Feeling Better with Kidney Failure, Part 1 by Shelley R. Epstein, VMD, CVH

Kidney failure in dogs and cats has many causes, but it does not have to be a death sentence. As you know, at Wilmington Animal Hospital we integrate whatever therapies work to do the most we can to help our patients. We have many tools in our box when it comes to helping dogs and cats with ailing kidneys!

Kidney failure in dogs and cats is not an all-or-none diagnosis. Pets don’t have either “good” kidneys or “bad” kidneys, but rather have varying degrees of good or bad. What does this mean?

The kidneys are made of millions of little functional units called nephrons. As we age- and by we, I mean our dogs, cats, and us- the nephrons start to shut down, one by one.  A human by the age of 40 has lost about 20% of these nephrons, and the only difference she would notice is possibly needing a little bathroom trip in the middle of the night. The rate at which this aging of the kidneys occurs varies from individual to individual.

The most common cause of kidney failure is getting old. As the healthy pet ages, if he is not afflicted with a problem that leads to his death, Mother Nature holds in reserve her mechanism by which no being may live forever- and that is called kidney failure. In other words, we all will die sometime, and if nothing else causes our death, then kidney failure will.

But…At Wilmington Animal Hospital, we have many tools that we use to slow down the rate of kidney failure while making cats and dogs feel good. In this first of two blogs on kidney failure, we’ll review the conventional options, including an exciting relatively new one.

First, what are some of the time-tested “conventional” treatments?

Conventional therapy for kidney failure is usually aimed at addressing the excesses and deficiencies that occur from a lack of kidney function.

The excesses include:

1.      Build-up of “uremic toxins.” The kidneys are not able to filter these out, so they remain in the bloodstream and suppress the appetite and sometimes cause ulcers in the mouth and gastrointestinal tract.

2.      Build-up of phosphorus in the blood. Like the uremic toxins, the kidneys simply lose their ability to filter this out of the blood and place it in the urine. High levels of phosphorus also suppress the appetite.

3.      Elevated levels of parathyroid hormone (PTH). This hormone increases as kidney failure progresses. And, like a vicious cycle, elevated levels of this hormone make the kidney failure worse. Wouldn’t it be nice to neutralize this pesky hormone?

The deficiencies include:

1.      Fluid loss. The blood runs through the kidneys, at which point the kidneys are supposed to put the fluid portion back into the bloodstream and put a limited amount of fluid down into the bladder for urine. With decreasing kidney function, more water goes into the bladder and less back into the bloodstream, causing dehydration.

2.      Protein loss in the urine because damaged kidneys leak protein from the bloodstream into the urine.

3.      Anemia. The kidneys produce a hormone which tells the bone marrow to make more red blood cells. In some cases of kidney failure, the kidneys stop making this hormone, and less red blood cells are produced. In addition, the presence of uremic toxins, or “uremia,” can shorten the lifespan of the existing red blood cells.

Collateral damage: Hypertension (high blood pressure)

Not every patient develops every problem above. Likewise, the conventional therapy is tailored to the individual patient’s needs:

1.      Fluid therapy to rehydrate and help flush out the uremic toxins. Some patients need hospitalization initially, but most can receive this therapy at home.

2.      Phosphate binders taken orally to bind up the phosphorus that is eaten in the diet. This prevents the phosphorus from being absorbed from the intestines into the bloodstream in the first place, so the phosphorus levels stay low.

3.      Diet modifications if the pet will allow it. Good luck with this with cats.

4.      Erythropoietin (EPO) injections to stimulate the bone marrow to make more red blood cells. Sound familiar? This is the “blood doping” hormone that got all those Tour de France cyclists in trouble. But at least we know it works.

5.      Oral medication to slow down the protein loss from the bloodstream into the urine

6.      Blood pressure medication which slows down the kidney failure and prevents other problems associated with high blood pressure

7.      Calcitriol therapy to combat elevated PTH levels. Read the next paragraph!

Calcitriol therapy is relatively new- it’s being increasingly used in veterinary medicine. We’ve been using it for the past 3 years with tremendous results. By lowering the PTH levels which are making the kidneys fail, the rate of the failure slows down, and, most importantly, the patient feels a lot better and eats more!

Calitriol is a vitamin D relative. It comes in a tasty liquid that is given either daily or twice weekly, usually with meals. Patient compliance is rarely an issue.  We are very excited to be able to offer this relatively safe and very effective treatment for your pets!

If your dog or cat is in kidney failure, or if you have an older pet who has not had his/her kidney function checked in a while, you might want to schedule a consult with one of our veterinarians:

WilmingtonAnimalHospital.com

(302) 762-2694