We have been performing hemodialysis at The Animal Medical Center for over 10 years and have recently added continuous renal replacement therapy (CRRT) to our program.
Animals, like people, have two kidneys that are in the abdomen close to the backbone. The kidneys have many roles, including filtering waste products, drugs, and toxins out of the blood stream and concentrating them in the urine for removal from the body. Normal kidneys can make the urine concentrated or dilute, based on the needs of the body, to prevent dehydration or water overload. The kidneys also regulate blood pressure and make certain hormones. When the kidneys fail, normal waste products build up to toxic levels in the body. Intravenous fluids may help flush these toxins out of the body. When this type of medical management is unsuccessful, dialysis is indicated to help remove these toxins.
The Animal Medical Center is the only veterinary facility that offers three forms of dialysis. The Nephrology team will evaluate each patient on an individual basis and recommend the most appropriate therapy.
Dialysis is available for both dogs and cats and can be used for acute or chronic kidney failure. Pets must be at least 2.5 kg (5.5 pounds).
Dialysis is used to treat:
When patients are first started on intermittent hemodialysis, they must be introduced gradually, to give them time to adapt. Thus, the first few treatments tend to be shorter with slower blood flow, gradually increasing speed and time of the treatment each day. Treatments are typically performed daily for few days in a row until the patient has adapted. Once the patient is adapted to the treatment, the treatments generally occur three days a week, until the patient recovers renal function. The standard treatment time during this maintenance phase is usually four hours for cats and five hours for dogs.
When patients are started on CRRT, the treatment is intended to be essentially continuous which requires 24 hour specialized nursing care. After these patients are stable, they will most likely be switched to intermittent hemodialysis.
Dialysis replaces many of the functions of the kidneys, but it cannot replace them all. Therefore, dialysis patients in the initial stages of treatment will need to stay in the hospital between treatments for ongoing medical care. This includes fluid treatments, antibiotics, anti-ulcer medications and many other medications. Because these animals are frequently vomiting, they need to get their medications by injection. Also when they are in this stage they will need constant monitoring of things like blood pressure, urine production, blood counts, etc.
Once the patient is more stable, and can take medications by mouth or by feeding tube (which is frequently needed during the recovery stage), they may be able to go home between treatments. The patient would then return on the three days a week treatment schedule.
The pet goes home with the dialysis catheter still in place. The catheter is covered by a bandage around the neck and needs no care at home other than to keep it clean and dry.
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.
Complete kidney shutdown can cause animals to die within four to five days. However, it can take up to four weeks for the kidneys to heal from acute injuries. Dialysis is intended to support patients during that healing time.
Not all pets with acute kidney failure can recover, even with dialysis. About half of these patients live when they were not expected to survive without dialysis to support them. Unfortunately, the other half of these patients cannot be saved despite all of our efforts. Of those who live, some recover completely with no lasting effectswhile others may end up with chronic kidney disease that requires a special diet and medications to help support them at home.
Some types of kidney disease have a better chance of recovery than others. Damage caused by infections and poor blood flow to the kidney can be successfully treated 50-75% of the time, whereas the chance of recovery from toxin induced kidney failure is only 20% with dialysis.
Pets with chronic kidney failure on life-long dialysis may live a year longer than they would have without dialysis.
Most animals take well to dialysis. After the initial dialysis treatment, they seem to look their worst, but they usually show signs of feeling much better by the end of the third treatment. They often appear much more alert, they show interest in being petted, and cats will begin grooming themselves. Some patients will even begin to eat and drink, which they couldn’t be coaxed to do before dialysis.
During the treatment, patients sit in a quiet room on a cushioned table with a blanket. A technician is always by their side to monitor their vital signs and respond to potential complications. Also, animals don’t seem to have the same degree of tiredness after dialysis that many people experience.
Any major medical or surgical treatment carries risks, and this is true for dialysis also. Some of the risks are due to the procedure and some are due to the kidney failure itself. The staff is trained to recognize potential problems, so immediate treatment or preventative measures can be used.
Hemodialysis is an intensive treatment that requires sophisticated equipment and specially trained staff. The average estimate for the care of a hemodialysis patient is $20,000-25,000 for the first 2-3 weeks.
Almost all patients considered for dialysis have already failed to respond to medical management, and the only other alternative is euthanasia. In some cases, particularly cats with chronic kidney disease, kidney transplantation may be available, and would usually be preferred over dialysis. Kidney transplantation is not suitable for cats that are severely sick, and sometimes dialysis may be necessary for a few weeks to allow time to arrange a kidney transplant. If kidney obstruction (typically from kidney stones or scarring after kidney stones) is the cause of the acute kidney failure, sometimes dialysis can be avoided by placing a tube directly into the kidney to drain the urine.
If your pet has kidney failure, and you are interested in pursing hemodialysis, you can make an appointment with a member of our Internal Medicine team by calling the AMC appointment desk (212) 838-7053.
You can also have your veterinarian call a member of the team to discuss your pet’s case at (212) 838-8100 or (212) 329-8618.
If your pet needs emergency dialysis after hours, bring him/her directly to the AMC for evaluation as our emergency department is open 24 hours a day. If emergency dialysis is indicated based on the emergency doctor’s evaluation, a member of the Internal Medicine team will be contacted.