Raw feeding
Encyclopedia
Raw feeding is the practice of feeding domestic dog
s, cat
s and other animals a diet
primarily of uncook
ed meat, edible bones, and organs.
Supporters of raw feeding believe that the natural
diet of raw meat, bones, and organs is superior nutritionally to highly processed commercial pet food. They mimic a similar diet for their domestic companion, as it is believed that a balanced raw diet has the benefits of giving the animal a healthier coat, cleaner teeth and breath, reduced stool volume and odor, and better overall health. They are commonly opposed to commercial pet food
s, which they believe are detrimental to an animal's health. Opponents believe that the risk of nutritional imbalance, intestinal perforations and foodborne illness
es posed by the handling and feeding of raw meat and bones would outweigh any benefits. The assertion that raw feeding is inherently better because it is natural
has also been criticized.
Few studies have been done to prove or disprove the numerous beneficial claims of a raw diet.
[the] dog was programmed to eat during its long process of evolution" and says that foods similar to those eaten by the dog's wild ancestors are more biologically appropriate.
Proponents have also pointed at the practices of some modern zoos which feed their captive carnivores raw meat and bones or whole carcasses. The curator of the Folsom City Zoo Sanctuary
has said that "Common sense suggests that there is no
more nutritious food we can offer to a carnivore
than the entire carcass of their natural prey type." While raw feeding is generally well accepted in European zoos, it is a controversial topic within American zoos. Concerns are similar to those expressed by opponents of raw feeding and includes dental impactions, airway obstructions, intestinal perforations, food contamination and social aggression. Benefits include better oral health, mental stimulation through processing of carcass (see Behavioral enrichment) and higher activity level.
Critics have pointed out the flaws in associating "natural" with better and Billinghurst himself warns against that stating "There are grave dangers that go along with the natural diet and natural conditions the ancestors or wild cousins of our dogs live with." Katie Merwick, who runs an animal rescue sanctuary cautions against "making a fetish out of what animals eat in the wild"(paraphrased)
s in cat food is changed significantly by heat processing. Pet food manufacturers must supplement the food after heat processing to replace those nutrients. Most raw feeders believe that supplements have reduced nutritional value compared to the same nutrients in raw food and that possible nutrients not yet recognized as essential by nutritional science cannot be replaced. The same rationale is used by some to reject supplemented home cooked pet food. Most owners claim a distinct change in pets' general health once shifting towards a raw food source.
Commercial pet foods, dry foods in particular, often contain a large amount of grains, which proponents of grain-free food feel are inappropriate for dogs and cats. Because cats are obligate carnivores, it is believed that a switch to a predominantly meat based raw diet would be especially beneficial (as compared to a raw diet for dogs) due to cats' relative inability to digest grains. Studies comparing the source of protein in dry cat food concluded that the digestibility of meat-based protein is superior to corn-based protein.
Veterinary surgeon and raw feeding proponent Tom Lonsdale states that food from dry or canned commercial kibble sticks to teeth and enables bacteria to proliferate, causing "sore gums, bad breath and bacterial poisons that affect the rest of the body". Lonsdale further states that dogs lack the necessary enzymes to digest grains and plant material and claims that grains cooked at high temperature can cause starch, proteins and fats to become "denatured
or toxic in variable degrees." The poorly digested grain is said to support toxin-producing bacteria in the lower bowel which may eventually lead to "poisons pass[ing] through the bowel wall into blood circulation" creating further problems in other organs.
is credited with starting the holistic pet care movement in the 1930s. In her books, she preached, amongst other things, that dogs require a natural diet of raw food. Australia
n veterinary surgeon
Ian Billinghurst, who published "Give Your Dog a Bone" in 1993 credited de Bairacli Levy's book as an inspiration.
This acronym was originally coined by Debra Tripp to mean "Born Again Raw Feeders". Debra later changed it to "Bones and Raw Food" after trying the diet on her own dogs. Debra met Dr. Billinghurst later at one of his seminars and he signed a copy of his book (Give Your Dog a Bone) thanking her for the BARF acronym.
Supplements are generally not used in a prey model diet although some followers do add fish oil
to the diet to compensate for the reduced amount of omega-3 fatty acid
in commercially raised grain-fed livestock.
Many who oppose raw diets believe that the Association of American Feed Control Officials
(AAFCO) standards that many commercial pet food comply with gives an assurance of quality that homemade food cannot give. One study that analyzed the nutritional content of three homemade diets (BARF, Ultimate and Volhard) and two commercial raw food diets (Steve's Real Food and Sojourner Farms) and compared it to the AAFCO standards, showed that nutritional imbalances occurred in multiple areas. Three of the diets had abnormal calcium
-to-phosphorus
ratios which can lead to hyperparathyroidism
and fibrous osteodystrophy in puppies.
A 12-month study undertaken for the Winn Feline Foundation by researchers from the UC Davis School of Veterinary Medicine
sought to compare the effects of a whole ground rabbit diet with a high quality commercial diet on 22 kittens and adolescent cats. The ground whole rabbit diet (including fur and organs) was frozen in small batches and thawed prior to feeding. The researchers noted the superior palatability of the raw rabbit diet. Significant stool quality improvements were seen in the raw rabbit diet group after one week. After one month, the raw diet group had firm, non-odorous and well formed stools while the commercial diet group had soft formed to liquid stools. The raw diet group also appear to have better coat quality. There were no differences between the groups in terms of growth rate, degree of inflammation in the intestinal tract and the numbers of bacteria in the upper small intestine, although a slightly higher number of cats in the raw diet group were shedding pathogenic organisms (Giardia
and Cryptosporidia) in their stools. Ten months into the study, one cat in the raw diet group died suddenly from dilated cardiomyopathy
due to a severe taurine deficiency. 70% of the group had heart muscle change compatible with taurine deficiency. The researcher ascertained that the raw rabbit diet contained the minimal requirement of taurine but speculated that bacteria in the rabbit carcasses might have broken down some of the taurine. The processing and grinding of the rabbit might have also caused some of the taurine to be destroyed due to the low level of vitamin E
in the diet. The authors conclude that "a natural diet may not always be as healthy as imagined, and that even measuring nutrient values may not predict how a diet will perform after being fed for many months."
While some proponents of raw diets recommend consultation with a veterinarian or animal nutritionist to verify that proper nutrients are being ingested, others dismiss the importance of AAFCO standards, claiming that AAFCO certification is not indicative of the quality of a diet. An AAFCO panel expert has stated that "although the AAFCO profiles are better than nothing, they provide false securities." Many cite that the oldest dog ever recorded, a 29-year-old Australian cattle dog named Bluey, died in 1939, several years before commercial pet food was invented, and that, of the two oldest dogs in recent years, one was fed primarily on kangaroo and emu meat.
of pets who eat raw bones, while others believe that ground bone should be used instead, to prevent the possibility for intestinal puncturing and dental fractures. The abrasion between bone and teeth when chewing is believed to scrape off dental plaque. Cartilage, ligaments, and tendons are thought to act as a natural dental floss. The chewing and tearing action is also believed to strengthen the jaw, neck and shoulder muscles, keep the digestive juice flowing and boost the neurological and immune system. Proponents of ground bones believe that the chewing of muscle meat may also assist in keeping teeth clean.
The use of whole bone creates a risk of dental fractures, intestinal obstruction, gastroenteritis
, and intestinal perforations. Wolf care managers questioned on the topic of feeding bones identified the presence of animal hide with hair as offering some protection from intestinal perforation in the wild. An analysis of the skulls of African wild dogs showed that the natural diet of wild carnivores does not prevent them from suffering the same oral disease as their domestic counterpart, although other studies have had results that claim otherwise. Raw diet proponents note that the same risks of obstruction, puncturing, and dental fractures are present in dog chews, with little evidence indicating that this is a serious problem particular to raw diets with bones. Some veterinarians state that chewing raw bone is an inadequate substitute for regular dental cleaning and tooth brushing.
. A study on 25 commercial raw diets for dogs and cats detected salmonella in 20% and Escherichia coli
in 64% of the diets. However, the E. coli strain that can cause severe illness O157:H7
was not tested for. An example of the severity of E. coli H157:O7 infections can be seen in affected greyhound
racing dogs fed raw meat as part of their diet. Known in greyhounds as "Alabama rot", the disease causes severe vasculitis
, cutaneous
necrosis
, renal failure
and death. It should be noted that racing greyhounds are typically fed raw meat classified as "not for human consumption", which may contain higher than normal levels of bacteria.
Raw feeders consider the risk overblown and claim that the stomach enzymes and short intestinal tracts of dogs and cats allow them to handle harmful bacteria. For example, an outbreak of salmonellosis
caused by tainted commercial dry dog food led to 62 cases of human infection but no reports of the disease affecting animals fed the tainted food. On the other hand, there has been a reported case where two cats fed a raw diet developed salmonellosis and died as a result. A veterinarian from the National Animal Poison Control Center suggests that the diarrhea in animals that raw feeders attribute to detox
ing could be caused by pathogens such as Salmonella, E. coli, Clostridium
and Campylobacter
. The purchase of good quality meat from reputable sources and proper food safety
practices such as defrosting meat in the refrigerator and not leaving food out for too long can reduce the proliferation of bacteria present in the meat.
Raw meats may also contain harmful parasites. As with bacteria, these parasites are destroyed during the heat processing of manufactured pet foods. Some raw diet recipes call for freezing of the final product, which greatly reduces (but does not necessarily eliminate) the potential for parasites. According to a former European Union
directive, freezing fish at -20°C (-4°F) for 24 hours kills parasites. The U.S. Food and Drug Administration (FDA) recommends freezing at -35°C (-31°F) for 15 hours, or at -20°C (-4°F) for 7 days. The most common parasites in fish are roundworms
from the family
Anisakidae
and fish tapeworm. While freezing pork
at -15°C (5°F) for 20 days will kill any Trichinella spiralis
worm, trichinosis
is rare in countries with well established meat inspection programs, with cases of trichinosis in humans in the United States mostly coming from consumption of raw or undercooked wild game. Trichinella species in wildlife are resistant to freezing. In dogs and cats symptoms of trichinellosis would include mild gastrointestinal
upset (vomiting
and diarrhea
) and in rare cases, muscle pain
and muscle stiffness.
A survey of accredited zoos worldwide showed a slightly increased risk of parasites and diseases in animals that are carcass fed as compared to commercial food fed. However, the researchers suggested that that may be caused by increased opportunistic preying and infected live preys may be the source of contamination.
warns that humans "risk exposing themselves to bacteria like Salmonella". A small study on the levels of salmonella
in the stool of 10 dogs that ate a raw diet found that 80% of the raw diet tested positive for Salmonella
and while 30 percent of the stool samples from dogs fed a raw food diet contained salmonella, none of the control dogs (commercial fed) contained Salmonella. The authors of the study concluded that dogs on a raw food diet may therefore be a source of environmental contamination, although they caution about the statistical significance of their results due to the small number of dogs studied.
Because of the potential animal and human health risks, veterinarian organizations and public health agencies believe that the risks inherent in raw feeding outweigh the purported benefits. Despite such concerns, there is no known incidence of humans being infected with salmonella by cats and dogs fed a raw diet. Again, proper food safety precautions such as wiping down preparation surfaces and careful disposal of stools can reduce the risk of infection.
As a result of that, several pet food manufacturers now offer frozen raw diet products for pet owners. Some consumers believe that many of the same issues they find with commercial pet foods exist with packaged raw diets, others use it due to its convenience and for products with AAFCO certification, its assurance of a nutritionally balanced product.
The commercial raw pet food market is estimated to be worth $169 million a year (2007 figures), less than 1% of total pet food sales figure in North America($18 billion). Growth is estimated at 23% per annum.
Many commercial raw pet food manufacturers now use High Pressure Pasteurization (HPP), a unique process that kills pathogenic bacteria through high-pressure, water-based technology. High Pressure Pasteurization is a USDA-approved, 100% natural process, and is allowed for use on organic and natural products.
, British Veterinary Association and Canadian Veterinary Medical Association have warned of the animal and public health risk that could arise from feeding raw meat to pets and have stated that there is no scientific evidence to support the claimed benefits of raw feeding.
More recently in 2007, The Sydney Morning Herald
(paraphrasing RSPCA Australia President Dr Hugh Wirth) reported that "the 'compromise attitude' of veterinary associations in Britain and Australia is that raw meaty bones should be fed to pets a minimum of three times a week for dental health."
s are influenced by academic departments and professional associations that rely upon funding from pet food companies. For example, Hill's Pet Nutrition
, makers of Science Diet
and a range of prescription-only food, is a major sponsor of the American Veterinary Medical Association. Another common belief is that veterinarians lack adequate education on raw diets or nutrition in general. Frequently, veterinary schools receive nutrition training that is sponsored or directly provided to students by pet food manufacturers. The Wall Street Journal reports that Hill's "spends hundreds of thousands of dollars a year funding university research and nutrition courses at every one of the 27 U.S. veterinary colleges" and that vets profit as much as 40% from sales of Science Diet and other foods sold from their offices. Raw feeders are often skeptical of the motives that some veterinarians have in recommending the commercial foods they sell, pointing out the conflict of interest in them doing so.
's study of 900 cats over a period of 10 years from 1932 to 1942. His results showed that cats that were fed 2/3 raw meat, 1/3 raw milk and a small amount of cod liver oil were disease free and healthy while those fed the same food with the meat cooked developed degenerative diseases and reproductive difficulties, with new generations plagued with health problems. The study was done before the importance of taurine in a cat's diet was known and it has been suggested that the group of Pottenger's cats on cooked food simply suffered from taurine deficiency as heating or cooking food causes a reduction in taurine content. Pottenger himself concluded that there was likely an "as yet unknown" protein factor that may have been heat sensitive. In a study on feline maternal taurine deficiency, the group of taurine-deficient cats exhibited symptoms similar to the Pottenger's cats on a cooked diet.
In another study, the cats were fed 2/3 milk and 1/3 meat. All groups were fed raw meat with different groups getting raw, pasteurized, evaporated, sweetened-condensed, or raw, metabolized vitamin D milk. The cats on raw milk were the healthiest while the rest exhibited varying degrees of health problems similar to the previous cooked-meat study. This study has been cited by raw milk
proponents as evidence of the benefits of raw milk.
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s, cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s and other animals a diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
primarily of uncook
Cooking
Cooking is the process of preparing food by use of heat. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental, economic, and cultural traditions. Cooks themselves also vary widely in skill and training...
ed meat, edible bones, and organs.
Supporters of raw feeding believe that the natural
Natural
Natural is an adjective that refers to Nature.Natural may refer too:In science and mathematics:* Natural transformation, category theory in mathematics* Natural foods...
diet of raw meat, bones, and organs is superior nutritionally to highly processed commercial pet food. They mimic a similar diet for their domestic companion, as it is believed that a balanced raw diet has the benefits of giving the animal a healthier coat, cleaner teeth and breath, reduced stool volume and odor, and better overall health. They are commonly opposed to commercial pet food
Pet food
Pet food is plant or animal material intended for consumption by pets. Typically sold in pet stores and supermarkets, it is usually specific to the type of animal, such as dog food or cat food...
s, which they believe are detrimental to an animal's health. Opponents believe that the risk of nutritional imbalance, intestinal perforations and foodborne illness
Foodborne illness
Foodborne illness is any illness resulting from the consumption of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as chemical or natural toxins such as poisonous mushrooms.-Causes:Foodborne illness usually arises from improper handling, preparation, or...
es posed by the handling and feeding of raw meat and bones would outweigh any benefits. The assertion that raw feeding is inherently better because it is natural
Appeal to nature
An appeal to nature is a type of argument that depends on an understanding of nature as a source of intelligibility for its claims, and which relies on that understanding for its outcome...
has also been criticized.
Few studies have been done to prove or disprove the numerous beneficial claims of a raw diet.
Natural diet
Raw food proponent Dr Ian Billinghurst (owner of the registered trademark 'Barf Diet' and the BARF World Distributor Network) argues in his books that the dog has evolved over many million years on a natural raw diet and logically, this is the ideal food source. He claims that processed foods are "not whatProponents have also pointed at the practices of some modern zoos which feed their captive carnivores raw meat and bones or whole carcasses. The curator of the Folsom City Zoo Sanctuary
Folsom City Zoo Sanctuary
The Folsom City Zoo Sanctuary is a zoo and animal sanctuary located in the city of Folsom, California in the United States, which has been open since 1963. It is essentially an animal sanctuary which allows visitors, as the animals in this zoo are not bred, sold or traded...
has said that "Common sense suggests that there is no
more nutritious food we can offer to a carnivore
than the entire carcass of their natural prey type." While raw feeding is generally well accepted in European zoos, it is a controversial topic within American zoos. Concerns are similar to those expressed by opponents of raw feeding and includes dental impactions, airway obstructions, intestinal perforations, food contamination and social aggression. Benefits include better oral health, mental stimulation through processing of carcass (see Behavioral enrichment) and higher activity level.
Critics have pointed out the flaws in associating "natural" with better and Billinghurst himself warns against that stating "There are grave dangers that go along with the natural diet and natural conditions the ancestors or wild cousins of our dogs live with." Katie Merwick, who runs an animal rescue sanctuary cautions against "making a fetish out of what animals eat in the wild"(paraphrased)
Objection to commercial pet food
The intense heat used to process commercial pet food destroys and reduces nutrients like vitamins, minerals, and enzymes. Studies with rats showed that the digestibility of amino acidAmino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s in cat food is changed significantly by heat processing. Pet food manufacturers must supplement the food after heat processing to replace those nutrients. Most raw feeders believe that supplements have reduced nutritional value compared to the same nutrients in raw food and that possible nutrients not yet recognized as essential by nutritional science cannot be replaced. The same rationale is used by some to reject supplemented home cooked pet food. Most owners claim a distinct change in pets' general health once shifting towards a raw food source.
Commercial pet foods, dry foods in particular, often contain a large amount of grains, which proponents of grain-free food feel are inappropriate for dogs and cats. Because cats are obligate carnivores, it is believed that a switch to a predominantly meat based raw diet would be especially beneficial (as compared to a raw diet for dogs) due to cats' relative inability to digest grains. Studies comparing the source of protein in dry cat food concluded that the digestibility of meat-based protein is superior to corn-based protein.
Veterinary surgeon and raw feeding proponent Tom Lonsdale states that food from dry or canned commercial kibble sticks to teeth and enables bacteria to proliferate, causing "sore gums, bad breath and bacterial poisons that affect the rest of the body". Lonsdale further states that dogs lack the necessary enzymes to digest grains and plant material and claims that grains cooked at high temperature can cause starch, proteins and fats to become "denatured
Denaturation (biochemistry)
Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...
or toxic in variable degrees." The poorly digested grain is said to support toxin-producing bacteria in the lower bowel which may eventually lead to "poisons pass
History
Herbalist Juliette de Bairacli LevyJuliette de Bairacli Levy
Juliette de Baïracli Levy, born on the 11th of November 1912, and died on the 28th of May 2009 was a European herbalist and author noted for her pioneering work in holistic veterinary medicine...
is credited with starting the holistic pet care movement in the 1930s. In her books, she preached, amongst other things, that dogs require a natural diet of raw food. Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n veterinary surgeon
Veterinary surgeon
Veterinary surgeon is a term used to describe:*The full title of a vet, who treats disease, disorder and injury in animals, in the United Kingdom and several Commonwealth countries**See also Veterinary medicine in the United Kingdom...
Ian Billinghurst, who published "Give Your Dog a Bone" in 1993 credited de Bairacli Levy's book as an inspiration.
Raw diet types
There are various differences in opinion within the raw feeding community. Issues include the question of whether dogs are omnivores or carnivores. Also, whether cats and dogs need plant material in their diet, and if so, the proportion of such material. The safety of whole bones is also a frequent topic of discussion. Recipes that are advocated range from those that include vegetables and grains, to a minimalist approach using only meat, bones, organ meat, and necessary supplements such as the Meat with Bone diet advocated by Michelle T. Bernard.Barf
The "BARF" diet, an acronym for Biologically Appropriate Raw Food or Bones And Raw Food was created by Billinghurst. A typical BARF diet is made up of 60-80% of raw meaty bones(RMB), that is bones with about 50% meat,(e.g. chicken neck, back and wings) and 20-40% of fruits and vegetables, offal, meat, eggs, or dairy foods.This acronym was originally coined by Debra Tripp to mean "Born Again Raw Feeders". Debra later changed it to "Bones and Raw Food" after trying the diet on her own dogs. Debra met Dr. Billinghurst later at one of his seminars and he signed a copy of his book (Give Your Dog a Bone) thanking her for the BARF acronym.
Prey model
The "Prey model" diet attempts to simulate the proportions of an actual prey animal in a pet's diet. Actual whole prey are used whenever possible, including whole rabbits, chickens, game hens and turkeys. Generally, the diet recommends 80% meat (including some 'meaty' organs such as heart), 10% bone and 10% organs (of which half is liver). Proponents of the whole prey model diet believe dogs and cats are both natural carnivores and therefore there is no nutritional or dietary need for anything other than meat, bones, and organs,. The supporters of the prey model also focus on feeding meats from a wide variety of animals, and some add small amounts of vegetable matter.Supplements are generally not used in a prey model diet although some followers do add fish oil
Fish oil
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid , and docosahexaenoic acid , precursors of certain eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.Fish do not...
to the diet to compensate for the reduced amount of omega-3 fatty acid
Omega-3 fatty acid
N−3 fatty acids are essential unsaturated fatty acids with a double bond starting after the third carbon atom from the end of the carbon chain....
in commercially raised grain-fed livestock.
Nutritional balance
As raw diets can range from meticulously prepared and tested to diets composed of a variety of meats and butchers' scraps, the nutritional balance of a raw diet can vary greatly depending on the recipe. However, supporters of raw feeding believe that not every meal needs to be "complete and balanced", and that nutritional balance can be achieved over time by feeding a wide variety of meats, fats, bones and organs from several sources, such as chicken, turkey, lamb, cattle, pigs, fish, rabbits, etc., and even wild game. The general belief among the supporters of raw diets is that pets have no more complex nutritional requirements than humans, and that a variety of ingredients over time will provide the pets with a sufficiently balanced diet.Many who oppose raw diets believe that the Association of American Feed Control Officials
Association of American Feed Control Officials
The Association of American Feed Control Officials is a non-profit organization which sets standards for the quality and safety of animal feed and pet food in the United States. AAFCO is a voluntary organization consisting largely of state officials who have responsibility for enforcing their...
(AAFCO) standards that many commercial pet food comply with gives an assurance of quality that homemade food cannot give. One study that analyzed the nutritional content of three homemade diets (BARF, Ultimate and Volhard) and two commercial raw food diets (Steve's Real Food and Sojourner Farms) and compared it to the AAFCO standards, showed that nutritional imbalances occurred in multiple areas. Three of the diets had abnormal calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
-to-phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
ratios which can lead to hyperparathyroidism
Hyperparathyroidism
Hyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone . The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels...
and fibrous osteodystrophy in puppies.
A 12-month study undertaken for the Winn Feline Foundation by researchers from the UC Davis School of Veterinary Medicine
UC Davis School of Veterinary Medicine
The University of California, Davis, School of Veterinary Medicine, is the largest veterinary school in the United States. Established in 1948, the school is the primary health resource for California's various animal populations. The school is ranked 2nd for veterinary schools in the country...
sought to compare the effects of a whole ground rabbit diet with a high quality commercial diet on 22 kittens and adolescent cats. The ground whole rabbit diet (including fur and organs) was frozen in small batches and thawed prior to feeding. The researchers noted the superior palatability of the raw rabbit diet. Significant stool quality improvements were seen in the raw rabbit diet group after one week. After one month, the raw diet group had firm, non-odorous and well formed stools while the commercial diet group had soft formed to liquid stools. The raw diet group also appear to have better coat quality. There were no differences between the groups in terms of growth rate, degree of inflammation in the intestinal tract and the numbers of bacteria in the upper small intestine, although a slightly higher number of cats in the raw diet group were shedding pathogenic organisms (Giardia
Giardia
Giardia is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada in the supergroup "Excavata" that colonise and reproduce in the small intestines of several vertebrates, causing giardiasis, commonly known as Beaver fever...
and Cryptosporidia) in their stools. Ten months into the study, one cat in the raw diet group died suddenly from dilated cardiomyopathy
Cardiomyopathy
Cardiomyopathy, which literally means "heart muscle disease," is the deterioration of the function of the myocardium for any reason. People with cardiomyopathy are often at risk of arrhythmia or sudden cardiac death or both. Cardiomyopathy can often go undetected, making it especially dangerous to...
due to a severe taurine deficiency. 70% of the group had heart muscle change compatible with taurine deficiency. The researcher ascertained that the raw rabbit diet contained the minimal requirement of taurine but speculated that bacteria in the rabbit carcasses might have broken down some of the taurine. The processing and grinding of the rabbit might have also caused some of the taurine to be destroyed due to the low level of vitamin E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...
in the diet. The authors conclude that "a natural diet may not always be as healthy as imagined, and that even measuring nutrient values may not predict how a diet will perform after being fed for many months."
While some proponents of raw diets recommend consultation with a veterinarian or animal nutritionist to verify that proper nutrients are being ingested, others dismiss the importance of AAFCO standards, claiming that AAFCO certification is not indicative of the quality of a diet. An AAFCO panel expert has stated that "although the AAFCO profiles are better than nothing, they provide false securities." Many cite that the oldest dog ever recorded, a 29-year-old Australian cattle dog named Bluey, died in 1939, several years before commercial pet food was invented, and that, of the two oldest dogs in recent years, one was fed primarily on kangaroo and emu meat.
Bones and dental health
Some proponents of raw diet claim noticeable benefit to the dental hygieneOral hygiene
Teeth cleaning is part of oral hygiene and involves the removal of dental plaque from teeth with the intention of preventing cavities , gingivitis, and periodontal disease. People routinely clean their own teeth by brushing and interdental cleaning, and dental hygienists can remove hardened...
of pets who eat raw bones, while others believe that ground bone should be used instead, to prevent the possibility for intestinal puncturing and dental fractures. The abrasion between bone and teeth when chewing is believed to scrape off dental plaque. Cartilage, ligaments, and tendons are thought to act as a natural dental floss. The chewing and tearing action is also believed to strengthen the jaw, neck and shoulder muscles, keep the digestive juice flowing and boost the neurological and immune system. Proponents of ground bones believe that the chewing of muscle meat may also assist in keeping teeth clean.
The use of whole bone creates a risk of dental fractures, intestinal obstruction, gastroenteritis
Gastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...
, and intestinal perforations. Wolf care managers questioned on the topic of feeding bones identified the presence of animal hide with hair as offering some protection from intestinal perforation in the wild. An analysis of the skulls of African wild dogs showed that the natural diet of wild carnivores does not prevent them from suffering the same oral disease as their domestic counterpart, although other studies have had results that claim otherwise. Raw diet proponents note that the same risks of obstruction, puncturing, and dental fractures are present in dog chews, with little evidence indicating that this is a serious problem particular to raw diets with bones. Some veterinarians state that chewing raw bone is an inadequate substitute for regular dental cleaning and tooth brushing.
Bacteria, viruses and parasites
While the intense heat used in manufacturing pet food destroys any potential bacteria, raw meats may contain bacteria that are unsafe for both dogs and cats. The US Government reported that in 2006, 16.3% of all chickens were contaminated with SalmonellaSalmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
. A study on 25 commercial raw diets for dogs and cats detected salmonella in 20% and Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
in 64% of the diets. However, the E. coli strain that can cause severe illness O157:H7
Escherichia coli O157:H7
Escherichia coli O157:H7 is an enterohemorrhagic strain of the bacterium Escherichia coli and a cause of foodborne illness. Infection often leads to hemorrhagic diarrhea, and occasionally to kidney failure, especially in young children and elderly persons...
was not tested for. An example of the severity of E. coli H157:O7 infections can be seen in affected greyhound
Greyhound
The Greyhound is a breed of sighthound that has been primarily bred for coursing game and racing, and the breed has also recently seen a resurgence in its popularity as a pedigree show dog and family pet. It is a gentle and intelligent breed...
racing dogs fed raw meat as part of their diet. Known in greyhounds as "Alabama rot", the disease causes severe vasculitis
Vasculitis
Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...
, cutaneous
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
, renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
and death. It should be noted that racing greyhounds are typically fed raw meat classified as "not for human consumption", which may contain higher than normal levels of bacteria.
Raw feeders consider the risk overblown and claim that the stomach enzymes and short intestinal tracts of dogs and cats allow them to handle harmful bacteria. For example, an outbreak of salmonellosis
Salmonellosis
Salmonellosis is an infection with Salmonella bacteria. Most people infected with Salmonella develop diarrhea, fever, vomiting, and abdominal cramps 12 to 72 hours after infection. In most cases, the illness lasts four to seven days, and most people recover without treatment...
caused by tainted commercial dry dog food led to 62 cases of human infection but no reports of the disease affecting animals fed the tainted food. On the other hand, there has been a reported case where two cats fed a raw diet developed salmonellosis and died as a result. A veterinarian from the National Animal Poison Control Center suggests that the diarrhea in animals that raw feeders attribute to detox
Detox
Detoxification is the physiological or medicinal removal of toxic substances from a living organism, including, but not limited to, the human body and additionally can refer to the period of withdrawal during which an organism returns to homeostasis after long-term use of an addictive substance...
ing could be caused by pathogens such as Salmonella, E. coli, Clostridium
Clostridium
Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores. Individual cells are rod-shaped, which gives them their name, from the Greek kloster or spindle...
and Campylobacter
Campylobacter
Campylobacter is a genus of bacteria that are Gram-negative, spiral, and microaerophilic. Motile, with either unipolar or bipolar flagella, the organisms have a characteristic spiral/corkscrew appearance and are oxidase-positive. Campylobacter jejuni is now recognized as one of the main causes...
. The purchase of good quality meat from reputable sources and proper food safety
Food safety
Food safety is a scientific discipline describing handling, preparation, and storage of food in ways that prevent foodborne illness. This includes a number of routines that should be followed to avoid potentially severe health hazards....
practices such as defrosting meat in the refrigerator and not leaving food out for too long can reduce the proliferation of bacteria present in the meat.
Raw meats may also contain harmful parasites. As with bacteria, these parasites are destroyed during the heat processing of manufactured pet foods. Some raw diet recipes call for freezing of the final product, which greatly reduces (but does not necessarily eliminate) the potential for parasites. According to a former European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
directive, freezing fish at -20°C (-4°F) for 24 hours kills parasites. The U.S. Food and Drug Administration (FDA) recommends freezing at -35°C (-31°F) for 15 hours, or at -20°C (-4°F) for 7 days. The most common parasites in fish are roundworms
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
from the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Anisakidae
Anisakidae
Anisakidae is a family of intestinal roundworms. They are also called the marine ascarids. The larvae of these worms can cause anisakiasis when ingested by humans, but do not reproduce except in marine mammals or seabirds.- Selected genera :...
and fish tapeworm. While freezing pork
Pork
Pork is the culinary name for meat from the domestic pig , which is eaten in many countries. It is one of the most commonly consumed meats worldwide, with evidence of pig husbandry dating back to 5000 BC....
at -15°C (5°F) for 20 days will kill any Trichinella spiralis
Trichinella spiralis
Trichinella spiralis is a nematode parasite, occurring in rats, pigs, bears and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being found commonly in undercooked pork products...
worm, trichinosis
Trichinosis
Trichinosis, also called trichinellosis, or trichiniasis, is a parasitic disease caused by eating raw or undercooked pork or wild game infected with the larvae of a species of roundworm Trichinella spiralis, commonly called the trichina worm. There are eight Trichinella species; five are...
is rare in countries with well established meat inspection programs, with cases of trichinosis in humans in the United States mostly coming from consumption of raw or undercooked wild game. Trichinella species in wildlife are resistant to freezing. In dogs and cats symptoms of trichinellosis would include mild gastrointestinal
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
upset (vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
and diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
) and in rare cases, muscle pain
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
and muscle stiffness.
A survey of accredited zoos worldwide showed a slightly increased risk of parasites and diseases in animals that are carcass fed as compared to commercial food fed. However, the researchers suggested that that may be caused by increased opportunistic preying and infected live preys may be the source of contamination.
Zoonotic risk
A possible risk of raw feeding is that of human infection caused by direct or indirect exposure to bacterial pathogens in raw meat and animal stools. For example the British Veterinary AssociationBritish Veterinary Association
The British Veterinary Association is the national body for veterinary surgeons in the United Kingdom and is a not-for-profit organisation. Its purpose is that of knowledge dissemination, and not professional validation or academic competence...
warns that humans "risk exposing themselves to bacteria like Salmonella". A small study on the levels of salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
in the stool of 10 dogs that ate a raw diet found that 80% of the raw diet tested positive for Salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
and while 30 percent of the stool samples from dogs fed a raw food diet contained salmonella, none of the control dogs (commercial fed) contained Salmonella. The authors of the study concluded that dogs on a raw food diet may therefore be a source of environmental contamination, although they caution about the statistical significance of their results due to the small number of dogs studied.
Because of the potential animal and human health risks, veterinarian organizations and public health agencies believe that the risks inherent in raw feeding outweigh the purported benefits. Despite such concerns, there is no known incidence of humans being infected with salmonella by cats and dogs fed a raw diet. Again, proper food safety precautions such as wiping down preparation surfaces and careful disposal of stools can reduce the risk of infection.
Commercial preparation
After the 2007 pet food recall, interest in raw and cooked homemade pet food grew tremendously.As a result of that, several pet food manufacturers now offer frozen raw diet products for pet owners. Some consumers believe that many of the same issues they find with commercial pet foods exist with packaged raw diets, others use it due to its convenience and for products with AAFCO certification, its assurance of a nutritionally balanced product.
The commercial raw pet food market is estimated to be worth $169 million a year (2007 figures), less than 1% of total pet food sales figure in North America($18 billion). Growth is estimated at 23% per annum.
Many commercial raw pet food manufacturers now use High Pressure Pasteurization (HPP), a unique process that kills pathogenic bacteria through high-pressure, water-based technology. High Pressure Pasteurization is a USDA-approved, 100% natural process, and is allowed for use on organic and natural products.
Veterinary position
Veterinary associations such as the American Veterinary Medical AssociationAmerican Veterinary Medical Association
The American Veterinary Medical Association , founded in 1863, is a not-for-profit association representing more than 81,500 U.S. veterinarians working in private and corporate practice, government, industry, academia, and uniformed services....
, British Veterinary Association and Canadian Veterinary Medical Association have warned of the animal and public health risk that could arise from feeding raw meat to pets and have stated that there is no scientific evidence to support the claimed benefits of raw feeding.
More recently in 2007, The Sydney Morning Herald
The Sydney Morning Herald
The Sydney Morning Herald is a daily broadsheet newspaper published by Fairfax Media in Sydney, Australia. Founded in 1831 as the Sydney Herald, the SMH is the oldest continuously published newspaper in Australia. The newspaper is published six days a week. The newspaper's Sunday counterpart, The...
(paraphrasing RSPCA Australia President Dr Hugh Wirth) reported that "the 'compromise attitude' of veterinary associations in Britain and Australia is that raw meaty bones should be fed to pets a minimum of three times a week for dental health."
Controversy
It is believed by many raw feeders that veterinarianVeterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
s are influenced by academic departments and professional associations that rely upon funding from pet food companies. For example, Hill's Pet Nutrition
Hill's Pet Nutrition
Hill's Pet Nutrition, Inc is a subsidiary of Colgate-Palmolive Company. They are a large scale provider of dog and cat foods.- History :In 1928, Dr. Mark L. Morris Sr. established Raritan Hospital for Animals in Edison, New Jersey. At the time, this was one of only two small animal hospitals in the...
, makers of Science Diet
Science Diet
Science Diet is a brand of cat and dog foods marketed by Hill's Pet Nutrition, Inc. . In the United Kingdom, Science Diet is known as Science Plan.- History :...
and a range of prescription-only food, is a major sponsor of the American Veterinary Medical Association. Another common belief is that veterinarians lack adequate education on raw diets or nutrition in general. Frequently, veterinary schools receive nutrition training that is sponsored or directly provided to students by pet food manufacturers. The Wall Street Journal reports that Hill's "spends hundreds of thousands of dollars a year funding university research and nutrition courses at every one of the 27 U.S. veterinary colleges" and that vets profit as much as 40% from sales of Science Diet and other foods sold from their offices. Raw feeders are often skeptical of the motives that some veterinarians have in recommending the commercial foods they sell, pointing out the conflict of interest in them doing so.
Pottenger's cats
One study used by many people feeding pets a raw diet to back up their claims of raw food being superior to cooked food is Francis M. Pottenger, Jr.Francis M. Pottenger, Jr.
Francis M. Pottenger, Jr. was the son of Francis M. Pottenger, Sr., the physician who co-founded the Pottenger Sanatorium for treatment of tuberculosis in Monrovia, California....
's study of 900 cats over a period of 10 years from 1932 to 1942. His results showed that cats that were fed 2/3 raw meat, 1/3 raw milk and a small amount of cod liver oil were disease free and healthy while those fed the same food with the meat cooked developed degenerative diseases and reproductive difficulties, with new generations plagued with health problems. The study was done before the importance of taurine in a cat's diet was known and it has been suggested that the group of Pottenger's cats on cooked food simply suffered from taurine deficiency as heating or cooking food causes a reduction in taurine content. Pottenger himself concluded that there was likely an "as yet unknown" protein factor that may have been heat sensitive. In a study on feline maternal taurine deficiency, the group of taurine-deficient cats exhibited symptoms similar to the Pottenger's cats on a cooked diet.
In another study, the cats were fed 2/3 milk and 1/3 meat. All groups were fed raw meat with different groups getting raw, pasteurized, evaporated, sweetened-condensed, or raw, metabolized vitamin D milk. The cats on raw milk were the healthiest while the rest exhibited varying degrees of health problems similar to the previous cooked-meat study. This study has been cited by raw milk
Raw milk
Raw milk is milk that has not been pasteurized or homogenized.-History:Humans consumed raw milk exclusively prior to the industrial revolution and the invention of the pasteurization process in 1864. During the industrial revolution large populations congregated into urban areas detached from the...
proponents as evidence of the benefits of raw milk.
See also
- Raw foodismRaw foodismRaw foodism is the practice of consuming uncooked, unprocessed, and often organic foods as a large percentage of the diet....
- Paleolithic dietPaleolithic dietThe modern dietary regimen known as the Paleolithic diet , also popularly referred to as the caveman diet, Stone Age diet and hunter-gatherer diet, is a nutritional plan based on the presumed ancient diet of wild plants and animals that various hominid species habitually consumed during the...
- A human diet based on a similar evolutionary rationale.
Articles
- The beef over pet food Salon.comSalon.comSalon.com, part of Salon Media Group , often just called Salon, is an online liberal magazine, with content updated each weekday. Salon was founded by David Talbot and launched on November 20, 1995. It was the internet's first online-only commercial publication. The magazine focuses on U.S...
, January 2006 - Bones of contention Dogs Today Magazine, September 2006
- BARF: Bones And Raw Food Overview of the BARF diet and issues.
- Should Your Dog Eat BARF? VetCentric.com
- Raw vs. BARF: Waging an Imaginary War On the perceived differences between BARF and raw feeding
- Her Great Danes Eat It Raw San Francisco Chronicle SFGate.com, September 2003
- Trends in Home-Prepared Diets for Pets Weston A. Price Foundation