By Ann-Marie Cole (Cert. Animal Nutrition, Dip. Canine Health & Nutrition, Dip Feline Studies, Cert. Holistic Health for Dogs)
Ultra processed are categories of feed that are high heat treated such as canned and extruded diets. In particular extruded diets aka kibble is the most popular category of pet feed in the world, but is it really a good choice for our pets to promote long term health and longevity?
In my opinion and experience, no. Every pet I’ve taken from a ‘premium’ vet recommended ultra processed diet and put into a fresh food diet has improved in health and vitality, puppies and kittens raised on thoughtfully constructed fresh food diets have thrived.
While most of these foods claim to meet one of the governing bodies nutrient requirements (typically AAFCO or FEDIAF) there is far more to consider than just whether it meets guidelines or is WASAVA approved.
Synthetic Nutrients: Most commercial ultra processed pet foods will require supplementation to put back nutrients that either were never in the main food ingredients or have been degraded from high heat processing. As natural bioavailable nutrients tend to be expensive most companies will put cheaper synthetic options in their foods to be more cost efficient to produce, often in the form of vitamin & mineral premixes, sometimes companies will only add what is essential. The issue here is that the body does not recognize some of the nutrients very well and some aren’t as bioavailable as natural forms. Some individuals can be sensitive to synthetic forms so it’s important to be aware if your pet has issues with tolerating foods that may appear as GI and allergy reactions.
Poor Quality Ingredients: Unless a pet food states it is made from human grade ingredients you can be almost certain that the ingredients are not fit for human consumption, they are often the waste products of the human food industries, condemned meats and even roadkill or dead animals sent to rendering facilities. Recalls have occurred from pet food being tainted with euthanasia drugs; it was found to be fats sourced from rendering facilities. Plant matter often from crops not suitable for human consumption and can be affected by mold. There is also a legal AAFCO definition that allows old bakery goods such as bread, cookies and cakes to be used in pet feed. Always look for food that states it uses human grade ingredients and even better if it’s made in a human grade facility.
Preservatives: some preservatives in pet feed can be naturally derived and safe, you may see rosemary or Tocopherols (essentially vitamin E either natural or synthetic) being used, however there are many chemical preservatives that are known to cause harm for example BHT, BHA, TBHQ, Ethoxyquin which are banned in Australia and other countries around the world for human consumption due to safety concerns including carcinogens, DNA damage and endocrine disruption, however they are still used in pet feed. One thing to understand about pet food labeling is when a supplier of an ingredient uses a preservative and not the pet food manufacturer the manufacturer does not need to disclose that preservative on their label, ethoxyquin is commonly used to preserve seafood in pet feed. While it can be tricky to identify if preservatives are present, always look for naturally derived preservatives on the label and assume if fish products are in the ingredients that they may contain ethoxyquin.
Pathogens: Contrary to belief you are more likely to have issues with pathogens in dry extruded dog food than you are with a fresh food diet. Many people are under the impression that dry foods being high heat processed are ‘sterile’ and this simply isn’t the case, a recent study found that of 35 dry dog foods tested 100% of them contain potentially harmful pathogens. For those concerned that raw fed dogs may be carrying a higher risk of pathogens, a study looking for a common pathogen that puts female dogs at risk of developing pyometra found that when they tested the rectal areas of female dogs showed that the raw fed dogs had a lower incidence of E.Coli than kibble fed dogs, and were thus at lower risk of developing pyometra. There have also been many more recalls for pathogens that not only have the potential to make pets sick but do make humans sick in the dry dog food category than fresh foods. It’s pretty clear that ultra processed feed puts your pet and your family at risk of harmful pathogens, in part as they not only contain pathogens but people tend to be more complacent about handling dry food and not washing their hands, food is often left in bowls for pets to graze on allowing small children to handle and potentially eat it, and often bowls are just refilled without washing after each meal. When feeding fresh food we are often far more cognizant to keeping food chilled, handling it appropriately, washing our hands, cleaning up promptly after preparing food and washing bowls after each meal.
Toxicity, Mold, Undeclared Ingredients and Adulterated foods Oh My!: Pet foods have had endless recalls and concerns for many issues from mold that introduces aflatoxin and mycotoxin risks (cooking does not remove the risk, they are toxic by-products from mold) that can cause GI upset, liver disease and even death, you do not need to see mold for it to be present. Adulteration with toxic substances such as euthanasia drug have also been reported and recalls taken place, through to foreign objects like plastics and metal. Vitamin pre-mixes have also been at the heart of some of the biggest recalls such as Hills prescription foods several years ago when there was a massive recall for excessive Vitamin D from unchecked food being put on the market leading to many canine deaths. Recently there is also speculation that copper may be included in some foods in amounts too high as there is no safe upper limit set by AAFCO, high levels of copper can lead to copper toxicity in dogs leading to liver issues. Melamine was also included in some premixes of plant matter to make the food appear to have more protein, this also lead to a massive recall and many pets died. Testing on foods over the years has also highlighted that many foods not only do not contain the nutrient profiles they claim to have with excesses and deficiencies being noted but undeclared ingredients are commonly found in pet feed, for example a lamb feed may also contain chicken and horse. One notable case was a brand that contained canine DNA, highlighting concerns of where the ingredients are being sourced. For dogs that are very sensitive to what proteins they can consume having a food you know has only the protein you want to feed in it is very important. These issues are present in all form of ultra processed diets including kibble and canned foods.
Carbohydrates: For the typical healthy dog or cat their need for starchy carbohydrates like those found in pet feed is low to zero, this is especially true for cats. The primary reason starchy grains and vegetables, legumes and pulses are used is to make the kibble form into crunchy hard balls, it also allows the companies to use less meat reducing the cost, sometimes the protein while incomplete will appear higher due to plant protein rather than animal protein that our carnivores truly need. As carbohydrates provide a rich source of energy many pets on these high starch diets struggle to maintain healthy weights and often become overweight. It has also been found that dogs on minimal carbohydrate and moderate to high fat diets have lower blood triglyceride levels than dogs on high carbohydrate diets. This not only causes issues for their joint health long term but can make them more prone to metabolic and endocrine issues, cats for example are known to be at higher risk of developing Diabetes Meletus when fed a dry diet. Please note that some medical conditions will rely on macronutrients being altered to adapt to rely on more carbohydrate for energy and less protein and or fat, this can still be achieved with fresh minimally processed diets though.
Rancid Fats: Fats are essential for optimal health, however they are not stable and will become oxidized rapidly when exposed to light, heat and oxygen, if the fats in the bag of kibble aren’t already rancid when you buy them they will rapidly begin to deteriorate once that bag is opened and air is in contact with the food. If you have no option but to feed dry food buy small bags and use it quickly, store in a cool dry place out of sunlight in it’s original packaging. When fats are rancid not only will your pet be less likely to want to eat their food (this can be a classic reason for having a ‘fussy’ pet), don’t forget their sense of smell in far greater than ours it can also lead to health issues. Always choose foods with more stable fats and if supplementing Omega fatty acids select brands that are sold in a stable form such as in a capsule to reduce oxidation from air and store in the fridge.
Moisture Deficient: All animals but especially cats should be consuming diets closer to their natural diets, that is around 70% moisture, most dry diets are around 10% moisture. While dogs can often drink enough to compensate cats have a very poor thirst drive and concentrate their urine, when eating dry diets they are going to be in a state of dehydration as they cannot drink enough water for optimal cellular hydration. Cats on dry food diets are known to be more likely to develop kidney and urinary tract disease. One thing many fail to realize is that to digest food optimally, you must also be optimally hydrated, to get the best out of your food you need to be well hydrated. Dry food diets do not make sense when you consider potentially the most important nutrient of them all, water! Thankfully canned foods do not have this concern.
Advanced Glycation End Products: This occurs when foods that contain protein and sugars undergo the Maillard reaction, these end products are known carcinogens, and can also lead to arteriosclerosis, diabetes, kidney disease, dementia and impaired immune function and gut health. This topic is huge, and research is still being done to fully understand it, but is potentially one of the most significant reasons why high heat processed foods should be significantly reduced if not removed from our pets diets in favor of raw or gently cooked foods. Surprisingly canned foods can be higher in AGE’s than kibble so this is something that affects all high heat processed foods regardless of it’s perceived quality. Let’s not forget that some ingredients in pet feed are high heat processed many times from rendering, through to extrusion, the thought of how high these AGE’s are in some foods is frightening.
These are just some of the concerns that spring to my mind when someone wants to know what to feed their dog or cat and want to know what ultra processed feed to choose. Simply put no matter what the perceived quality of the brand is, none of them are without serious issues that will effect your pets long term health.
What do I suggest? Minimally processed foods, these are foods that ideally are human grade, have high animal based protein, minimal to no starchy carbs and is moisture rich. Rated from most recommend to least…
1. Raw diets that are human grade and balanced, either commercial or DIY/homemade
2. Gently cooked that are human grade and balanced, either commercial or homemade
3. Rehydrated Freeze Dried, unless offered as a topper or treat on moist food always rehydrate as they are more devoid of moisture than kibble.
4. Canned can be handy for those who need a shelf stable option, ideally use these in rotation with fresh foods to reduce issues with AGE’s and potential toxicity issues.
5. Air Dried, for those who absolutely need a dry food (not for cats) for dogs air dried can be handy for travel and emergencies, they are heat processed but not to the extent of extruded foods. Try to use it in combination with fresh foods.
Hopefully this help guide you to understanding why I don’t rate ultra processed foods, if you have no option but to feed kibble or canned foods, do your best to include fresh wholefoods as much as possible to reduce some of these issues, studies have shown that including even 20% of a pets diet in fresh wholefoods will improve their health, but if feeding more than 10% of the diet in fresh foods ensure it is balanced.
What are some great wholefood additions to improve your processed food?
· Oily fish like sardines, salmon or mackerel to provide fresh Omega fatty acids
· Eggs, natures powerhouse of quality protein and nutrients
· Fresh raw or lightly cooked meats (no processed meats like sausage, bacon etc…)
· Veggies, either finely chopped pureed raw veg or steamed and mashed vegetables. (Very small amounts of low starch veg for cats)
· Berries
· Bone Broth (make sure it’s pet safe)
As with anything new, start with a small amount and work up if your pet tolerates it.
References for further reading:
Truth About Pet Food – https://truthaboutpetfood.com/
Which Pet Foods are recycled garbage? Truth About Pet Food - https://truthaboutpetfood.com/which-pet-food-ingredients-are-recycled-garbage/
Assessment of the content of macronutrients and microbiological safety of dry dog foods - https://www.sciencedirect.com/science/article/pii/S0034528823003223?via%3Dihub&fbclid=IwAR1bbzbp3R74RMrSxaEhaRiq2DphJaQ7W44W42OymLhMUBuwswXWYmvgKZ0#bb0425
Characterization of Escherichia coli in Dogs with Pyometra and the Influence of Diet on the Intestinal Colonization of Extraintestinal Pathogenic E. coli (ExPEC)- https://pubmed.ncbi.nlm.nih.gov/35622773/
Study: Cats eating dry food have increased risk for developing Type 2 diabetes- https://www.veterinarypracticenews.com/study-cats-eating-dry-food-have-increased-risk-for-developing-type-2-diabetes/
Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3704564/
Immunomodulation by Processed Animal Feed: The Role of Maillard Reaction Products and Advanced Glycation End-Products (AGEs) - https://www.frontiersin.org/articles/10.3389/fimmu.2018.02088/full
Do you know what AGEs are? | David Turner | TEDxCharleston - https://www.youtube.com/watch?v=LvwMXqyrKG0
A Diet for Your Cat's Urinary and Kidney Health - https://hare-today.com/feline-nutrition/health/diet-kidney-disease-and-the-urinary-tract