Dog Diet: Kidney Failure and Diet

August 30, 2022
Diana Bocco
Reviewed By: 
Dr. Farshad Goodarzi - Animal Nutritionist
5 minute read

Kidneys play a very important role in the body, filtering out unwanted substances and toxins so they can be released through urine. The kidneys also regulate the balance of fluid and electrolytes in the body by continually filtering the blood. When the kidneys aren’t working properly, a lot of things in the body go wrong –toxin levels go up, causing nausea and vomiting, blood pressure starts to increase, and dogs become dehydrated. This leads to an imbalance of certain electrolytes. The kidneys are also partially responsible for red blood cell production and help with calcium metabolism.

Kidney problems can cause a number of issues that destabilize the body and can make your dog feel very sick. The sooner you catch the condition, the better your chances of helping your dog feel better again.


The easiest answer to this is … nobody knows. Sometimes it’s a combination of factors that over time cause the kidneys to “wear out.”

Acute kidney failure, which happens suddenly, is often the result of an accident. For example, your dog might ingest antifreeze, garden pesticides, or even human medication. Severe dehydration, severe bacterial infection, trauma (like being hit by a car or a fall) and untreated UTIs can also sometimes lead to acute kidney failure.

Chronic kidney disease is more of a mystery. Vets know it’s more common in older dogs and can be worsened by dental disease. But in some cases, it can also be genetic, triggered in dogs with diabetes or those receiving cancer treatment.  

According to The International Renal Interest Society (IRIS), breed is also a risk factor, as Shar Pei, Bull Terrier, English Cocker Spaniel, Cavalier King Charles Spaniel, West Highland White Terrier, and Boxer are more predisposed to kidney problems. They also point out that some commonly used medications, including non-steroidal anti-inflammatory drugs (NSAIDs) for pain, certain bactericidal antibiotics, and even some vaccines, can also increase the risk of chronic kidney disease.

Other potential risk factors include kidney infections and kidney stones, as well as leptospirosis.

IRIS also points out that there are some indications that diets with “high inclusion rates of inorganic forms of phosphate may lead to kidney damage in cats.” There haven’t been studies done on dogs, and more work is needed to understand why this affects cats, but it’s something to keep in mind: diet can sometimes have a direct effect on kidney health.


Detecting kidney disease can be very tricky. The easiest way is through a blood test that measures things like blood urea nitrogen (BUN), creatinine and phosphorus. Your vet can also check your dog’s SDMA (symmetric dimethylarginine), a marker for early kidney disease. When these numbers are elevated, it’s a sure sign that something’s amiss with the kidneys.

Of course, if you don’t notice any symptoms, you would have no reason to have your dog’s kidneys checked. And that’s when trouble starts. According to Pet Health Network, by the time you’re able to detect kidney disease, the kidneys are likely functioning at only 25% to 33% of their capacity.

Early signs of kidney disease can be tricky to recognize, but two things you often notice is increased thirst and urination. Dogs might also have “accidents” inside the house even though they’ve been housebroken for years or suddenly cannot get through the night without having to go out to urinate at least once. As these can also be signs of diabetes, it’s important to talk to your vet as soon as possible to rule out other diseases. Kidney disease often affects appetite and might cause dogs to be tired and lethargic as well. Vomiting and diarrhea are also possible.


Unfortunately, there’s no treatment available that will completely heal the kidneys and reverse kidney disease. There are a number of supplements you can use to stabilize them, and with the proper course of treatment, you might actually lower some of the numbers that are causing symptoms.

Intravenous (IV) fluid therapy is one of the most common ways to treat kidney disease, as IV fluids will help flush toxins and improve how your dog feels. If your dog has high blood pressure or is losing protein in his urine, your vet will also prescribe medications to control this.


A diet change is the most important thing you can do to help your dog’s kidneys. As a general rule of thumb, you want to feed your dog so that the pressure on the kidneys is minimal. Therefore, they need food which keeps the amount of unwanted substances at its lowest in the body. They also need food that keeps the optimum balance of electrolytes in the body. They will need the right amount and ratio of calcium and phosphorus as well as sodium, potassium and other minerals.

According to the Veterinary Medical Center at Tufts University, “pets with kidney disease should be fed diets reduced in phosphorus, protein, and sodium and supplemented with omega-3 fatty acids from fish oil.” Reducing phosphorus in the diet is especially important, as keeping phosphorus low is essential to slow down the progression of kidney disease.

Indigestible proteins produce a lot of waste products that the kidneys then have to deal with, so reducing the amount of crude protein your dog eats (by using highly digestible proteins instead) will be essential to make him feel better. Protein is the source of amino acids, which means you cannot completely eliminate protein from your dog’s diet, or his health will suffer further. But according to Today’s Veterinary Practice, you can make sure that you’re feeding high-quality protein – so even if you reduce the overall amount of it, you’re still providing optimal nutrition.

In a study comparing the lifespan of dogs with Chronic Kidney Disease eating a renal diet compared to a “regular” maintenance diet, the dogs eating a prescription renal diet lived significantly longer. In fact, after two years, 65% of dogs eating the maintenance diet had died from renal-related causes, but only 33% of those eating the renal diet had died for the same reasons.  

Pets with kidney disease should not eat snacks like cheese, as this contains both high protein and lots of sodium.

There are plenty of commercial renal foods available that are designed to provide all the nutrients to help the kidneys. This is a good first step for pet parents who feel overwhelmed with what to feed their dogs after the initial diagnosis.

Dogs with kidney disease can also do well on a homemade diet, but cooking it yourself can be very tricky. If this is something you want to pursue, you should contact a veterinary nutritionist to ensure you are feeding the proper amount of proteins, carbohydrates, veggies, vitamins and minerals, especially calcium and phosphorus, so your dog can get all the nutrients he needs without affecting his kidneys.


Fresh food has many benefits, as vitamins and minerals are supplied from natural sources. One of the most important components of a healthy kidney diet is high-quality protein. At Cola’s Kitchen, we use no preservatives, artificial products,  animal byproducts or “meals” from diseased livestock. Our tasty, fresh meals include things like human-grade salmon, veggies & fruits, which would provide healthy protein and omega oils that can help protect the kidneys.

Remember to always talk to your vet about food if your dog is sick to determine what his needs are.

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Cola's Kitchen precision diet is the first truly tailored diet for a unique approach to nutrition. Our diets are individually formulated and balanced to address the most precise nutritional requirements of your pup.

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