April 01, 2013
Story at-a-glance
- In part 1 of a 3-part series on raw food diets for pets, Dr. Becker begins the discussion by reviewing the ancestral origins of today’s dogs and cats.
- From a genetic standpoint, domesticated canines and felines are essentially the same as their wild counterparts, who are carnivores.
- Dogs and cats have not evolved from meat-eaters to vegetarians, but you wouldn’t know it from the ingredients used in the vast majority of commercial pet foods on the market.
- Fortunately, dogs and cats are adaptable, resilient animals. Otherwise, the biologically inappropriate convenience pet foods they’ve been fed for the last century would wreak even greater havoc on their health.
- High-carbohydrate, low-moisture commercial pet foods have created significant metabolic and physiologic stress in our pets and have become the root cause of most of the inflammatory processes and degenerative disease we see in veterinary medicine today.
By Dr. Becker
Today and over the next couple of weeks, I’ll be discussing my favorite topic, raw food diets for pets. I want to talk about some of the myths and truths surrounding raw food diets, but before we get to the good stuff, it’s important to have a foundation of understanding about basic nutrition.One point that no one argues is that for optimal health to occur, animals must consume the foods they were designed to eat. I call this a species-appropriate diet. So vegetarian animals must eat vegetation for optimal health. And carnivorous animals must eat fresh whole prey for optimal health.
Origins of Dogs and Cats
A good place to start a discussion of our carnivorous pets is to go back to the roots of the dog and the cat prior to domestication. The domestic dog, whose taxonomic name is Canis lupus familiaris, is a domesticated form of the gray wolf, which is a member of the Canidae family of the order Carnivora.Most scientists believe dogs were domesticated from gray wolves about 15,000 years ago. But DNA analysis published in 1997 suggests that the transformation from wolves to domestic dogs occurred more like 130,000 years ago.Data suggests dogs first diverged from wolves in East Asia, and these domesticated dogs quickly migrated throughout the world. Of course, humans began selectively breeding dogs to create animals that suited their needs and their likes.The earliest evidence of cat domestication is a kitten that was found buried alongside a human approximately 9,500 years ago in Cyprus. Researchers have gained major insights through DNA testing into the evolution of cats by showing how they migrated to new continents and developed new species as the sea levels rose and fell.A 2008 study revealed that lines of descent for all house cats, of the species Felis catus, probably came from self-domesticating African wild cats up to 10,000 years ago. And as happened with the domesticated dog, humans began breeding cats to suit their fancy. Today, over 80 breeds of cats are recognized by one registry or another.
Today's Cats and Dogs are Carnivores Just Like Their Wild Ancestors
Despite humans’ desire to create certain physical characteristics in dogs and cats – this is called their phenotype or how animals look externally – their genetic makeup remains essentially the same as their wild ancestors, which should tell you something about the foods they should still be consuming.Of course, all animals are biologically equipped to assimilate and digest foods they were designed to eat. For example, earthworms are naturally designed to process dirt. The entire GI tract of worms, from the mouth to the other end where waste is excreted, was designed for this purpose.Cows are designed to eat grass, and their GI tracts are set up perfectly for this. They have big, round, flat teeth used to grind grasses and an unbelievable range of motion in their mandibles, allowing them to chew, chew, chew, and chew. Cows have a lot of range of motion laterally in their jaws.Dogs and cats do not have this range of motion in their jaws. Their jaws move up and down only, like a trap door or a hinge, because dogs and cats are gulpers, not chewers. They don’t have chewing teeth. Dogs and cats have incredibly sharp interlocking teeth designed to rip and tear flesh.They also have very short GI tracts compared to vegetarian animals that need to ferment foods, as carnivorous animals consume foods with potentially very heavy pathogen loads. The bodies of carnivores are designed to get foods in and back out very quickly.The ancestral lifestyle of a carnivore includes lots of variety and seasonal variability, meaning certain prey was more prevalent at certain times of the year. They thrived consuming fresh, living, whole animals. But carnivorous animals do not eat clean foods. Dogs and cats did not evolve to consume sterile foods. They have digestive tracts that are designed to be resilient and handle the loads of naturally-occurring bacteria that are present in the foods they eat. Their food in the wild was moisture-dense, meaning the prey they consumed was primarily water.The carnivorous lifestyle required a tremendous amount of exercise and exertion. Food was not served to them, so they had to stealthily catch it. This provided intense stimulation of all the senses, plus nervous, skeletal, endocrine, and circulatory system involvement. Carnivorous animals had daily rigorous workouts in an attempt to catch enough food to stay alive.
Most Pet Food is Biologically Inappropriate for Dogs and Cats
What’s very important for pet owners to know is that “pet food” is a relatively new concept. So, “dog food” and “cat food” you buy from the supermarket has only been around a little over a hundred years.However, animals have hunted prey or, in the case of dogs, scavenged -- for millions of years. And although recent research suggests domesticated carnivores were able to adapt to some degree to starch in the diet as humans became planters and farmers of grains, dogs and cats have most definitely not evolved into vegetarians over time.Over the last hundred years, major pet food companies have produced most of their products using a base of corn, wheat, rice, or potato. However, our carnivorous pets have not evolved to be able to process those foreign foods.The good news is dogs and cats are adaptable and resilient unlike other species, for example, snakes. If we suddenly forced snakes to eat grains or consume vegetation, they would simply die, demonstrating rather visibly and quickly that they were not provided the correct food source.Dogs and cats are among the most resilient animals on the planet. They are able to withstand really significant nutritional abuse, in my opinion, without dying. Degeneration does occur as the result of an inappropriate diet, but sudden death does not.So one of the reasons we’ve been able to deceive ourselves into believing convenience pet foods are good for dogs and cats is because they don’t die immediately of acute starvation. For a hundred years our pets have been fed inappropriate diets that have kept them alive, but far from thriving like their wild relatives. Instead, we’ve created dozens of generations of nutritionally weakened animals that suffer from degenerative diseases linked to nutritional deficiencies – a link the traditional veterinary community has not acknowledged.The Pottenger cat study is one example of how our current system of nourishing pets creates chronic disease.The truth is that our pet population provides a place for recycling waste from the human food industry. Grains that fail inspection, uninspected pieces and parts of waste from the seafood industry, leftover restaurant grease, deceased livestock, and even roadkill is collected and disposed of through rendering -- a process that converts all sorts of human food industry waste into raw materials for the pet food industry.These raw materials are purchased by huge pet food manufacturers – makers of the big name brands your parents and friends have probably used for the last 50 years. These manufacturers blend the rendered fat and meat with a large amount of starch fillers. They add bulk vitamin and mineral supplements, and then they extrude the mix at high temperatures, creating all sorts of toxic reactions including advanced glycation end products and heterocyclic amines. They call this “pet food” and sell it to customers at an unbelievable profit.Is the entire system flawed? Yes. But pet food industry giants are realizing that pet owners are becoming more educated about their flawed system, and they are trying to clean up their image. We are beginning to see words like “natural” and “no byproducts” on labels. We’re beginning to see “grain-free” and “naturally preserved” on labels as well. Manufacturers are hearing the grumbles of educated pet owners and are changing their marketing to try to regain lost customers.
Common Pet Food Myths Many People Actually Believe
I find it amazing that pet parents buy into marketing gimmicks that human parents would never fall for. For instance, how often have you heard a pediatrician say, “Never feed your baby anything but X brand of baby food, because feeding a homemade diet could be dangerous to your child’s health?” Never. But you do hear it often in the veterinary world.Or how about this one: “Switching your brand of baby food could lead to GI problems, so feed only one brand or type of baby food to your children for the rest of their lives to avoid GI problems.” You would never hear this, either, from a competent pediatrician. And yet, you hear this type of advice all the time in the veterinary industry. It’s startling to me to know that entire generations of people actually believe pets must have “pet food” to be healthy.And there’s a host of other myths you’ve probably heard. For example, pets can derive all the nutrients they need for vibrant health from a dry nugget that can be fed day after day, year after year. Or that if you don’t feed crunchy foods to your pet, his or her teeth won’t be clean. Or canned food is too rich, and raw food is just a recent trendy craze that could be risky.A lot of people also believe their veterinarian wouldn’t recommend X brand of food if wasn’t good for their pet... that all cats should eat fish and drink milk... that veterinarians are the people to trust for the most up-to-date information pertaining to nutrition... or that disease, degeneration, and poor vitality have nothing to do with day to day nourishment. All myths.
So... What are the Facts?
Number one, carbohydrates are not a necessary component of a carnivore’s diet. Cats have no taste receptors for sweet flavors and have low rates of glucose uptake in the intestine. They should not be fed any type of grain that metabolizes into sugar.Cats have no salivary amylase to break down starches, either, and dogs have very low amylase secretion.Also, cats never hunted fish from the ocean – fish is not an evolutionary food source for them.The intense heat used to process commercial pet foods diminishes or destroys the benefits of vitamins, minerals, and enzymes in food. Processed pet foods require supplementation to replace lost nutrients.The heating process also significantly reduces the digestibility of amino acids in pet food.And digestibility of meat-based protein is proven to be superior to plant-based protein – the type used in most inexpensive commercial pet foods -- for dogs and cats.So in a nutshell, for 99.99 percent of their time on earth, dogs and cats have consumed a natural diet. For .01 percent of the time, they have consumed an extruded, processed diet. Dogs and cats evolved to consume a low-carbohydrate diet. But for the last century, the majority of pet owners have fed pets a high-carbohydrate, low-moisture diet. This has created significant metabolic and physiologic stress, and convenience pet foods have become the root cause of most of the inflammatory processes and degenerative disease that plague today’s dogs and cats.
