The SDMA Kidney Test: The Canary in the Coal Mine
Most pet owners would probably not get much out of their veterinarian talking about symmetric dimethylarginine . Abbreviated SDMA, this is a newer test for use in dogs and cats, operating on the presence of a biomarker that shows up earlier than traditional blood tests (BUN-blood urea nitrogen and creatinine) when kidneys either age or are affected by pathology. On average, SDMA can detect kidney disease onset up to 17 months earlier than the traditional blood tests.
So a pet owner might ask, “why is this potentially relevant to my pet?” Let’s start with the fact that once kidneys lose their tissue, they cannot regenerate or replace it. So, the earlier a veterinarian is on to the fact that a pet is “slipping” with regard to kidney function, the sooner pre-emptive measures can be taken to preserve the kidneys. Recommendations include lower protein (yet high quality protein) diets, phosphorous-binding drugs and potassium supplements to help the longevity of these pets affected. In our clinic we recommend Hill’s K/D (simply standing for “kidney diet” in both dogs and cats. Veterinarians at Hill’s have shared with me that dogs and cats that have been diagnosed with chronic kidney disease have twice the longevity when on K/D food, versus feeding commercially available diets.
Just as in humans, as go the kidneys, so goes the duration of life. It is estimated that half of all cats over the age of 10 suffer from chronic kidney disease. Kidney failure is the number one natural cause of death in cats, and in the top three of dog causes as well.
My first discussion concerning SDMA was three years ago, when the test was being released from the research level to the commercial laboratory level. The chance meeting I had was with one of the research team members from Oregon State University, at a veterinary conference in Tampa. No, it was not in a lecture hall, but at a lunch table. Complete strangers, we were taking our lunch break at the same time and we sat together at a table getting acquainted. Once he heard I was in practice, he asked me if I had heard of the SDMA test. When I told him yes-I had read something about this early detection test, he proceeded to tell me all about the work he and his team were up to on SDMA. He said that it would no doubt be on every senior pet profile before long.
Well, you guessed it. Fast-forward to 2017, and SDMA has become the “third” kidney function test. SDMA is now included on all our dog and cat send-out blood panels from IDEXX labs. Moreover, since this biomarker enzyme acts as an early detection vehicle regarding kidney function, it is often showing higher-than-normal values before BUN and creatinine values rise.
When I interpret these tests for pet owners, I simply refer to SDMA as the “canary in the coal mine” regarding kidney disease. SDMA will surely sniff out renal disease prior to the other blood tests!
Dr. Chris Duke