Elvis, Hemodialysis Patient at Penn VetIn both humans and animals, healthy kidneys clean blood by removing excess fluid, minerals, and wastes. Kidneys also make hormones that keep your bones strong and your blood healthy. When kidneys fail, harmful wastes build up in your animal's body, blood pressure may rise, and you animal's body may retain excess fluid and not make enough red blood cells. When this happens, your animal will need immediate treatment to replace the work of its failed kidneys.

In severe cases of kidney disease, hemodialysis is the most  effective method of replacing the lost function of the kidneys.

Information Regarding Hemodialysis at Penn Vet

  • Penn Vet will be unable to offer extracorporeal therapies for the foreseeable future.

Our Internal Medicine team is happy to consult with referring veterinarians on these cases regarding whether it is wise to pursue dialysis, other treatment options, pros, cons, and estimated costs.

Referring Veterinarians can call: 877-736-6838.

Contact Us

For more information or to make an appointment, contact:

Appointments: 215-746-8387

About Hemodialysis

Here are some typical questions our clients ask about hemodialysis:

What can hemodialysis treat?

  • The most common indication for hemodialysis is acute kidney injury.  Patients refractory to medical therapy, as well as oligoanuric patients, are candidates for hemodialysis. Nephrology patient at Ryan Hospital

    Electrolyte disturbances, such as hyperkalemia, can be managed with hemodialysis very quickly and effectively.  

    Chronic kidney disease can also be managed with hemodialysis (typically a four-hour session two or three times a week). Cost, however, can be a limiting factor that prevents most clients from pursuing this option for lifetime management.  

    Hemodialysis is often utilized in cats for stabilization prior to kidney transplantation.  

    Ultrafiltration therapy is a method to remove excessive fluid accumulation in patients with iatrogenic fluid overload (often seen with oligoanuric acute kidney injury) or congestive heart failure.

What is hemoperfusion?

  • Hemoperfusion is performed to help remove certain toxins from blood.  Large toxins or those with strong protein binding are unable to be removed across the filter during hemodialysis; therefore a charcoal cartridge is used to purify the patient’s blood.  This therapy can be quite effective for various intoxications, most commonly NSAIDs.

What other toxicities can be treated with hemodialysis?

  • Ethylene glycol toxicity can be devastating. Animals who become azotemic have a poor to grave prognosis.  Dialysis can be performed to support them while azotemic, but it may take three months or more before renal function returns (if at all). 
  • Canine hemodialysis patient at Penn VetHowever, ethylene glycol is very efficiently dialyzed, and nearly all ethylene glycol can be removed from the patient’s blood within one dialysis treatment. Patients who have been exposed to ethylene glycol, but have not yet become azotemic should be referred for hemodialysis immediately. 
  • Dialysis may remove the toxin in one treatment, thereby preventing renal damage from ever occurring. 
  • The nephrotoxin found within lily plants is unknown; however it is thought to be removed via hemodialysis.  Because of the grave prognosis once a cat has become azotemic after lily intoxication, hemodialysis should be considered in patients who have been exposed, however have not yet become azotemic. 
  • It has not yet been determined if the nephrotoxic component of grapes, raisins, and currants is dialyzable.

How long will my animal require hemodialysis?

  • The duration of dialysis therapy is quite variable.  Many toxins (such as ethylene glycol, lily Ryan Hospital blood donor, Fosseingestion, etc.) can be removed with a single treatment. 
  • Oligoanuric patients with acute kidney injury may only require one to three treatments until they become polyuric, thus often allowing the reintroduction of traditional management. 
  • Patients with severe kidney injury may require weeks to months to regain kidney function.  Dialysis is initially performed on an inpatient basis, then patients are transitioned to outpatient dialysis when stable.

What is the prognosis for patients requiring hemodialysis?

  • The survival for acute kidney injury patients treated with hemodialysis is approximately 50 percent, however there is a wide variability in mortality. 
  • Infectious etiologies (leptospirosis, pyelonephritis) have upwards of 90 percent survival, whereas toxicity (azotemic ethylene glycol or lily) is closer to 10-40 percent. 
  • While 50 percent overall survival may sound poor, remember that nearly 100 percent of these patients have already failed medical therapy.

In hemodialysis, your animal's blood is allowed to flow, a few ounces at a time, through a special filter Ryan Hospital, Hemodyalisys Equipmentthat removes wastes and extra fluids. The clean blood is then returned to their body. Removing the harmful wastes and extra salt and fluids helps control your animal's blood pressure and keep the proper balance of chemicals like potassium and sodium in its body.

Dialysis is available for both dogs and cats and can be used for acute or chronic kidney failure. Dialysis is used to treat:

  • Acute or chronic kidney failure
  • Animals for whom standard therapy (intravenous fluids, medication, etc.) has proven ineffective
  • Animals with life-threatening complications of kidney failure (e.g. high potassium levels and fluid in the lungs)
  • Animals who have eaten a poison that can be removed with dialysis

When dialysis is used for acute kidney failure, it is continued until the kidneys recover function or it becomes clear that the kidneys are not going to heal.  

Most of the time, whatever kidney repair is going to happen will occur within four weeks.  Occasionally the kidneys will heal sooner, and sometimes they take longer than four weeks to heal.  There is no way to predict recovery time at the outset.

With chronic kidney failure, the kidneys are permanently damaged. Dialysis is continued three times a week for the rest of the patient’s life.  In this case, kidney transplant is the only alternative to chronic dialysis.

Apheresis is a Greek term for "taking away" and is the therapeutic process of removing a portion of a patient's blood, while returning the remainder back to the patient. This is performed to remove toxic or pathologic substances from blood or to replace an abnormal component of blood.

When blood plasma is removed and donor plasma is administered to the patient the procedure is called Therapeutic Plasma Exchange (TPE) . Additionally, red blood cells and white blood cells can be exchanged (in the case of severe red blood cell parasitemia and other conditions) or reduced in quantity (in the case of leukemia). Platelets can also be removed, however this is typically performed for the purposes of collecting a platelet-rich blood product for donation.

TPE is the most commonly performed type of apheresis and has been used to treat a variety of diseases in veterinary medicine. Often, this procedure is performed to treat severe immune-mediated diseases, where circulating antigen-antibody complexes or other pathologic factors are contributing to disease. Diseases that are candidates for TPE include:

  • Immune-mediated hemolytic anemia (IMHA)
  • Immune-mediated thrombocytopenia (IMT)
  • Myasthenia gravis (MG)
  • Immune-complex glomerulonephritis (GN)
  • Lyme-associated nephritis
  • Pempahigus foliaceus (PF)
  • Polycythemia
  • Systemic lupus
  • Leukemia
  • Hyperviscosity syndrome
  • Pure red cell aplasia (PRCA)
  • Immune-mediated polyarthritis (IMPA)
  • Acute polymyositis
  • Polyradiculoneuritis
  • Immune-mediated encephalitis
  • Hyperlipidemia
  • Acute hepatic failure
  • Drug overdosage
  • Exogenous toxin removal (i.e., amanita)
  • Others

Diseases have varying schedules for treatment. To discuss if your patient may be a candidate for apheresis or TPE, please contact our nephrology team.

Renal transplantation is a treatment option for renal failure in cats. It is important to recognize that renal transplantation is a treatment for renal failure, and not a cure. The goal of renal transplantation is to provide a good quality of life for a cat that would otherwise be unable to survive; however, “normal” life expectancy is not yet achievable by today’s technology.

The Feline Renal Transplantation Program at Penn Vet was successfully initiated in February 1998 by Dr. Lillian R Aronson, VMD, DACVS, Associate Professor of Small Animal Surgery. After she received her VMD and finished an internship at the University of Pennsylvania's School of Veterinary Medicine, Dr. Aronson completed a small animal surgical residency at the University of California, Davis.

Learn more about Renal Transplantation at Penn Vet. 

Consultations and Referrals

Please inquire to learn more about the extracorporeal therapies now being offered at Penn Vet. 


Referring Veterinarian Office of Ryan Hospital
Vet Phone line: 877-736-6838
email: megann@vet.upenn.edu

We will gladly consult on any cases that you feel will potentially benefit from blood purification. Please call or contact us with any questions.