Kidney disease and kidney failure are becoming a common occurrence in dogs. One of the first signs is that your dog drinks and urinates more and asks to be let outside several times a day. This is because dogs with kidney disease are unable to concentrate their urine, meaning they produce a large volume of urine, with subsequent thirst and dehydration.
If this happens to your dog, it’s important to feed him the right food to support his kidneys. So here’s what you need to know about kidney diet for dogs .…
What The Kidneys Do
The kidneys are your dog’s water and toxin filtration system. Their main job is to remove waste products from your dog’s bloodstream and regulate fluids. When the kidneys malfunction, large amounts of fluid are flushed out of the body with the urine.
The wastes in your dog’s blood come from normal breakdown of muscle tissue and from his food. Waste that isn’t removed builds up in the blood and becomes toxic to the body, so your dog can experience nausea, loss of appetite and vomiting.
The kidneys also regulate the body’s level of important minerals like sodium, potassium and phosphorus. Phosphorus is the reason many veterinarians recommend low protein diets for dogs with kidney disease. The level of protein in diets for dogs with kidney disease is an important and often controversial question.
What To Feed Dogs With Kidney Disease
The best food for a dog with kidney disease is a fresh, whole food diet that contains high quality, digestible protein. This may not be what your veterinarian suggests.
Traditionally, vets have recommended restricting protein because they believe protein is poorly metabolized by dogs with kidney failure. This has proven to be incorrect.
Researchers used to believe that dogs were the same as rats they’d studied, so they thought lowering protein would support the kidneys. But in fact, studies have consistently shown that low protein diets don’t improve kidney function or survival times in dogs.
As long ago as 1985, researchers at University of Pennsylvania noted an earlier study of dogs who’d had 75% nephrectomy (kidney removal). That study showed that dogs fed the highest protein level (56%) had higher renal function measurements compared to dogs fed reduced protein.
“There was no evidence of deterioration of renal function in dogs fed the high level of dietary protein. […] These results suggest that the deleterious effects of high protein feeding seen in rats do not occur in dogs with comparable reduction in renal mass.”
Dogs need high quality protein to maintain muscle mass, and it’s especially true in older dogs. In a 2008 study, DP Laflamme DVM said …
“Protein restriction for healthy older dogs is not only unnecessary, it can be detrimental. Protein requirements actually increase by about 50% in older dogs, while their energy requirements tend to decrease. When insufficient protein is provided, it can aggravate the age-associated loss of lean body mass and may contribute to earlier mortality.”
So that means low protein could even shorten your dog’s life.
What dogs with kidney disease need is high quality, digestible protein, preferably in the form of a fresh, whole food raw diet. Keep reading for more detail about the best kidney diet for dogs.
But first, why should you avoid prescription kidney diets?
Why Avoid Prescription Kidney Diets?
As mentioned earlier, the main problem is that these diets are protein-restricted. And what protein they do contain is poor quality. Here are some other problems with prescription kidney diets:
This is unnecessary and potentially harmful. Reducing sodium can lead to tissue dehydration. Your dog needs good trace minerals and salt to help his body retain moisture properly.
Prescription kidney dits are intended to put weight on your dog. However, they use “junk” like high carbohydrates and poor quality fats to put weight on. Again, dogs need high quality protein to maintain muscle mass.
Dogs with kidney disease can get dehydrated easily, so they need moisture in their food. While canned kidney diets have more moisture, kibbles are very low in water. Kibbles are usually about 10-15% moisture compared to as much as 85% in fresh food diets.
Omega-3 Fatty Acids
In processed form, these fats can easily become rancid, making these supplements ineffective and even harmful. It’s better to add omega-3 supplements to your dog’s fresh food diet just before feeding.
Most commercial and prescription diets are laden with preservatives, artificial colors and synthetic vitamins and minerals. All these additives need to be excreted through the kidneys, creating further stress on these organs..
But … there is one good thing about these diets, and that’s that they’re low in phosphorus. This is the most important factor in diets for dogs with kidney disease.
The Problem With Phosphorus
Phosphorus can create extra work for the kidneys. If the kidneys don’t remove phosphorus, it can lead to dangerous calcium deposits in the organs. Protein is high in phosphorus and that’s why vets recommend low protein diets.
But you can still feed a fresh food diet and give your dog proteins that are low in phosphorus. This chart shows the phosphorus content of several different protein sources.
You can see that sardines are high in phosphorus, so it’s okay to feed a sardine as a treat, or to add omega-3 fatty acids, but you wouldn’t want to give a whole meal of sardines. Near the other end of the scale you’ll see wild duck is low in phosphorus, so that is a great meat source if you can get it.
Nitrogen Trap To Lower BUN
If your dog’s lab tests show a high BUN (Blood Urea Nitrogen) the nitrogen trap can help lower the nitrogen (contained in protein) and BUN levels. The nitrogen trap helps divert the waste products of protein metabolism from the bloodstream into the colon, which reduces the burden on the kidneys.
There are many ways to do this. The easiest is to add blended leafy greens to provide enzymes and whole food vitamins. Add probiotics and the prebiotics that feed them. Raw garlic, mushrooms and dandelion greens are good sources of prebiotics.
How To Support Your Dog With Kidney Disease
Here are a few more things to keep in mind if your dog has kidney disease.
Feed High Quality Protein
Again, avoid kibble and other commercial diets, including prescription kidney diets. Instead, feed your dog a fresh, whole food diet with easily digestible protein. Raw diets are more easily digestible for most dogs.
Feed high quality protein to maintain muscle mass. As well as the low phosphorus foods shown above, eggs are a great source of digestible protein for your dog. Your dog also needs high quality fat for energy.
Feed organ meat as 10-25 percent of your dog’s diet. It’s especially important to feed your dog kidneys. The nutrients in kidneys can help support the kidney itself. If you can’t get kidneys easily, feed glandular supplements that contain kidney and other organ meats.
Keep Your Dog Hydrated!
Fresh food diets go a long way to adding moisture to your dog’s diet. But always make sure your dog has access to fresh, clean filtered or spring water. Monitor your dog closely for signs of dehydration. If his stool is hard and dry or he seems lethargic, you need to get more fluids into him. Ideally you can do this by making sure he gets plenty of moisture in his diet. But if he gets very dehydrated, ask your vet to teach you how to give subcutaneous fluids at home. That way you don’t need to take your dog to the clinic for fluids.
Help support your dog with regular detoxification. Helping his body remove waste will ease the burden on his kidneys.
Herbs and Supplements
Ask your holistic veterinarian about herbs and supplements that can help your dog. Some options include …
Dandelion, parsley and urva-ursiall support the kidneys. Add some fresh chopped herbs to your dog’s food, giving a pinch per 10 lbs, up to 1 Tbsp for a dog 100 lbs or larger. If you buy dried herbs, capsules or tincture, assume the dose on the label is for a 150 lb human and adjust the recommended dose for your dog’s weight.
Medicinal mushrooms have properties that can support kidney health. Cordyceps has especially good affinity for the urinary tract.
Rehmannia is a Chinese herb that nourishes the kidneys. There are other Chinese formulas that include this herb as well. You’ll need help from a Traditional Chinese Veterinary Medicine (TCVM) practitioner (find one at ahvma.org) to tell you which combination and dosage is best for your individual dog.
These guidelines will help support your dog’s kidney function. As always, fresh foods win out over commercial foods, especially in the face of chronic disease.
Finco DR, Brown SA, Crowell WA, et al. Effects of dietary phosphorus and protein in dogs with chronicrenal failure. American Journal of Veterinary Research. 1992 Dec;53(12):2264-2271.
Martin, WF, Armstrong, LE & Rodriguez, NR Dietary protein intake and renal function. Nutr Metab (Lond) 2, 25 (2005).
DP Laflamme, Pet Food Safety: Dietary Protein. Topics in Companion Animal Medicine, Volume 23, Issue 3, 2008, Pages 154-157,
John L Robertson et al. Long-term renal responses to high dietary protein in dogs with 75% nephrectomy, School of Veterinary Medicine and School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, and Baltimore City Hospitals, Baltimore, Maryland, USA, Revised 23 May 1985.