Сыроедение для домашних животных: польза, риски и особенности

Practice of feeding animals uncooked meat, bones, and organs
Raw feeding is the practice of feeding domestic dogs, cats, and other animals a diet consisting primarily of uncooked meat, edible bones, and organs. The ingredients used to formulate raw diets vary. Some pet owners choose to make home made raw diets to feed their animals but commercial raw diets are also available. The practice of feeding raw diets has raised some concerns due to the risk of foodborne illnesses, zoonosis, and nutritional imbalances. People who feed their dogs raw food do so for a multitude of reasons, including but not limited to: culture, beliefs surrounding health, nutrition, and what is perceived to be more natural for their pets. Feeding raw food can be perceived as allowing the pet to stay in touch with their wild, carnivorous ancestry.

Diet plays a significant role in promoting both good bone and good dental health through the maintenance of the calcium to phosphorus ratio. Up to 99% of a dog's calcium and 85% of phosphorus are found in bones and teeth. Finding foods that provide sufficient amounts of calcium to maintain a good ratio is challenging, as many foods that are high in calcium are also high in phosphorus. For this reason, creating a homemade raw diet with an appropriate calcium:phosphorus ratio may prove difficult, especially without the analysis techniques that are available to commercial food producers. For this reason, these fatty acids are especially essential for skin health and many raw diets make sure they are properly supplemented. To improve skin and coat health, essential fatty acids are supplied in excess of the Association of American Feed Control Officials (AAFCO) requirements, which results in improved coat sheen and skin health. Omega 6 fatty acids, linoleic acid in particular, play an important role in skin barrier function. Maillard reactions are problematic as when this reaction occurs, a reducing sugar binds to the amino group on the amino acids, making the amino acids unavailable to the animal. Thus, some forms of food processing may reduce the amount of available essential nutrient in a dog's food. This means that the amino groups of the amino acids in the meat will be unbound and nutritionally available to the dog for use. However, the risk assumed by not cooking or processing meat is the same as when handling raw meat for cooking at home. So long as good home and personal hygiene is maintained, there is no increase in threat to health.

There are various differences in opinion within the raw feeding community. Issues include whether dogs are omnivores or carnivores, whether dogs need plant material in their diet and if so, in what quantities. The safety of whole bones use is also a frequent topic of discussion. Raw diet recipes can range from meat with a wide selection vegetables and grains, while other are more minimalist, using only meat, bones, organ meat, and necessary supplements. An example of an minimalist approach to raw feeding is the Meat with Bone diet advocated by Michelle T. Bernard. Critiques of raw diets include the concern with the possible nutrient imbalances that can arise feeding any type of raw diet.

The BARF diet was originally defined as Bones And Raw Food diets but has since been changed to Biologically Appropriate Raw Food. The original BARF diet was popularized by Dr. Ian Billinghurst, advocating feeding 60% raw, meaty bones. The rest of the diet is to be composed of a wide variety of foods including vegetables, grains and legumes.

The "prey model" diet attempts to create a diet that simulates the proportions of ingredients and nutrients seen in a prey animal's diet. In the wild, a predator gains nutrients not only from the meat and organs of the prey they are eating. A wild animal would also gain nutrients from the food their prey has previously consumed. This diet aims to simulate all the nutrients that the wild animal would obtain. 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 natural carnivores and do not have any nutritional needs besides what is found in meat, bones, and organs. The supporters of the prey model also focus on feeding meats from a wide variety of animals. Some also add small amounts of vegetable matter to simulate the consumption of stomach contents of prey animals. 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. This problem can be partially mitigated by using grass fed meat, which has more than double the omega 3 content as grain fed meat.

According to a study on homemade raw diets, very few owners follow a recipe, and this results in a risk of nutritional imbalance. Raw fish has high level of thiaminase activity that can breakdown thiamine and lead to a deficiency. The Association of American Feed Control Officials (AAFCO) provides standards that guides many commercial pet food companies. This level of supervision does not occur with homemade food and this can predispose them to a variety of deficiencies and imbalances. One study 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, showing nutritional imbalances in the homemade diets. Three of the diets had inadequate calcium to phosphorus ratios, which may lead to hyperparathyroidism and fibrous osteodystrophy in puppies. As well, homemade diets were proven to have deficiencies in vitamin D, important for bone health by facilitating calcium absorption in the gut, which contribute to storage in bone, and vitamin E, which improves overall immune function by reducing oxidative stress. Antioxidants improve the destruction process by scavenging the free radicals. Another issue with raw diets is the non inclusion of carbohydrate sources, due to the common misconception that dogs cannot digest starch. According to a paper published in Nature, dogs have acquired the ability to digest starch and it can be used as a readily available energy source. Furthermore, the inclusion of dietary fiber sources is important for a dog's gastrointestinal health and stool quality. others dismiss the importance of AAFCO standards, claiming that AAFCO certification is not indicative of the quality of a diet.

While the intense heat used in manufacturing pet food or cooking meat destroys any potential bacteria, raw meats may contain bacteria that can be unsafe for both dogs and cats. The United States government reported that in 2006, 16.3% of all chickens were contaminated with Salmonella. 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. An example of the severity of E. coli O157:H7 infections can be seen in affected greyhound racing dogs fed raw meat as part of their diet. Known as "Alabama rot", this disease presents as severe vasculitis, cutaneous necrosis, renal failure and death. A contributing factor might be that racing greyhounds are typically fed raw meat classified as "not for human consumption", which may contain higher than normal levels of bacteria. Another study assessed the bacterial load in various types of dog food by analyzing 240 samples from raw meat dog diets, commercial dry dog food, or commercial canned food. Salmonella enterica was found in almost 6% of the raw diets, while Escherichia coli was found in almost 50% of the raw diets. E. coli was also found in the commercial dry and wet dog foods, but in lesser amounts. This study determined that bacterial contamination is more common in raw meat diets than commercial dry or canned foods. Most dogs that carry Salmonella are asymptomatic. Proliferation of bacteria in any meat can be reduced by following proper food safety practices such as defrosting meat in the refrigerator or by cooking raw meat, both of which reduce the risk of pathogens. Raw meats may also contain harmful parasites. As with bacteria, these parasites are destroyed during the heat processing of cooking meat or manufacturing pet foods. Some raw diet recipes call for freezing meat before serving it, which greatly reduces (but does not necessarily eliminate) extant 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. There are some myths associated with raw pet food, like that it is more likely to contain salmonella than meat found in grocery stores. Human grade raw pet food (meaning all ingredients are human edible) is produced under USDA inspection and is no more likely to contain bacteria like salmonella than the meat consumed by humans found in local grocery stores.

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. A small study investigated the levels of Salmonella in the stool of 10 dogs that ate a raw diet. It was found that 80% of the raw diets tested positive for Salmonella and 30% of the stool samples from dogs fed raw food contained Salmonella. None of the control dogs fed a commercial feed contained Salmonella. The authors of the study concluded that dogs on a raw food diet may be a source of environmental contamination, although they caution about the generalizability of their results due to the small number of dogs studied. Cats being fed raw meat can also increase the risk of toxoplasmosis as well as other foodborne illnesses. In addition to raw food diets, commercial dog food may also contain Salmonella contamination. The Centers for Disease Control and Prevention released a general warning about Salmonella contamination of commercial dry dog food and treats. As a result of the potential animal and human health risks, some agencies assert 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. There have been isolated cases of humans contracting Salmonella from household pets, but it is undetermined whether raw food was the cause.

Veterinary associations such as the American Veterinary Medical Association, 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. Veterinary associations often organize debates and panels to further the understanding of health and nutrition when feeding dogs. In 2016, the British Small Animal Veterinary Association Congress, discussed the health implications and nutritional balance of raw feeding. The consensus of the panel was that raw feeding could potentially lead to health and nutritional imbalances when owners did not comply with guidelines, and that education of owners was critical.