Why Dry Food Is Not A Healthy Diet For Cats And Dogs

August 21, 2012

Photo of Dr Patrick Mahaney and Jodi Ziskin Lecture at The Healthy Spot in Santa Monica, CA

Dr Patrick Mahaney and Jodi Ziskin Lecture at The Healthy Spot in Santa Monica, CA

I’m featuring a guest blog post by Jodi Ziskin, Certified Pet Nutrition Consultant (with a Master of Science in Holistic Nutrition), as we share common perspectives about the health value of dogs and cats attain from eating a whole food-based diet instead of processed foods.  Go Jodi….

I am on a mission to help cats and dogs live healthy, happy lives. One of the topics I feel is truly important for all pet guardians to discover is that a dry food diet is not a healthy choice for any pet.

Cats and dogs need a varied diet. Feeding the same food day after day, week after week, year after year can create nutritional deficiencies as well as increase the chance for food intolerances. That’s the mild stuff.

Here we go!

Dry pet food was created approximately 100 years ago simply as a convenience for people. Unfortunately, it is a truly unnatural diet for cats and dogs. One of the questions I ask my clients is: Have you ever seen a kibble plant?

With very few exceptions, dry food is manufactured using very high heat. This destroys many of the nutrients found in the raw ingredients. Some estimate that 50% of the amino acids are destroyed as well as nearly 100% of the vitamins and minerals. That is one of the reasons synthetic vitamins and minerals are often added back in. The thing is, cats and dogs do not assimilate synthetics. In addition, the once healthy omega 3 fatty acids in the food also become rancid during the cooking process. Of course, the heat also eliminates most of the moisture content.

On average, dry food contains around 12% moisture. Compare that with the 75 – 80% liquid content in natural prey, raw, homemade, and canned foods.

A cat or dog drinking copious amounts of water can consume around 50% of what is available in the aforementioned food forms. This is a far cry from what they actually need. Remember – hydration includes electrolytes like potassium, magnesium and calcium as well as many micro-minerals.

What does this all mean? Well, many pets on an all-dry diet become chronically dehydrated. This is especially true for cats who naturally have a very low thirst drive and will often not even drink water until they are 75% dehydrated.

A dry only diet is a major contributor to obesity, diabetes, irritable bowel syndrome/disease, constipation, kidney disease, liver disease, joint problems, skin issues and more.

These are not my opinions – these are facts. I asked integrative veterinarian Dr. Patrick Mahaney, VMD, CVA to explain more.

”Dehydration is truly one of the primary enemies of our pets’ bodies and occurs when there is a loss of body fluid or a lack of liquid consumption, both of which reduce overall blood volume,” said Dr. Mahaney. “Lack of sufficient moisture consumption combined with increased liquid output results in dehydration and the emergence of a variety of otherwise preventable pet health conditions (kidney and other organ failure, lethargy, etc).”

“All body parts suffer when there is deficient fluid to enhance the movement of blood through the arteries and veins and lymph in the lymphatic vessels,” he continued. “Thick blood and lymphatic fluid inefficiently perfuse and drain body tissues, resulting in lack of oxygenation and nutrient delivery, reduced toxin removal, and deficient white blood cell activity in all organ systems.”

Dr. Mahaney, who practices Traditional Chinese Veterinary Medicine (TCVM), explained why dry food is categorized as Yang (warming).

“Dry food is inherently yang, as the majority of the naturally occurring moisture has been cooked out. In comparison to moist and whole foods options, dry format has a drying effect on the body by requiring the secretion of liquids (saliva, gastric acid, bile, pancreatic enzymes) to facilitate digestion. Additionally, water must be consumed in association with dry food consumption as the body is unable to secrete sufficient moisture to efficiently digest most dehydrated foods,” shared Dr. Mahaney.

“Inflammation associated with arthritis, cancer, immune mediated ailments (like Immune Mediated Hemolytic Anemia or Thrombocytopenia [IMHA or IMTP]), and inflammatory associated illness (inflammatory bowel disease [IBD], allergic skin disease, etc.) are conditions of excess yang (or deficient yin) and are exacerbated by the further addition of dryness or heat to the body,” he explained. “Reduction of dry food and provision of moist foods having yin or neutral energies are means of addressing inflammation from the perspective of traditional Chinese veterinary medicine (TCVM).”

How Dry Food Leads To Obesity

Because of the lack of nutrients, dogs and cats will eat more dry food just to try to meet their nutritional requirements. Most dry foods also contain grains*, which have no place in the diets of carnivores, like dogs or obligate carnivores, like cats. When stomach acids break down these grains, it causes a spike in blood sugar. Insulin is then released by the pancreas to bring the blood sugar back to normal levels. What the insulin can’t handle then gets stored as fat in the body.

*Note: in many commercial foods, grains such as wheat, corn, and soy that have been condemned for human consumption due to excessive pesticide residue can be used without limit in food intended for animals.

Dry Food And The Clean Teeth Myth

Simply put, dry foods do not keep teeth clean. That’s like telling you to eat granola or crackers and not brush your teeth! Starches from dry food (even grain-free dry foods contain starch) adhere to teeth and become the breeding ground for bacteria (plaque). The best way to keep the teeth of cats and dogs clean is to provide them with raw bones after meals. Alternatively, brushing the teeth with toothpaste made especially for pets is a great idea. It is important to have your vet check your pet’s teeth during their annual exam. Most pets will need a professional cleaning from time to time.

Why Pets Love Dry Food

In order to attract dogs and cats to their food, pet food manufactures add flavor enhancers. This is a spray of fats, artificial colorings and flavorings, including MSG, which is added as the food cools. Not only does this help the food become more visually appealing to YOU (trust me, your pet does not care what color his/her food is), it actually causes your pet to become addicted to the food!

Convenience Over Health

“Canned and dry cat and dog foods evolved out of a desire for owner convenience and the emerging role of the companion animal as a member of the household,” explained Dr. Mahaney. “After all, why feed your pet the discards of your kitchen table if you can feed a nutritionally complete and balanced pet food?”

According to Dr. Mahaney, this is where the proverbial ball was dropped and the public’s opinion began to shift to the belief that processed foods are more beneficial for pets than whole foods.

“When a pet owner’s desire to merely open a bag or can and fill their pet’s bowl with processed dry or canned foods (and then just walk away) supersedes the interest in cooking a home prepared diet or feeding a fresh, commercial available meal, then convenience wins out and pets’ health suffers,” Said Dr. Mahaney.

“Unfortunately, our canine and feline companions have suffered as a result as cancer, allergic conditions (inflammatory bowel disease, allergic skin disease, etc) obesity, and metabolic disease (hypothyroidism, diabetes, kidney and liver abnormalities, etc) are occur in increasing numbers in pets eating commercially available foods containing feed-grade ingredients.”

If your pet simply loves to crunch on dry food, then think of serving it as more of a treat or side dish – much like you having chips with a nice sandwich. Try to keep dry food to less than 10% of your pet’s overall diet.

There are very few dry foods I ever recommend (and always as an accompaniment to a high quality diet). All are from companies that use ingredients fit for human consumption, that do not include by-products or rendered ingredients and that cook at lower temperatures and for less time.


Jodi, thank you trekking to California and teaming with me to educate pet lovers at The Healthy Spot (as pictured).

Thank you for reading this article.  Your questions and comments are completely welcome (I’ll respond).

Please feel free to communicate with me through Twitter (@PatrickMahaney) and follow my adventures in veterinary medicine by liking Patrick Mahaney: Veterinarian Acupuncture Pain Management for Your Pets on Facebook.

{ 15 comments… read them below or add one }

Jana Rade August 21, 2012 at 1:16 PM

Are there any studies available, which I don’t think there are … Since THEIR SCIENTIFIC STUDIES are the sword the food companies wave around and got many vets to believe in. Common sense does not compute and cannot compete with “hard scientific data”. Are there ANY studies available?

JW August 22, 2012 at 6:30 AM

Where is the post recommending a good wet food that doesn’t break the bank if you have multiple dogs AND is good quality? I’m sure you don’t want me going and feeding my dog the cheapest canned food from the grocery store, do you?

adrienne August 22, 2012 at 6:36 AM

what should we feed them?

Jennifer August 22, 2012 at 3:33 PM

What are the few dry foods that you do recommend? I have a cat who will not eat anything else.

TheOldBroad August 22, 2012 at 4:11 PM

“Unfortunately, our canine and feline companions have suffered as a result as cancer, allergic conditions (inflammatory bowel disease, allergic skin disease, etc) obesity, and metabolic disease (hypothyroidism, diabetes, kidney and liver abnormalities, etc) are occur in increasing numbers in pets eating commercially available foods containing feed-grade ingredients.”

Do you have any studies (not performed by a pet food company) regarding the “increasing numbers”? What are the chances that simply having better heath care and living longer allows these maladies to present?

Re: Dry food does not clean teeth. Amen to that! Wish I had a sentence or two that would convince some people of that.

P.S. Can’t believe the raw-food advocates haven’t found this post. That usually provokes some lively comments.

Dr Amy August 24, 2012 at 4:40 PM

I appreciate this post very much! I shared it on my Facebook page. You made some great points. I did my own “little” raw feeding study–partly out of my curiosity and desire to learn, partly to raise awareness and with hope more studies would be done. I did blood and urine values pre-feeding trial, at 6 months and at 12 months. See my web site if you want to know the results. I also blogged on the experience and tried to record “the good, the bad and the ugly” with complete openness but most of it was good! Not a cure all for all my concerns but a very positive change. Plus I found out PRE trial one of my dogs had a serious kidney disease I would not have known about until too late, so that was a blessing! Dr Amy (veterinarian).

Rod August 26, 2012 at 6:45 PM

“Scientific” studies slamming home-prepared (particularly raw food) diets for dogs and cats are universally sponsored by pet food conglomerates and are conducted by “board certified veterinary nuritionists” (which is code for “in-the-kibble-tankers”). So, THEIR research is inherently biased and laden with conflicts of interest.

Now the intellectually incurious lap-dogs, the AVMA and the AAHA, have condemned home-prepared raw diets, and every bought-and-paid-for kibble peddler is citing these groups in an onslaught of attacks on the moms and pops who care enough for their pets to prepare the best possible meals for them.

Patrick Mahaney August 29, 2012 at 11:19 PM

Thank you for your comments. Feeding multiple pets in the household can certainly be a challenge from both a perspective of what is the healthiest for them and for the possibility of their different medical needs. The canned foods that I have seen that appears to have whole chunks of meat, vegetables, and grains include Party Animal and Merrick. I am sure that others exist as well.
As for store bought commercially available food that is actually dry but becomes almost can-like when you hydrate it, my preference is The Honest Kitchen. Their foods are actually human grade (and can be labeled as so) as they are prepared in manufacturing facilities that are inspected by the FDA.
You can always take portions of your own healthy meats, vegetables, and greens and include them in your dog’s food as a means of reducing other processed dry foods and treats.
I hope to see you back again on my blog!
Thank you,
Dr. PM

Patrick Mahaney August 29, 2012 at 11:25 PM

Actually, there was a study done in 2003 by Drs Gerard Lippet and Bruno Sapy titled The Relation between the Domestic Dog’s Well-Being and Life Expectancy: Statistical Essay. The study showed that dogs consuming home prepared food lived nearly 3 years longer than those consuming in industrial food (“retail sold dog food”). Dogs that eat home prepared food mixed with industrial food also live longer.
This is the first of such studies with which I am familiar, but I hope to find others in time.
Dr. Janice Elenbaas from Lucky Dog Cuisine informed me of and gave me information about this study.
Thanks for your comments,

Patrick Mahaney August 29, 2012 at 11:29 PM

I suggest feeding your pets human grade foods comparable to those YOU eat provided you eat a whole food-based diet containing freshly prepared correct meats, vegetables, and grains. Consider that the number one nutritional disease in pets is obesity, and the majority of pets in this country eat processed dry or canned foods as their primary food source. So, when people get all wrapped up in food having to be nutritionally complete and balanced in every bite, they forget to look at the big picture and don’t take into consideration the lack of whole food based nutrients in most pet foods.
If you don’t wish to cook yourself, then there are commercially available options such as Lucky Dog Cuisine and The Honest Kitchen.
Thank you for your comments and I hope to see you back again on my blog.
Dr. PM

Patrick Mahaney August 29, 2012 at 11:32 PM

I don’t recommend cats eats kible-based dry food. My suggestion is that you try a human grade, whole food-based diet like the Honest Kitchen. There foods are cooked and dehydrated, so all you have to do is add water, left the food sit, and serve.
In doing a food transition, make sure to slowly add the new food and reduce the previous food over a period of at least seven days. You can always doctor up any food by adding warm meat broth, such as beef, turkey, fish, pork chicken.
Thank you for your comments.
I hope to see you back again on my veterinary blog.

Jana Rade August 29, 2012 at 11:40 PM

Actually, I think that home-cooking can be quite affordable if you connect with a farmer; many of the cheaper cuts, organ meats, and things like hearts and tongues can come quite cheap.

Once we got a huge box of meaty bones for free, there was still a huge amount of meat on them too.

Patrick Mahaney August 29, 2012 at 11:43 PM

I don’t know of any specific studies revealing cancer rates, but the Morris Animal Foundation page reports:
Cancer is the no. 1 cause of death in dogs over the age of 2, and an estimated 60 percent of Golden Retrievers die of cancer. Research in human medicine is beginning to indicate that an individual’s ability to repair DNA correlates with his or her susceptibility to cancer.

Additionally, CanineCancer.com reports:
Cancer is the number 1 concern of pet owners and
the number 1 natural cause of death in older dogs.
The most common forms of cancer are:
• breast • skin • bone • connective tissue
• oral • lymphoma

I don’t know how people got the premise in their head that dry food cleans teeth. I hope that we can change that perception over time and pattern is realized that animals eating a whole food based I tend to have fewer issues with dental disease than those eating processed foods. This is a clinical experience based perception that I hold from my years of clinical practice.

Thank you for your comments,

Patrick Mahaney August 29, 2012 at 11:47 PM

Hey Dr. Amy,
Thank you for your comments.
Sounds like you did your own food trial such those performed by AAFCO, yeah did you certainly upped the anti-by performing:
1. blood and urine testing
2. diagnostic testing at times zero, six, and twelve months (instead of just at time six months)
I look forward to reading about your studies and results from your website.
I look forward to further correspondence with you as we both are passionate about the whole food phenomena for our pets and patients.

Patrick Mahaney August 29, 2012 at 11:53 PM

Thank you for your comments.
I do agree that we must question the true validity of such studies that are performed by corporations producing processed pet foods.
What I think is greatly lacking in the hats loving community is a general lack of common sense. I like in the comparison, or lack thereof, to Choose My Plate recommended by the USDA.
For humans, you don’t see the recommendations to eat highly cooked, dry, and processed foods instead of fresh, whole food-based diets. Why do we then think that this food style is most appropriate for pets just because it’s ‘nutritionally complete and balanced” (on which I feel way too much emphasis is placed by the pet food industry).

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