Dialysis and Renal Replacement Therapy in Dogs

Dialysis is used to treat kidney failure. There are two types of dialysis: hemodialysis and peritoneal dialysis. When most people talk about dialysis, they are referring to hemodialysis. This involves filtering the dog’s blood through a machine called a hemodialyzer to cleanse it of toxins and waste. This machine contains a solution called dialysate, which is separated from the blood through a dialyzer membrane. Dialysate attracts toxins and waste from the blood through the membrane. Because the IV is long and large, an IV port may be left in place under the skin until the treatments are completed. A single hemodialysis treatment lasts between three to five hours. Peritoneal dialysis essentially uses the dog’s abdomen as the dialyzer membrane. Dialysate is administered to the abdomen and absorbs toxins and waste for several hours. The waste material is then drained.

Continual renal replacement therapy (CRRT) is similar to dialysis, but takes longer. Toxins are removed at a continuous rate between 24 to 48 hours. This procedure is meant to filter the blood of toxins just as the kidney would. With CRRT, fewer treatment sessions are required. It is less commonly performed than dialysis, is more invasive, and will require sedation or anesthetization as well as hospitalization. However, it is also associated with fewer complications.

Hemodialysis

1. A thorough physical examination is carried out at the start of each session.
2. Dogs will lie on a soft pad and wear a special harness for the duration of the session. This is meant to comfortably restrain the dog while still allowing him to move.
3. The dialysis catheter is unwrapped and cleaned prior to insertion.
4. Blood samples are taken and analyzed before treatment begins.
5. The lines hooked to the dialysis machine are attached to the catheter lines.
6. The dialyzer extracts blood while simultaneously replacing it with specialized fluids to keep the dog stable during the procedure.
7. Up to one cup of blood is cleaned at a time before it returns to the body, and new blood is drawn into the machine. This cycle continues for several hours until the treatment is complete.
8. Dogs are allowed to eat and drink during the procedure.
9. Once the dog is stable, he is released from the treatment center.

CRRT

1. Steps 1-4 are repeated.
2. The dog will be sedated or anesthetized.
3. The catheter is connected to a special machine, which will filter the blood over a 24 to 48 hour period.
4. Sedation or anesthetization is typically required for the full duration of treatment.

The efficacy of dialysis and CRRT will depend on the overall health of the dog and the nature of the disease. Improvement is typically seen within four weeks. However, healing times will vary based on the individual case. Some dogs, particularly those with chronic kidney failure, may need to remain on dialysis for the rest of their lives.

Most dogs will be lethargic on the return home, and will spend the day sleeping. Postprocedural pain is not usually a problem. Dietary changes are often recommended in conjunction with treatment. Some dogs will require intravenous fluid supplementation at home. For these cases, a veterinary dialysis specialist will train you. Stressful situations should be avoided, and the dog should be kept calm as much as possible. Follow-up appointments will be scheduled to administer additional treatments, monitor healing, and conduct additional tests.

The cost of dialysis and CRRT will vary based on the number of treatments needed as well as standards of living and additional costs incurred. The average price of dialysis and CRRT, for the first two to three treatments, ranges from $3,000 to $4,500. Subsequent treatments typically cost $600 to $700 each. This price may not include the cost of hospitalization.

Complications from dialysis may include, but are not limited to:

• Nausea
• Loss of appetite
• Metabolic bone disease
• Carnitine and taurine deficiency
• Complications and infection associated with dialysis catheter placement

Dogs undergoing dialysis for chronic kidney failure will require treatment for the rest of their lives. The only alternative treatment for chronic kidney failure is kidney transplant.

These complications are not associated with CRRT. The primary complication with CRRT is blood clotting in the CRRT circuit. The dialysis specialist will discuss all potential complications with you prior to treatment.

Kidney disease and kidney failure are difficult to prevent because the cause often remains unidentified. Dietary changes may help prevent kidney disease. Poisons and toxic substances should be kept out of reach of pets at all times to prevent ingestion. Dogs treated for kidney failure, particularly chronic kidney failure, should not be bred.