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The Pet Renal Code (Kidney Disease in Dogs and Cats)

Chronic Renal Failure (CRF), also called Chronic Renal Insufficiency (CRI), is a serious, terminal condition so it’s important that dogs and cats with CRF have their health managed by a veterinarian. It’s critical for people to know how this condition progresses so they can reduce their pet’s end-of-life suffering.

This post contains details that I often mention to people who have pets with renal (kidney) issues. My own cat, Meek, had CRF. I hope that others can learn from hearing about my experience with Meek so their pets can live longer, more comfortable lives. It was painful to see Meek’s frustration with food near the end of his life: he’d walk to his dish and act like he wanted to eat, but he’d sniff it and walk away disappointed. One detail that I wish Meek’s vet had made clear to me was that animals with CRF die of starvation. They stop eating because they feel nauseous. If I had known this, I would’ve kept a closer eye on Meek’s eating behavior so I could’ve had a chance to give him anti-nausea and antiacid medications (pills or creams rubbed into their ears). More times than I can count, I’ve seen the simple addition of those medications add months and even years to the lives of animals who have stopped eating enough or stopped eating altogether. I also would’ve done weigh-ins every few days. And I would’ve put an end to his suffering sooner than I did.

Please don’t despair if your dog or cat has kidney failure or kidney insufficiency. Many animals with renal issues can live long after they’ve been diagnosed, as long as their eating is properly managed.

Jump to: What is CRF | What are symptoms of CRF | What causes CRF | How is CRF diagnosed | How is CRF managed | Select sources

What is Chronic Renal Failure (CRF)?

Meek, my first cat with CRF

CRF results when the kidneys no longer effectively eliminate waste products, which causes waste to accumulate in the body. Basically, pets with CRF are poisoned by the bodily waste that their kidneys are unable to filter. As CRF progresses, they may experience electrolyte imbalances, anemia, and blood pressure problems.

With early detection, proper diet, and hydration, pets with CRF can remain active and comfortable for a long time.

What are symptoms of CRF?

There are many symptoms and behaviors that could indicate that an animal has CRF. The most telling signs are increased thirst and excessive urination. Both of which can lead to health problems of their own.

Additional symptoms are loss of appetite, weight loss, nausea and vomiting, increased licking of their lips, excessive drooling, dehydration, constipation, hunching over the water bowl, oral ulcers, a grinding or crackling sound in the jaw, and stomach irritation. As CRF progresses, some pets also experience worsening breath, muscle wasting, weakness, lethargy, increased sensitivity to sound, electrolyte imbalances, anemia, blood pressure problems,and depression. Of course, not all pets have all the symptoms at the same time.

Meek’s initial symptoms were that he would act very hungry and would run to his dish when I gave my cats dinner, but he’d sniff the food and walk away looking disappointed. He was clearly very hungry but something about his usual favorite foods made him feel icky. So Meek ate less and lost weight. He also began drinking more water and, of course, producing more urine. As his CRF progressed, Meek lost some muscle mass and had more difficulty jumping up onto his favorite perches and beds, he spent more time sleeping in dark secluded places, and was pretty lethargic.

It’s vital to begin treatment as soon as a CRF diagnosis is made since symptoms don’t usually appear until approximately 70% of renal function is lost. That’s because only 30% of kidney capacity is needed for normal functioning.

What causes CRF?

Scientists have not yet identified the exact causes of CRF, but there is evidence of a variety of contributing factors including high blood pressure, low potassium levels, acidified diets, dental disease, kidney infections, congenital kidney disease, fasting (which often happens to pets who go missing and to cats who get stuck in trees), and the use of certain medications.

CRF can occur at any age, but it usually occurs in older animals. These days pets live much longer than they used to and their bodies eventually wear out just as human bodies do. CRF is one of the ways their organs wear out.

In older cats CRF one of the leading causes of illness and death, so some veterinarians recommend having geriatric cats checked for CRF during every annual exam, including a blood test, urinalysis, and blood pressure measurement.

How is CRF diagnosed?

CRF can only be accurately diagnosed with urinalysis and blood tests.

Once a dog or cat is diagnosed with CRF, you’ll be working closely with your veterinarian to manage and monitor the progression of the disease. General veterinarians are capable of managing CRF for the long-haul. However, veterinary internal medicine specialists or nephrologists may know more about the latest CRF treatments.

How is CRF managed?

I can’t stress enough how important it is to have veterinarians oversee the care of pets with CRF. If your pet is diagnosed with CRF, you’ll be working closely with your vet to manage the disease.

Slowing the progression of CRF is important because there is no known cure for this disease. The goal of all treatments for kidney disease is focused on making the kidney’s job a little easier by controlling the amount of waste products sent through the kidneys. This is done primarily through diet, although medications and hydration therapy (diuresis) are also frequently used.

Most veterinarians recommend foods formulated specifically for pets with CRF. These foods are low in protein, salt, and phosphorus and are designed to reduce the amount of waste materials that kidneys must filter out. Lower salt and phosphorous intake helps control electrolyte imbalances that are common with CRF.

It’s critical for dogs and cats with advanced stages of CRF to continue eating. When animals – especially cats – feel nauseous, they associate food with queasiness and they’ll stop eating (at least for a while) the type of food that they recently ate. Not eating makes them feel much worse. It’s better for pets with CRF to eat non-prescription food if they’ll eat more, than for them to eat prescription food and eat less. It’s of the utmost important for pets with CRF must continue to eat because it is usually starvation that finally ends their lives. That is what happened with my darling Meek, and if I had known sooner that this was how his life would end I would’ve put him out of his misery sooner.

Offering a variety of flavors and textures (pate, chunks in gravy, raw)  is an important aspect of keeping pets eating, so having a variety of foods with a variety of novel meats (like venison, duck, kangaroo, and brushtail) in your cupboard is very helpful for dogs or cats who refuse other meats. Meek, like most animals with CRF, would try a food and love it so much that he’d eat a lot of it. Then at the next meal he’d run to the food as if he was going to eat it all again, but instead he’d sniff it and walk away without eating a single bite. I had a huge variety of foods in the cupboard so I could offer Meek something different as soon as I saw him turn away a certain type of food.


Most people avoid giving treats to pets with CRF, but there’s a point when we want to treat them to something special. Giving them an occasional treat won’t make too much difference during later stages of CRF. Offering treats is another way we can keep these animals eating. There were times when I would sprinkle treat crumbles on top of Meek’s food in order to tempt him to eat more.


Moisture in the diet is important for all pets, and it is absolutely essential for those with CRF. Having moisture in their system helps the kidneys function efficiently. The more water they drink, the better. (Read more about getting cats to drink more water.)

Feeding canned food and also mixing in extra water is ideal for animals with CRF.

Constant access to fresh water is also a must.  Keeping the water at room temperature is best because bodies absorb it more readily. Using automated pet water fountains is a great way to encourage pets to drink more water.


Pets with CRF who are eating an appropriate diet don’t need supplements. However, if they urinate or vomit frequently, their bodies might lose water-soluble vitamins. Multivitamins for pets are available in tablets and liquids, providing plenty of options for hiding vitamins in food if necessary. As always, consult with your veterinarian before giving supplements. Your veterinarian can recommend the most suitable supplements.

Other treatment options

As CRF progresses in a dog or cat, more aggressive approaches are used. Everyone must work with their veterinarian to decide how aggressive they want to be in treating their pet.

Toxin levels rise as CRF advances, and experts believe animals become more uncomfortable with an overall sensation of feeling unwell. Human patients with similar conditions do not describe their condition as painful, rather they just feel a bit blah. Dehydration, in particular, can make patients very uncomfortable.

Some people treat CRF aggressively by using subcutaneous fluids, giving appetite stimulants, force-feeding, having kidney transplants, and doing dialysis. Veterinarians don’t consider these approaches to be prolonging their agony because there is no significant pain associated with kidney failure until the end-stages. Even then, the main symptoms are weakness, lethargy, nausea, and discomfort.

If this article is helpful & you’re able, please consider sending a thank-you tip/donation. Even small donations will help me keep my business running during the travel industry slump that has brought pet sitting to a screeching halt. Thank you! (FYI, for a sliding scale fee starting at $30, I offer consultations to help people solve their specific cat-related issues. Let me know what I can help you with.)

(Note: Nonexclusive use of this article has been granted to other pet industry organizations but Kari Kells retains copyright.)

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