Evolutionary Nutrition for the Cat
Written by Sarah Griffiths (reprinted with permission)
Edited by Dr. David Ruish, DVM
HISTORY OF THE CAT
The cat began her domestic life with humans approximately 3500-4000 years ago in Egypt. Cats were prized for their carnivorous nature and were used to hunt the mice and rats that infested grains stocks along the Nile River. They were also used by humans to hunt fish because of their keen carnivore senses and ability to detect movement below the surface of the water. Felines became so important to the Egyptians that they enforced laws to protect them. Over the years, cats have gained popularity and are one of the most commonly owned household pets. The cat's predatory nature has served us well for centuries and we have come to love and cherish them because of their unique instincts and abilities. Cats have remained virtually unchanged since the time of their domestication and this means that for them to be healthy and live to their full potential; they must be fed a species appropriate raw meat-based diet. Their instincts and keen senses have evolved over millions of years and have allowed them to become one of the most successful carnivores on the planet coupled by their ability to live side by side with humans. Four thousand years on the evolutionary scale is not nearly sufficient for the cat to have adapted to eating a kibble-based diet.
Order: Carnivora Family: Felidae Genus: Felis Species: Felis sylvestris catus
Genetically, the closest living relative to our feline friends is the African Wild Cat (felis sylvesris lybica). The Lybica group ranges through Africa and the Middle East except for the rainforests of western Africa. This wild cat inhabits woods, plains and mountains. It has evolved in a desert climate and this is evident in behaviors of the wild and domestic sub-species eg. their love of heat and sun exposure and their preference for burying feces in sand are a few. This species (except for certain domestic breeds) does not do well in fog, rain and snow, another indication that their true environment is a desert climate.
ANATOMY AND PHYSIOLOGY
Cats are considered true or obligate carnivores because of the physiology and the anatomy they have evolved. Anatomically, the cat has the typical enlarged canine teeth, used for grabbing, holding and subduing prey. The hinges of the feline jaw do not have the ability for lateral chewing motion. It can only be used to crush prey items and cannot be used for mastication. They have keen diurnal and nocturnal vision, allowing them to see prey in the dark and sneak up on them with great stealth. The cat has muscular back legs which makes them adept at pouncing on prey in ambush attacks. They have the ability to move their ears independently so that sound bounces back at different rates depending on how close or far away their prey might be. This allows the cat to be able to know where its prey is even before it can see it. The cat also possesses long whiskers that pick up the minute vibrations their prey make when walking, also allowing them to tell where prey is before they catch sight of it. Lastly, cats have sharp, retractable claws in their toes which allow them to grab and hold prey down with great ease while the windpipe is crushed by the cat's strong jaws.
Physiologically, the cat is quite unique in many ways. A high protein diet is necessary in maintaining proper health since certain liver enzymes that are used to break down proteins are always active where they are not always active in other species. This means that the cat uses part of its protein intake just to fuel this ongoing process. Compared to omnivores and herbivores, carnivores have short, highly acidic digestive tracts with a relatively small liver and pancreas, meaning a decreased ability to break down foods that do not have enzymes present (cooked food). Cats also do not possess the ability to covert beta carotene into vitamin A. They must have a natural source of vitamin A from animal sources such as liver, heart, fat and muscle meat. Because of their desert cat ancestry, they also have the ability to obtain almost all of their required water from the prey animals that they eat. This is an important survival tactic when water is scarce in a desert environment. Eating whole prey items allows the kidneys to stay healthy because they do not have to drink a lot of water to compensate like they do when given a dry food diet. Canned food and raw food diets contain anywhere from 67-73% water which is appropriate for the cat. However, dry foods contain only between 6-10% water, leaving the cat systemically dehydrated. Cats also need this water intake for the kidneys to process the high amounts of protein that they obtain from food. Over a long period of time in this state, the kidneys and other organs will be put under stress and may cause damage or failure earlier in life than expected. Kidney disease is the number one killer of domestic cats. On raw and canned food diets, a cat can obtain over 90% of its total required intake of water which will, in turn, keep kidneys and other organs functioning properly.
Because cats have no nutritional requirement for carbohydrate, they obtain most of the energy they need to travel, hunt, and metabolize from fats. These fats must be animal fats because of the limited ability of the cat obtain fat from vegetable sources. Fats carry water soluble vitamins (D, E, A & K), linoliec acid and arachidonic acid. All of these nutrients are essential to the cat. Cats deficient in fatty acids and arachidonic acid can be listless, have dry skin and dandruff, increased susceptibility to infection, fertility problems and poor blood platelet function.
Carnivores such as felines can convert glucogenic acid and glycerol from animal sources into glucose and this is how they maintain proper blood glucose levels. Cats that do not get these in adequate sources can have problems with liver and pancreas function and can develop diabetes, a disease that is becoming more common in domestic cats.
Cats must obtain 10 of the 20 essential amino acids through their food. Unfortunately, the nutrient sources in processed foods may not always a biologically appropriate source for a cat.
THE DIET OF THE CAT
Based on the evolutionary information and nutritional requirements above, the cat should eat a diet based on whole prey animals such as birds, rodents, and fish. Foods can include raw quail carcasses, chicken necks, pheasant necks, ground chicken, turkey, and rabbit plus poultry heart and liver. Ostrich can also be used. Also, carp fish, herring and salmon can be fed once a week. It is also recommended to add fish oil (salmon or herring) to the diet for increased essential fatty acids. There are many reputable raw food diets on the market today and you may even learn to make your own with the help of a veterinarian versed in the raw food diet. You must always keep in mind that cats need whole prey items to sustain proper health (about 90-95% meat, bone & organ). This means that you must roughly calculate the amount of meat, bone and organ that your cat is getting. You may even include a small amount (about 5%) of wheat or oat grass into the diet. You may either break it down in the blender or leave it whole for the cat to munch on it as she/he wishes. According to Dr. Deborah Greco of the Animal Medical Centre in New York, cats should be eating mice and cannot be sustained properly on a dry food diet. She announced this at the 2003 American Veterinary Association Conference in Denver, Colorado. For more information, visit Catnutrition.org. According to the Kruger National Park website in Africa where African Wild Cats roam free, it has been documented that the favorite food source of these cats in mice and rats but when these foods are unavailable, they will eat birds, arthropods, rabbits, hares and have even been known to take down baby antelope!!!
KIBBLE VS. RAW
There are several major ways that kibble and raw diets differ:
- Kibble usually contains grain content (wheat, corn, barley, oats) that is more plentiful than the meat content. This is a problem for 2 reasons:
a. Cats have no nutritional requirement for grain or carbohydrate.
b. Cats do not produce enzymes to digest grain and obtain nutrients from it.
- Kibble diets contain cooked meat and meat by-products which are also hard to digest and absorb nutrients from as they contain no enzymes. Enzymes are destroyed during the cooking process.
- The nutritional analysis information listed on every bag of kibble is based on laboratory test results. The food sources present in the kibble may contain the appropriate nutrients but the bioavailability (digestion and absorption) may be poor. There has never been a bioavailability test done on any brand of kibble. This means that no one knows if our cats are actually absorbing adequate nutrients from the food they are eating. There are also no long term studies conducted for how dry foods affect cats over their entire lifetime except for Dr. Pottenger's study done from 1932-1942 which concluded that cooked diets are very detrimental to the heath of the cat. Usually test trials on kibbles are short, under 1 year and are conducted on younger animals.
- Because the pancreas of the cat is so small, it must work hard to break down commercial cat food. This means that pancreatic enzymes are depleted quickly and used to break down food with inadequate nutritional content. In turn, the body uses an unfortunate survival tactic: it begins to absorb enzymes and other essential nutrients from its own tissues to maintain the equilibrium of the body. This can only remain and equilibrium for so long and may prove to shorten the life spans of our dear feline friends.
- Kibble is systemically dehydrating to cats, as their bodies have evolved to absorb water from their prey. To compensate, they must drink large amounts of water to stay hydrated. This puts extra strain on their kidneys.
- Kibble and canned cat foods often contain toxic fillers like preservatives and dyes. Sugar and other taste enhancers are also found in some commercial foods to entice animals to eat it. Eating these substances daily can pose health risks.
- Often, synthetic vitamins are added to commercial feline diets. These vitamins are not molecularly/nutritionally equal to the natural source vitamins found in raw food sources. Kibble has only been formulated in the last 100 years. It is absurd to assume that dogs have evolved to eat kibble based diets in this short amount of time. Evolution of physiological and anatomical proportions takes hundreds of thousands, if not, millions of years.
In comparison, the raw diet is rich in fresh meat sources. Meat, bone, organ and small amounts of pureed vegetation are filled with the enzymes needed to properly digest and assimilate nutrients. Nutritional analyses have been done on several types of raw prey items and they do contain all the essential nutrients required by the cat. Bioavailability of prey items has not been studied in a laboratory but it has definitely proven to make for resilient animals in the wild. Wild felines are capable of surviving in harsh conditions with few or no chronic health problems. Kibble has only been fed to cats for approximately 100 years, whereas raw meat diets have fed the order Carnivora for 60 million years.
MAKING THE SWITCH TO RAW
The most successful way to switch your cat to a raw food diet is to begin adding a good quality (no additives, high protein) canned cat food to the diet. Eliminate any dry food as quickly as possible and begin to mix small amounts of raw into the canned food. You may find your cat needs anywhere from 3 days to 4 weeks to make the transition smoothly. If you are noticing loose stools or vomiting early in the process, cut back the amount of raw food being fed. Use the original amount of raw meat the cat was comfortable on and begin increasing the raw more slowly than before. It takes time to build up a proper acidic environment in the gut. This can lead to indigestion in some cats during the transition. Always make sure the meat you are feeding is fresh and of good quality. Unlike dogs, cats only eat fresh prey items.
During the transition to a raw meat diet, you should begin to notice positive changes in your cats' health, including a shinier coat, cleaner smelling breath, cleaner teeth that can be maintained with bone chewing instead of dental work, and better overall organ health e.g. an appropriate decreased water consumption = healthier kidneys. Problems that have improved on raw meat diets include but are not limited to skin problems, allergies, kidney and liver problems, pancreatic problems, and poor dental health.
On another note, animals that have any kind of existing health concerns or are having trouble making the switch to a raw diet should only proceed with a raw diet plan approved by a veterinarian versed in raw feeding for cats. For more information on holistic nutrition and veterinary practice, visit Vancouver Animal Wellness Hospital at 105 East Broadway, Vancouver, BC, Canada.
BOOKS & READING
The Ultimate Diet: Natural Nutrition for Dogs and Cats by Kymythy Shultz
The Barf Diet by Dr. Ian Billinghurst, DVM
Nutrition of the domestic cat, a mammalian carnivore. MacDonald ML, Rogers QR, Morris JG.
Annual Review of Nutrition 4: 521-562
Carbohydrate metabolism of the cat Kienzle E Journal of Animal Physiology and Animal NutritionŠ 70: 89-96
• The African Wild Cat - Felis sylvestris
• Cat Nutrition from the American Veterinary Association
• Feline Future's E-book "The Backyard Predator"
• Kruger National Park Online - Felis Sylvestris lybica
• Dr. Pottenger's Cat Nutrition Study
• Feline Nutrition & Nutritional Requirements
The above information is not meant to be used to treat animals for medical problems nor should it take the place of proper veterinary medicine. For more information on raw feline diets, please contact a veterinarian who has experience with the diet and uses it to supplement their practice.
ABOUT THE AUTHOR
Sarah Griffiths started working in a pet store at the age of 17 and worked as the reptile/amphibian keeper, learning basic herpetology for over 30 species of snakes, lizards and frogs designing natural terrain environments for different species of reptiles and amphibians. She moved into species appropriate nutrition when she managed a raw food dog and cat store for 2.5 years and her first dog and cat became patients of Adored Beast Veterinary Clinic. She worked for 1 year as a domestic/wild animal trainer and keeper at Creative Animal Talent Inc. in Aldergrove, BC and had the unique pleasure of helping raise a pack of Timber Wolf cubs and working with another pack of adult Arctic Wolves. Forming a bond through food was a very important part of raising the cubs and she saw first hand that the diet she her dogs were thriving on was the same diet the wolves ate. Sarah has also had the honor of working with several species of large cats including Cougars, African Servals, Caracals, Fishing Cats, Cheetahs, Geoffrys Cats, Asian Leopard Cats, Asian Golden Cats, Rusty Spotted Cats, a Clouded Leopard and an Ocelot. She currently works as a volunteer at Mountainview Conservation and Breeding Centre in Langley, B.C. which includes over 100 endangered species including 14 species of wild cats, two packs of African Wild Dogs and brown hyenas that are fed raw carcass diets. Sarah is currently entering her third year of four at the Vancouver Homeopathic Academy to receive a diploma in homeopathic medicine for humans. Other education she has received and is enrolled in include: Veterinary Nutrition: An Integrative Approach from Standard Process Nutrition, Exotic Cats: Husbandry and Basic Medicine from The Veterinary Information Network, Diploma of Feline Nutrition and Diploma of Canine Nutrition from Oxford College in England. Sarah's goals include practicing homeopathy for animals, obtaining a degree in Zoology specializing in Carnivores, working towards the conservation of wild habitats across the world and starting a rescue centre for exotic cats, canines and primates that need homes. Sarah currently has 2 Bullmastiffs, a Great Dane, 4 cats and a Percheron Draft Horse, all of which are fed on biologically appropriate diets.