Category: Medical Care

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One last swift kick to this dead horse…

…and then hopefully we’ll move on?

The one article that has gotten the most attention on this website is my critique of Renafood and why it’s (if you’ll pardon mon français) utter horseshit. Renafood supporters will periodically poke in and sing its praises, claiming their cats are doing fantastically after starting Renafood.

I want to make something really clear here: to all those people, I’m really, really happy to hear that your cats are doing well. I’m shaking my pom poms and cheering their fuzzy butts on. May they live long and prosper, and snuzzle you when you need it most, and knock your keys under the couch, and drool on your boobs because they’re so happy, and bring you their little felt octopus for you to throw so they can run after it and then promptly bat it under the oven, and freak out for no discernible reason in the middle of the damn night so you scream a little and then feel embarrassed because dude, it was just your cat being a spaz per usual. Kick that CRF in the ass.

All those heart-warming stories of how Renafood has worked wonders, however, are inevitably accompanied by the story of how the caretakers have improved the diet in some way. Switching from dry to wet is an immense improvement. Switching from those terrible low-protein, completely unpalatable kidney formulas to something the cat will actually enjoy eating is an even bigger improvement. Prolonged fasting will screw a cat with CRF up but good, because it sets up a horrible feedback loop: the cat feels nauseated and ill from CRF, then is given unpalatable low-protein dry food, so he’ll avoid eating it, and then his body starts breaking down his muscle mass to feed the unrelenting protein engine that keeps feline bodies running, and he’ll feel even more ill and eat even less because it’s a really stressful process that releases some truly nasty by-products into the bloodstream that his wrecked kidneys are incapable of dealing with. So on. So forth. Phosphorus restriction and a high-quality wet diet—or more importantly, a high-quality diet that your CRF cat is willing to eat on a consistent basis, period—will manage his condition better than just about anything; if you’re giving him subcutaneous fluids, even better. But first and foremost is to keep the cat eating. A cat who ain’t eating is a dead cat.

What I’m trying to say here is: a massive diet improvement is what’s making your cats’ lives better. And good on you for making that switch. The fact that you’re making the switch concurrent with or in addition to using Renafood speaks volumes. The bloodwork numbers don’t lie, but I think the credit for the improvements lie with a source other than a pill that (and let me be explicit here) can’t actually work the way the manufacturer claims it works because it makes no scientific sense whatsoever.

If somebody has a cat with kidney disease and uses Renafood to treat it but hasn’t made any other modifications to the diet prior to starting Renafood wants to speak up about how using Renafood miraculously improved kitteh’s bloodwork numbers, I’d love to hear it. Until then: I love hearing how your cats are doing well. I’m completely unconvinced that Renafood is doing anything. Instead, I’m applauding your diet management skills and the obvious love you’re showering on your companions.

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Renafood Redux, or: The Reply Comment that Ate the Blog

Given the relative obscurity of this cat blog and the fact that I update it once every never, I was really surprised to see a notification pop in my e-mail that somebody had left a comment on my Renafood post. A very long comment. From a vet working for Standard Process, the manufacturer of Renafood. I started replying to the comment, and suddenly realized that I’d written more than 1,300 words of reply. So: time for a new blog post! One about substantive issues, even, instead of pictures of fluffy kittens. I’m going to quote him verbatim in this post, so don’t feel like you need to run over to my Renafood post to read everything he wrote.

Dr. Cameron wrote:

I have been a practicing veterinarian since 1982, and I have used Standard Process supplements in animals (and my own family) for the past 20 years. I am now employed by Standard Process as a technical support veterinarian. I help veterinarians integrate nutrition into their clinical practices. I would like to respond to this post.

The author of the above post expresses skepticism on the value of using herbs, botanicals (plants) and glandular materials to support compromised organs (in this case, his/her cat’s kidneys). He/she lists multiple points of concern.

1. The author does questions the quality control of the ingredients in Renafood (or supplements in general). I would invite him to view a video of how supplements are made at Standard Process on our website (www.standardprocess.com). Standard Process Inc. produces all supplements under the same stringent regulations used in the manufacture of pharmaceuticals. We are inspected by the FDA, USDA and other regulatory organizations multiple times per year. Each supplement we produce is tested by our in-house laboratory up to six times before it is released to the public. Quality control is taken very seriously at Standard Process Inc.

My response:
Thank you for taking the time to respond to my post. Regarding the quality of your supplements: since I’m unable to inspect your factory, and given that you’re an interested party, I’ll take your word that your products do, in fact, contain what they do, unlike the majority of companies (who also make substantially similar claims regarding quality control).

Dr. Cameron wrote:

2. You don’t believe that herbal detoxification is possible. I would be happy to provide you with references of how herbs and foods can affect detoxification mechanisms in the body. After 28 years of practice and years of clinical experience with these products, I can attest to their value. The FDA does not allow supplement companies to make any claims on their products in relation to specific diseases, so will not be doing so. The fact is that most chronic disease have been linked to nutritional deficiencies, so providing quality nutrition to compromised cells can improve their ability to function.

My response:
If you are willing to point me to some peer-reviewed literature regarding a) the biochemistry behind herbal detoxification and b) the actual efficacy of herbal detoxification, I’d love to read it. I’ve tried for years, and the lack of good evidence eventually led me to my skeptical stance today. I would also like to point out that this statement:

The fact is that most chronic disease have been linked to nutritional deficiencies, so providing quality nutrition to compromised cells can improve their ability to function.

Has nothing to do with detoxification; malnutrition is separate and different from detox. Somebody suffering from scurvy needs vitamin C, not an herbal cleanse devoid of vitamin C. Furthermore, while accepting the relatively uncontroversial assertion that some chronic diseases are linked to nutritional deficiencies or other bad dietary practices, it doesn’t necessarily follow that taking commercial vitamin or glandular supplements will cure or correct the conditions. (Diabetes mellitus comes to mind; so do certain types of liver cirrhosis and gout.)

Dr. Cameron wrote:

3. Cell determinants. As I mentioned, we are severely restricted by the FDA as to what we can say about our ingredients, so the information is vague and difficult to get a clear picture.

My response:
I would first like to begin by disagreeing that the FDA restricts what you can say about how your ingredients work. The FDA regulates the health and structure/function claims a supplement company can make about its products, i.e., what the products’ health benefits are. As far as I know, there is no law or regulation that restricts the dissemination of truthful scientific information explaining the biological or chemical pathways in which particular compounds work. Most of the most stringent regulations directly relate to labels in particular; as far as I know, detailed information sheets aren’t “labels”. In fact, please refer to Section 403B of the Federal Food, Drug and Cosmetic Act:

(a) IN GENERAL.—A publication, including an article, a chapter in a book, or an official abstract of a peer-reviewed scientific publication that appears in an article and was prepared by the author or the editors of the publication, which is reprinted in its entirety, shall not be defined as labeling when used in connection with the sale of a dietary supplement to consumers when it—
(1) is not false or misleading;
(2) does not promote a particular manufacturer or brand of a dietary supplement;
(3) is displayed or presented, or is displayed or presented with other such items on the same subject matter, so as to present a balanced view of the available scientific information on a dietary supplement;
(4) if displayed in an establishment, is physically separate from the dietary supplements; and
(5) does not have appended to it any information by sticker or any other method.

(b) APPLICATION.—Subsection (a) shall not apply to or restrict a retailer or wholesaler of dietary supplements in any way whatsoever in the sale of books or other publications as a part of the business of such retailer or wholesaler.

Dr. Cameron wrote:

For more information on how protomorphogens, cell determinants, or glandular tissues can be of therapeutic value, look at the more recent subject of Oral Tolerance Therapy. OTT is touted as a ‘new and promising’ therapy for a number of diseases, using cell extracts from various glands to treat specific glandular diseases. This can help explain how eating some kidney can help a compromised kidney. This is what the catalog is talking about when supplying cell determinants.

My response:
From a quick check, Oral Tolerance Therapy seems to be a therapy related to autoimmune diseases, especially T-cell mediated disorders. To grossly oversimplify: the idea is to feed somebody with an autoimmune disorder (say, irritable bowel disease or rheumatoid arthritis) extracts from the relevant tissues to help reduce the immune system’s hyperresponsiveness and therefore reduce the attendant inflammation. However, even if it were proven to work consistently (and I think the science is still kind of uncertain on that), and assuming for the moment that protomorphogens work in the same way OTT does, most incidences of chronic feline kidney disease, as far as I know, are not due to autoimmune disorders. For example: my cat Eric’s polycystic kidney disease in particular had nothing to do with his immune system and everything to do with the fact that he’d inherited an autosomal dominant gene from one of his parents for PKD. The majority of feline kidney disease is, as far as I know, idiopathic. Additionally, the mechanism by which Oral Tolerance Therapy works also seems completely different from what is suggested in the Standard Process literature about protomorphogens. OTT works by desensitizing the immune system so it doesn’t attack the body’s own tissues. I can’t speak on how protomorphogens work, since the information sheet was confusing and opaque, but the sheet seems to claim that protomorphogens affect cell division directly, and to target specific cells or tissues in specific organs. If I’m wrong about this, I’m certainly open to being shown where and how.

Dr. Cameron wrote:

Your not understanding what cell determinants are does not qualify you to say they do not exist or cannot be of clinical value. But I will agree that the writing could be more precise.

My response:
If I’m wrong about this, then I’d love to be educated on the fact—in fact, I would love to have a primer on just exactly what protomorphogens are and how they work. I’ve sent a copy of the Standard Process fact sheet to biochemist friends of mine, and they’ve come right out and said that the “mineral template” idea is nonsensical and not how cell determinants work; they also pointed out that substances that could have the sort of dramatic effect on cells claimed by Standard Process would be along the lines of hormones, mutagens and teratogens, and almost definitely not qualify as a mere supplement—it would be regulated as a drug by the FDA. It doesn’t help that “protomorphogen” seems to be a trademarked term of art, so searching science journal databases doesn’t turn up anything, and Googling merely turns up information sheets and promotional materials written by Standard Process or by sites selling Standard Process supplements.

Dr. Cameron wrote:

4. Dr. Royal Lee spent his life fighting the FDA, and yes, he was brought up before them several times. He was an outspoken critic of the adulteration of foods that came into common practice starting in the 1920’s (bleaching of flour, high-heat processing of foods, processing of foods to increase shelf life, the addition of sugar to so many foods, etc.) He constantly wrote letters to the FDA and other industry leaders pointing out the negative health effects these foods were having. As a dentist, he saw oral pathology due to nutritional deficiencies. This is how he came to start Standard Process Inc. – using quality food sources to replace the trace nutrients that were being lost in the food supply. The FDA and others took offense at his criticism and did go after him. Some of his claims (back in the 1930’s and 1940’s) were that these processed foods would lead to increased obesity, heart disease, cancer and diabetes. Are we seeing any of these conditions today? Are they increasing in frequency? Do we eat a lot of processed foods? Do our animals? As veterinarians, we are seeing the same increase in the same diseases in our pets as in humans. Be sure you check other sources besides QuackBusters.

My response:
I think it’s misleading to imply that Dr. Lee was prosecuted because he spoke out against processed foods and refined sugars. He made specific health and medical claims about his supplements and the FDA cracked down on him, and their statements about Dr. Lee being the “largest publisher of unreliable and false nutritional information in the world” concern the false medical claims on his products. Whether or not he’d drawn attention by speaking out against refined foods and existing food processing methods is beside the point; he was guilty of medical fraud because of the various claims he made regarding the efficacy of his supplements for treating various acute and chronic diseases and disorders. If you’re looking for a source beyond Quackwatch, perhaps this particular Notice of Judgment from the FDA regarding Dr. Lee’s products will be more satisfactory. (This is merely the first I found of many; if you go to the Notices of Judgment archive and search for “Royal Lee,” many more hits come up.) Here are the diseases that Dr. Lee claimed various supplements cured, which I’ve excerpted from the bottom of page 2 and on through page 3 of the Notice:

(1) pneumonia, tuberculosis, influenza, colds, whooping cough, measles, and mumps

(2) puerperal sepsis, infection of ear, infections of genito-urinary tract, infections of mucous tract, infections of gastro-intestinal tract, infection of respiratory tract, infections of sinuses, focal infections, and infectious diseases

(3) high blood pressure, low blood pressure, overweight, and underweight

(4) arteriosclerosis, high blood pressure, aortic aneurism, aortic insufficiency, valve leakage, coronary occlusion, coronary thrombosis, or dementia

(5) arthritis, hemorrhagic conditions of the urine, albuminuria, heart disorders, menstrual and ovarian disorders, Bright’s disease, leg ulcers, anemia, wasting of muscles, paralysis, muscular weakness, chronic diseases, amenorrhea, colitis, cystitis, children’s diseases, women’s diseases, liver disorders, dysmenorrhea, eczema, gall-bladder disease, gastritis, eye disorders, and cardiovascular disturbances

(6) acne, acute or chronic alcoholism, angina pectoris, Addison’s disease, adrenal hypertrophy, agranulocytosis, apoplectic sequellae, atrophy of glands or muscles, achlorhydric anemias, backward children, burns, cataracts, chlorosis, chorea, diabetes mellitus, epilepsy, toxic goiter, hyperthyroidism, hyperglycemia, hypertension, hypotension, asthma, hay fever, hyperemesis of pregnancy, sexual impotency, insanity due to endocrine failure, menopause disorders, migraine, menstrual dysfunction, paralysis agitans, phlebitis, poliomyelitis, paralytic sequellae, pancreatic dysfunction, pernicious anemia, nephritis, ideopathic [sic] ovarian disorders, prostate enlargement, peptic ulcers, sclerosis, rheumatic fever and varicose veins

(7) atrophy of organs and glands (testes, liver, spleen, thyroid, pituitary and salivary), infections and degenerations of eyes, physical weakness, nervousness, insomnia, gland swelling in general, renal calculi, bronchitis, endocrinopathies of childhood, nervous indigestion, neurasthenia, disorders of pregnancy, sterility, hypogalactia, retarded growth, loss of hair, fatty infiltration and degeneration of the liver, symptoms of nerve degeneration, Paget’s dermatosis, gastro-enteritis, infantile gastro-intestinal disorders, glycosuria, malnutrition, sprue, low resistance, kidney and bladder disorders, renal dysfunction, formation of stones (calculi), excessive growth of lymphoid tissue, lympathic gland enlargement, loss of weight and vigor, low vitality, stunted growth, emaciation, enlargement of liver, kidney and spleen, acidosis, and [prevention of] carcinoma

The substances to which these claims were attached? Various vitamin and mineral supplements (including A, C, B-complexes) that included various plant and animal extracts, and Catalyn (mostly milk sugar and various wheat extracts, with other plant materials and some “glandular extracts”). I think the list speaks for itself. If still not convinced, I’m certainly happy to dig through more old FDA paperwork and show what exactly the FDA’s beefs were with Dr. Lee’s products and the sorts of medical claims he made about his vitamin and food supplements.

Dr. Cameron wrote:

You make many judgements without much background information. This is the negative side of internet freedom, because people reading your biased opinion will take it as fact. This is unfortunate.

I would be happy to discuss this with you if you would like more information.

Tom Cameron, DVM 800-848-5061

My response:
I’m not a biologist nor a chemist, but I’m trained in the scientific method, and I’m a skeptic and a critical thinker. I’m open to being educated regarding protomorphogens; I’ll admit that the paucity of literature on this topic makes it somewhat suspect in my eyes, but again, my research was hampered by the fact that protomorphogen is not a scientific term but a trademarked term of art, and the Standard Process sheet was not at all clear. I am more than happy to receive information regarding protomorphogens and the way Renafood is supposed to work. I would prefer links to publicly-available documents so that any readers can read exactly what I’m reading as well and draw their own conclusions, but if that’s not feasible, then I would appreciate it if you would e-mail me more information at my gmail.com address (my username is misshepeshu—I’m giving my e-mail address this way to confound spambots).

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Renafood

One of the first things the vet gave me to give to Eric was Renafood, a supplement consisting of various detoxifiers, including beet juice. I’m skeptical that it actually does anything for two main reasons:

1. I feel doubtful about the efficacy of herbal detoxification in general, partly stemming from a skepticism about the quality control and potency of the herbs in any given supplement, and partly stemming from skepticism that herbal detoxification actually works in the way described. I mean, look: my cat’s kidneys are fucked. Thoroughly, utterly fucked. I’m not sure how or why minute amounts of carrot and beet might help him filter waste material more effectively, unless they’re somehow rebuilding his nephrons for him.

2. The logic of some of the claims presented in the Renafood information sheet. So, Renafood contains bovine kidney extract. That extract apparently holds “tissue cell determinants” that will instruct the kidneys to Shape Up, Son. I have no idea what a “tissue cell determinant” is, though I have a very vague memory of learning about cell fate determination—thanks, high school biology! But the information sheet doesn’t give any sort of helpful definition of what these tissue cell determinants do other than talking about something that sort of vaguely sounds like cell fate determination. Quoting from the information sheet:

The bovine kidney PMG extract found in Renafood contains cellular determinants that regulate cell activities. Genetic coding determines the proteins unique to cells in each tissue, gland and organ. Cellular proteins are the foundation of the cell’s nutrition. Similarly, bovine kidney contributes innumerable materials produced in the organ itself, such as acids, enzymes and hormone precursors—each captured and preserved to offer their innate benefits to the corresponding tissues in humans to promote optimal health.

Huh. That sure sounds like a fancy way of saying…nothing much. Prepare for a bulleted list!

  • The first sentence makes an assertion that the cell determinants in Renafood regulate activities, and the next sentence is a more-or-less correct statement about cell fate determination, but doesn’t tell me how Renafood affects the genetic coding of cells.
  • The sentence after that reads like a complete non-sequitur. Cellular proteins may or may not be the foundation of a cell’s nutrition (I don’t know enough about biochemistry to begin unraveling what this deceptively simple sentence means), but how does that relate to the thesis sentence or to the conclusion?
  • Furthermore, what do they mean by “cellular proteins,” especially in this context?
  • The first part of the last sentence is more-or-less true, because it’s essentially talking about the kidney extract providing proteins, fats and vitamins, but you can feed real food (like, oh, I don’t know, fresh kidney) and, if the Renafood claims are true, get the same effect.
  • This information sheet from Standard Process explains what cell determinants do and how they relate to protomorphogens (which is apparently what constitutes the bovine kidney extract in Renafood), but it sounds even more gobbledegooky. The cell determinants in protomorphogens are apparently the mineral templates on which chromosomes are constructed. This is, near as I can determine (and I’ve confirmed this with biochemist friends just to make sure I didn’t miss something about cell biology) complete nonsense. Seriously.
  • I’ve read the info sheet through three times, and I’m still not entirely sure how Renafood keeps cells healthy or helps regenerate cells, because I don’t see how the leap from digestive system to bloodstream to cell division is made—there’s a lot of talk about “affinity” and thermostability and how important cell determinant are, but very little actual science. The most credible-sounding scientific bits aren’t supported by any references, and most importantly, they’re not connected to how the supplement’s supposed to work. Speaking as a former technical writer, this is probably the shoddiest bit of technical writing I’ve ever seen.
  • It doesn’t help that Royal Lee, the founder of Standard Process, has been prosecuted for criminal misbranding. The FDA has in the past characterized him as “probably the largest publisher of unreliable and false nutritional information in the world.” Given how lackadaisical the FDA has been and continues to be about food and drug regulation, these aren’t just fightin’ words, them’s strong fightin’ words.
  • Taken as a whole, it sounds like Standard Prociess is claiming that eating Renafood will somehow stimulate kidney cells to work better through a mysterious process involving “cellular determinants.” If that’s not science-esque, I don’t know what is. (“Science-esque 2: This time, it’s not Science-esque 1!”)

In short: I’m not sure I buy into the idea that this does anything. I’m giving it to Eric right now because he loves it, and it doesn’t contain anything that seems overtly harmful. But my woo-woo meter is on alert, and if you want to save yourself $16, I’d argue that this supplement doesn’t do anything other than provide a nice source of vitamin A and a tasty snack.

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Calcitriol therapy for chronic kidney disease

Calcitriol molecule
Calcitriol molecule

If you want to read about all the different things I’m doing for Eric to help control the symptoms of his polycystic kidney disease, check out the diet modification and polycystic kidney disease tags.

Given the terrible shape of Eric’s kidneys, it became pretty clear to both the vet and me that we needed to take some pretty decisive steps to control his symptoms; however, neither of us wanted to go with the “throw everything at Eric and see what sticks” approach. We considered and rejected the following ideas:

  • Using an ACE inhibitor to control blood pressure and proteinuria (largely because there’s no protein in his urine—yet)
  • Subcutaneous fluids (he hates, hates, hates being stuck and the stress almost definitely isn’t going to be worth the benefit)
  • Phosphate binders (his blood phosphorus is completely normal)
  • Restricting his protein intake. Protein restriction is a really bad idea for cats, even sick cats. So far, all the studies I’ve encountered that advocate strongly for a limited protein diet for CRF cats either 1) inferred this from rat and human studies, or 2) failed to distinguish between the effects of high protein intake vs. high phosphorus intake. I’ll write a more detailed post in the future about the importance of maintaining protein intake, even in the face of renal failure.

That’s not to say that we won’t consider using ACE inhibitors and phosphate binders in the future. We’re drawing blood every couple months and monitoring him closely, and we’ll change our course accordingly depending on what the bloodwork tells us.

However, Eric is an excellent candidate for is calcitriol, which I’ve been giving it to him since last week, and so far, it seems to be working quite nicely.

What’s calcitriol?
It’s the most biologically active form of vitamin D. Vitamin D’s most basic form is as a vitamin precursor (7-dehydrocholesterol is the type found in animal tissue, for the geeks in the crowd). After ingestion, 7-dehydrocholesterol is normally transported to the skin, where UV radiation helps convert it to another form of vitamin D, cholecalciferol. When you buy vitamin D supplements, it normally comes in the form of cholecalciferol; cholecalciferol is also found in animal tissue, like liver and egg yolk. Now, cats are by and large unable to convert 7-dehydrocholesterol to cholecalciferol, which means they need to ingest cholecalciferol to meet their vitamin D needs. This normally presents no problems whatsoever, because animal tissue provides plenty.

However, cholecalciferol needs to make two stops before it becomes biologically active:

1. It stops in the liver, which adds a hydroxyl group and turns it into calcidiol.

2. It makes a final stop in the kidneys, which adds another hydroxyl group and turns it into its active form, calcitriol.

Why give it to a cat with chronic kidney disease?
So, cats with chronic kidney disease often get into a Spiral of Doom with phosphorus, calcium and vitamin D. That’s partly because mammals depend on vitamin D for proper regulation of phosphorus and calcium levels, and vitamin D requires proper kidney function in order to become calcitriol.

So here’s how the Cycle of Doom starts when a cat’s kidneys are in such bad shape that he’s showing signs of renal failure:

Calcitriol levels start dropping, because the kidneys can no longer produce adequate amounts. In response, blood calcium levels begin to drop, and phosphorus levels start to rise.

In response to the drop in blood calcium levels, the cat’s parathyroid glands start releasing parathyroid hormone *PTH). This hormone stimulates calcitriol production in the kidneys, mobilizes calcium from bones to help raise blood calcium levels, and encourages the kidneys to excrete phosphorus while retaining calcium.

But the kidneys are completely wrecked–they’re Scotty, trying to tell Kirk that they’re giving it all they can, cap’n, but they cannae do it. After a while, so much phosphorus is swimming around in the blood that it begins combining with calcium to produce calcium phosphate crystals, which are deposited in the soft tissue and proceed to inflame the tissue and otherwise behave like hooligans. In the meanwhile, blood calcium drops lower than ever because it’s now being bound by the phosphorus, and the PTH instructs the body to withdraw calcium from bones in a desperate attempt to keep SOME calcium in the bloodstream, which seriously weakens the integrity of the bone structure.

So yeah. Doom. Doomy doom DOOOOOOM.

But this cycle can be averted if you administer calcitriol before the metabolic screwiness begins—that is, before blood phosphorus levels start climbing and before the blood calcium drops precipitously. See, calcitriol controls the amount of PTH circulating in the bloodstream, because a sufficient quantity of calcitriol is a signal to the parathyroid gland to stop secreting PTH, effectively nipping the destructive cycle in the bud. The amount of calcitriol you need to give is incredibly minuscule, because you want to keep the parathyroid glands happy; you don’t really want to affect either the calcium or phosphorus levels in the blood.

So how little is “incredibly minuscule”?
Eric is getting 12.5 nanograms a day right now. Yup, you read that right: nanograms. He’s getting 12.5 billionths of a gram.

Any downsides and side-effects to giving calcitriol?

  • Hypercalcemia (elevated calcium levels) is one of the dangers of calcitriol therapy, which, if you allow to continue unchecked, can lead to all sorts of problems. This means that if your cat’s bloodwork shows elevated calcium to begin with, calcitriol therapy is a pretty terrible idea.
  • If you’re giving a phosphorus binder that contains calcium, it’s probably not the greatest idea to throw calcitriol on top of that, too.
  • Furthermore, if your cat’s phosphorus levels are high,  giving calcitriol may be a bad idea, because calcitriol encourages the kidneys to retain phosphorus and increases the absorption of phosphorus from the gastrointestinal tract. Eric’s calcium and phosphorus levels were normal, which makes him an ideal candidate. We’re going to follow up with a blood draw in two weeks to make sure his calcium levels aren’t dangerously elevated.
  • I just want to stress that regular bloodwork is a sensible idea for cats with any kind of chronic kidney disease in general, but when you’re administering substances like calcitriol, which can potentially alter critical blood values in already sick cats, you should definitely schedule a couple of follow-up blood tests a couple weeks after starting the meds and very closely monitor your cat for changes in appetite and other behavior.
  • It also seems to give Eric mild nausea that lasts a couple of hours, so I’m feeding it mixed up in a teaspoon of canned Wellness Kitten, and splitting it into two doses given 2 hours apart, with dinner right in between. That seems to help. The reaction may be due to the tuna-flavored oil suspension that it comes in, however, as opposed to the calcitriol per se.

Noticed any changes since starting calcitriol?
Eric’s energy levels and appetite have shot up since starting calcitriol, and that makes me a happy camper. He actually knocked over the garbage a couple days ago, something he hasn’t done in months. At first, I was all “RAAAAAGE!” but then I realized that this meant he was feeling sassy again, and was all “Awwww, he must be feeling better.” Who knew I’d be happy about something like that, eh?

I’m waiting to make a final judgment when I see the bloodwork results in a few weeks, but so far, I’m pretty happy with the changes I’ve noticed. If your chronic renal failure kitty’s bloodwork shows normal phosphorus and calcium values, talk to your vet about the possibility of calcitriol therapy.

References I used and works linked to in this post:
Small Animal Clinical Nutrition, 4th Ed., by Michael S. Hand, Craig D. Thatcher, Rebecca L. Remillard & Philip Roudebush. Mark Morris Institute, 2000.

The Mar Vista Animal Center page on calcitriol and its therapeutic use in kidney failure.

The Wikipedia page on calcitriol.

“Ineffective Vitamin D Synthesis in Cats Is Reversed by an Inhibitor of 7-Dehydrocholestrol-Δ7-Reductase” by James G. Morris, published in Journal of Nutrition, vol. 129, pp. 903-908, 1999.

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On Squash, Fermentable Fiber and Feline Kidney Disease

One of the squashes from our garden
One of the squashes from our garden

One of the things I did to modify Eric’s diet after finding out about his polycystic kidneys was to reintroduce squash into his diet. In the past several years, I had dropped feeding vegetables to my cats entirely, largely because I was feeding them whole ground animals and canned Wellness and Evo on the side. I figured that the canned food was providing plenty of vegetable matter. Now that Eric’s sick, however, I’m much more draconian about feeding mostly raw food—partly because it’s better for him, and partly because Eric prefers it over the canned, which is strange because in the past his sole food preference, near as I could tell, was HOORAY FOOD OM NOM NOM NOM.

I added the squash back into Eric’s diet largely because I remembered reading back in the day that squash helps trap nitrogenous waste that would otherwise make it into the bloodstream. Today I went on an article hunt to see whether this had any sort of scientific basis, or if it was one of those raw feeding myths that get passed around because it sounds so damn good.

Assessing the Evidence

Therapeutic use of fiber in chronic kidney disease (or, if you’re old-school, chronic renal failure) is much more well-studied in humans than it is in cats. There seems to be some evidence that the consumption of soluble/fermentable fiber leads to increased excretion of nitrogen via poopin’ vs. peein’, thus lowering the amount of nitrogenous waste circulating in the blood and therefore eliminated by the kidneys. But what about cats?

I’ve found one decently reliable study that specifically looks at cats. It’s by researchers at Iams, so it’s not exactly woo-woo; research from the Iams lab is about as mainstream as it gets. The researchers found that feeding moderately fermentable fiber (mostly beet pulp and fructo-oligosaccharides) to cats decreased serum nitrogenous waste and increased fecal nitrogen excretion. The study proposed the following hypothesis as to why this would happen:

The beneficial bacteria in the cat’s lower intestine feed on the moderately fermentable fiber, creating short-chain fatty acids (SCFAs) in the process. SCFAs not only do all sorts of nifty things, such as keep the intestine cells happy and healthy, they also increase blood flow. The increased blood flow to the intestine results in more urea being circulated to the intestines, and the bacteria, which also produce urease (an enzyme that denatures urea), convert the nitrogenous wastes to carbon dioxide and ammonia, which are then incorporated into the bacteria themselves and then pooped out by the cat, as opposed to circulating to the kidneys to be peed out.

This sounds really good and really plausible, and the results show pretty unequivocally that fermentable fiber helps reduce the urea load in the serum, which means less work for damaged kidneys, but keep these things in mind:

1. This study is really small, involving only sixteen cats.

2. They were fed the diets containing fermentable fiber for relatively short periods of time—two weeks total for with an active waste collection period of eight days.

3. The decreased waste could be due in part to the decrease in protein digestibility. The study noted that the protein digestibility decreased to 87-91% with the fermentable fiber blends.

4. As far as I could tell, they didn’t actually actually draw any blood and run blood panels; they looked at urine and feces only.

So the verdict right now is: it probably does help a little bit, but as with anything scientific, the people in the white coats need to study it more. Given that steamed squash doesn’t contain anything harmful to cats, and given the potential benefits vs. potential dangers (yes, there’s a decrease in protein digestibility from the fiber, but Eric’s getting so much high-quality protein in his food that I’m not worried about marginal decreases at this point), I decided to go ahead and give Eric a heaping tablespoonful of pureed squash per day, which comes to about 10-15% of his total food. I created a mix from a gem squash harvested straight from my garden and organic butternut from the store. He loves it. I don’t need to mix it in with the food; it’s a lurid orange dot amidst the raw rabbit and Nature’s Variety, and he often eats it first. I suppose we’ll find out whether it does anything when we test his blood again in January.

Fiber Content for Various Squash Species

If you’re curious about the fiber content of different species of squash, here’s the information I looked up on the USDA National Nutrient Database per 100 grams of raw squash (unless otherwise noted):

Butternut squash: 2.0 g  (86.41% water)
Acorn squash: 1.5 g (87.78% water)
Generic winter squash: 1.5 g (89.76% water)
Pumpkin: 0.5 g (91.6% water)
Canned pumpkin: 2.9 g (89.97% water)

Canned pumpkin has almost double the fiber content of raw butternut (on a dry matter basis) and six times more than raw pumpkin, which is interesting. It looks like you can get more bang for the buck by feeding canned pumpkin. Eric likes the fresh stuff much better, however, so I’m sticking with it for now.

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Eric’s Kidneys

(Note: Parts of this were posted previously to my Livejournal as well. I’m playing catch-up over here to get to Story At Hand, as it were.)

About a month ago, Eric, my little chow hound who’d scarf up stray cornflakes I’d drop on the floor, my little orange dude who’d dive into the trashcan to find choice rancid leftovers, suddenly became fussy over his food. It manifested in the weirdest way, too: he seemed reluctant to chew. He’d nibble and lick very daintily at his food, and then spit out large chunks of it, almost as if chewing hurt his mouth.

Concurrently, I noticed that I was refilling the water dishes a lot more frequently than I ever had. I didn’t think too much about it; Portland was going through a heatwave, and not only were both cats drinking a lot more, water was also evaporating somewhat faster than it normally would.

But that chewing thing, man. That worried me. Eric has always had bad teeth; I’ve often described his breath as “doom and destruction,” and that’s been true ever since he was a little kitten. So I was all “Oh shit he needs another dental” and hauled his furry butt into the vet, even though he’d had an annual exam just a couple weeks before.

Continue reading “Eric’s Kidneys”