Are Processed Foods at the Root of All Feline Illness?


Diabetes, arthritis, kidney disease, heart disease, low immunity, even cancer – all of these diseases are ultimately caused by chronic inflammation. Inflammation is the body’s natural response to healing by bringing an increased immune response to the site of an injury or infection, but when inflammation becomes chronic, it damages the body and causes illness.

Processed foods aggravate chronic inflammation

It has long been accepted in human medicine that processed foods cause and aggravate chronic inflammation, and this is also true for our cats. Highly processed pet foods may well be at the root of many of the degenerative diseases we’re seeing in pets. Ironically, many veterinarians recommend these diets to their patients as the ultimate in “complete, balanced” nutrition. “Most small animal veterinarians spend the majority of their time as clinicians treating inflammation,” says  Dr. Steve Marsden, one of the chief educators of veterinarians worldwide in complementary veterinary medicine, with board certifications in Chinese herbology, acupuncture, and naturopathic medicine. “For some, it is disheartening how they have to continually reach for the same old anti-inflammatory drugs, with all their attendant side effects. More alarming, too, would it be, if they realized the diets they sell in their front office were actually the cause of all that inflammation.”

Metabolic syndrome

A processed diet high in fat or carbohydrates creates a vicious cycle of sustained oxidative stress and damage from inflammation, which can eventually lead to insulin resistance, obesity and cardiovascular disease. This is often referred to as Metabolic Syndrome. This has been well documented in human medicine, and is probably even more true for an obligate carnivore like the cat.

Once Metabolic Syndrome is present, inflammation becomes more entrenched and less likely to resolve itself. Conventional treatment with corticosteroids only amplifies insulin resistance, and can result in full-blown diabetes.

Genetics also play a role in the development of disease, but cat guardians have no control over that. They can, however, control what they feed their cats.

Could unprocessed diets cure and prevent recurrent inflammation?

Studies on the human side have shown that food processing plays a major role in creating Metabolic Syndrome. In a study conducted in New Zealand on overweight, hypertensive humans, one group was asked to consume 62% of their daily calorie intake in the form or raw food, the rest as prepared or cooked. The control group ate a normally cooked or processed diet. After six months, the two groups were switched. While on the raw diet, participants experienced dramatic declines in metabolic syndrome markers and demonstrated weight loss and a reduction in blood pressure.

The case for a raw diet

Unfortunately, raw foods have been much maligned by the veterinary medical establishment, and a recent position statement by the American Veterinary Medican Association essentially advised member veterinarians to discourage the feeding of raw diets. “Raw foods are the pariahs of the pet food industry, and are generally dismissed out of hand as unproven at best, and dangerous at worst, by the majority of veterinarians,” says Dr. Marsden. “This professional antipathy seems to have resulted in studies of raw pet foods to date being strikingly unimaginative. Research into raw meat diets has almost exclusively and repetitively focused on their potential as a source of bacterial exposure, despite this largely being common knowledge among veterinarians and consumers.”

What the AVMA and veterinarians who speak out against a raw diet overlook is that food processing does play a major role in the inflammatory process. Raw diets have a lower glycemic index, which helps reduce insulin resistance, inflammation and post-oxidative stress. Says Dr. Marsden “While outbreaks of food borne illness have not been identified despite the abundant use of these diets, there is no question that some risk exists. No attempt has been made, however, to hypothesize what kinds of benefits the diets might provide that, in owners’ minds, justifies assuming this risk.”

Cat guardians who are feeding raw diets usually find some pretty dramatic benefits even after just a few meals. For these cat parents, who witness anything from clearing up chronic skin conditions and diarrhea to improved hair coat and a stronger immune system, these benefits more than justify the perceived risk of feeding these diets – a risk that can be minimized by following simple common sense principles of basic food handling.

Making informed decisions about what to feed

Even though the raw food segment of the petfood industry is growing, it is unlikely that the industry will embrace the message that food processing causes illness. It is up to cat guardians to educate themselves about the dangers of overprocessed foods, and make an informed decision about what they feed their cats for optimum health. Hopefully, as more cat guardians demand better nutrition for their feline family members, veterinarians and the petfood industry will find ways (and fund studies) to make safe, unprocessed foods to end the vicious cycle of inflammation in our cats.

A raw diet may not be for every cat, or every cat guardian. However, the argument for minimally processed raw or home-cooked diets is compelling.


For further reading on this topic, please refer to the Feline Nutrition section on this site. Dr. Lisa Pierson’s site contains a wealth of information about feline nutrition

Photo: istockphoto

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25 Comments on Are Processed Foods at the Root of All Feline Illness?

  1. Donale Simmons
    January 30, 2021 at 3:29 pm (6 months ago)

    my cat snowball is in the emergency care with kidney disease i feel bad because i feel its my fault we took snowball for his yearly shots for rabbies and lukeimia and the next day he was off everything about him was off then 4 days later we took him back for dental work they told us that they could not complete his mouth work because of this kidney issue now he’s in the emergency vet hospital with kidey issues snowball is such a good boy he doesn’t deserve this i’ll give anything to have him healthy again in the meantime he’s still in the emergency vet hospital fighting for his life

  2. Kitty Cat Chronicles
    August 5, 2014 at 10:26 am (7 years ago)

    My cats are on a raw diet, and we all love it! One of my cats, Sophie, is prone to chronic upper respiratory infections. Antibiotics rarely do much, and if they do get rid of the infection, it only takes about a week before it’s back. When I started feeding the raw diet, Sophie’s sinuses and infection cleared up almost immediately. It was like magic! If we run out of raw and I don’t get a chance to make more, I keep canned food on hand. After just a couple of meals of canned food, her sinuses are clogged again and she is sneezing out yucky boogers. The raw diet has been a wonderful cure for my Sophie, and my other cats love it too.

  3. Carmen Anderson
    February 15, 2013 at 4:49 pm (8 years ago)

    You haven’t mentioned canned Wellness cat food. Do you recommend it? It’s what I use and I’m wondering if I should now change to the raw diet?

    Thanks much, Carmen Anderson

  4. Tom
    December 19, 2012 at 12:42 pm (9 years ago)

    Agreed this is a very good and interesting topic, thanks Ingrid. We’ve been interested in the whole raw/alternate foods versus processed food debate for some time. It makes total sense if you think about it, and whether a cat should eat what there systems are designed for or essentially meat flavored cereal like ours currently do isn’t really much of a debate. I’ve always been amazed they will eat the processed stuff in the first place.

    I think it is as you said, for most of us we figure it’s either very time consuming or very complex to fix the raw or precooked stuff yourself and we just don’t have the time or don’t make the time. add in the perceived and real risk factors and most of us just don’t do it. I don’t know enough about this yet to say what we’re going to do but we’re definitely looking to move away from the dry stuff we’re using now at some point in the fairly near future.

  5. Tracy Dion
    October 26, 2012 at 1:26 pm (9 years ago)

    This is very important information, Ingrid. Great post! I’ll be sharing on both CatCentric’s social media pages and my own.

    And thanks so much for the shout-out; I’m immensely gratified! :-{}

    • Ingrid
      October 27, 2012 at 6:08 am (9 years ago)

      Thanks, Tracy – and thanks for all you do to spread the word about species-appropriate nutrition for cats.

  6. Jynx
    October 25, 2012 at 3:44 pm (9 years ago)

    Ingrid, I appreciate the information here, and have been considering at least a wet diet for my cat since I brought him home last year. However, he has food allergies, and so many of the pre-prepared raw foods have so many unnecessary additives. Cranberries, really? Honey? I don’t know exactly what all my cat is allergic to, except chicken, turkey, and all kinds of fish, for sure, but I am very suspicious of all the other things that come in most “natural” cat foods. Why is all this extra stuff considered healthy for cats, just because it’s considered healthy for humans?

    It makes it very difficult for me to find a single-source protein diet for him, and right now he’s on a dry food diet only, (Duck and green pea) with some freeze-dried lamb treats on occasion (although too many of those give him terrible gas! Whew!). I’ll admit some of my problem is cost – I’m really beyond poor right now, or I’d be buying him fresh ducks and grinding them up myself, I’m sure! The pure ground duck “chubs” I’ve found have very high bone content, but I can’t mix them with something less expensive, like chicken, because of his allergies.

    What am I trying to say, here? I guess I’m wondering if you have suggestions for creating a raw or at least wet diet for my cat when I can’t use things like chicken, turkey, salmon (salmon oil shows up in otherwise single-source protein foods constantly), beef, eggs, and kelp, cranberries, guava, yucca, gelatin, jojoba, and pure extract of sunshine?

    Thanks for the article and your fantastic blog!

    • Ingrid
      October 25, 2012 at 10:22 pm (9 years ago)

      There are some commercially prepared raw diets for cats that have few or no “add ons” in them, Jynx. You may want to check out Felines Pride, Hare Today, and Rad Cat. Alternately, you can make your own, using rabbit or duck as a protein source. I understand that cost is an issue for you. I believe Hare Today lets you order in bulk, so that keeps down shipping cost. Does the duck and green pea diet you feed come in a canned version? Even making that small change may be worth the additional cost. I hope this helps.

      • Laura
        October 26, 2012 at 3:06 pm (9 years ago)

        We feed Feline’s Pride (we are lucky enough to pick it up at their manufacturing facility). They sell the vitamin packs separately if you want to buy your own protein source locally & make your own. Try rabbit–it worked wonders for our Bengal. If you can talk to Jennifer, the sales rep she is super knowledgeable and very helpful!

  7. Robin Olson
    October 25, 2012 at 8:14 am (9 years ago)

    Hurray! Another great post, Ingrid.

    I’ve been feeding raw and advocating raw for many years. It’s tiring feeling like you have to be on the “down low” and not tell your Vet you do this because they often disagree. They get their nutritional information from the big pet food companies who often sponsor their tuition and their one or two our classes on “nutrition”, controlling the flow of information and making it difficult to see anything other than the promise the science overrides common sense when it comes to feeding our cats.

    I’ve seen the amazing changes in my cats from feeding raw. My rescue group asks adopters to NEVER feed dry kibble of any kind-they can only feed canned grain free or raw. We do a lot of education and many people are heartbroken when they realize they fell for the marketing pitch, the pretty photo on the bag. They want to do right for their cats and when they realize they were causing them harm, it’s pretty humbling to witness.

    I’m stunned that this is a battle of any kind and I’m sickened by the fear mongering by big pet food manufacturers. I’ve seen some of their “studies” which are based on clearly ridiculous “facts”. The truth is out there and I’m glad you’re helping more people see the light and the great benefit feeding a species appropriate diet can do for your cats.

  8. Esme (@cococroissants)
    October 22, 2012 at 11:27 pm (9 years ago)

    We do not eat raw-however we only get wet food and since we started 6 months ago Penelope has only had 2 asthma attacks which is a huge improvement-on one every 3 weeks.

  9. Rykerz Boyz 'n' Allie
    October 22, 2012 at 2:41 pm (9 years ago)

    We agree completely. Allie’s 100% on raw food (except for the ‘treats” her dad slips her when she manipulates him with The Look). Faraday’s on Freeze-dried raw (with a grain free wet food used as his “treats”).

    Maxwell’s our lone holdout, with grain-free kibble. Every time I set out food for Allie or Faraday, I offer it to Maxie, but he isn’t interested. Not giving up hope though! It’s made such a huge difference in the silkiness of Allie’s coat.

    And hopefully Allie will shed that extra pound she’s carrying, too….

    • Ingrid
      October 22, 2012 at 8:08 pm (9 years ago)

      I’m glad you’re already seeing the benefits of the raw food with Allie, Lisa. Hopefully, Maxwell will come around eventually.

  10. Laura
    October 22, 2012 at 9:50 am (9 years ago)

    We feed a raw diet to 2 of our cats–the other 4 wont even smell or taste it. Our 1 year old was raised on it and I am amazed at the brightness of her eyes, the softness of her coat and her flexibility. We were able to solve our foster cats (now our foster failure!) chronic digestive issues with a raw rabbit diet. He gained weight, had so much more energy, but most importanly had normal stool. We have a cat at the vet now for bladder crystals & the vet is pushing Science Diet prescription and I’m so afraid to feed it since he’s been eating a holistic diet for 2 years.

    • Ingrid
      October 22, 2012 at 9:51 am (9 years ago)

      Laura, I would consult with a holistic vet on an appropriate diet for your kitty with crystals.

  11. Michael O'Donoghue
    October 22, 2012 at 9:13 am (9 years ago)

    inflammation is the result of too much pro inflammatory ingredients compared to anti inflammatory ingredients, much processed food had too much pro inflammatory ingredients, but just because it is raw does not make it balanced. There is still much to learn about nutrition. We must remember that pet food companies likes Hills pet Nutrition and Iams of P&G where started by a single man with a bold vision to improve pet nutrition, they went out into the world made their diets and sold them to the world, eventually they have now become multinational companies. The healthiest diets will succeed in the long run, just needing a bold new entrepenuer

    • Ingrid
      October 22, 2012 at 9:31 am (9 years ago)

      A properly formulated raw diet is balanced, Michael. Nobody who advocates raw feeding suggests that pet owners feed a chunk of raw or ground meat to their pets. Education is key – as it is with all nutrition. While I don’t disagree that the original founders of these pet food companies that have been assimilated into conglomerates such as Colgate-Palmolive (Hill’s) and Nestle (Purina), had a vision to make pets’ lives better, I think that vision has not been served well.

      To draw an anaolgoy to human health: feeding a commercially processed canned or dry food vs. a properly balanced raw or homemade diet is like the difference between eating Campbell’s soup and making your own soup from fresh, organic ingredients.

  12. Nancy Leeper
    October 22, 2012 at 8:53 am (9 years ago)

    I have kitties with health problems, but I must admit a raw diet scares me with our food supply as tainted as it is – salmonella, e coli, etc. Do you have any recommendations for a cooked diet, and is ther one suitable for kittens as well as adults?

    • Ingrid
      October 22, 2012 at 9:03 am (9 years ago)

      Nancy, consider that all of the recent pet food recalls were for dry food, not raw. However, I do understand that a raw diet is not for everyone, and if it exceeds your comfort level, a homecooked diet is a good option.

      Balance It and both provide asistance and recipes for balanced homemade diets.

    • Carolyn Sturgill
      October 25, 2012 at 9:44 am (9 years ago)

      You have a couple things to consider here:
      1. Research. Make sure you find a good site for information on balanced raw diets. and are two of the best. If you go on some recipe you found posted on a random site, you could endanger your cat by not feeding a balanced, supplemented diet.
      2. Cats have super fast digestive systems. Consider cats in the wild when making digestive comparisons, as domestic cats are not far evolved from them. Cats will eat prey whole (mice, birds) including all manner of icky innards 🙂 and also will leave/bury/hide their prey and come back to eat it more than once – after bacteria has built up.
      3. Surprisingly, the biggest germ problem you’ll have is your own health, and that is to say, clean up the surfaces the raw meat has touched, just like you’d do while cooking your own food.

      Finally, don’t let the length of the recipes scare you. I just made 10lbs of raw last night in 20 minutes flat, including the time I spent looking for the plunger for the grinder 😉

      A note about patience. You’re going to need it. Many cats do not suddenly love raw food. Oddly, some of my sicker rescues have taken to it quickly, as if they knew they needed it, but you have to transition them to raw, and give them time and encouragement.

      • Ingrid
        October 25, 2012 at 10:33 am (9 years ago)

        Good advice, Carolyn. For those new to raw feeding, I actually recommend starting with a commercially prepared raw diet – it takes the “overwhelm” factor out of it, and it’s as easy as opening a can: simply thaw and feed. For the brands I recommend, please read:

        Not all cats are hard to transition to raw food, although some, especially the hard core dry food addicts, can be challenging. Here’s advice on how to transition:

        • Carolyn Sturgill
          October 25, 2012 at 10:57 am (9 years ago)

          Thanks Ingrid 🙂 This is a great topic, as I do personally believe that commercially processed foods are at the root of most far-too-common illnesses in cats, such as diabetes, allergies, IBD and renal issues. Your article is well-done!


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  1. […] Feed a species-appropriate, minimally processed diet. Ideally, this means a raw or homecooked diet, with a grain-free canned diet being the next best choice. Highly processed foods, especially dry food, create a constant state of inflammation in the body that may well be at the root of all feline illness. […]

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