Will a 7-day renal diet lower my cat's kidney SDMA levels, or longer?

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! I am sorry that Tony is experiencing early kidney disease. Yes a prescription diet has been shown to help with chronic kidney disease and there is a chance it could lower the SDMA and other kidney values. It will help with progression. I would be sure your Vet has checked a urine sample for protein and infection as well as a blood pressure. There are medications that can and should be started if those things are abnormal. I wish you and Tony the best!

SDMA (symmetric dimethylarginine) is a renal biomarker specific to kidney function. It has proven to be a more reliable indicator of kidney function than creatinine which enables veterinarians to detect kidney disease earlier. Once elevated, it usually will not go back down. A complete blood chemistry would check for any underlying diseases that might be causing kidney damage. Diseases like diabetes, hyperthyroidism or Cushing’s disease. If Tobi is on any chronic medications (like an NSAID (Rimadyl etc.) those may cause a decrease in kidney function. A urine bacterial culture might be indicated and an x-ray for possible urinary tract stones. You should have his blood pressure checked as hypertension is often associated with kidney disease. Tobi will need to continue to have the SDMA monitored as well as the other kidney values ( BUN, CREA, Phosphorus). If you want more information as to how the kidneys are functioning you could request a urine protein:CREA ratio test. The urine protein:creatinine ratio is a simple test that measures how much protein is being lost through the kidneys. It is used to determine whether a pet may have serious kidney disease. The test involves measuring the amount of protein and creatinine in the same urine sample, and expressing the difference between the two values as a ratio. Also, an abdominal ultrasound can be done to look at the architecture of the kidneys. This should be done by a specialist. They will also measure the kidneys to see if their size is appropriate. Kidney disease cannot be "fixed" but it can be managed especially if caught early with the SDMA test. Tobi should be placed on a prescription diet to help support the kidneys. Talk with your vet about this. I hope this helps. If you have any more specific questions please post again. Best wishes to you and Tobi.

Response to the k/d diet can vary significantly depending on the stage of kidney disease and also whether there are other therapies implemented simultaneously. If the kidney disease is mild, the k/d diet can improve blood work values in as little as 4-6 weeks.

I would probably call this stable as well - some values are up while others are down. While these parameters are related to kidney function they do not directly measure kidney function and there are other things that could make the values vary slightly day to day. While a kidney diet can slow the progression of disease I doubt that adding a little cat treat to the food has made much of a difference and it is more important that Tony has a good appetite.

Thank you for submitting your question regarding Tony. I agree that he is in the early stages of kidney failure based on the lab results you have provided. Kidney disease can cause low levels of potassium so it is good that you are supplementing him. Kidney values can fluctuate up and down a bit, but you want to assess trends over time to see how he is doing. SDMA and creatinine are more sensitive indicators than BUN. I would ask if his phosphorus level is in the target range for his degree of kidney disease (based on the IRIS staging) and make sure he has had his blood pressure measured recently. I hope this information helps!

Yes, by its nature kidney diets tend to be less enticing than other ranges (being lower in salt etc) and can take some time to gain full acceptance. As long as he has no gatrointestinal side effects and is eating more than 75% of recommended amount I would not be overly concerned but any less than this I would continue with the mixed diet and gradually reduce the last stage over 2-3weeks. Kidney diets are extremely effective, and although less than ideal, a mixed senior/kidney diet is still helpful (unlike many prescription foods which should be fed exclusively)

Unfortunately kidney values can not be interpreted without a urinalysis and specific gravity. Elevated BUN is not always CKD but this would be more likely in the face of poorly concentrated urine ( pred will also effect this). CKD is staged via what is called IRIS. This takes in to account creatinine, protein in the urine, and blood prressure. SDMA is newer and thought to be an earlier indicator then BUN/creatinine as these as insensitive markers of kidney function. This has now been incorporated in to the new IRIS scheme. What i would recommend for your kitty is a urinalysis and blood pressure to better stage. For early stage CKD kitties a renal diet is recommended. It is also important to treat any high blood preesure or significant protein in the urine as these can worsen kidney function. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!