Understanding Extracorporeal Renal Replacement Therapy (ERRT)

AKI is a sudden and sometimes reversible loss of kidney function. In these cases, ERRT acts as a support system, helping to keep the patient stable while the kidneys have time to recover. It can remove accumulated toxins and help reduce signs such as nausea, lethargy, and loss of appetite.

·       Oliguria or anuria: When a pet is producing little or no urine despite appropriate fluid therapy, ERRT may be needed to remove excess fluid and waste products.

·       Fluid overload: If fluid administration is contributing to breathing difficulty, heart strain, or other complications because the patient cannot excrete enough urine, ERRT can physically remove excess water.

·       Severe metabolic imbalance: ERRT may be indicated for dangerous electrolyte or acid-base abnormalities, such as severe hyperkalaemia or acidosis, that do not respond adequately to medical management.

For animals with AKI, dialysis is generally intended to be short term, lasting days to weeks and occasionally longer, depending on the cause of injury and evidence of renal recovery. Treatments may be needed daily at first, then less frequently as the patient stabilises.

CKD is an irreversible and progressive decline in kidney function. ERRT does not cure CKD, and its role in chronic cases varies depending on local availability, ethical considerations, patient welfare, owner goals, and whether kidney transplantation is a realistic option.

·       Acute-on-chronic crises: When a pet with stable CKD suddenly deteriorates because of dehydration, infection, toxin exposure, or another treatable problem, ERRT may help remove toxins and support the patient while clinicians attempt to return them to their previous baseline.

·       Management of severe uraemia: In advanced CKD, medications such as anti-nausea drugs and appetite stimulants can reduce the effects of retained toxins, while ERRT can remove some of those toxins directly. However, if ERRT is used for ongoing CKD management, treatment would usually need to continue for the rest of the pet’s life.

·       Bridge to transplant: In some regions and in selected feline cases, dialysis may be used to stabilise a cat before kidney transplantation. Where transplantation is not available or is not considered ethically acceptable, chronic dialysis should be considered very carefully.

Because chronic dialysis can require multiple treatments each week and may impose a significant burden on the animal and family, quality of life should be discussed openly before treatment is pursued. If there is no realistic prospect of renal recovery or transplantation, euthanasia may be an appropriate and compassionate consideration when ongoing treatment cannot provide an acceptable quality of life.

Another important use of extracorporeal therapy is the emergency removal of certain ingested toxins. Pets may ingest human or veterinary medications at toxic doses, potentially leading to kidney or liver injury, neurological complications, or death. Common examples include nonsteroidal anti-inflammatory drugs, some antiseizure medications, and antifreeze containing ethylene glycol.

Many toxicities require only one extracorporeal treatment to remove enough toxin to reduce the risk of serious complications, although the treatment plan depends on the substance involved, the dose, timing, patient size, and clinical status. Speed is critical. If a pet has ingested a potentially toxic medication or chemical, owners should contact a poison control hotline and seek urgent veterinary attention. Referral to a hospital that offers ERRT or ECTR may be recommended when extracorporeal removal is likely to improve outcome.

International renal interest society best practice consensus guidelines on the use of continuous renal replacement therapy in dogs and cats

The Veterinary Journal Volume 315, February 2026,106548

doi: 10.1016/j.tvjl.2026.106548. Epub 2026 Jan 7.