In this video, Dr. Karen Becker discusses new trends in commercial pet food, and why low-carb, grain-free kibble is not, despite marketing claims, a good alternative to raw or ancestral diets for pets.
By Dr. Becker
Today I'd like to discuss a new trend in pet food: low-carb, grain-free kibble.
Many proactive, integrative, and holistic veterinarians have long recognized the nutritional drawbacks to commercially available dry pet food.
Most popular dry formulas don't contain clean ingredients – those approved for human consumption – and they aren't biologically balanced for obligate carnivores (cats), and scavenging carnivores (dogs).
However, in the late 1980's and early 1990's, we saw the production of better quality dry foods that contained more diverse ingredients. Coincidentally, during this same period, pet owners began to see the benefits of home-cooked diets because they could control the quality of the food they fed their dog or cat.
Although improvements to commercial dry pet foods addressed some of the quality control issues -- and began to address the biological appropriateness of ingredients – they didn't address one important fact. Companion animals were still consuming an entirely dead, inorganic, over-processed diet that was extruded and cooked at very high temperatures, rendering it devoid of any of the health benefits of living foods.
Dogs and Cats and Living Foods
Dogs and cats evolved to consume living foods – unprocessed foods. Maintaining pets on diets of completely cooked and refined foods clearly has a negative impact on their health.
The introduction of commercially available raw foods in the late 1990's offered tremendous additional health benefits because many varieties combined USDA-inspected meats with wholesome veggies in a much more biologically appropriate form. Several AAFCO-approved homemade recipes also became available and gave options for living foods, which was fabulous.
To argue whether raw food diets are appropriate for pets doesn't make much sense. Dogs and cats have consumed a variety of small prey for thousands of years.
Fortunately, knowledgeable vets and concerned pet owners have wisely forfeited the idea that cats can become healthy vegetarians and dogs will thrive on an entirely grain-based diet.
The Challenge of Feeding Your Pet Well
Even though many people want to match the food they feed their dog or cat as closely as possible to the animal's ancestral diet, there are difficulties in doing so.
Insufficient freezer space, cost, nutritional imbalances in poorly designed homemade diets, and issues sourcing healthy ingredients and commercially available raw diets have caused many pet owners to look for more practical, convenient options.
And pet food manufacturers are trying to fill the void with the introduction of low-carbohydrate, grain-free kibble (extruded, pelleted) diets.
Pet food companies claim these formulas are a convenient alternative to raw food, but nothing could be further from the truth.
One reason is because an essential feature of actual raw food is that if it's left out on the counter, it will soon be covered with maggots. No raw food can be kept at room temperature because by the end of the day, it will be putrefied and disgusting. Leave a bowl of kibble out on the counter in the morning, and guess what you'll find late in the evening? That same bowl of food, unchanged. It was dead in the morning, and it's still dead.
Kibble is processed, which means the ingredients are no longer raw. And they have been thoroughly cooked through the extrusion process, which means they're no longer full of the moisture that is critical for normal metabolic balance in cats and dogs.
The bottom line is there's no way kibble can be an alternative to raw food.
The Biggest Problem with Kibble: Lack of Moisture
But if low- or no-carb, grain-free, high-protein formulas are exactly what dogs and cats were designed to consume, then what's the problem with kibble?
The major concern is with the lack of moisture content.
Our carnivorous companions were designed to consume moisture-rich foods. Raw foods are about 70 percent moisture. Grain-free, dry foods are about 12 percent moisture. Huge difference!
The ancestral diet of dogs and cats is up to 70 percent water. Rabbits and mice are composed primarily of water.
Our pets' bodies have evolved to consume a diet that is rich in moisture and is neither extruded nor baked. When raw foods become kibble, several strange things happen to the raw ingredients, but the most detrimental is that the food becomes too dry.
This requires your pet's body to provide sufficient moisture to reconstitute the food in the digestive tract. Although an animal's body will make a noble effort to consume extra water to compensate, most pets and certainly most cats simply can't make up the difference.
The Association of Feline Practitioners recommends that owners feed cats a diet of primarily canned or raw food instead of dry food for this very reason. A lifetime of minor dehydration is stressful to multiple organ systems and can easily be avoided by feeding foods that have not been dehydrated, dried, kibbled, or extruded.
Another Big Problem with Kibble: Poor Quality Protein
Another concern with kibble is low quality protein sources.
For years, protein has gotten a really bad rap, and proactive vets have been trying to re-educate the public about protein – the quality of it and a dog's or cat's requirement for it.
We know protein requirements actually increase as pets age, which is contrary to what many people are led to believe. Older pets must combat catabolic processes (destructive metabolism) and need the biological availability of certain protein sources.
A food can be high in protein (for example, snouts and feathers are pure protein), but very difficult to digest. The biological availability of a protein source is its usefulness to the body. Protein that is indigestible is not useful.
The most notable physiologic changes that occur from a dehydrated, ultra-high-protein diet are kidney, liver and metabolic stress.
These convenient foods, meant to be alternatives to our pets' ancestral diets, look great at first glance, but they pose potential health risks when fed as the sole source of nutrition for an indefinite period of time.
Your pet's body is resilient. He can eat a trendy, grain-free, low-carb dry food and maintain relatively good health for a while. But your goal should be to provide a diet that really is close to your dog's or cat's ancestral diet and meets his biological requirements. So I don't recommend a lifetime of any brand of kibble because the moisture content is simply not sufficient to maintain your pet's health.
A species-appropriate diet for carnivores means it's grain-free – no corn, wheat, rice, millet, or oatmeal. It is maintained in its biologically correct form – raw, whole, unadulterated, un-denatured meat. It contains all the moisture needed for your pet's body to process the food with very little metabolic stress.
My first recommendation is to feed a raw-food diet. It's grain-free, moisture rich, living, and of course, it's fresh (unless you let it sit out on the counter, which I'm sure you won't!).
My next recommendation is canned food or a gently dehydrated (air dried) raw food that can be reconstituted with water to contain at least 70 percent moisture.
The difference between air dehydrated foods and extruded foods is temperature.
Foods that are not cooked or extruded at high temperatures retain more nutritional value. When air dried foods are reconstituted with water prior to feeding, they also become moisture rich and significantly healthier than any dry kibble on the market.
And finally, remember to check with pet food manufacturers to make sure whatever food you choose is nutritionally balanced.
Many of the new niche pet foods popping up on store shelves are intended for 'intermittent feeding only' – it generally says that on the label. This means they don't meet AAFCO standards for a complete balanced pet food. They must be fed in rotation with other nutritionally complete foods to create a balanced diet for your companion.