Renal Failure in Cats


Chronic Renal Failure

Question: Dr Richards, Misi (pronounced MEE-shee) is a 15-year-old domestic short hair cat. We boarded our 4 cats recently with our vet, and his staff noticed that Misi drank too much water. Commercial lab results indicated CRF (Chronic Renal Failure).

April 10: Blood BUN 58 (ref. range 14--36), Creatinine 3.2 (range 0.6--2.4) April 12: Urine SG 1.015

While still boarding, Misi started canned k/d food and daily flushing with 100 ml Lactated Ringers SQ.

Dr G analyzed Misi's blood on his own analytical system:

April 19: Blood BUN 40.7 (reference range 16.0--36.00), CREA 3.78 (reference range 0.80--2.40)

Ambiguous: BUN down, but Creatinine up. (But--different lab.) Well, not all that bad if the results really are comparable. As I understand it, BUN levels matter more, and it went down nearly a third, and is close to the upper end of the reference range. Yes, he still has CRF, but the BUN level isn't bad.

We brought Misi home and continued the k/d feeding and 100 ml/day SQ.

I brought Misi back to the vet for testing: April 29: Blood BUN 48, CREA 3.6 I brought Misi back to the vet for hospitalization and 48 hours of Lactated Ringers on IV, 1000 ml/day (for 2 days). In house results:

May 1: Blood BUN 44, CREA 3.3.

That's disappointing. It's not much to show for the IV therapy. The home SQ therapy at one tenth the rate (100 ml/day vs 1000 ml/day) appears adequate now. And it's much cheaper! Plan: continue 100 ml SQ every other day, and continue k/d (or a more palatable alternative if we find one). So, Dr Richards -- any comments? Are we missing anything? Dick

Answer: Dick- At the present time I think that the researchers in kidney failure in cats pretty much agree that the purpose of fluid therapy in cats with chronic renal failure is to keep them adequately hydrated so that their kidneys can function to the maximum capacity that is left. The idea that we could give additional fluids and cause diuresis as an alternative to dialysis has pretty much been abandoned. This probably explains why the daily SQ fluids work as well as the IV fluids did.

I am usually reasonably content when the progress of renal failure is arrested because the kidneys can hypertrophy and learn to do a better job over time, as long as they are not progressively damaged. It would be nice to see more rapid improvement but the situation so far wouldn't make me feel like treatment wasn't helping.

There are a wide number of choices in things that might help cats who have kidney failure. It is usually not possible to do all these things, but this is at least a partial list:

1) If hypertension (high blood pressure) is present, or even suspected, it can help a great deal to use medications to lower blood pressure. We prefer amlodipine (Norvasc RX) and we usually use 1/4th of a 2.5mg tablet once a day.

2) Potassium supplementation helps most cats feel better when CRF is present. We put the potassium in the SQ fluids but this does make the fluids a little uncomfortable (probably a stinging sensation) for some cats. Alternatively, potassium can be supplemented orally.

3) Using calcitriol helps some cats feel better. The phosphorous level in the blood stream has to be below 6 in order for this to feasible, though. An alternative is to use phosphate binders to lower phosphorous levels. 4) Gastrointestinal protectants like famotidine (Pepcid Rx) can be helpful in some cats.

5) Appetite stimulants help some cats. We usually use cyproheptadine (Periactin Rx) for this -- but don't do it unless it is necessary.

6) Diet can help a great deal. If your cat needs some variety, Purina's NF and Iams Moderate Protein/Low Phosphorous diets are good and I think that Waltham makes a similar diet, as well.

7) When anemia occurs it can be very helpful to use erythropoeitin. This is a little bit of a hard choice to make since it causes problems in some cats due to the human origin leading to antibody formation against this hormone. It can really make a big difference in some cats, though, so don't rule it out entirely over worries about antibody formation.

You often have to pick and choose among medications because cats will only allow so much nursing care and medication administration in a day without getting upset. If there is any chance of hypertension and we can only use one medication we usually use the amlodipine. If we can get away with potassium in the SQ fluids we do that and then try to use calcitriol (when appropriate) or GI protectants if they seem necessary. Good luck with this. Mike Richards, DVM 5/6/2002

Dental lesions in CRF cat

Question: My 17 year old siamese was diagnosed with chronic renal failure a year ago. Her teeth are not in good shape and I am worried that this could worsen her condition. The vet told me she has a reabsorbtion lesion that is painful. When my cat yawned today I saw a black spot on her back tooth that looks like it could be a cavity. One vet told me that putting my cat under anesthesia to pull/clean teeth would be too risky; her kidneys wouldn't be able to filter the anestethia and she could die. Another vet scolded me and said that she needed the tooth pulled b/c the lesion is painful. I am really worried that my cat is in pain but I'm afraid to put her under to get her teeth pulled. I would appreciate your advice on this matter. My cat's latest blood tests are: BUN 40.3, Creatnine 3.25

Thank you, Cathy

Answer: Cathy-

I think that dental lesions are painful enough that overall health improves when they are dealt with. So I almost always want to pursue anesthesia. However, there is some increase in risk when kidney disease is present and it is important to realize this and to compensate for it. The major risk to cats with kidney disease is low blood pressure occurring for a significant length of time during an anesthetic procedure. Giving fluids intravenously during the procedure helps to reduce this risk. In some instances a procedure may be short enough that it seems unnecessary to do this, but it is a good precaution for most anesthetic procedures in cats with kidney failure. It is also a good idea to try to rule out high blood pressure prior to the time that the anesthetic is given. Many cats with kidney failure have high blood pressure because of the effects of the kidney failure on the blood pressure regulatory system. It is good to consider this possibility when planning which anesthetics to use. With care, I think that anesthesia in patients with kidney failure is nearly as safe as in patients without this problem but it is necessary to consider it when planning the anesthetic procedure.

There is a small risk of death with anesthetic procedures but the increase in the quality of life for so many patients outweighs this risk, in my opinion. Some people view death as such a prohibitive risk that they are willing to tolerate a lot of discomfort to avoid any anesthetic risk. This is a value judgment that has to be made by each person making this decision and so both vets are entitled to their opinion. While I favor being willing to take a small risk to increase the quality of a patient's life, it is just my personal opinion. I try to present both sides and let my clients make the decision based on their view of the benefits and risks. It is just really important to remember that patients with dental disease are often in pain, so there is often a great benefit to dental care, even if it does require anesthesia. Sometimes, an increase in drinking and eating after dental care causes significant improvements in illnesses like kidney or liver failure, too.

Mike Richards, DVM 6/5/2001


Question: Dear Dr. Mike,

Thanks for all your efforts. Reading about how other people are dealing with their cat's problems has encouraged me greatly!

Murphy, my male shorthair stopped eating and was diagnosed with CRF right after New Years. His numbers were so high they were off the scale at my vet's lab so we had to send them out. His BUN was over 130, creatine over 12 and he was anemic. Also had low thyroid and retic 1.6%. He had been loosing weight very gradually. 2 Years ago he was 10.5 lbs and Jan 1st he was 7.4Lbs.

We started a regimen of diureses 2 x daily, initial injections of Winstrol V, B12 and iron shots and force feeding A/D. Murphy recovered somewhat and started eating again. We tried Eukanuba multi-stage renal which supposedly has urea filter in it. A week later his BUN/creat numbers had come down but were still very high.

I started diuresing him at home in an effort to reduce the stress of visits to the vet. One night he went into convulsions. I was about to call it quits but Dr. R suggested phenobarbitol once daily at night. We also have him on Winstrol V 2 x daily pills. His head started to sag so I gave him some

The good news is that now his numbers are BUN 29 and creatine 3.98. Which is a huge improvement, although I don't know what numbers we should be looking for ( I don't mean normal range but numbers that can continue to sustain life!).

The bad news is that he has gotten very weak and wobbly. I can see a pulse in his neck (bouncing fur). He is still loosing weight, now a week later at 6.9 lbs. He is anemic - Hct 17.1, Hgb 5.08 (we don't have red blood cell count). He received another shot of B12 and iron and a slow release corticosteriod and seems to feel a little better. He nibbles occasionally but has no interest in K/D (he likes A/D more) so I am pureeing K/D and force feeding him 30cc - 50 cc a day which is about all I can manage to get in him, only having two hands. I am taking him off the phenobarbitol as my vet thinks the wobbly may be induced by pheno toxicity. Also I have tapered off the Winstrol V because it seems to agitate him and keep him awake.

1. I would appreciate any comments you might have regarding his candicacy for Epogen ( are we likely to succeed with B12 in curbing his anemia) versus blood transfusion.

2. Any comments regarding use of Winstrol V or corticosteriod which I haven't seen in the CRF lit?

3. As with you my vet has no facility for checking BP. Should we proceed with enalapril (vet doesn't have amlopidine)?

4. He has been a chronic vomiter (often with hairballs). Should we go ahead with PepcidAC or do we need a test first. Will the PepcidAC interefere with his nourishment intake which is essential given his current condition?

Any comments and suggestions would be greatly appreciated. Michael

Answer: Michael-

We usually wait to recommend the use of Epogen (Rx) until the hematocrit is below 15 and/or the cat is showing clinical signs of anemia (which would include weakness, tiring readily, increased respiratory rate). We wait because there are cats who become sensitized to the Epogen and produce antibodies against it. When this happens, the Epogen must be stopped and it can't be started again. So it just seems better to wait to use it until it is really needed. We have cats whose hematocrits are dropping off who start to produce red blood cells again when their kidney values improve, so there is some hope of a partial recovery. I am not sure that Vitamin B12 plays a huge role in this but most veterinary texts recommend supplementing it and it seems safe to do that. It may be necessary to supplement iron if Epogen is started. I don't usually use anabolic steroids (Winstrol-V Rx is an anabolic steroid) but some vets suggest using nandrolone (DecaDurabolin Rx), 10 to 20mg per cat once a week, since there have been some reports of liver problems in cats associated with the use of stanozolol (Winstrol-V) even though many vets have never seen this effect. Weakness is frequently associated with low potassium levels in the serum and it may help a lot to supplement potassium. This is easy to do if you are giving subcutaneous fluids at home. Your vet can just add potassium to the fluids in an appropriate amount for the amount of fluids you are administering.

I think that is best to use famotidine (Pepcid AC tm) if you are seeing any signs of gastrointestinal problems since uremia can be very irritating to the digestive tract.

The last part of your question is the hardest to answer. We have drawn blood from cats for routine reasons and found BUN values as high as 105 and creatinine values as high as 6.5. These are cats whose owners were unaware of any clinical signs relating to kidney disease. On the other hand, many cats will stop eating when the BUN is around 75 or the creatinine above 4.5. So I tend to think that there is a variable response to poor kidney function in cats. However, since both values are below the ones we usually associate with poor appetites and general lethargy, there is a good chance that Murphy can go on for some time if you take the steps necessary to keep him comfortable, which you are doing.

Good luck with this.

Mike Richards, DVM 2/6/2001

Feline CRF/Diabetes

Question: Hi Dr. Mike: I would appreciate any advice you could give us. We have four cats. Three are 13 and one is 11. Our 13 year old spayed female kitty, Sasha has never had any health problems other than allergies (sneezing) for which she receives a Depo injection every 4-7 months for the past 3 years and one sinus infection one year ago. On Aug. 31 we noticed excessive drinking and frequent urination. The next day, blood test revealed: glucose 439, urea nitrogen 46, creatinine, 1.7, total protein 8.9, ALT(SGPT) 160, globulin 5.5, triglycerides 381, phosphorous 5.6, BUN creatinine 27, absolute lymphs 534. Starting 9/5 Sasha stayed at vet's office for 4 days for glucose monitoring. Home on 9/8 using 2 units of Humulin L every morning. 9/10 Frequent visits to litter with no urination, excessive drinking. 9/11 Dx of cystitis with urine specimen. Vet gave her antibiotic injection. 9/15 Glucose was reduced insulin to 1 unit every morning. 9/27 Lethargic & frequent urination. 9/28 Another blood test: glucose 23, urea nitrogen 109, creatinine 5.2, total protein 9.3, phosphorous 16.4, bun/creatinine 21, globulin 5.9, amlase 1855, triglycerides 42, DPK 604, GGTP 45, Magnesium 2.7. Vet discontinued insulin and gave her subq fluids. 2 days later, still lethargic, no appetite, green discharge from the nose. For the next 4 days she stayed at the clinic for IV fluids and antibiotic injection every day but came home every night to sleep with us. She then had subq fluids for the next 2 days, then every other day since. On 10/4 (3rd blood test) glucose 235, urea nitrogen 78, creatinine 3.3, phosphorous 10.5, BUN/creatinine 21, CPK 664, osmolality, calculated 339. I just started this week giving her subq's at home. 200ml each time. She has eaten w/d for the past 4 years, before that c/d. We are now giving her c/d dry and a/d canned to help her gain some weight. She has always been petite at about 8.5 to 9 lbs.but went down to 7lbs. At the moment she seems to be doing great. She has to be next to us all of the time which is how she was before getting sick. She also constantly brings us "presents" like socks, etc. from the bedroom. I am concerned about the diabetes and if the insulin had anything to do with escalating the deterioration of the kidneys. She will be having another blood test this Friday. Hopefully, if the results are good, we can reduce the frequency of the subq's. I read that dandelion leaves are good to rejuvenate the kidneys but then read that it's a diuretic so I haven't used it yet. Your input would be greatly appreciated. We'd do ANYTHING to keep her well and never want her to suffer. Thank you....ileana

Answer: Ileana-

It is good that you are making progress with the diabetes. It has been our experience that many of the other organ problems identified in initial lab work will improve dramatically when the blood sugar levels are adequately controlled. Diabetes affects every organ's function to some degree. Unfortunately, it is not uncommon for diabetes to co-exist with cholangiohepatitis (a form of liver disease), pancreatitis or kidney failure, since all occur in about the same age range cats and all are reasonably common problems. In those cases, it is necessary to treat each problem separately but concurrently. Often it is possible to manage multiple problems.

I checked into dandelion and its only proven effect is diuresis, which can be good in kidney failure patients, as long as they have adequate water intake --- so I would not stop the SQ fluids until you are sure that Sasha is drinking well on her own, as a minimum standard. In all honesty, I think it is best just to continue the fluids but perhaps cutting back on the amount or giving them at longer intervals may be possible. Unproven, but commonly mentioned effects of dandelion are liver oriented, including increasing bile flow, which is beneficial if it happens. There are also some reports of improvement in diabetic management through the use of dandelion. The PDR for Herbal Medicine suggests making sure that bile duct closure is not a problem prior to using dandelion. Continued improvement in liver enzyme levels would be a strong indication that this is not the case.

It sounds like you are doing well so far. I hope that success has and will continue.

Mike Richards, DVM 10/26/2000

Sub-Q fluids for renal failure in elderly cat

Question: Dr. Richards:

We're recent subscribers who wish, first of all, to thank you from our hearts for the service you provide. As caretakers for a family of 13 felines, we've found the Digest invaluable re. serious health issues we were in despair of comprehending, let alone resolving. The information you've provided has enabled us to ask more-comprehensive questions of our vets and better understand their answers, which ultimately means we've been able to make more-informed decisions.

Our momcat has just turned 19 and appears in every way, except for joint stiffness when she first arises from resting positions, exceptionally healthy. Her appetite is good, she drinks a decent amount of water, and, wonderfully, her interest in life is as keen as ever. Three years ago a routine blood test showed her kidneys to be "functioning at about 30%" of desirable ability. She was placed on thrice-weekly sub-q fluids (150 ml.). A year later this routine was bumped back to twice weekly; this past December we retreated to once weekly.

Last month circumstances forced us to take her to a new vet for her fluids when she'd gone two weeks without. This vet insisted on checking her BUN before sub-q'ing (in addition to a thorough exam); when the results came back, they were well within the normal range. We waited another two weeks--still, with no fluids administered--and checked her BUN again. The reading was exactly the same.

The new vet says a) fluids administered at such lengthy intervals as had been our prior routine would serve no real purpose in assisting renal function; and b) whatever Momcat's situation three years ago, at the present time she (and her kidneys) are fine. While we rejoice at not making her undergo a weekly invasive procedure, realistically we must question whether new vet is right re. a).

Thanks so much for making your time and knowledge available to those of us beyond the locale of your practice. We truly appreciate your compassionate interest in the welfare of strangers.

Shelly & Elliot

Answer: Shelley and Elliot-

I pretty strongly disagree with your second vet when it comes to long term fluid therapy for cats with chronic renal failure. It would be nice to know the original lab values that prompted your original vet to consider long term fluid therapy but presuming there was evidence for renal insufficiency at that time, I would support the continued use of fluid therapy. I prefer to teach my patients to give the fluids themselves but that is the only difference in my approach. I have not been able to find studies to support or refute the value of long term administration of fluid therapy but my practice experience and even Momcat's experience, so far, suggests it is helpful.

Dehydration is the major enemy of the kidneys, especially when they are not operating with much reserve capacity. Administration of fluids helps to prevent further damage associated with dehydration. I believe that we see far fewer kidney crisis situations in cats whose owners administer fluids on a regular basis and that this practice has increased the survival time of cats with kidney insufficiency in our practice. I am sure there is disagreement over the value of long term fluids but my vote is for them

Mike Richards, DVM

Feline Renal failure and eating

Question: Dear Mike,

Thanks for the advice you gave me regarding Max, my cat.

I had previously understood that the majority opinion was that cats with renal chronic renal failure should have a low protien diet (eg KD). I did read an article in the USA which suggested that opinion had changed and instead higher (high quality) protien foods are being recommended.

Max's bloods have stablised for the last year but she has recently lost weight. Although she has previously liked KD (dried) I wondered if I should offer her something more appealing.

Thanks for our your help with Max, John

Answer: John-

I still think that k/d is an acceptable diet because it does contain high quality protein ingredients, it has a low phosphorous level and it does help to make the urine slightly basic. The last two things are still considered to be very important in managing renal failure. However, it does seem acceptable at this time to have a more moderate protein diet. I think that both Purina nf and Walthams diet ( I can't remember the name of their kidney diet) are a little higher in protein.

The difficulty in changing diets is that it is hard to evaluate things like phosphorous level in commercial cat foods, making it hard to figure out how to add them to a diet that also contains one of the specialized diets or utilize them in renal failure alone.

At our practice we go by the principle that the most important thing is to get a cat with renal failure to eat regularly. After that, we work on their diet and try to control phosphorous levels and to stick with foods that are not likely to produce acidic urine (so none of the diets like Purina Special Care or Alpo Urinary Formula that are made for cats with lower urinary tract disorders). I think it is acceptable to use regular commercial diets and a phosphate binding agent, like Amphogel (Rx), if that is what it takes to get a cat to eat well. For many clients it is easiest to stick with a commercial renal failure diet, just to avoid giving additional medications, though. So if she likes k/d I don't think I'd be overly concerned about switching diets. If she is growing bored with it, you do have options, both in specialized diets and in the use of regular commercial diets with additional medications to bind phosphorous.

I hope this clarifies things some. If not, just keep asking questions.

Mike Richards, DVM 5/24/2000

Advanced renal failure

Question: Dear Dr. Richards or Dr. Mike, I am a subscriber to VetInfo. I have found many answers to my questions on your website and through asking my vet. I do have a couple of questions I'd like another viewpoint on. My cat is 17 years old. She gets SubQ fluids every other day and tapezole every day. I take her to see the vet regularly, every six to eight weeks right now. The vet monitors her closely. My question is one I hope you can answer as accurately as possible. I need to be prepared mentally for my cat's death. I need to know the signs that tell me when she is nearer to dying. I watch her closely. She's losing weight slowly. She eats very little so I feed her two tbsp. five times a day of a concotion of baby food, vitamin powder, egg yolks, oil, karo syrup. She is still losing weight and sleeps quite a bit, but doesn't seem to be depressed. She still enjoys my company and follows me to sleep in whatever room I'm in. My vet has let me know that I have to eventually give her Sub Q fluids every day. I don't want to do it until it's absolutely necessary because the rocess is uncomfortable for her. She shivers the whole time the needle is in. When do I know I should switch to every day? But most of all, how do I know when she's closer to the end of her life? How long do cats on Sub Q live, usually? She's been on eight months. The vet asst. said her urine may smell less strong as her kidneys fail because she can't process her body's poisons as well. Right now her urine does not smell as strong as it used to. She seems to want to drink water a lot. She looks at the water longingly and drinks some. Are the fluids I give to her Sub Q enough to sustain her? Does she still need to drink on her own? Is dying from this disease painful? Do cats usually die from kidney failure or complications due to kidney failure? Will there be sudden pain or what? I know I've written quite a few questions. If you don't have time to answer, would you recommend a book on cat diseases or on geriatric cats? I've looked in the book stores and I don't see any on these specific subjects, just a short section on some of the diseases and not much at all on older cats. I think I've gotten everything I can online. Thank you for any information you can pass my way. Sincerely, Laurie

Answer: Laurie-

You may want to check the link to the feline chronic renal failure website that is in the link section on our site. The people who run that are very helpful and the information is good.

It helps to warm the fluids slightly when you give them. We do this by running the IV tubing through a bowl of warm water. Just putting one coil of the tubing in the water seems to help a whole lot. Some people recommend warming fluids in other ways. We use bag warmers in the clinic, too, but I don't even know if they are available anymore. Clinics with big incubators sometimes put fluids in them for a few minutes. I have heard of microwaving fluids but would be very reluctant to advise this after having seen some pretty bad thermal burns in baby birds fed formula that was heated in a microwave. That might cut down on the shivering. Fluids at room temperature are usually about 30 degrees Fahrenheit colder than the cat, so the shivering is natural as the cat tries to warm back up after the fluids are administered.

I have asked a couple of people I knew who had kidney failure what it felt like. They said it is not painful in the sense of sharp pain but that it was uncomfortable, like having the flu, when it was time for dialysis. Since we don't do dialysis in cats I suspect that they may feel under the weather a little bit most of the time. But since we can give fluids daily this is probably a relatively minor discomfort until the kidneys get bad enough that they don't respond to fluid therapy anymore.

The most reliable sign of discomfort associated with kidney failure is usually lack of appetite but cats vary a lot in how they respond to this problem. Some eat right up until the time their kidneys fail completely and others are picky even when they only have slight elevations in enzymes related to kidney function. It is necessary to use your knowledge of your cat to decide when the situation has become intolerable to her. I really think that most pets who are close to their owners figure out a way to tell them that they are uncomfortable too often. Some cats being to avoid contact, some hide, some just stop responding to their owners and almost all of them stop eating.

It sounds like you are close to the time when daily fluids would be more beneficial. It might be a good idea to check her T4 level and make sure the Tapazole dose doesn't have to be adjusted downward due to the weight loss. Appetite stimulants help many cats. If her phosphorous levels are high using phosphate binders can be helpful. Cats feel a lot better when their phosphorous levels can be controlled. Calcitriol is helpful in making some cats feel better but it is important to evaluate phosphorous levels prior to using this medication. If your cat is anemic it may be helpful to use erythropoietin but medication has to be carefully considered, too. Some cats develop antibodies to erythropoietin and since this is a hormone that naturally occurs in cats the development of antibodies can be a serious problem. On the other hand, severe anemia is debilitating and there is a point where this treatment is worthwhile.

If you need more information on any of these therapies I will be glad to try to provide it.

Mike Richards, DVM 3/12/2000

Renal failure

Question: Dr. Richards,

My 10 1/2 year old cat has been diagnosed with renal failure in January. My vet states that Max's kidneys are only working at about 25%. I am seeking information on treatments or medication that may be helpful.

Currently Max is receiving 2 sub-Qs per week. I am giving him a pepcid AC 10 mg. 2 times per day. (This really helps). He is also on Winstrol to increase his appetite. I give him metoclopramid for nausea as needed. He starts on vitamin D tomorrow (calcitriol).

He is eating about 1/4 of a cup of food per day or less. He prefers dry but will eat some canned food. I am feeding him any brand that he will eat. I have tried NF and RD but he does not eat them. He drinks water at a good rate. Before his illness he ate 1/2 cup per day of SD for the last 6 years. He has lost at least 6LBs. (was 15LBs and am estimating him at 9LBs).

Overall he is stable, although I realize that he is border line and must be monitored.

Do you have any suggestions to increase his appetite? Are there any other drugs that will help improve his condition? Why has this happened to a relatively active cat - I would have expected it at 15 years but not now.

Any help you can give me would be greatly appreciated. Would you please reply by return email?

Thank you, MJ

Answer: MJ-

I can't explain why some cats develop renal failure earlier than others. If Max is Persian, then I'd worry about polycystic kidney disease but if not, an explanation may be hard to come by. It is a good idea to try to rule out diseases and disorders that might be contributing to renal failure, such as hyperthyroidism, hypertension and diabetes. Most likely, your vet has considered these and ruled them out, but it might not hurt to check. It is also important to continue to monitor for these other conditions as time goes on.

I have had pretty good luck using cyproheptadine (Periactin Rx) for appetite stimulation and we have also used diazepam (Valium Rx) when necessary.

I think it is more important that cats eat well, than to try to control what they eat, when renal failure is present. So I lean towards letting my patients eat what they prefer, if they won't eat the diets that are better for them. I use Kellogg's motto on this: "No diet is good for someone until they eat it."

I think that it is reasonable to use medications for hypertension, even if a clinic doesn't have the means to measure blood pressure and possibly even when it doesn't appear to be present. Enalapril (Enacard Rx) has been shown to help in some renal disorders independently of its blood pressure effects and amlodipine (Norvasc Rx) really seems to help many of our renal failure patients feel better, as well.

There is a link on our link page to a feline chronic renal failure web site that is very good. You might want to check this out, too.

Mike Richards, DVM 2/20/2000

Renal Disease

Q: Dot is a 16 year old American Short Hair female feline. She has been losing weight for over 2 years. She was plump all her life. She is now very, very thin. My vet says she has significant kidney failure.

Recent Tests: Kidney Failure - yes Diabetes - no Thyroid - normal

Despite her appearance, she acts completely normal. She runs and frolics. Her appetite is generous, as always. She does not appear to drink more water than she ever did.

My Question: My vet has not recommended any treatment except for a low protein diet ... which I implemented with Hill's Feline k/d. She does share some regular wet 9-Lives food with her adopted brother, Sam. But she loves the k/d. Let's face it, she loves most food I provide her.

Is there nothing else I could be doing to reduce the effects of kidney failure before she shows symptoms other than weight loss? I don't want to do things that will significantly reduce our quality of life: Dot's and mine.

Thanks very much, Jim

A: Jim-

There are a couple of things that may be worth consideration as further treatment for renal disease at this stage. In addition, we have become absolutely convinced that a few cats with hyperthyroidism have total T4 values in the low end of normal range and that even more have total T4 levels within the normal range. Consequently, in cases in which hyperthyroidism seems very likely based on the clinical signs we have begun using free T4 analysis as a way of sorting out which cats might have hidden hyperthyroidism. Since kidney failure can cause increases in the free T4 it is necessary to consider using a T3 suppression test if the free T4 is high as further confirmation of the condition in cats with renal failure. It is sometimes more practical just to do the T3 suppression test but it is more involved. I would consider retesting for hyperthyroidism with the history you give for your cat.

At the present time there are two relatively new recommendations for cats with renal failure.

Calcitriol (Vit D3) administration appears to help slow the progression of renal disease and its use is advocated by some specialists for virtually all cats affected by renal failure. I do not know how other vets obtain this medication but we have been using a compounding pharmacy to get it. There is some conflicting information on the use of calcitriol and we have not been as aggressive in recommending its use as its advocates. The cases we have used it in do seem to benefit and we are much more likely now to recommend it than in the past.

Enalapril (Enacard Rx) and amlodipine besylate (Norvasc Rx) have traditionally been advocated for hypertension that results from kidney failure but now veterinarians are starting to use them earlier, hoping to prevent the hypertension and hoping that there will be beneficial effects on the kidneys. I think it is reasonable to do this since many cats will develop hypertension if untreated and there are potential benefits.

Fluid therapy, usually given subcutaneously, has been the mainstay of treatment for renal disease in cats. It is relatively easy to administer fluids and most cat owners can learn to do it. Not everyone is comfortable about using needles and not every cat is cooperative enough but when it can be done fluid therapy seems to help a lot. I prefer to start it before a crisis has occurred and to use a maintenance routine of fluids several times a week. Not all vets are comfortable allowing clients to administer fluids and some vets feel that fluids are not helpful until the renal disease is advanced. While I disagree arguments can be reasonably made for both approaches.

There is information on the website on renal disease and a link to a very good website on chronic renal failure in cats. You might want to check both of these things out as well.

Hope this helps.

Mike Richards, DVM 4/6/99

Renal failure and liver mass in 15 year old cat - Prednisone treatment

Q: Dear Dr. Mike: Last week we took our approx. 15 year old cat to Cornell for diagnostics because his appetite was poor and he was losing weight. They found chronic renal failure and a mass in the liver. We chose not to treat it aggressively--he is old and weak--and basically took him home to die. The vet gave us prednisone for him--5 mg twice a day--advised us to have him euthanized in about a week. It is now a week and he is eating well and seems comfortable. My local vet says prednisone provides a sense of well-being but that the disease will eventually be overwhelming and he will stop eating again. My question is: how long might he last? I know there is no hope for him, and we really want to do the right thing and not have him suffer. Yet it doesn't seem right to have him put to sleep when he seems to be doing fine. Can you give us any insight as to how things might progress? Your website has given us much information;

thank you.

A: James-

I can't give you an average lifespan for the liver mass without knowing what the mass is. But that probably isn't very important, because averages really don't apply to an individual patient very well, anyway. I think that your philosophy is just right -- while your cat feels comfortable, continue to enjoy the time that you do have and when signs of discomfort or progression of her illnesses progress, then consider euthanasia.

It is important not to give up on the treatment of one life-threatening illness due to the presence of another. In this case, the renal failure is important to treat even though there may be a potentially fatal liver mass. There is a lot of information on our site on treating kidney failure. A more recent recommendation that is not on our site is consider the use of angiotensin converting enzyme inhibitors (ACE inhibitors) such as enalapril (Enacard Rx) to keep hypertension under control and improve circulation in the kidneys. The rest of the recommendations on our site --- subcutaneous or intravenous fluid therapy as needed, potassium supplementation, phosphate binders if necessary, appetite stimulants if necessary and good supportive care still hold.

I am pretty sure that the Cornell veterinarians have given you their best estimation of the time that they thought your cat had left for a comfortable life but often these estimates turn out to be wrong. You should feel confident in your ability to judge your cat's general well being after living with her for 15 years. Trust your instincts and ask your vet for advice when you have questions about how well she is doing.

I do not want to give you false hope but there are two or three patients in my practice who I thought would surely die within a few days --- more than six months ago. Take this one day at a time, spoil your cat a little and trust your instincts. You almost certainly will know when the time has come to consider euthanasia.

Good luck with this.

Mike Richards, DVM 2/28/99

Last edited 07/01/05


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...