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At Food Fur Life, we advocate for and encourage the feeding of raw food. That said, a (properly balanced) home prepared food made with all human grade ingredients, even if cooked, will always – in our opinion – be a superior choice to any commercial canned or kibble. This is why we formulated the EZComplete premixes to properly balance food whether the meat used with the premixes is cooked or raw. The premix powders for dogs and cats includes both pancreas and digestive enzymes so all pets fed food made with our premixes are consuming those needed enzymes. We understand there may be personal reasons to cook. With that in mind, we share the information in this article to help you make informed choices: whether or not to cook, and if cooking, which method will both suit your lifestyle and be most healthful for your pets.
When we first entertain the idea of homemade food for our pets, it’s quite common to have questions, if not concerns, about raw feeding and bacteria. Unless we are lucky enough to have a veterinarian that is knowledgeable about raw feeding, these questions often grow into fears once we chat about the diet change (if the notion of homemade food is not completely discouraged). The only consideration when it comes to cooking for our pets, typically, is the fear-based potential for bacterial contamination. We treat the question "to cook or not to cook?" as if cooking is benign, and has no impact apart from making food “safer.” Sure, we all know we need to account for nutrient loss. But the decision to cook for our pets is not so straightforward. There are other important factors to consider – especially if it is cancer or an inflammatory disease that prompted us to explore making food for our furry family members.
Having eaten cooked food for anywhere from 400,000 to 1.8 million years, humans have adapted to eating cooked food. Our pets, naturally hunters and scavengers, have not. In their evolutionary timeline, commercial foods only became a part of their diet full time within the last few decades. Cooking their food may have unintended health consequences, as they are perfectly designed for eating not just raw meat and organ, but what we would consider contaminated raw meat and organ.
Of course WE would likely get sick if we ate raw meat contaminated with bacteria. But this an instance where we should not humanize our pets. Veterinarians are quick – and rightly so – to point out the nutritional needs of our pets are quite different than our own. Of course those differences extend to the defense systems of our bodies versus those of our pets. Of course our pets are well adapted to their natural evolutionary diets of hunting and scavenging. And of course our pets have biological mechanisms in place to protect them from this risk that we do not. We address this topic specifically for cats in our article “Why You SHOULD Feed Your Immune Compromised Cat Raw Food.” The defense mechanisms for dogs are the same, featuring lysozyme-containing saliva; an extremely acidic stomach acid when fed a species-appropriate diet (that maintains its pH when food hits the stomach); and stomach acid that contains a very high concentration of hydrochloric acid (10x more than a human's).
So what is the real difference between raw and cooked?
Cooking:
- Depletes nutrition. Heat destroys a portion of some nutrients. Thiamine, one of the most heat-sensitive B vitamins, can be reduced by up to 70% in cooked meat. Obviously these nutritional changes can be accounted for when constructing the diet, as we did, when formulating EZComplete premix.
- Alters the protein structure. Heat denatures proteins, altering the structure. While this generally reduces digestibility for our pets, it does take the body less work to break down once ingested. This can be important for some animals with impaired GI systems. However, if one is going to cook, the method is important, as discussed in this article.
- Can create cancerous compounds. High heat such as grilling, frying or roasting over 310F to a well done state creates cancerous compounds (heterocyclic amines (HCAs)). As we note in our "How To Prepare" instructions, if baking in the oven, adding water to the pan, covering the meat with foil, and cooking to rare will minimize Maillard Reaction compounds from forming.
- Can create compounds that cause oxidative stress and inflammation. Broiling, roasting and frying (cooking with high dry heat) creates Advanced Glycation End products (AGEs). AGEs are associated with oxidative stress and inflammation in humans, processes that eventually cause most chronic diseases, including diabetes, chronic kidney disease (and in humans, at least, cardiovascular disease and neurodegenerative diseases). In an article titled “Finally! A Study That Proves Processed Pet Food Can Cause Disease,” Dr. Becker notes “A direct link exists between the amount of processed foods consumed and the level of AGE in the blood. The reverse is also true: eat foods low in AGE and AGE blood levels decrease. In fact, studies show that when people with diabetes eat a low AGE diet, it improves insulin sensitivity and kidney function.” In this article, she reviews her interview with Dr. Danielle Conway, who conducted a pilot study to examine AGEs in pet food. This study revealed the less processing that occurs, the less heat applied, the more moisture maintained, the lower the AGE.
- Destroys enzymes. Cooking destroys the enzymes present in all food. There is no method of cooking that preserves them. The importance of enzymes to our pets cannot be over-emphasized, as the lack of enzymes in the diet overworks their organs. If you are feeding commercial (non-raw) foods, it is best to include a plant-based digestive enzyme. Plant-based enzymes function in a wider pH environment, are tasteless, and usually well accepted by pets. As with all new things, please introduce these slowly and work up to the recommended dose over a few days. There is no need to add enzymes to EZComplete as the premix already contains them.
Why are enzymes so important to our pets?
Enzymes are present in all living animal (and plant) cells: they are the catalysts of all naturally occurring biochemical processes that take place in our (and our pets’) bodies. Without enzymes, we cannot utilize the nutrition we eat, and neither can our pets. The processes that enzymes catalyze would take so long without them, we couldn’t survive. As we have discussed in numerous articles, cats are not “just” carnivores, cats are metabolically inflexible hypercarnivores. Biologically, cats have made no adaptations to eating anything other than their natural diet, comprised almost solely of animal tissue. And that diet is raw. Dogs may have made very minor adaptations to eating a diet that includes some carbohydrates, but they remain carnivores, and they, too, thrive on a fresh food diet complete with its enzymes intact.
As Dr. Jean Hofve explains in the Spring 2012 issue of IVC Journal in her article, “Enzymes,”
“The thousands of enzymes produced by the body aid in a wide variety of chemical reactions. There are two major classes of enzymes: metabolic and digestive. Digestive enzymes are produced primarily in the pancreas and released into the duodenum to help digest food coming from the stomach. The intestines themselves also secrete amylase and other digestive enzymes.” Dr. Hofve goes on to note that “Research in animals has shown that the production of digestive enzymes is independent of diet. That is, animals are biologically programmed to produce specific types and amounts of digestive enzymes in response to food ingestion, regardless of what food they actually eat. Only major evolutionary shifts, such as changing from omnivorous to insectivorous lifestyles, affect these systems. Our carnivorous pets have not, and cannot, adapt their digestive functions to processed diets, which, after all, have only been widely used for a few decades.” [Bold, our emphasis]
In the wild, cats eat the entire animal. In the wild, dogs may not eat the stomach contents, but they do eat the nutrient and enzyme-rich organs. Our cats' and dogs' digestive and metabolic systems are designed to benefit from the enzymes consumed in their prey. When we feed our pets cooked food, we are providing food that is devoid enzymes. While cooking is a form of "predigestion" (in that it alters the structure of the proteins in any food making it consumer fewer calories to break down), humans have had, as discussed above, at least four hundred thousand years to adapt to cooked food. So it is that our organs, especially our pancreas, are much larger relative to body size compared to that ratio in any other animal. Dr. Hofve addresses this in her IVC Journal article on enzymes for pets. The bottom line is that we have had hundreds of thousands of years to adapt to this change in food eating. It is only within the last few decades that dogs and cats have been fed solely commercially prepared foods - 100% dependent on our cooked, literally processed-to-death foods, that require long lists of vitamins and minerals be added to create nutritionally acceptable food. We see the impact of this change to a diet lacking any fresh raw food or any hunted or scavenged prey in the top health issues cats suffer and with at least 34% of dogs suffering from chronic pancreatitis. As Dr. Hofve explains,
“Evidence … strongly suggests that eating foods devoid of enzymes as a result of cooking, food irradiation, and microwaving causes an enlargement of the pancreas and also stresses associated endocrine glands [in our pets]… In all of nature, the human pancreas is three times larger, as compared to total body weight, than that of any other animal. What is interesting is that when mice are fed cooked foods, the ratio of their pancreas weight to total body weight becomes approximately that of a human’s. When they are switched back to a raw-food diet, their pancreas shrinks back to normal size. The most obvious conclusion is that the pancreas becomes hypertrophied, or enlarged, because it is forced to keep up a high digestive enzyme output."
It would seem this process is happening to our cats and dogs. In a 2008 review article on pancreatitis by researchers at Texas A&M, it was noted that necropsy examination of the pancreas of 115 cats (both sick and healthy) discovered findings consistent with pancreatitis in 67% of cases (including 45% of “apparently healthy cats”). Let that sink in a moment. Two-thirds of cats had an enlarged pancreas consistent with chronic pancreatitis. While the researchers at Texas A&M questioned the clinical significance of this as 45% of seemingly healthy cats had an enlarged pancreas, with pancreatitis making its way into the Top 10 list of reasons for a vet visit, can we really believe the impact of eating a solely processed food diet has no impact? Because it isn't just cats. In our dogs, a 2007 study found that "The prevalence of chronic pancreatitis was 34 per cent... Chronic pancreatitis is a common, under-estimated disease in the first-opinion dog population." No, we do not know that lack of enzymes in the diet is a cause of or even contributor to pancreatitis. But as the incidence of pancreatitis causing illness in our cats and dogs is rising to alarming rates, we should be mindful of their need for additional enzymes if eating cooked foods.
It is a true testament to the resilience of our cats and dogs that so many do as well as they are, having had zero time in the scale of the species to adapt to many of the dietary changes we have forced them to make. The lack of enzymes is just one of many.
Is cooked food ever appropriate for my pet?
Older pets being transitioned to homemade, or pets with very damaged or sensitive GI tracts, may only be able to eat cooked food comfortably until their GI tracts have had time to heal.
When your pet has a bout of diarrhea or vomiting, or if your pet has inflammatory bowel disease and/or pancreatitis and is in a flare, feeding a bland diet of plain cooked meat for a short period of time is often recommended to help settle the GI tract.
Am I harming my cat or dog if I feed cooked meat?
There are no studies of the impact of Maillard reaction compounds or Advanced Glycation End products in cats or dogs. But if we suspect those compounds may present similar health problems to our cats and dogs as to ourselves, it is best to be mindful of the problem and make informed cooking choices. Low temperatures and moisture minimize AGEs and do not produce Maillard reaction compounds (likethe cancerous heterocyclic amines). A slow cooker on low, the stove top in simmering water, or our baking instructions using moist heat (adding water to the pan and covering the pan with foil) are the best choices. With high heat, dry cooking (typically grilling, frying or roasting), the food will contain these compounds. Of course, as with everything, moderation is advised. You can provide your cats and dogs a tasty treat, but don't feed them something cooked via such high heat all the time.
In addition to cooking at lower temperatures and with moisture, you can further minimize the impact of cooking by adjusting the "doneness" of the meat. If you are not convinced our pets are safe eating raw meat, consider lightly cooking the meat instead of cooking it to well done. The surface of the meat is the only area that may have been exposed to bacteria, so it is only the outside of the meat that needs to be cooked. There is no need to cook the meat all the way through. Importantly, this approach offers our pets the opportunity to benefit from some primarily raw food with most of its structure, nutrition, and enzymes intact.