to leak protein. A condition called Glomerulonephritis is the result and all sorts of abnormal kidney function can occur due to the damaged glomeruli.


Although not proven to be a result of an autoimmune disorder, the deposition of protein called Amyloid can actually occur in any tissue of the body. The kidneys are most commonly affected and since the protein deposition destroys normal function, renal amyloidosis can be particularly serious due to the fact that kidney tissue does not repair itself. 


Amyloidosis is fairly common in Abyssinian, Siamese, and Oriental Shorthaired cats.