Age And Kidney Failure May Not Be A Factor In Anesthesia

“Dr. Randolph, is she just too old to have surgery?”

Thirty years ago this client’s statement would have applied to any pet over six years of age.

Twenty years ago that age limitation might have been set at age ten.

For the last ten years age, alone, is not a consideration for which patients we will anesthetize and which ones we won’t.

Today we have excellent diagnostic tests, such as the chemistry profile to determine whether kidneys, liver and other blood parameters are in a satisfactory range to ensure safe anesthesia. We have detailed complete blood counts (CBCs) to know whether there are sufficient cellular elements such as red blood cells, white blood cells and platelets for safety. The urinalysis yields data we can use along with the blood test results to know even more about the body’s overall health.

In 2010 we are three generations ahead of inhalant maintenance anesthetics we used in 1980 when I graduated from Auburn University’s College of Veterinary Medicine. Where a pet with a borderline liver or kidneys might not have survived even a short anesthetic procedure thirty years ago, today the same pet might emerge healthy from even a lengthy surgery or dental care.

Which brings us to today’s post about our precious poodle, Pearl.

Recently we noticed that Pearl had lost weight. Perhaps we suspected prior to “recently,” but were in denial. As she grows older and is losing her vision and her hearing, we really aren’t up to more bad news. Frankly, we still haven’t gotten over the loss of her brother, Peyton and probably never will.

Pearl has always been a dietary self-regulator, never eating more than she needs for proper health and nutrition. As a result, she’s always had a trim build, and we are able to just scoop up a bowl of food, put it on the floor while we have supper and pick it up later. We first began to notice that there was more food than usual left in her bowl. She has eaten Prescription Diet t/d in the original size for years and years, but when I accidentally brought home the “small bites” version of t/d we noticed that she ate it better.

Even though her physical examination was mostly normal, just to be sure she wasn’t having any metabolic problems I submitted samples for a chemistry profile, CBC, urinalysis and thyroid level.

Everything came back normal except for her kidney numbers, which are about twice the maximum of normal. As bad as that sounds, it’s really not so bad for a 16-year old dog. Still, it does mean she is in kidney failure, and that will likely be the cause of her eventual demise.

So, what does Pearl’s kidney failure have to do with anesthetizing old dogs? Read on.

After we discovered that Pearl no longer wanted to eat a large kibble like t/d, and we had her abnormal laboratory test results, we decided to change her diet to Prescription Diet k/d instead.  k/d is formulated specifically for patients with kidney and liver problems. For some time her breath has been a little objectionable, but I began to notice that there seemed to be “foul” component to it now, which implied infection might be present. Further investigation proved that calculus buildup was substantial, as is common in older dogs, and that infection in the gums was a problem.

After long discussions and prayer, Brenda and I decided to proceed with anesthesia, dental cleaning, polishing and fluoride treatment for Pearl.

The night before her procedure I administered Convenia to Pearl to begin the process of lowering oral bacterial numbers well before the procedure.

We began the day by introducing fluid therapy to flush waste products from the bloodstream that the kidneys were not removing. After an hour on the IV pump we transitioned Pearl to surgery, anesthetized her, and began to remove the calculus above and below the gumline. That part was uneventful and our Cardell monitor assured us that all systems were operating as they should. We polished her teeth, applied a fluoride treatment and woke her up.

To continue flushing out waste products we maintained Pearl on the IV pump for the remainder of the day until it was time for both of us to go home.

The next day Pearl was spry, just as if nothing had ever happened. She is eating normally, jumping on and off furniture like she always does and generally healthy and happy.

The infection smell on her breath is gone.

Convenia will continue to protect her for 14 days from infectious bacteria that might have been released into the bloodstream during the dental cleaning, so that they do not cause problems in the heart, liver, kidneys or other organs.

Removing the oral inflammation and infection will prevent those problems from taking a further toll on her kidneys, a cost she cannot afford.

Having been safely anesthetized and her teeth shiny and healthy, Pearl can expect to survive longer with kidney failure than she would have with ongoing oral disease taking its toll.

More on kidney failure Monday.


  1. I have an almost 14 year old Coton de Tulear white creatinine of 2.2 and phosphorus 7.7 at her last bloodwork. CBC was a 4.6. She was supposed to go under for dental last week but two different certified dental vets did not feel comfortable putting her under with her levels that had came back. She now has a broken tooth and I am concerned about her anesthesia risk and what could happen with her kidneys after. I am also concerned if the tooth is not removed and her being in pain or infection getting worse.

    • Medication can get the phosphorous down. Fluid therapy can get the creatinine lower, at least temporarily. Possibly your veterinarian can find a board-certified veterinary anesthesiologist who will travel to his practice and formulate and administer an anesthetic protocol that adds safety. Best wishes to you and thanks for reading, Dr. Randolph.

  2. The vet could not do the operation to take out the mammary growth as ,u dog has too high a count in her kidneys for a safe outcome. I am praying for an answer to this anomaly as the growth makes her mobility and life in general a huge burden . I am hoping for a vet who will have the means to anaesthetise her safely in order to extract said growth.
    Regards Alison

    • Perhaps you can be referred to a specialty hospital with a board-certified surgeon and a board-certified anesthesiologist. IF the numbers are not TOO bad that combination of specialists would speed the rate of the procedure and add a level of expertise that could improve safety. Please be in touch and let us know how that turns out, Dr. Randolph.

  3. How interesting: our 16 year old Scotty has a mammary growth which was going to be removed but we have been told that because of adverse kidney tests she would be unable to get rid of the anaesthetic properly post op and would be therefore vulnerable.
    Your situation and usage of Convenia couldn’t be more timely if , that is , the vet involved agrees.

  4. Interesting read. My 16yr old chihuahua is in need of a dental. He is diabetic, has a grade 6 heart murmur with CHF and labs just came back with a BUN OF 92 and Creatinine of 2.7. I am very nervous to go through with the dental now, it is scheduled for 2 days from now. Two different vets (at the same clinic) are advising to go ahead with the dental. They say “there are risks” but can’t be anymore specific than that. They say they think the benefits of a dental outweigh the risks. He has been on antibiotics for a month for a mouth infection. Prior to that was feeling terrible and not eating ( I assume due to dental pain.). Since the antibiotic therapy he is feeling amazing, the vets are guessing with discontinuing the ABO the pain will return. So hard to put him at risk now that he is feeling so great. Your thoughts would be greatly appreciated. Thanks!

    • Wow, Traci, what a tough position to be in. Whenever I’m in a tough spot, I call on God. (For that matter, I call on Him when the spot is not so tough.) Spend some time in prayer and see what guidance He sends you. You have two doctors advising you to proceed, that indicates they are quite confident. That’s a good sign. Listen to the Holy Spirit and write back and let me know how your baby is. I’m praying for you to have discernment and wisdom. Thanks for reading, Dr. Randolph.

      • Yes, I did indeed pray about it. We went ahead with it last Thursday so this is day 4 post op. It went very well. A total of 4 teeth were extracted due to infection. My old boy is doing well. Not much of an appetite back yet, other than that he’s at about 75% of where he was before the dental. I’m hoping by 1 week out he’ll be back be close to 100%. Thank You and God Bless

      • Hi Dr. I am in a similar situation. My dog has a lump that is too small to test to find out if it is cancerous according to my vet.

        My dog has a stage 1 kidney disease and has a BUN of 110 and a Creatinine of 2.3.

        Would you say it’s safe to proceed with anesthesia to put her under to remove the lump?

        • I am not your dog’s doctor, therefore, I have NO standing to make such a decision. Your options: Have this discussion with your local veterinarian OR have him refer you to a board-certified surgeon. You could even take the interim step of having a board-certified internist evaluate your dog for anesthesia safety, then have the internist advise the surgeon. A specialty practice with all of these disciplines under one roof makes that latter option easy. I’m saying a prayer for your dog’s safety and for you to make the right decision. Thanks for reading, Dr. Randolph.

  5. Interesting. I had resolved to not bring 14-year-old Ginger the greyhound to have a 3-pound lipoma removed from her abdomen because I feared she wouldn’t survive the surgery. Her blood work and high blood pressure of 275/145 the morning of the surgery made the Vet want to cancel the surgery and test whether renal failure was the culprit last year. It was stage 2 renal failure and been on Fortekor since. I’m assuming it may have progressed to stage 3 today. Keeping her big lipoma from ripping through the skin has been tough. It bleeds and she needs a compression belt around her waist constantly because it hangs really low. I need to clean it every day and it’s hard to keep her from licking it constantly. Other than that she bounces up and down when it is dinner time or time for walks. It is obviously bothering her, but I feel euthanasia is too soon….. so maybe surgery would be a good idea… Thank you for posting this.

    • I think about this article a LOT. My father had his 100th birthday last year. How many times has he been anesthetized since he was 80? I’ve lost count. He had major abdominal surgery when he was 98. On the other hand, I have several five-year-old patients with such severe maladies that I would not consider anesthetizing them. The only way we’ll know whether anesthesia is safe for Ginger the Greyhound is to have a current examination, get updated laboratory values, including blood pressure. If your veterinarian is against doing the surgery, consider having him refer you to a board-certified surgeon. The group we use has a board-certified anesthesiologist, which allows the surgeon to focus more on the surgery while providing maximum safety for Ginger. When our Willie needed anesthesia for a diagnostic procedure recently, the anesthesiologist used a cocktail of medications tailored just for his ailment, age and physical condition. He bounced back like nothing happened. However, if the examination or the “numbers” just aren’t good, surgery may not be an option. Thanks for reading, and, please, keep us posted on Ginger the Greyhound.

  6. I find it very troubling that you deleted my comment, which was just a description of my experience, but am more troubled by your blog post title misleading people like me. You know that it is not true to say that kidney failure is “not a factor” in anesthesia. After my dog died the doctors told me that chronic kidney disease is the *biggest* factor in predicting an acute kidney injury from anesthesia. You need to edit your blog title so you don’t mislead more people in the future. If you are a licensed vet you know that you shouldn’t be misleading people with false statements. Something more measured would be appropriate. I.e., anesthesia can still be an appropriate choice despite age and kidney function, despite the risks.

    • Thou jumpest to conclusions. Ours is a very busy practice, and I work on this blog, for free, in my “spare” time. Your initial comment came in two days ago. Yesterday I took our own dog to a board-certified veterinary internist for a second opinion and a procedure we were not equipped to perform. Thus, I was unavailable all day yesterday. We didn’t delete your comment; it just took us a mere 48 hours to get you a reply. When I wrote this article I was thinking of patients in need of dental care with mild elevations in BUN and creatinine. It’s rare to be faced with anesthesia for patients in renal failure as advanced as yours, usually because they are so old they don’t have much time left. The situation you describe with your pets seemed to be a root abscess that needed to be drained by extraction, a completely different circumstance. To widen the applicability of the present article’s scope, we have made modifications to the title. Again, our deepest sympathy on your loss, Dr. Randolph.

      • Sorry for saying you had deleted it, I was mistaken, I apologize. I’m still a bit emotional over the whole thing. What you noted below is helpful to know. I am glad the dentist at least tried, since the alternative of just doing antibiotics forever probably wouldn’t have been a great option. It’s interesting to hear about the kidney function going beyond the creatinine/ BUN/ potassium/ phosphorus numbers, perhaps that is why he was so sensitive to Gabapentin as well (even before the dental), a drug filtered through the kidneys. I think you are right that there was no choice but to do the dental. Maybe if I had realized the kidney injury earlier after the dental then IV fluids could have helped, but that might be wishful thinking.

  7. (Re posting because it looks like I posted this in the wrong place)

    My dog passed away recently a few days after dental extractions and anesthesia with a board certified veterinary dentist. He had stage III CKD, and had numbers that were relatively stable for over a year. Creatinine 3.5 or so. I didn’t fully appreciate the risks involved in the anesthesia. He seemed pretty rough after the dental but he then seemed to get better in the first few days after, but was extremely sensitive to the Gabapentin prescribed for pain. Then within a few days he stopped eating and drinking and new bloodwork showed an acute kidney injury, kidney values all severely worsened, likely from the anesthesia. We tried IV fluids but he passed away within a day. I had been advised to do the dental by three of his different vets (including the vet dentist and a kidney specialist). Only his general vet was concerned, ironically, but still recommend it. I guess I did the right thing, but I’m not happy about it. The prior year, during a prior dental, a different vet dentist at the same office had identified the tooth that later got infected as having problems, but said it wasn’t justified to take it out yet. If he had taken it out last year, the subsequent dental could have been avoided. Maybe this story will help someone else in the future dealing with similar issues.

    • Our deepest sympathy on the loss of your baby. If I had that many experts recommending proceeding with the dental care, I’d have done the same thing. It is the nature of renal failure that, without some incredibly complex and expensive testing, it’s difficult to know the exact extent of kidney damage. These tests are performed in people all the time, but they are prohibitively expensive for most pet owners. It’s likely that your dog had little functional kidney tissue left, pushing him over the edge. Even in that case, however, you took the plunge to remove what sounds like a chronically bothersome and dangerously infected tooth to drain an abscess. Without that care, he likely wouldn’t have survived. My comments are conjecture, not having access to examine him or see his full laboratory test results, but they likely fit. Please be comforted by the knowledge that you did everything possible. Dr. Randolph.

  8. I’m in a similar situation, my dog (Shih-
    tzu) is 12 years old, she has kidney failure and dog dentists won’t anesthetize her to clean her teeth because of her kidney disease…
    and also they don’t put her on restraints because they don’t want to stress her out cause of her blood pressure…

    is there anything I can use to heal/soothe her gums?

    I’ve read it is possible to anesthetize her- specially if she stays in the hospital for at least 24hrs to rehydrate her intravenous + other things I don’t have much knowledge about.

    But obviously I do not want to make a dumb step and put my dog in danger…
    Sometimes her teeth hurt and won’t eat, should I do monthly/weekly hospital visits to rehydrate her + “spoon” feeding her? I was thinking of giving her food through a syringe… anything helps.

    • Ask your pet’s doctor whether he would refer you to a nearby board-certified veterinary dentist, and get that dentist’s opinion of anesthesia for your baby. Write back and let us know what you find out. Thanks for reading, Dr. Randolph.

  9. Hi,

    I have an eight year old shih-tzu maltese mix at home. She’s just as spunky as when she was a puppy and nothing ever concerned us about her. We knew she needed to get her teeth cleaned, however, and the opportunity finally presented itself, so we took it. My mother brought her in to her appointment (8/20/20), but received a call in the afternoon to tell us that her kidney numbers were horrible. Needless to say, they didn’t do the cleaning. She stayed at the hospital for three days on IV fluids and more tests were run. The vet concluded that she has chronic kidney disease and that she is in kidney failure. How? We don’t know. The vet does not understand why she does not display ANY symptoms, besides in her blood work. She appears to be a happy healthy dog, even now. Some of her numbers improved greatly during her hospital stay and she has been placed on special food, a supplement, and Pepcid AC. She went back for a check up today (9/8/20) and her numbers were near normal, except for one that actually increased. I’m not sure exactly which component it was, but it definitely went up. The doctor now wants to go through with the teeth cleaning as he saw mostly improvement. I’m terrified to send her back and have her possibly not wake up, but also scared of what may happen if we leave her teeth in the current condition. My mom thinks she’ll be fine since she doesn’t have any other symptoms. Any advice would be much appreciated. I’m not ready to lose her.

    • The main advantage of getting those teeth and gums healthy is that it may slow down the damage to the kidneys from chronic inflammation. While there is risk, if your doctor is willing to do the procedure, he or she probably knows all the right things to do to offset the risk, to the degree possible. Meet with him if you have questions or need reassurance, pray for her to have a safe and effective procedure (I’m saying a prayer for her right now) and go where his advice, your heart and guidance from the Lord lead you. Thanks for reading, Dr. Randolph.

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