Kidney Disease in Cats

Army Capt. Todd French, officer-in-charge of the Guantanamo Bay Veterinary Treatment Facility, checks the heartbeat of a kitten that was brought into the clinic, April 13. The clinic treats pets of service members and Department of Defense employees who work with Joint Task Force Guantanamo and U.S. Naval Station Guantanamo Bay. JTF Guantanamo conducts safe, humane, legal and transparent care and custody of detainees, including those convicted by military commission and those ordered released by a court. The JTF conducts intelligence collection, analysis and dissemination for the protection of detainees and personnel working in JTF Guantanamo facilities and in support of the War on Terror. JTF Guantanamo provides support to the Office of Military Commissions, to law enforcement and to war crimes investigations. The JTF conducts planning for and, on order, responds to Caribbean mass migration operations.

Kidney disease, in the form of Chronic Renal Failure (CRF), also called Chronic Kidney Disease (CKD), is a common problem in older cats. I have seen natural kidney failure in cats as young as 4 years, but it occurs far more frequently in much older cats.

However, due to the melamine contamination of pet food in 2007, a great many cats (and dogs) developed Acute Renal Failure due to the poison. The tens of thousands of pets who got sick but recovered are likely to have some kidney impairment in the future, and the principles of treating CKD will also apply to them.

The most noticeable symptom is an increase in water consumption and urination (“drink-a-lot, pee-a-lot syndrome”). A blood test should be done if you notice these symptoms, as there are several conditions that can cause this. The increase in drinking and urinating in CKD is due to loss of the kidney’s ability to concentrate the urine. The kidneys have a very large reserve capacity, and symptoms of failure are not seen until approximately 75% of kidney tissue is nonfunctional. In my experience, kidney failure is the most common cause of death in older cats.

Laboratory tests are needed to definitively diagnose CKD. A blood test alone is usually not sufficient; a urinalysis must be taken at the same time the blood is drawn. Kidney disease is likely present when the cat is “azotemic” AND the urine is not sufficiently concentrated. “Azotemia” means that there is an increase in particular compounds in the blood; specifically blood urea nitrogen–BUN–and/or creatinine. The measurement of urine concentration is called Urine Specific Gravity (USG). If the cat’s USG is less than 1.035 (1.030 in dogs) AND azotemia is present, then kidney function is abnormal. BUN and/or creatinine may be high if the animal is dehydrated (common in cats who eat a lot of dry food, or during hot weather or after a stressful car ride). They may also be increased in animals on a high protein diet. As long as the kidneys are able to concentrate the urine, small elevations in BUN and/or creatinine are usually not a cause for alarm.

Causes of CKD

Recent research suggests a link between vaccination for feline distemper and immune-mediated inflammation of the kidneys, which is thought to be the cause of CKD. Annual boosters for distemper are completely unnecessary. Be sure to discuss all recommended vaccines with your veterinarian. A cat with kidney disease should not be vaccinated at all. (See our article on vaccination for more information.)

Long-term feeding of an all-dry-food diet is also suspected as a factor in CKD. Cats’ kidneys are highly efficient and adapted to life in the desert, where they would get most or all of their water from eating their prey. Cats eating dry cat food take in only half the water that cats on a canned or homemade diet get; this chronic dehydration can cause stress on the kidneys over time. Dry diets also predispose cats to lower urinary tract disease (FLUTD, LUTD, FUS, crystals, stones, cystitis) because they force such a high degree of urine concentration. Chronic or recurrent bladder disease may also be a factor in the development of CKD.

Another recently revealed risk factor is fish and other seafood in the diet. Recent research (2013) revealed that a substance called domoic acid, a very stable, heat resistant toxin produced by certain species of algae that accumulates in mussels, clams, scallops, and fish, can cause serious kidney damage at levels 100 times lower than what the FDA allows in seafood. This means that not only can a legal level of domoic acid in any seafood harm the kidneys, but your cat may also be eating fish that are condemned for human consumption due to excessive domoic acid, which may be processed into pet food. Based on this new research, we must recommend avoiding fish and seafood as major ingredients in your cat’s diet at any age. However, the small amount of fish meal used as flavoring or as a source of Omega-3 fatty acids in many cat foods is probably safe, as long as it is not preserved with ethoxyquin, a synthetic preservative.)


CKD is considered progressive and incurable (although this may not be 100% accurate; see Traditional Chinese Medicine below). When the process is advanced, scarring causes the kidneys to become small and lumpy, and the amount of functional tissue is greatly limited. The most significant problems caused by the loss of function are dehydration, build-up of blood toxins, and anemia. These can cause weight loss, lethargy, vomiting, loss of appetite, weakness, and other signs of illness.

Some cats are able to maintain their body weight and live relatively comfortable lives for months to years, while others succumb to the disease more quickly. In conventional medicine, there are drugs that can minimize anemia, help keep the parathyroid glands balanced, and control high blood pressure; and phosphate binders to prevent phosphorus precipitates from further damaging the kidneys. However, these may not be palatable, and may cause adverse reactions. It may also be important to supplement potassium in the food and/or fluids. Some of the best and simplest treatments include:

Diet: The Protein Controversy

You may have heard that restricting protein is recommended for cats in kidney failure. Although this has been the “standard” treatment for decades, as far as cats are concerned, it has always been–and remains–very controversial. High protein/high phosphorus diets will not cause kidney disease in a normal cat, and restricted protein does not prevent kidney failure in a healthy cat. Some experts suggest that protein has no effect on the ultimate progression of renal disease. Research also shows that even very high protein diets do not make renal failure worse in cats (although high protein does worsen the disease in dogs and humans). (One pet food maker recently completed a study it claims shows that its restricted-protein diet increases lifespan in CKD cats. However, because the study has not been published, it is impossible to evaluate the data, which is contradicted by other research.) The real culprit is actually phosphorus, which meat contains in large amounts. The only practical way to restrict phosphorus is to restrict protein. Decreasing phosphorus intake (by restricting protein) can help some cats feel better, so it may be worth a try in a symptomatic cat. Adding a phosphate binder may also be needed.

However, some studies have suggested that excessive restriction of protein may actually cause further damage to the kidneys and other organs, because there is not enough protein for normal body maintenance and repair. Experts say that these diets are not appropriate until the BUN (Blood Urea Nitrogen) is at least double what it should be normally (about 60-80 mg/dl).

Furthermore, there is one big problem with using the protein-restricted commercial diets: many cats don’t like them, and won’t eat them. Obviously, it does little good to provide a special diet if the cat is going to starve to death! Experts emphasize that it is much more important to feed the cat what he likes and will eat, and maintain weight and body condition, than to be overly concerned about protein content. (Please note that if you add any other protein source to the diet, it will completely negate any possible beneficial effect from the low-phosphorus renal diet. It is useless to feed both a renal diet and a normal protein food or meat-based treats at the same time.)

Let me say this again, because it is the single most important thing to know about CKD: feed the cat anything she will eat! IF THE CAT WON’T EAT IT, IT WON’T HELP THE CAT! Weight loss is your cat’s worst enemy in this disease; so let the cat eat what she wants!

Because water balance is so crucial, it is best to feed a high-moisture diet to help keep the cat hydrated; do not feed only dry food. Feeding mostly or only canned food, even though it is high in phosphorus and protein, provides the moisture and calories that these cats need, in a very palatable form that most cats will happily eat. You can also get low-phosphorus renal diets in canned form. Dry cat food causes dehydration even in healthy cats, and is not appropriate for  CKD cats (unless, of course, it’s the only food he will eat!).

The best thing you can do is feed a home-prepared diet; but only if the cat will eat it! If the cat has never eaten homemade food, or does not have a hearty appetite, this is not a good time to make this switch! There are several good books on home cooking for animals, such as Dr. Pitcairn’s Guide to Natural Health for Dogs and Cats, by Richard Pitcairn, DVM, and Susan Pitcairn. (Rodale Press. ISBN 075962432.) They discuss why a diet made from fresh, raw foods is important, and provide recipes, including a special recipe specifically designed for animals with kidney disease. Another excellent book is Home-Prepared Dog and Cat Diets: the Healthful Alternative by Donald R. Strombeck, DVM. (Iowa State University Press. ISBN 0813821495.) If you choose to use Dr. Strombeck’s recipes, I suggest substituting 1 capsule of taurine (250 mg) for the canned clams, since clams do not contain enough taurine for proper maintenance. Or visit Dr. Lisa Pierson’s website for detailed articles and instructions on homemade cat food.

Traditional Chinese Medicine (NEW!)

Practitioners have found that several herbal formulas may be helpful in slowing and even reversing early chronic kidney disease, and reducing inflammation in the kidneys. Please consult the AHVMA directory to find a practitioner near you.

Holistic Supplements

Several nutritional supplements may be helpful for cats with kidney disease. Omega-3 fatty acids have been shown to be very beneficial in CKD. Antioxidants are also important, since chronic low-grade inflammation is the biggest underlying factor in the development of kidney disease. The highly digestible algae, Biosuperfood, contains enzymes and antioxidants as well as many trace nutrients that may be helpful. (For detailed information or to order BioSuperfood, please visit Optimum Choices.)

A nutritional supplement called “Renafood” from Standard Process, is a very good renal detoxifier and helps to maximize kidney function in cats. Give one or two a day. Most cats eat them readily if they are crushed into the food. They also have a specific formula for cats, Feline Renal Support, that I have had good reports about. Call Standard Process at 1-800-558-8740 to find a distributor in your area. Renafood is a human product, which in my experience works much better than their cat product Feline Renal Support, so be sure to insist on Renafood.

Remember, though, that the basic diet is the most important factor in your cat’s health, and no supplement will make up for poor quality nutrition. For more info on feeding, choosing a good food, and switching to a better diet, see the article library.

Recent resesarch shows a benefit from probiotics (friendly bacteria) in cats with CKD. Kidney blood values (BUN and creatinine) decreased significantly when cats were given a probiotic product in canned food. This probiotic is now available as Azodyl™, which your veterinarian can prescribe.

Supplemental Fluids

Your veterinarian can give your cat subcutaneous fluids in the clinic, or teach you how to give them at home. This is the least intrusive and most beneficial treatment you can give your cat. Cats in chronic renal failure drink a lot of water, but they cannot drink enough to compensate for the loss of water through the kidneys. Subcutaneous fluids are an excellent way to help keep the toxins flushed out of the bloodstream and make the cat feel much better. If the cat is sick or not eating, it may be necessary to hospitalize it for a few days for intravenous fluid therapy, followed by subcutaneous fluids at home as needed. (Click here for detailed instructions). The recent development of a semi-permanent “port” that can be inserted in the cat’s skin has taken much of the hassle out of this procedure; talk to your vet about having this installed. It is best to have this procedure done by a veterinarian who has lots of experience with these ports since there can be many complications.

Holistic Veterinary Care

Homeopathy, herbs, essences (such as Spirit Essences), or acupuncture may be able to help your cat feel better and live a better quality of life. Click on this link for a directory of holistic veterinary practitioners by state.


An amino acid combination called RenAvast is being promoted to “reverse” kidney disease in cats. They do have one study that generally supports the product, but the data is not strong, and the conclusions they draw may be overly broad and optimistic. Nevertheless, veterinarians are using the product with some success in cats, both in terms of lab values and clinical response. Please discuss it with your veterinarian if you would like to try this product, as it is a prescription product.

What About Stem Cell Therapy?

My alma mater, Colorado State University, is actively researching stem cell therapy for feline CKD. Currently (October 2011) it is strictly experimental; it’s also difficult and potentially dangerous, as well as expensive. Please click here to read Dr. Patty Khuly’s article on the current status and future of stem cell therapy in animals.

Other Resources

The Feline CRF Information Center is an incredible website devoted to cats in renal failure. You can find out just about everything there is to know about this disease here, as well as explore a host of excellent links to other feline health sites. You can also sign up for their email list, which can be a great resource and support for guardians of CKD cats.

Pet Loss Support

Ultimately, fighting CKD is a losing battle, and may carry a great emotional cost to the family. Losing a beloved cat to CKD is just as traumatic as losing a human family member, but friends and family don’t always understand. There are many resources to help you through the difficult times and tough decisions you will have to make for your cat, and to support you afterward. Many of these are listed on the Feline CKD pet loss support page.

Click here to read Floppy Cats’ interview with Dr. Jean about kidney disease.



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48 comments for “Kidney Disease in Cats

  1. Jean Hofve DVM
    January 30, 2015 at 8:36 am

    (Note: I have compiled all your comments above for ease of reading.)

    As the article states, “Dry cat food causes dehydration even in healthy cats, and is not appropriate for CKD cats.” This applies to k/d as well as dry crunchy treats. k/d is for sure not appropriate for a cat *without* CKD. You wouldn’t give medicine to a healthy cat, would you? As Hippocrates said, “Let food be thy medicine and medicine be thy food.” k/d is medicine, and intended only for sick cats.

    Personally, I do not “believe” in restricting protein. One of my own cats has CKD and is in his 3rd year of the disease at age 16; he is on one medication for blood pressure, and eats regular high-protein food. He is doing well and has a great appetite. I had another cat who lived to age 20 after being diagnosed at age 15; she was a cantankerous old girl, and let me know in no uncertain terms that she would rather die than have to take pills or submit to any other treatment. So she received no treatment and stayed on her regular, high-protein wet diet.

    However, 99% of conventional vets would disagree with my philosophy. So if you want to follow your vet’s program, then none of the foods I recommend are appropriate, because they are all high in protein and fat, and low in carbs, including my favorites, Instinctive Choice, I and Love and You, and Only Natural.

    As for getting her to eat a particular food, see this article: Switching Foods

    It does sound like you might want to seek a second opinion or even change vets, considering your dissatisfaction with the current vet. A second opinion is always advisable in pretty much any case. Even if you plan to stay with your current vet, he should not be offended by you wanting the benefit of a fresh point of view.

  2. lionandlamb
    January 29, 2015 at 9:31 am

    I need to reorder food for my 5 cats, one of which is a senior with KD. I have been using Dr. Pierson’s chart looking for the ones with low phosphorus, carb, and sodium. It’s a bit daunting to give them variety, especially when I read over and over that fish is not good for cats, at all. Anyway, I stumbled on the where I see your endorsement of their Power Pate canned foods, which includes a seafood one too. Would you endorse these for a kd cat? And, do you know what the phosphorus, carb and sodium levels are? I am waiting for an answer back from the company on this too. I hope they are willing to disclose. I see on Dr. Pierson’s chart that she will not buy from companys (like Blue Buffalo and By Nature) that will not disclose that info. P.S. I am printing out your article and advice and will go over it with my vet. He’s a caring guy and conveniently close for me, but I just don’t think he’s on the ball as far as diet goes. He’s still brainwashed by the pet food companies.Are the dental treats bad for kd disease? Also, I bought a bag of Hill’s k/d Feline Renal Health dry food at my vet’s recommendation. I asked him “it won’t affect Surprise’s kd adversely” he said no. I just started and only give her 1/4 cup a day just to tie her over so I don’t have to open another can. I buy alot of Weruva plus one cat is on Rx venison and rabbit for IBD. So my food bills are enormous.

    I’m trying to offset my cat food costs. It’s very expensive having 5 cats (the last two were from doing TNR) with the litter and vet bills and all. Had a ringworm situation here too with 4 of the 5 cats which was a fiasco. My vet dropped the ball on that too … he didn’t know what it was and I had to go to a specialist.

    Oh, forgot to mention, at the urging of my vet to try to get her to eat them (“because he says it really does make a difference”), I’ve tried the “low protein” canned foods but she doesn’t like them.

    How concerned should I be about the carb and sodium content … for both my kd cat, and my younger ones? It sure narrows down how much variety I can give them, especially if I exclude fish, which is their favorite, of course.

  3. Jean Hofve DVM
    May 19, 2014 at 8:57 am

    The safe upper limit of Vitamin A for cats is 187,500 IU per 1000 calories. Cats need about 200 calories per day, so that translates to a safe upper limit of about 37,500 IU per day. Renafood contains 770 IU per per tablet. Even if you’re feeding a “complete and balanced” food that contains Vitamin A, it is extremely unlikely that giving Renafood will approach anything remotely like a toxic dose.

  4. lsig
    May 16, 2014 at 8:30 am

    I’ve read in other places that the Vitamin A in Renafood is too much for cats. What’s your take on that?

  5. jhofve77
    November 28, 2012 at 10:35 am

    Thanks for the good report! I’m so happy that she is doing so much better!

  6. Ashley Stearns
    November 28, 2012 at 9:36 am

    Hi, Dr. Hofve. I didn’t want the year to end without updating you on our CRF kitty’s progress. I realize your site deals with holistic approaches to disease management, and, as you know, we have benefitted enormously from the information we’ve found on it. We have been determined to do for this CRF kitty everything *inexplicably* denied to us with our previous CRF kitties, and we have been chagrined at the amount of treatment that entails. We want to share what we’ve learned so no one else goes through the needless agony we went through, watching our beloved Huckleberry die. First, we learned the reason the lomatium and goldenseal worked is because our kitty had a systemic e. coli infection, for which we’ve been treating her with Zeniquin. Again, the big drink/big pee went away immediately. Next, because one of her elevated liver enzymes wasn’t resolving on the Zeniquin, her doctor put her on metronidazole. Now, she’s being treated for both aerobic and anaerobic infections (the metronidazole also works on certain parasites; her previous doctor had been concerned about the possibility she may have also had liver flukes since she lived in Hawaii and may have eaten geckos). Interestingly, her lipidosis resolved on the metronidazole, as is the elevated AST (SGPT). We continue to give her the BioSuperfood, the milkthistle/dandelion tea and turmeric, and to feed her only grain-free (Wellness wet, Champion’s Orijen dry) food. For a kitty who’s supposed to be the equivalent in age on a 72 year-old human, she’s pretty spry – even, kittenish. We realize her scarred kidney is never going to get better, but we’re confident her liver and spleen are, and, even though we have to feed her warm food every 3 to 4 hours because she’s still bilious, we can see her healing almost each day. We hope every kitty who needs the same type of care she needs gets it, and we hope you will post our comment for them. Thanks, again, and happy holidays to you and Jackson.

  7. Ashley Stearns
    September 29, 2012 at 3:15 pm

    Hi, Dr. Hofve. I know you’re busy, but I wanted to share something with you that’s sort of, in my mind, miraculous. Michi came to us 4 months ago with kennel cough and other problems: her mistress had died a few weeks before, she had been without food about a week before she and her mistress were discovered, and she had to make a 4,500+ plane trip. She was seriously dehydrated, and we thought, initially, her water consumption was stress. When we got her chemistries back, we learned that wasn’t the case. We started her on Dr. Pritcairn’s diets. I was treating her then with goldenseal and lomatium for the kennel cough, and noticed her peeing decrease somewhat dramatically. At the time, I didn’t know what to attribute it to – our being unfamiliar with her stage of CRF, the new diet, her hydration recovery, or the antiviral/antibiotic. This past week, both my husband and myself acquired colds, and when Michi started sniffling, I put her back on the goldenseal and lomatium. To my utter shock, she has begun waking us at 4:00 AM again with her very boisterous playing AND she hasn’t had a big pee in 3 days – quite an anomaly, since she was having at least one HUGE pee a day, and several others besides. It occurred to me that if distemper vaccines are the suspected culprit in CRF, then the contamination is likely viral in nature, and, that being the case, no wonder Michi is faring better in the lomatium. So I’m wondering – have you used it with your CRF patients and found the same thing? Dr. Pitcairn had such a moving story about using goldenseal with his sick son, I feel as ecstatic about Michi’s experience with lomatium, I want to tell everyone about it. Thanks, again, for your help.

  8. jhofve77
    September 28, 2012 at 10:37 pm

    Thanks Ashley, glad to help! :)

  9. Ashley Stearns
    September 28, 2012 at 12:40 pm

    Thank you so much, Dr. Hofve. Those articles on Biosuperfood are TERRIFIC, and I am looking forward to trying it myself. Also – I was glad to have found a holistic vet in my area through the directory on your website, which is fantastic! Thanks, again. I know Michi can look forward to the best possible care for her CRF, which really helps ease our minds and hearts.

  10. jhofve77
    September 27, 2012 at 10:02 pm

    Sorry, I cannot prescribe for your kitties; dosage may vary depending on age, weight, stage of disease, etc. Please read the linked articles on Biosuperfood, which answer your other questions.

  11. jhofve77
    September 27, 2012 at 9:55 pm

    As it states in the article, I do recommend a homemade raw diet for CRF cats. However, some cats do not tolerate high protein and their symptoms get worse. It’s a very individual matter how a cat will respond. You are fortunate that your cat normalized on the high-protein diet; but that is definitely not the case for all cats. However if your vet has any references showing that phosphorus is “not an issue” with raw foods, I would love to see it.

    Canned food is cooked, but at a lower temperature than the rendering and extrusion processes that dry food undergoes. Unless a CRF cat also has digestive problems, canned food should not be any more difficult for a CRF cat to digest than a normal cat.

    I have known and recommended Feline Instincts for nearly two decades. :)

  12. Ashley Stearns
    September 27, 2012 at 5:29 pm

    Hi, Dr. Hofve: PLEASE tell us how much human RenaFood we should use for our kitties instead of the kitty RenaFood, as you suggest here, and, the Biosuperfood makers say their BioPreparation F2-3 is the same as their Biosuperfood except that it’s freeze-dried to make it more efficiently absorbed by animals; have you a preference for the human Biosuperfood therefore, and, if so, how much do you recommend? I am using Dr. Pitcairn’s recipes. Thank you.

  13. alittlesquirrely
    September 25, 2012 at 7:03 am

    Yes, meat is very high in phosphorus, but then I don’t understand, why does the BUN, Creatinine, and Phosphorus leval go DOWN TO ALMOST NORMAL after the cats are on this RAW diet? My cats have had normal values for 2 years now. My vet said that phosphorus is “not an issue” with RAW food, and this seems to be the case. Apparently heating protiens to high temperatures as in canned food, changes the structure and makes it difficult to process for all cats especially for CRF cats. And as they keep reminding us, cats in the wild do not make campfires and BBQ their mice. Are you familiar with Feline Instincts? They have several wholistic veterinary consultants. I would be very interested in hearing your evaluation of their products after talking to them. Seriously, I know this is a controversial issue, but you are the most well known on the internet and we all highly value your opinion.

  14. jhofve77
    September 24, 2012 at 1:34 pm

    Unfortunately, this is absolutely not true. Meat by itself is VERY HIGH in phosphorus. That’s why the “renal” foods have no meat in them.

  15. alittlesquirrely
    September 23, 2012 at 9:40 am

    Taake a look at Feline web site. My CRF cat has been on their raw food diet (ground chicken) with “renal support formula” add-in powder for almost 2 years and he loves it. I also add 1/4 tsp spirulina per day to it,(great appetite stimulant) and give him 3/4 ml of “Nordic Pet” fish oil for pets. The other cats get raw diet with the regular add-in powder. (all the vitamins and other things they need). We all know dry food is the worst, but canned food, isn’t much better. Sure you could add phosphorus binders to the canned, BUT with the raw food THERE IS NO ISSUE WITH PHOSPHORUS!!! I repeat NO PROBLEM, and they are getting the meat they need, but you must add a good suppliment powder like Feline Instincts sells. It is the heating/cooking to high temperatures of the canned food that causes the problem. Raw food is not cooked! I started this because of my holistic vet’s advice.

  16. jhofve77
    February 28, 2012 at 12:08 pm

    A grain-free food will likely be higher in protein, and thus phosphorus, than a regular food. However you can check this chart to find the foods that are relatively lower in phosphorus:
    Be sure to call and confirm with the manufacturer as this info may be outdated; mfr’s change formulas all the time.

  17. Karen Orenstein
    February 25, 2012 at 3:30 pm

    My 11-year-old Siamese was recently diagnosed with early stage kidney disease. I am a believer in both conventional and holistic medicine/treatment. My conventional vet says to get him on a prescription, low protein diet (if he’ll eat it). My holistic vet says not to do that, and to make sure he stays on grain-free wet food. So, first off, I’m torn as to whose advice to follow (I trust them both…), but I think there is universal agreement that low phosphorus is critical. So, I’ve been searching for a grain-free wet food that’s low in phosphorus, but I’ve been having trouble finding one. Does anyone know of a low phosphorus, grain-free food? Many, many thanks if you can help me.

  18. Ingrid Sotelo
    February 7, 2012 at 4:42 pm

    Hi Judy,

    I also have a cat diagnosed with kidney disease. My local vet provided me with this recipe:

    Restricted Protein/Phosphorous Diet for Cats
    1/4 cooked liver
    1 large egg, hard-cooked
    2 cups cooked rice
    1 T. fat (bacon grease or vegetable oil)
    1 t. calcium carbonate (TUMS)
    Balanced supplement which fulfills the Feline MDR for all vitamins and trace minerals
    Braise the meat, retaining fat. Dice or grind liver and egg. Combine all ingredients and mix well. This mixture is somewhat dry and the palatability may be improved by adding some water (not milk). Yield 1 1/4 lbs.
    Moisture %………………66.8
    Protein %…………………..8.7
    Fat %………………………..6.2
    Carbohydrate %………..18.3
    Ash %……………………….2.0
    Calcium %………………….0.3
    Phosphorous %………….0.16
    Sodium %………………….0.03

    I am also supplementing it with Biosuperfood F2 and Feline Renal Support.
    Hope this is helpful.
    Good luck !

  19. Judy Novella
    January 31, 2012 at 10:54 pm

    For an easy starter diet click here…doesn’t lead to a recipe.
    I have been searhing for two weeks for a grain free kidney disease home made recipe that is balanced and found nothing. on disability and over $850 in vet bills and no diet yet. please I have been cooking for them grinding food 4 years recipe and too much phospherous I am sure have 6 cats…need a diet for a newly diagnosed kidney cat that is healthy for the other normal cats who could be on their way to testing positive for renal…want generic kidney grain free diet and your link got my hopes up…calling vets they don’t know…need something. Now started commercial weruva but at 6 cats a day that is $18 a day and over drawn and credit carded out. I could make better cheaper at home with a recipe please! desperate emotionally and financially! Have a freezer full of homemade too afraid to use unless dilute somehow…need something.

  20. jhofve77
    January 10, 2012 at 7:28 am

    Try contacting the manufacturers directly; they may be able to help you.

  21. Ingrid Sotelo
    January 9, 2012 at 2:37 pm

    Sorry, correction: the products are: Feline Renal Support and Azodyl, not Biosuperfood and Azodyl.

  22. Ingrid Sotelo
    January 9, 2012 at 2:09 pm

    Help !
    Your website has been extremely useful and supportive ever since my beloved 16 yr old Joy was diagnosed with CKD a few months ago. He is stable now, on canned Science Diet K/D, which he is starting to get tired of. My local vet kindly provided me with a homemade recipe, but unfortunately she refuses to get for me any of the products that you recommend, such as Biosuperfood F2 & Azodyl because they are not FDA approved. This has been extremely frustrating, since there are no holistic vets where I live. My question is: how else do I get these products that are only available through vets ?
    Thank you for providing us cat-lovers with such a wonderful website & for helping us go through this process.

  23. jhofve77
    December 21, 2011 at 10:20 am

    Sorry, I can’t give specific veterinary advice for your cat. The answer would be affected by the exact lab values for your cat, history, age, etc. Please consult your veterinarian about any and all supplements for your cat.

  24. Silvia
    December 21, 2011 at 8:36 am

    Hi, my cat has just been diagnosed with CFR and we’ve been trying to give him prescription food without much success. If we manage to feed him the prescription food, will giving some spirulina interfere in the phosphorous management from the prescription food? I’ve been hearing a lot of good things about spirulina and I would like to give it a try. Thanks a lot for the information.

  25. jhofve77
    December 5, 2011 at 3:04 pm

    You need to contact the manufacturer, Standard Process; their phone number is given in the article.

  26. Rosa Maria
    December 5, 2011 at 1:37 pm

    Where can I buy Renafood for my CRF cat? I live in Spain but I don’t mind ordering from anywhere in the world regardless of cost. Please help

  27. jhofve77
    December 2, 2011 at 4:23 am

    Sorry, I cannot give specific veterinary advice in an individual case. Please discuss your cat’s diet and condition with your veterinarian; or if you are not satisfied with the care he has received, seek a second opinion.

    High protein is not a problem for healthy cats, and in no species does it *cause* kidney disease. Wild cats, of course, eat a very high protein diet for their entire lives. Commercial pet food has many problems that we’ve written dozens of articles about! Foods that were recalled in 2007 directly caused kidney damage. But the main cause of feline kidney disease, especially in older kitties, appears to be unnecessary over-vaccination for feline distemper.

  28. mclifford
    December 2, 2011 at 2:21 am

    My cat has been losing weight for a while. We got him wormed and took him for his teeth to be cleaned. His blood profile showed increased BUN and Creatine which may simple have been down to the stress of the journey to the vets and the previous starvation for the op. The vet suggested putting him on a renal diet and to test his blood after 1 month.

    At first he was eating the renal diet and when he was retested, his reading went back within range. As a precaution the vet suggested leaving him on the renal diet but he will NOT eat it.

    I have tried all brands and all flavours Royal Canin, Hills KD and Purina NF. I end up throwing it in the bin. I really dont know what to feed him but of course i will not starve him.

    There is a brand called Applaws in the UK which is a natural food. Trouble is it is higher in protein than the renal food so i am in a no win situation.

    He is not drinking excessively or vomitting and is generally interested in food until i put the renal in front of him. He then walks away and would rather starve than eat it.

    It seems we humans are poisoning our animals with commercial food. In the wild do cats have the same problem with high protein in their diet?

    I really dont know what to do for the best. It is all very well the vet saying be strict but how can i when it is a choice between my cat eating or not.

    I am due to get his blood tested again soon as I am not sure he definitely has the disease.

    Any advise would be appreciated.

  29. jhofve77
    November 27, 2011 at 9:35 am

    Sorry, I can’t give veterinary advice for individual cases. Please work with your veterinarian when adding any supplements to your cat’s diet. If you are interested in holistic care, check the directory at for a practitioner in your area.

  30. Kathy Ryan
    November 26, 2011 at 11:42 am

    Abby is our 14 year old American shorthair who has dental problems and the beginnings of kidney disease. Our vet sells and recommends an expensive dry food, k-d, however we’re reluctant to purchase it as Abby doesn’t like it or any dry food as it’s hard for her to chew. We’ve been feeding her Fancy Feast Classic as it’s wet and is easy to swallow. We add is tiny bit of Benefiber to her food which seems to aid regular bowel movements. She has a good appetite and drinks water frequently from the tap or from bowls and glasses that we have placed throughout the house. We plan to get her dental work and a blood pressure check in a few days. She’s also had blood work done (that’s how we learned about her chronic renal insufficiency). Abby’s urinalysis results weren’t definitive or diagnostically clear enough. We’ve read about a homeopathic, nutritional supplement for cats with kidney disease named “Tripsey” which evidently tastes good. Would you recommend Tripsey or another nutritional supplement for a cat with kidney disease? Thanks in advance for getting back to us about this matter.

  31. jhofve77
    November 21, 2011 at 12:55 pm

    Sorry, I cannot give individual veterinary advice, please discuss your cat’s diet with your veterinarian.

  32. Nat Wall
    November 20, 2011 at 11:52 am

    My cat was diagnosed with kidney failure & he went home after 3 days of overnight at the clinic on fluids- He is home with RX & fluid therapy & worst special food. He was totally flat & low energy on this new food. I used to feed him with Newman’s Own but was told it was too high in protein . But after seeing him tanked, I got him back on his natural food & his energy went up the roof. How come? the low protein diet is supposed to be good but he’s almost lifeless & sleeps all day.

    Can I feed him the good energy food & what is the acceptable phosphate %? Thanks!

  33. jhofve77
    September 29, 2011 at 7:16 am

    Get him onto canned food only (*no* dry) if he isn’t already, and add extra water to the food. Learn how to give him fluids at home. Hydration is critical in these kitties! If he’s a dry food addict, read Switching Foods/!

  34. Jackie Manke
    September 28, 2011 at 5:57 pm

    My cat was diagnosed with Chronic Renal Failure last week. He has been treated and is doing well now. The problem is that he doesn’t want to drink much water. I bought him a fountain and he won’t look at it. Do you have suggestions on how I can entice him to drink?

  35. jhofve77
    July 22, 2011 at 8:28 am

    Vetri-Science is a very reputable company and they make great products, although I don’t have any experience with this one. It looks like a good supplement, but it does not do what Renafood does, which helps to detoxify the kidneys and improve function at a cellular level.

  36. Josephine
    July 22, 2011 at 7:47 am

    I cannot find the supplier of Renafood in my area (Hong Kong). We have a supplement called Renal Essentials (by Vetri-Science). Have you ever heard of this product and do you think we should give it a try? Thanks.

  37. jhofve77
    April 13, 2011 at 8:53 am

    You would need to discuss this with your own veterinarian; we cannot give specific veterinary advice for a particular animal.

  38. Barbara Callahan
    April 12, 2011 at 12:41 pm

    Is it safe to give my 17 year old, 6.3 lb. CRF cat Azodyl and Renafood? She also gets a little over one gram of Epikitin daily.

    Thank you.

  39. Shannon
    April 7, 2011 at 11:04 pm

    Hi Dr. Hofve,

    My wonderful cat Max just had his yearly physical, and I just found out that his kidney levels (not sure whether BUN or creatinine)are a bit high. He is 13 years old and has been in excellent, vibrant health – he looks and acts like a 5-year old cat, and is spoiled rotten!

    I am doing some research now in order to have a fuller discussion with my vet to clarify important issues and options. She did say when I spoke to her yesterday that the kidney levels could decrease with change in diet and better hydration, so I am hopeful that that can happen.

    Your above article is extremely helpful and informative, and supports my gut feeling about nutrition in particular; yesterday at the pet store I saw that all so-called “senior” cat foods are also low-calorie! Max does not have any extra pounds to lose (though his weight has been stable, within an ounce, for years, and still is).

    I will speak with my vet about many of the points you brought up in your article, but I wanted to ask you a nutrition question. I bought a new type of human-grade wet cat food yesterday (brand: Weruva and Fussie Cat, same company makes both) and Max LOVES it. I am able to mix water into it as well to increase hydration, and he is definitely eating it much more than his previous wet food (Wellness).

    What concerns me is that the three flavors I picked up all have tuna in them. Can you please give me your opinion about cats consuming tuna, especially if kidneys are a bit taxed? I looked at your home made food recipe in a different article, and noticed that tuna was not listed among protein options.

    I would greatly appreciate your opinion in this matter. Also, is it true that his elevated kidney function could be returned back to normal, or is it just a sign of inevitable CRF?

    And lastly: when will a serum be made to extend our cats lives by decades and decades?!?

    Thank you for an excellent article, I so appreciate the valuable information.

  40. jhofve77
    March 20, 2011 at 9:51 am

    If you feed *any* other food along with k/d, it completely negates any and all benefits from the restricted protein/phosphorus. Also, k/d is alkaline, while c/d is acidic–again eliminating the desired effects. c/d is also very high in fat. These foods are all made with poor quality ingredients (see our article on Selecting a Good Commercial Pet Food for guidelines to use when choosing a food).

    As stated in the article: “Let me say this again, because it is the single most important thing to know about CRF: feed the cat anything she will eat! IF THE CAT WON’T EAT IT, IT WON’T HELP THE CAT! Weight loss is your cat’s worst enemy in this disease; so let the cat eat what she wants!”

    If you are interested in holistic treatment and nutritional therapy, please visit the directory at to find a practitioner in your area, or one who will work with you over the phone.

  41. Michel
    March 20, 2011 at 7:58 am

    We have two brothers, one (Gaby) has kidney failure . Both 18 years old and wonderfull and full of beans . The vet has put Gaby on a low fat (no flavor !) diet : we feed him a mix of K/D, G/D and C/D just to get him to eat the stuff. Both were fed High quality human grade cat food for 17 years. Also Gaby is taking Epakitin and Fortekor.
    Gaby has lost weight with the above diet and I am concerned
    thank you for your input and this great website

    Michel,Lisa, Gaby and Damien

  42. jhofve77
    February 27, 2011 at 3:03 pm

    No, there’s no one diet in particular; I recommend working with a holistic vet to create an individualized diet and therapeutic plan; directory at If you are interested in making food at home, instructions can be found at; she does have recommendations for kidney issues.

  43. vitskaia
    February 24, 2011 at 11:19 pm

    Help! Do you have a diet to recomment for an older cat with CRF?

  44. jhofve77
    January 16, 2011 at 1:33 am

    Yes, I agree with much of what he says; but the establishment would point out that this article is ancient history: 1998. The low-protein myth has become ever more entrenched, with the companies that make such diets publishing only the research favorable to them. Recently I was asked by Colorado State University to stop quoting them, because the four CSU professors I learned from (and who maintained that opinion ever since) have all moved on or retired. Whatever happened to the respect given to wisdom gained from experience? I guess the lesson is: don’t look to academia for original thinking any more! Now it’s all about following the dictates of Science Diet, Purina, Waltham’s–i.e., the ones who donate the big bucks to vet schools. Personally, I still recommend feeding cats actual nutritious food that they enjoy–certainly not over-processed slaughterhouse waste loaded with artificial preservatives, synthetic vitamins, and other toxic chemical additives. Ack!

  45. Jlee
    January 15, 2011 at 9:59 pm

    Great article and great website, Dr. Hofve!

    Have you read this article which also address the controversy and “mythology” of low protein diets in dogs? (There may be two links here)

    Mythology of Protein Restriction for Dogs with Reduced Renal Function by Kenneth Bovee DVM

  46. jhofve77
    January 11, 2011 at 10:44 am

    Dry food does not do anything for the teeth, and is very dehydrating, which stresses the kidneys. I’d recommend getting a second opinion as soon as possible; there may be more going on with that history and dramatic weight loss.

  47. Edie Passov
    January 10, 2011 at 9:34 pm

    My Abssynian, Simba, male 3/20/99, had been vomiting and had loose stool for the past 6 mos. Ias told to keep him on dry food/dental diet due to his possibly losing teeth due to gyngivitis which is common in this breed. I have been diligent about only giving him a tiny amount of flavored soft food (Whiskas type brands for variety of flavor. He was diagnosed with renal failure and I was told to give him 1/4 tablet of Pepsin lx/day.

    He had a great appetite before and doctor said he was overweight. He shound be 10 lbs and at one time he was 14 lbs. I was able to reduce amounts both in dry and wet food and his.weight went down to 2 lbs. In the past 6 mos he has lost 2 more lbs and is down to 10.2 lbs.

    I am now wondering if I should return to

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