Chronic Kidney Failure In Cats

Naughty, but healthy!
Naughty, but healthy!
Old and decrepit Johnny Cat.
Old and decrepit Johnny Cat.




Kidney failure is one of the most common causes of death in older cats.  Acute renal (kidney) failure is quite different from chronic renal failure, and is not as common.  Acute renal failure (ARF) happens suddenly, and is usually from an infection, a poison (i.e. antifreeze or Easter lilies), or a drug reaction.  Chronic renal failure (CRF) develops slowly, over months to years, and can be caused by infections, problems with the immune system, inherited kidney problems, or cancer; however, most often the cause cannot be found. 


Some signs of CRF are: drinking more and urinating more; going to the bathroom outside the litter box; loss of appetite; weight loss; constipation; loss of energy; and “just not doing right”.  Things a veterinarian may find on a general health examination that would make him/her suspect kidney problems include dehydration, sores inside the mouth, kidneys that are the wrong size or shape, or painful kidneys.  Tests that might need to be done include collecting urine for examination, blood tests to look at specific kidney values, testing for feline leukemia or FIV (two viruses that effect the immune system), or checking for hyperthyroidism (an over-active thyroid gland can cause kidney and heart problems).  Other useful tests that may or may not be needed include x-rays (sometimes with a dye injected into a vein to see how well the kidneys filter out the dye), ultrasound, kidney function tests, or a kidney biopsy.


If kidney-specific blood values (BUN and creatinine) are high, the veterinarian may want to give your cat some fluid therapy under the skin or in a vein and then recheck those values.  This is because the values can go up just from being dehydrated.  Cats with kidney failure are usually at least a little bit dehydrated, for several reasons: 1) they are generally urinating out more than they can take in; 2) they may be vomiting or have diarrhea, contributing to fluid losses; 3) kidney failure can lead to stomach upset, so they may not want to eat or drink.  Constipation can be an indicator of dehydration, so if your cat has been diagnosed with kidney failure, and you notice that it is constipated or has hard, dry stools, it may be time for some fluid therapy.


If the BUN and creatinine are high even after your cat has been given fluids, it usually means that it has lost at least 75% of normal kidney function.  A little of this function can be recovered, but most of the damage is permanent.  The parts of the kidney that are permanently damaged develop scars, which make the kidneys smaller and harder than normal—something the veterinarian may be able to feel.  The parts that aren’t damaged have to work twice as hard, which means they wear out more quickly than they ordinarily would.  Because of this, CRF is considered an incurable, progressive disease that ultimately results in death, unless a kidney transplant is done. 



Since CRF is not curable, treatment is aimed at slowing the progression of the disease and minimizing symptoms so the cat is more comfortable.  The cornerstone of therapy is a change in diet.  Things that are known to slow the progression of disease are slightly decreased protein intake (3.5 grams of protein per kilogram of cat per day) and decreased phosphorus intake.  Cats in renal failure usually need extra potassium and vitamin B, too.   There are several commercial ‘kidney failure’ diets available, including Hills Feline k/d and Purina NF.  Kidney failure tends to ruin a cat’s appetite, so adding tuna fish juice, clam juice, chicken broth, or warming the food may be necessary to encourage cats to eat.  There are some drugs that can help, too, and a feeding tube can be placed and safely maintained for months, if need be.


Sub-cutaneous (under the skin; also called “sub Q”) fluid administration can be very helpful, since these kitties are prone to dehydration.  Some cats need it every day; others may only need it once a week or so.  Other medications to control nausea, vomiting, or stomach acid production may be needed, as well.  Cats in renal failure can develop hypertension (high blood pressure), too, which may or may not need to be treated.  Some need vitamin D supplements, since the kidneys are supposed to help make vitamin D.  Another common side effect of chronic kidney failure is anemia (low red blood cell count), because the kidneys make the hormone that stimulates red blood cell production.  There is an injectable form of this hormone available, but at $2,000 for a vial that may last 3 days, it’s a little too pricey for most people to try.  If an infectious cause is suspected, antibiotics may be needed for one to two months.   A well-controlled CRF cat may live for months or even years with proper treatment and monitoring, but a normal life span cannot be expected.  Cats with other problems on top of the CRF (i.e. hyperthyroidism, diabetes, cancer, certain viral infections) are difficult if not impossible to control, and may only live for days to weeks after the diagnosis is made.




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Comments 40 comments

Mighty Mom profile image

Mighty Mom 8 years ago from Where Left is Right, CA

Excellent hub. We had to put our beloved 18-year-old Penny down this summer. But we tried everything we could to slow her renal failure. We did subQ fluids every night. She even had acupuncture, which did some good. In the end, her little kidnesy just gave out. It was a slow and painful (for her and for us) last few months.

I hope not to go through this again anytime soon!

Senior Cat 7 years ago

I just had my cat put down at 21. Everyone was in awe over her age but it doesn't mean either of us were lucky. She was diagnosed with kidney disease when she was about 17. She craved water and peed in the box a lot. Don't let the vets tell you that you'll know it's time for her to pass when she stops eating. This cat never stopped eating until her teeth started falling out and her breath turned really bad(apparently a kidney failure symptom that most cats never have to experience). The vets never mentioned this would happen with the teeth. Also, her stool turned rock hard (even though she was still passing it). The vets never mentioned that would happen either. Maybe I've witnessed what most vets don't know about. But she still had energy to run to me from across the room, even a few days before she was put down. This is a nasty disease if the cat persists on till the end. If they're still eating and have energy, but their constipated and they're breath turns really bad... it's time to invest in a lot more medical treatment or put down respectfully. No one should have to live like this.

Shannon 7 years ago

I just had to put down my 5 month old Kitten.- My boyfriend and I took her to the vet hospital, because she was sick.- It happened so sudden and quickly! The vet did test's and it turned out to be renal failure (kidney) failure. Over 75% of her Kidney's stopped functioning, and we just didn't know why. He kept saying the only thing it could be is anti-freeze, (which is impossible in our case) and I told him all things in our home including flowers. He said that was not possible so it must have been a (hereditary) case for her as she was just a kitten.- Later to find out, I looked and yes. Flowers can be very dangerous and poisonous for cats or kittens and LILY'S are DEADLY to cats. - Causing renal failure,..... and die within 3-7 days.- This is so sad, thankfully our other beautiful kitten is healthy.- Will go back to the vet on Monday to tell them about our findings, and to let everyone know how dangerous some flowers are for cats.- Our little patches could still be alive if it wasn't for those beautiful Lily's.- ~ ~ RIP Patches we love you.

Debbie 6 years ago

Thank you Senior Cat for your story. I have a 21 year old cat also who had blood tests and were not highly elevated but 2 weeks since she has lost a tooth (this morning I noticed) and has really bad breath. I appreciate your story as I also was not told of these side effects. We go to another vet this week...Thank you for sharing, I appreciate it!

Cappy 6 years ago

Another thank you Senior Cat for your story. My kitty went through much of the same. I put her down 2 weeks ago and am still grieving. Mine made it to 22 years old. She stopped taking care of her coat and it became very dull. She slept most of the time and always looked tired whenever she awoke. Sometimes she became disorientated and would meow loudly. She drank a lot. She had hard time walking. And, during her last two weeks she stopped eating and her breath was quite bad. In the end, she was merely existing, not living. I had to do right by her.

Sue M. 6 years ago

Our 2 and a half year old kitty is the ICU due to CRF. He was a very active cat and one day, he just wouldn't move or eat. When we found out, over 75% of his kidneys was not functioning. The cause cannot be determined. Our hearts are broken and at this point, we can only pray...

Sanja 6 years ago

My poor 15 year old cat died yesterday. She was eating well but was still skin and bone...Her fur looked terrible and she was sleeping most of the time. My heart is broken and I am guilt striken for allowing her to be like that for past 6 months. I new it was wrong but I just wanted her next to me for longer. Yesterday, her could not move or eat, I tried to accommodate her...but she had a little seizure and died. I will never forget the way she looked with her eyes open..I left her little body with the vet; I hope she is still around me and that she will forgive me for not being better mum.

ryan 6 years ago

we had flowers in the house and didn't realize that there was a kind of lily in the bunch and my kitten go into it and we didn't notice any strange behaviour until it was too late see you only have about 12 hrs before the cat or dog goes into acute renal failure and we were too late it only took three days before he was beyond treatment so make sure to check what kind of flowers are in your house because they are very deadly too animals

Andrea 6 years ago

My cat, Strider (nearly 12 y.o. now), was diagnosed with CRF (acute stage) in 2008 and had to spend a week at the clinic. His creatinin levels were so high that the vets were uncertain he'd make it, but he did. Unfortunately, the damage to his kidneys was high by then and he's been having nasty ups and downs since.

We managed the disease quite well with meds and sub-Q fluids until a couple of months ago, when the azotemia sipked up again and is now nearly-impossible to control. Things are not exactly good right now, but he's still enjoying life and doing pretty much all the things he's always liked, so my (and the vet's) mission is to keep him as comfortable and happy as possible for as long as he can handle it without it becoming a burden. It's hard, exhausting and sad, but he's worth it.

Irish 4 years ago

In America the Shamrock plant sold in many stores is an Oxalis. If eaten by a cat it will cause the same crystal in the kidneys as anti-freeze. Most people don't realize these lucky clover plants are toxic!

Kat 4 years ago

Our Hymalayan Yoda just had his 10th Birthday and has CRF. It is heartbreaking to read all these stories and know what is ahead for our fur-baby. He is drinking water but won't eat, has a kidney infection on top of it so we won't know for a few days what the outcome will be. Just praying and I'm sorry for all of your losses.

Patricia 4 years ago

My cat Nicki was put down on Monday 3/26 and I held him in my arms and cried...he was nearly 17 and vet could not say if it would work or for how long with hospital stay and meds and Sub Q fluids every I decided to say goodbye and see you again

James 4 years ago

Gizmo was 21, but he was obviously showing signs that he was ready to go. We didn't try anything because he was in pain, so on April 3rd, at 20:29, we put Gizzy down. We're gonna miss you mate :'(

Bill 4 years ago

Eliot made it to 21. I saw him decline over the last six months. On Friday March 30th he was drinking water and fell over. I had to have him put down an hour later. I held him until he was gone and felt him slip away. I miss him terribly as he had always been by my side for the last 21 years.

fusy 4 years ago

My 14 year old has Kidney failure.We have known for 8 months.The Vet said there's nothing we can do for her

:0(. She is always hungry and she eats all day long. She even steals food off my plate. All's she does is eat and poop,She doesn't gain any weight I know it is just a matter of time. All's I can do is feed her and love her.

Retired Vet profile image

Retired Vet 4 years ago from MidWest Author

I know how hard it is to lose a friend the way you all have--I've been through it way too many times myself. It sounds like you gave your cats great lives!

Fusy, did they test your kitty for hyperthyroidism? Most cats that are in kidney failure feel sick to their stomachs, so they aren't hungry. Hyperthyroidism makes them very hungry, but they lose weight no matter how much they eat. It can cause kidney failure, but there is medication for hyperthyroidism that can possibly improve her quality of life and give her a longer life.

Good luck!

Fusy 4 years ago

Thank You very much I will bring her to another Vet and have her tested for Hyperthyroidism. I live in Costa Rica and my Spanish isn't very good. I have been to 2 Vets and they didn't speak English. They both did blood tests and I know they said kidney failure.She has never had a problem going pee.I will change Vets and find one that speaks English. Thank You,Thank You,Thank you. I now have hope.

fusy 4 years ago

Retired Vet,

My cat has been tested, and she does have hyperthyroidism. My new Vet is looking into the treatment(Methimazole),It is not readily available in Costa Rica.I don't understand this because I have read that it is the same medicine they use for humans with hyperthyroidism.

I have been reading up on the Homepathic cure.Do you have anything to say about this treatment???

Thank you in advance.

Retired Vet profile image

Retired Vet 4 years ago from MidWest Author

I'm sorry, I don't know anything about homeopathic remedies. There's a new food from Hills Science Diet that is supposed to help. I'm surprised about the inavailability of methimazole, too. Maybe you could order it online from another country....

mark 4 years ago

our 20 year old cat lucy passed away thismorning,,she was sick a week or two ago then started to come good,,eating and drinking but not really gaining weight,,she had started to go to the toilet anywhere and everywhere ,,not as per normal outside,,,she was a little off last night but not to bad,,but thismorning she was cold and could not move,,,i wrapt her in a towel and held her and tried to make her comfortable,,my son who has grown up with her for all these years gave her a cuddle and said good bye as we new the vet would not make it intime,,,,if i had of known these symtoms of renal failure two weeks ago i would have had her to the vets,,but i think it wouldn't of mattered in the long run,,she passed with out pain and with us there beside her at home,,much nicer then at vets clinic

fusy 4 years ago

Mark, I'm very sorry about the loss of your cat Lucy. My cat is doing better now that I'm feeding her 6-7 small meals a day. She isn't gaining any weight but she doesn't vomit anymore either.I hope when her time comes she will go peacefully like your Lucy did.

mark 4 years ago

thanks fusy, lucy stopped vomiting aswell,,which made us think she was getting better,,i hope your cat gets stronger and you get to spend more time with her,,lucy had a good life and was loved by all of us,,she knew that at her passing ,,im sure she waited until we got up in the morning so she could say goodbye aswell

Lou 4 years ago

Our cat is 10 years old and was not eating and losing weight. When we took him to the vet he had to have surgery to have a tooth removed. When he had blood work done they discovered he also had advanced renal disease. We brought him home last night hoping he would be feeling better. He is like a rag doll today. Won't eat, drink and can barely stand up or lift his head up. Before the surgery he was not eating but was still active. It is heartbreaking to see him this way. We just lost our son and brother 6 months ago. This is like salt on our wounds. I can't bear the thought of losing our Lou but question the selfishness on our part about watching him suffer.

Matt 4 years ago

the second of my cats (the most unusual and wonderful kitty I've ever known) just died at age 11, also from kidney failure, though I'm not sure whether it or the preceding case was acute or chronic.

That they both died young, of the same condition is worrisome to me, for the health of my dog, any future kitty, and my family.

All I can think of is that ours is an old home with lead paint, and that my wife and her friends smoke cigarettes in the den.

Any brainpower input about this would be highly appreciated.

Mary 4 years ago

We just lost our precious 3yr girl, Stinky, on Tuesday to Kidney failure. So heart breaking since just 3 weeks ago, she was fine. Took her to the vets because of allergies and she was given a cortisone shot. Right after that, she started to look lethargic. Not happy with my old vet, I took her to a new vet. She is the one who suggested Stinky have blood tests and a short hospital stay to Iv fluids. The next day we got the news. Brought our baby home 3 days later with meds and Sub Q fluids. Look like she was feeling like herself again until I gave her the 3rd shot of Procrit and she started feeling lethargic again. 2 days later, her gums turned black like a Bing Cherry and started to bleed. Of course that was this past Saturday and the new vet was closing for the day by the time I called. They said she'd be fine and to bring her in Monday morning. I did and that was when the vet suggested to put her down. I couldn't bring myself to do it alone. My husband was already at work. So I brought her home where she just peacefully went to sleep the next day. This all happened WAY TOO FAST! I am so angry at the first visit for not seeing the signs like anemia and dehydration. I miss Stinky so badly. The heart of our home has such a huge hole.

Nic 4 years ago

My beautiful kitty poppy was diagnosed with chronic renal failure at Christmas 2011. So far she has lost more than half of her body weight and when you pat her it's just bones. She is always looking for food and drinking and urinating slot. Ive tried all the presciption iets and she only eats each for a day or two and then wont touch it. She is so skinny now that im feeding her anything she will eat. She still comes out to say hello during the day and still enjoys a pat but she is slowing down. I cry everyday when I see her and I'm scared for the day that I will have tto say goodbye. She has been on daily meds since the diagnosis and She is going to have some sub q fluids today and waiting on more blood tests and a thyroid test which will come back tomorrow. I just want to keep her comfortable until the end. Im so sorry for all of your losses it's so painful because you are losing a member of the family.

Cassie 4 years ago

My cat was diagnosed oct 2011. He has been on 600 cc of fluids a week so 200x3 days it has been working quite well until this past sunday he was not acting normal (purring, happy, all over me, wanting attention non stop) he did not want me around and would not eat or drink. He has his fluids that day also. The next morning i took him in and he was diagnosed with high blood pressure his kidney levels and his red blood cells were actually good. Now today, tuesday he has his fluids and is acting odd again his heart rate is very fast and he is very lethargic. Let me add he started his bp med monday .25mg. Vet didn't warn me that this could happen again. Has anyone experienced the high blood pressure and CRF ? He is 14 and truly has been well controlled the past eight months, but with this high bp i can see that he is suffering. Does it take a week for the meds to start working?

Retired Vet profile image

Retired Vet 4 years ago from MidWest Author

High blood pressure is very common with CRF, and it can take a lot of rechecking and changing drug dosages to get it under control--plus it isn't always controllable. He could have hyperthyroidism at the same time, as well, which can contribute to high blood pressure.

The worst thing about CRF is that it won't get better. You may be able to keep the symptoms under control for a little while, but the kidneys won't heal, and in fact will continue to be damaged, with new symptoms forming. Deciding how far to go with treatment is a very personal decision, and for me, I have always felt like I got it wrong, you know? Either I felt like I tried too hard and kept my own pet alive against her will (my golden retriever, Dandy), or I didn't try hard enough and could have gotten him/her a few more comfortable days (multiple other pets). As much as I hate to say this, when I'm helping clients decide whether or not it's time to let go, it often comes down what will leave them with the least amount of guilt.

If it helps at all, know this: animals do not seem to fear death the way we do. They fear pain, starvation, loud noises, and isolation, but when they are ill and death is inevitable, I have seen them give up or even seek out death. When the bad days out number the good, when your friend is not enjoying life any more, know that you did what you could and that sometimes the most loving gift you can give is the gift of lasting peace.

Cassie 4 years ago

Thank you. I actually work in hospice and I know all about the good over the bad days. This has just started three days ago and it seems he does better the day without the sub q fluids but like i said three days... I will call today and see what to do next. And even these last three days i can not watch him even suffer like this. He was tested for hypothyroidism four months ago but was negative. Had him teated bc he became more vocal. They then said nothing about high bp. Anyway, bottom line i want this to get better and i know it may not of course.

Retired Vet profile image

Retired Vet 4 years ago from MidWest Author

I'm sorry. It makes sense to me that he's worse on the days he receives fluids, because animals are subject to "white coat syndrome" just like we are; the stress of the car ride and vet visit will bring his blood pressure up and tire him out.

Poor little guy. I wish you both the best.

Cassie 4 years ago

Thank you so much. I will not let this go on long at all. If the BP meds do not work i will have to make the decsion. I can not watch him suffer and its just not fair for him. Like i said he had a great eight months after being diagnosed and that i am grateful for. I have never had to make this kind of decsion. I am 24 and i have had pepper since he was 8weeks. He has grown up with me. We have a very special bond. I will give it two weeks with the bp meds and go from there. We will see. I appreciate your advise and responses.

Cassie 4 years ago

I do the sub q fluids myself so no stress of a car ride there!

belle 4 years ago

what long sentences

Sharon 4 years ago

My 14 year old cat Cody was diagnosed with CRF in May this year. He was losing weight but still eating. We had his on Fortekor for his hbp and sub-Qs at home every other day. He was fine until he stopped eating. The vet said he had gingivitis and a decayed tooth that could be causing him pain when eating. We decided to let him have dental surgery given that if he didn't eat, he would starve. During the surgery, the vet put in a feeding tube. He was suffering with that tube, vomiting frequently with the cocktail of meds he was on and completely spacey. Two weeks later, I saw pus ooze from his dressing and brought him to the vet immediately. It turned out that the opening where the feeding tube was at was oozing pus. The tube was removed and he was visibly more comfortable. After 2 days of force-feeding, he started eating on his own. A little at a time, but no vomiting. He even started moving around more which was great to see. Yesterday, I had to work late so by the time I got back, he had already gone 7 hours without food (canned variety). He ate but later, refused his usual two-four hour feeds. I had to force feed him last night, this afternoon and again this evening. He also started having difficulty walking. His legs would give out after a few feet. I know I should end his suffering but I know he's not ready to go. He's fought the vet/nurses with every ounce of strength left in him during any procedure they have done on him. 4 year ago, I had to put my advanced CRF cat Chelsea to sleep and watched him push the lethal dose needle away with all his might even though he could no longer stand and was suffering from seizures. I can never get that image out of my mind. Now, faced with this cat of similar personality, I just don't know what to do. End his suffering early and watch him resist it till the end or let him go on his own terms but watch him suffer through it.

Sharon 4 years ago

I forgot to mention that Chelsea was a male cat. We adopted him at the age of 6mths from an old lady who thought he was a "she" and named him Chelsea! He already responded to that name by the time we got him so we kept it that way.

diane 4 years ago

My cat jake had started being sick for a few days the vet said it mite be a stomach bug but he got worse over the next 2 days and stopped eating and drinking lots and just lying around the house no energy and his balance was all over the place we took him bk to the vets and they ran tests and they came bk showing acute renal failure he was put on iv fluids for 2 days and started eating again. We brought him home tonite and he is more alerrt and still eating but he is sleeping alot he isn't his old self . We have to take him bk to the vets in a week for a check up hes on royal canin renal food . I just hope he can fight this as weve had him 7 years now and hes such a big part of the family he even keeps our 6 year old cocker spaniel in check.

Shirley 4 years ago

I took my cat (who ive had since he was 9wks old-now 15yrs old) to the vet last week, he had stopped eating. The vet told me that he needed some dental work done. Then he called me later that day to tell me that my cat has severe kidney failure. The vet told me that as the levels of toxins in his kidneys are extreemly high & as hes 15 years old, theres nothing hes willing to do. I got to bring him home and he started eating again & junping about like he normally does. I had planned on taking him in on the monday to get him put to sleep however they've told me that hes not in any pain & hes not suffering. Now hes hardly eating at all, ive tried everthing. Although he is still drinking lots & purring away. Now i don't no what to do. Any ideas on food thats best for this?

silvercatblues 4 years ago

I had to put my 7 year old female down. One day she was healthy, the next she was sleepy, sick, keeping to her self, drinking lots of water. The Vet ask what I fed her, I told him mostly dry food. He said he is seeing more cats getting this disease at a much younger age. Since cats don't drink much water, dry food puts a huge strain on the Kidneys. A few years of dry food and you will more than likely wear the Kidneys out. What ever you can do to get your cat to drink water do it. Make it fun and interesting to drink water. Feed your cat at least one wet meal a day. Plus, it might be noted that if you leave dry food sitting out all of the time, your cat will eat more than it will drink causing huge problems down the road with the Kidney's. Cats can get by on a small amount of dry food broken down in small meals. A quarter cup each feeding can feed 2 adults at a time 2 to 4 times a day.

Dry feces are a good indicator your cat is not getting enough fluids. Tuna should be avoided as it has dangerous levels of Mercury. Cat Grass is also good for them. If you can grow a patch in your home they will eat it.

Vomit is a good indicator something is wrong, most people think its normal for a cat to puke. It could be a hairball, or something much more serious. Plus, if you can afford it, buy the best food money can buy. I loved her so much, life isn't the same without her.

MEGAN 3 years ago

My 12 yr. old boy persian kitty has kidney disease. Should I put him down or spend a bunch of money keeping him alive with meds and special diets? I feel horrible. Torn!

janice 2 years ago

just found out my 18 year old cat has kidney disease,plus they say he has some teeth that need to be pulled. i just keep thinking hes too old to have his teeth pulled i don't want him to be in pain and i don't want to let him suffer.What to do,He wont be able to eat.I cant make up my mind .Hes sitting on my lap as I type this,Hes my best friend . He is all I have

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