A prescription kidney (renal) diet is a cornerstone of treatment for chronic kidney disease in dogs. In a randomized trial, dogs with kidney failure that ate a renal diet had fewer uremic crises and lived longer than dogs on regular food.1,2 These diets limit phosphorus, contain moderate amounts of high-quality protein, and add omega-3 fatty acids.2,3 Most vets start one at IRIS Stage 2, or earlier if there is protein in the urine.4,5 This guide explains what kidney diets change, when to start, how to help a picky dog eat, homemade diets, and treats and foods to avoid.
Key safety points
- Always keep fresh water available. Never limit water for a dog with kidney disease.3
- Never feed grapes, raisins or dried currants. No amount is known to be safe.6,7
- Don't force-feed a kidney diet, which can make your dog refuse it. Call your vet if your dog eats poorly.8
- Talk to your vet before changing food, adding supplements or cooking at home.9,2
What the Research Shows
- Kidney diets help dogs live longer. In a 2-year trial of 38 dogs with kidney failure, 33% of dogs on a renal diet died of kidney causes, compared with 65% on regular food. Dogs on the renal diet lived about 13 months longer.1,2
- Dogs that stuck with a kidney diet lived longer. In a study of 116 dogs with CKD (Stages 2 to 4), those that ate a kidney diet, commercial or vet-formulated homemade, at least 75% of the time lived longer.10
- Home recipes often fall short. None of 67 published home-cooked kidney diet recipes met all nutrient recommendations, and 95% of the dog recipes were low in choline.11,12
- Phosphorus is key. In dogs with experimentally reduced kidney function, 75% of those fed less phosphorus survived 2 years, compared with 33% fed more.2
What a Kidney Diet Changes
- Less phosphorus. This is one of the most important changes and the least controversial.3,2
- Moderate, high-quality protein. Too much protein adds to the waste the kidneys must clear, but too little causes muscle loss and other problems. Whether restricting protein slows kidney disease in dogs is still debated.8,2
- More omega-3 fatty acids from fish oil, which reduced protein loss in the urine and slowed decline in research dogs.2,13
- Less sodium, reduced gradually.8,2
- Extra B vitamins, which are lost in the larger volume of urine, and usually extra potassium, because low potassium is common in dogs with kidney disease. A few dogs have high potassium instead, so your vet will check.8,2
Kidney diets are prescription foods. Over-the-counter foods contain much more phosphorus, protein and sodium.9
When to Start a Kidney Diet
Most vets recommend a renal diet from IRIS Stage 2, or from Stage 1 if there is persistent protein in the urine.4,5 See kidney disease in dogs for how staging works.
If Your Dog Won't Eat the Kidney Diet
Getting a dog with kidney disease to eat is often the hardest part.9 Dogs that lose muscle or stop eating tend to do worse, so keeping your dog eating matters.10,15
- Try a different flavor or another brand of kidney diet.2
- Ask your vet about medicine for nausea or to stimulate appetite.9,4
- A little honey or maple syrup may tempt some dogs (not for diabetic dogs); count it as part of the treat allowance.16
- Don't add supplements, broths or extra meat without your vet's advice, and wait until your dog is fully switched to the new diet before adding anything.14,16
- If your dog still won't eat, your vet may suggest a home-cooked diet designed by a nutritionist, or a feeding tube.2,4
Homemade Diets
A home-cooked kidney diet can work, but only if it is formulated for your dog by a board-certified veterinary nutritionist (ACVIM Nutrition, formerly ACVN).2 Recipes found online or in books often have serious problems: in one study, none of 67 published kidney diet recipes met all nutrient recommendations, and most dog recipes were low in protein or key amino acids.11,9
Treats and Foods to Avoid
Keep treats to no more than 10% of your dog's daily calories.16
Better choices
Lower-phosphorus fruits and vegetables such as apples, watermelon, blueberries, bananas, green beans, zucchini, broccoli and carrots.16
Avoid
- Most meats, jerky, bully sticks, rawhides, pig ears, antlers and bones, which are high in phosphorus or protein16
- Salty foods and snacks, since kidney diets limit sodium9,8
- Grapes, raisins, dried currants, tamarind, and homemade play dough made with cream of tartar6,7
- Chocolate, onions, garlic and avocado16
Ask your vet before giving eggs, cheese or other protein-rich foods.
Water
Dogs with kidney disease lose more water in their urine, so they need fresh water available at all times. Never withhold water.3,4 Canned food adds water to the diet and may help dogs that don't drink enough. In later stages, your vet may recommend extra fluids given under the skin.14,4
Frequently Asked Questions
What is the best dog food for kidney disease?
A prescription kidney diet chosen with your vet. These are low in phosphorus and have the best evidence in dogs.
Can I buy kidney dog food without a vet prescription?
Kidney diets are prescription foods sold through your vet. Over-the-counter foods are much higher in phosphorus, protein and sodium, so ask your vet which diet fits your dog.
What should dogs with kidney disease not eat?
Grapes, raisins, high-phosphorus treats such as jerky and rawhide, salty foods, chocolate, onions and garlic.
Are eggs good for dogs with kidney disease?
Ask your vet first. Eggs are a protein-rich food, so they should only be part of a vet-approved diet.
Should dogs with kidney disease eat a low-protein diet?
Kidney diets use moderate amounts of high-quality protein. Too little protein can cause muscle loss.
Should I limit my dog's water?
No. Dogs with kidney disease need fresh water available at all times.
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Sources and further reading
This article was written and fact-checked on October 18, 2026 against current veterinary references and specialist guidelines:
- Jacob F, Polzin DJ, Osborne CA, Allen TA, Kirk CA, Neaton JD, Lekcharoensuk C, Swanson LL. Clinical evaluation of dietary modification for treatment of spontaneous chronic renal failure in dogs. J Am Vet Med Assoc. 2002;220(8):1163-1170.
- Witzel Rollins A. Dietary Guidelines for Dogs with Chronic Kidney Disease (CKD). Today's Veterinary Practice, July/August 2018.
- International Renal Interest Society. What pet owners should know. IRIS, accessed October 2026.
- International Renal Interest Society. IRIS Pocket Guide to CKD. IRIS, June 2026.
- Van Vertloo L. Renal Dysfunction in Dogs and Cats. Merck Veterinary Manual (professional version), reviewed March 2025, updated March 2026.
- Hayes C. Grape, Raisin, and Tamarind Toxicosis in Dogs. Merck Veterinary Manual (professional version), reviewed September 2024.
- Handley H. Journal review: Wegenast CA, et al. Acute kidney injury in dogs following ingestion of cream of tartar and tamarinds. Pet Poison Helpline, December 2022.
- Fascetti AJ, Delaney SJ. Nutritional Management of Chronic Renal Disease. UC Davis School of Veterinary Medicine, June 2018.
- Tufts Your Dog. Diet for Dogs with Kidney Disease. Your Dog (Cummings School of Veterinary Medicine at Tufts University), undated.
- Pedrinelli V, Lima DM, Duarte CN, et al. Nutritional and laboratory parameters affect the survival of dogs with chronic kidney disease. PLoS One. 2020;15(6):e0234712.
- Larsen JA, Parks EM, Heinze CR, Fascetti AJ. Evaluation of recipes for home-prepared diets for dogs and cats with chronic kidney disease. J Am Vet Med Assoc. 2012;240(5):532-538.
- Pet Food Industry. Home-prepared diets for pets with CKD. Petfoodindustry.com (summary of Larsen et al. 2012).
- Brown SA, Brown CA, Crowell WA, Barsanti JA, Allen T, Cowell C, Finco DR. Beneficial effects of chronic administration of dietary omega-3 polyunsaturated fatty acids in dogs with renal insufficiency. J Lab Clin Med. 1998;131(5):447-455.
- Elliott DA, Lefebvre H. Frequently asked questions: chronic renal failure. In: Pibot P, et al., eds. Encyclopedia of Canine Clinical Nutrition. IVIS, 2008.
- Rudinsky AJ, Harjes LM, Byron J, Chew DJ, Toribio RE, Langston C, Parker VJ. Factors associated with survival in dogs with chronic kidney disease. J Vet Intern Med. 2018;32(6):1977-1982.
- Linder DE, Gibeley M. What Treats Can I Give My Dog With Kidney Disease? Petfoodology, Cummings School of Veterinary Medicine at Tufts University, May 2018.
About this article
Last updated : new page, written using IRIS, Tufts, UC Davis and Merck Veterinary Manual guidance and published research on kidney diets in dogs.
This page is for general information and is not a substitute for an exam by your veterinarian.
