RFVS Position Statement 1.0
Benefit, Bugs, Balance and Bones
Introductory Statement
Benefit, bugs, balance and bones: these are the four major criticisms of feeding a raw meaty bones diet (RMBD) to cats and dogs as stated by the World Small Animal Veterinary Association in 2011, claiming harm to pets and pet owners. We, the Raw Feeding Veterinary Society (RFVS), strongly contest these criticisms, namely that there is a lack of evidence for the proposed benefit of raw food, that there is a threat of food-borne infection, that it does not offer dogs and cats a complete and balanced diet and that there is a risk associated with feeding raw, bony material to pets. We shall fully counter each of these four criticisms with current and referenced argument. Lastly, we will define a ‘gold standard’ for the whole pet food industry.

Disagreement exists within the veterinary profession about the proper diet for cats and dogs. The feeding of a raw meaty bones diet (RMBD) is receiving increasing attention as the raw pet food industry continues to grow [1].

There is a ‘seventeen-year gap’ between research being published and its practical application in first opinion practice [2]. Lessening this gap is a priority, and given this Internet savvy age it is sometimes difficult for first opinion practitioners to keep up with their client base [3]. Freeman et al. reviewed the risks and benefits of feeding an RMBD. The review noted that pet owners who choose to feed an RMBD do not rank nutritional information provided by vets highly [4]. In this age of access to current science, our client base is often ahead of the game in terms of nutritional knowledge. With priority given to keeping themselves and their families healthy by eating fresh, unprocessed foods, they are often not prepared to feed processed pet food to their pets. The RFVS works with owners who choose to feed an RMBD, raising the profile of our profession from the negative perception with which it is currently held in this growing generation of ‘Internet-educated experts’. The Raw Feeding Veterinary Society (RFVS) significantly reduces the seventeen-year knowledge gap by accessing current nutritional research, and applying the principles in day-to-day practice.

Taking a ‘One Health’ approach to nutrition, the veterinary profession understands that the health of our species is inextricably interwoven with that of animals and the environment [5]. The RFVS has a close association with nutrition researchers from all scientific disciplines: zoological sciences, human nutritional scientists, biological sciences, ecologists and bacteriologists focused on the microbiome.

The RFVS strives to be a source of current nutritional knowledge relating to the feeding of raw food to pets as the demand for species-appropriate food continues to grow [6]. The diversity of our nutritional research base is reflected in the RFVS’s annual conference programme.

By accessing nutrition research from the many and varied scientific disciplines, the RFVS recognises that a pet food should meet the minimum nutritional needs of a pet as a starting point. The food must be safe for the animal being fed, and for the pet owner handling the pet food.

The form and function of the food being presented is also a priority for the RFVS. Environmental enrichment is a lesson learnt from the zoological sciences. The physical and functional form of the food fed needs to meet the physiological and psychological needs of our companion animals. The RFVS considers our pets to be ‘captive carnivores’ [7].

In this era of evidence-based medicine, the current and emerging science supports the feeding of a raw prey based, species-appropriate diet to domesticated carnivores (cats and dogs) for optimal health and well-being. Failing to provide cats with opportunities for predatory-type behaviours can result in obesity or boredom and frustration that can express itself as over-grooming, stress-associated disease or misdirected aggressive behaviour [8].

It is important that, as a profession, we define the gold standard evolutionary diet of our companion animals by which to compare all commercially made raw, cooked and processed pet foods. The need for a gold standard diet was first discussed in 2002 by Professor Nick Cave, board certified veterinary nutritionist, and colleagues [9] and has not been re-visited or defined since confirming the seventeen-year gap between knowledge and practical application.

The National Research Council of the National Academies saw the need to add a chapter on digestive physiology, which had not been previously included, in its revised 2006 edition of Nutrient Requirements of Dogs and Cats. The new chapter covers the digestive compartments and functions, the hormonal aspects of digestion and the measurement of, and factors affecting, digestion [10]. Dogs’ canine and incisor teeth are used to subdue prey, slash the hide and muscle, and grasp and hold prey, while the carnassial pair of teeth (upper fourth premolar and lower first molar) have two shearing edges to trap and cut food in a self-sharpening motion [11]. Dogs are defined as scavenging opportunist carnivores. Cats are defined as obligate carnivores. A cat’s natural diet is primarily small prey mammals, with a lesser proportion of insects, birds and small reptiles when available. Dogs will engage in scavenging behaviours, and both cats and dogs will occasionally chew on grasses. The nutritional ecologist David Raubenheimer based at Sydney University states that ‘cats fed commercial pet foods will be held in a chronic state of nutritional imbalance. This raises welfare concerns, and also in the long term will likely affect cat metabolism and health’ [12].

Based on evidence from the wider nutritional literature, the RFVS defines the gold standard diet for pets as:

The gold standard diet is as close to the evolutionary diet of dogs and cats as is practically possible, is made from fresh frozen raw meaty bones, meats, organ meats, fruits and vegetables, minimally processed by mincing and freezing. The diet contains no added synthetic supplements, additives or preservatives.

The World Small Animal Veterinary Association (WSAVA) issued the WSAVA Nutritional Assessment Guidelines in 2011, which have become the practising nutritional standard for many veterinarians around the world [13]. ‘Practical pet foods’, as defined by the European Pet Food Industry (FEDIAF), dominate the veterinary industry [14]. Practical pet foods feature in the WSAVA Nutritional Assessment Guidelines. Practical pet foods are by definition manufactured from cereals and various rendered animal by-products. They are then supplemented with synthetic vitamin and mineral mixes to make up for the deficiencies due to poor ingredients and processing. Their shelf life and appearance are maintained with additives and preservatives.

Practical pet foods may contain wheat, milk, soybean, corn and many other ingredients not considered part of the evolutionary diet of cats and dogs. They may also contain additives and preservatives such as carrageenan, guar gum, xanthan gum, propionic acid and sorbic acid.

The RFVS offers support to vets and vet nurses who choose to work with the WSAVA Nutritional Tool Kit but need to cater to the growing group of pet owners who choose to feed raw, unprocessed, real food diets rather than commercial cooked ‘practical pet foods’.

WSAVA issued the following position statement in 2013 on the risks of raw meat-based diets:

Raw Meaty Bones Diets (RMBDs) have a high risk for contamination with bacteria, parasites, and other pathogens. In addition to the risks of nutritional inadequacy and contamination with bacteria and parasites, other health concerns for an animal eating an RMBD include risks from ingestion of bones if they are included (e.g., constipation, diarrhea, dental fractures, gastrointestinal obstructions) and diet-induced hyperthyroidism from excessive ingestion of thyroid tissue. There is currently no properly documented evidence of health benefits for RMBD, but there are well documented risks. As such, the World Small Animal Veterinary Association Global Nutrition Committee recommends that RMBD not be fed to dogs and cats [15].

The position statement has not been updated since then, making it difficult for vets and vet nurses to support their raw-feeding client base.

The RFVS is constantly reviewing current peer-reviewed nutritional studies from all scientific disciplines and is in a position to promote the principles and practical aspects of species-appropriate nutrition. The education of veterinarians and allied veterinary professionals and the pet-owning public is a priority for the RFVS.

As practising vets, it is important we give pet owners clear, practical feeding strategies that can be followed in their busy lives. In a biologically ideal world every hunting carnivore would be fed on live prey. This is the gold standard. Clearly, this is socially unacceptable, morally questionable and impractical. A spectrum of lesser alternatives are available which will always be a trade-off between convenience, belief, cost and practicality.

This document is a summary statement of the current research supporting the safe feeding of RMBD to cats and dogs. In addressing the WSAVA position statement released in 2013, it is our duty as members of the RFVS to address the specific concerns that WSAVA has highlighted.

  1. The lack of documentary evidence of the health benefits of RMBDs.
  2. The high risk of contamination.
  3. The risk of nutritional inadequacy or nutritional excess.
  4. The risk from ingested bones.
WSAVA Problem 1: The Lack of Documentary Evidence of the Health Benefits of RMBDs

Veterinary professionals and owners alike who are experienced raw feeders will anecdotally and consistently report that feeding an RMBD to both cats and dogs will improve their energy, bring a sheen to their coat, clear scurf, lessen unwanted odours, improve stool quality, make weight loss easy and thrill fussy eaters. This is to be expected of a diet that is species-appropriate, easily digested and eaten enthusiastically. As raw feeding vets we observe clinical improvement in our caseload with a simple change to feeding an RMBD. It is not only that the diet is raw but by definition a species-appropriate raw diet changes the macronutrient profile of the food being fed. Practical pet foods are carbohydrate rich; raw pet foods are protein rich and low in carbohydrates. We observe our gastrointestinal cases improving on an RMBD. Given the established and emerging science of the ‘gut microbiome’ and its role in health and disease, we recognize the impact of a species-appropriate diet on propagating a healthy microbiome. A healthy microbiome is pivotal to a well-functioning immune system. As a result of feeding a species-appropriate RMBD we observe the resolution of an array of immune-mediated disorders. Atopy can be manageable without the long-term use of pharmaceutical drugs. In cats we observe that the alarming array of inflammatory gastrointestinal diseases clinically improve in response to an RMBD. Feline lower urinary tract disease (FLUTD) can be addressed long term with an RMBD in conjunction with short-term medical management. In both cats and dogs, diabetes can be reversed if caught early. Weight loss is easy. Anecdotally it appears that effective preventive strategies to reduce the epidemic of pet obesity are in our hands when we recommend an RMBD.

The following peer-reviewed literature supports the anecdotal observations.

Digestibility studies support the improvement seen in coat quality and energy levels, given that nutrient absorption is improved on an RMBD. Digestibility of crude protein and fat is improved in raw foods compared to dry practical pet foods [16–19].

In dogs suffering from gastrointestinal disease, one recent study has highlighted the difference in the make-up of the microbiome between a healthy and a sick animal [20]. In dogs suffering from inflammatory bowel disease, bacterial groups within the phylum Fusobacteria have been reported to decrease in the gut [19]. Studies have shown that feeding raw meat to dogs increases the same phylum in the gut, making an RMBD a positive influence to improve a dysfunctional microbiome [21–23].

In a study, from Iowa State University [24], a group of pet dogs were used to model and test RMBDs intended for captive zoo carnivores. Owing to functional and anatomical similarities between the digestive systems of domestic dogs and their wild counterparts, dogs serve as an experimental model for nutrition studies for exotic captive canine species. This study turned on its head the veterinary notion that our pet dogs are no longer the ‘evolutionary equivalent’ of their canine ancestors and have somehow morphed into omnivores eating human food. Let’s be clear: our domestic pet dogs have the anatomy and physiology of a scavenging carnivore: an unhinged jaw for tearing and shearing prey with no capacity for a side-to-side movement for grinding food, low stomach pH and a short gastrointestinal tract. Although domestication has given dogs an increased ability to digest and utilise starch in their diet, at the RFVS we recognise that the ability to digest starch is very far removed from the ability to thrive on a predominantly starchy diet [25]. The ability to digest starch varies both at the breed and at the individual level.

The Iowa study found that nutrients in RMBD were highly digested by domestic dogs. The diets did not result in clinical signs of gastrointestinal upset. The RMBD had a positive effect on the dogs’ general health status as measured by serum chemistry, electrolytes and a complete blood check. Histology of the gastrointestinal tract and associated tissues using chamber evaluation of intestinal integrity and barrier function indicated improvement in both intestinal integrity and barrier function on an RMBD. Given that atopic dermatitis and other skin diseases may be seen as a manifestation of a more systemic problem involving gut dysbiosis and increased intestinal permeability, it follows that these conditions will improve on an RMBD [26].

A recent study in the Veterinary Journal took a look at the effect of kibble and raw meat diets on peripheral blood mononuclear gene expression in dogs [27]. The study found that diet influences canine immune cell gene expression. This suggests that diet is a critical factor in the maintenance of cellular defence systems, immunity, inflammation, redox regulation, metabolism, and DNA repair, which ensure optimal health and reduce disease risk. In humans, owing to recent innovations in gene expression technologies, the profiling of human blood to determine predictive markers associated with health status has become a feasible prospect. This exciting study gives us an opportunity to predict health status and the benefits conferred by diet in dogs.

In a working example of a One Health model, the KetoPet Sanctuary (ketopetsanctuary.com) was set up in 2014 to rescue shelter dogs diagnosed with cancer. Shelter dogs diagnosed with cancer arriving at the sanctuary are placed on a raw ketogenic diet (high fat, adequate protein, very low carbohydrate). A raw ketogenic diet mimics a dog’s ancestral diet and closely replicates how canines might eat in the wild. For most of canine history, dogs were naturally in a state of ketosis much or most of their lives. A raw ketogenic diet is found to be effective in improving outcomes for dogs with cancer. A ketogenic diet supplies energy in the form of fat and protein which ensures stable blood glucose, improves insulin sensitivity and reduces inflammation [28].

Dogs with idiopathic epilepsy may exhibit behaviours that resemble attention deficit hyperactivity disorder (ADHD) symptoms seen in humans. A ketogenic diet may be able to improve some of these behaviours, and provide potentially anxiolytic effects [29].

In a randomised clinical trial in 2012, the positive effect of a raw diet was reported in relation to the formation of calcium oxalate uroliths [30]. Lower calcium excretion was found in the urine of dogs eating a commercial RMBD, compared with excretion in dogs eating a commercial dry extruded diet. The RMBD contained half as much calcium, less than a third as much sodium and considerably more water than did the dry extruded diet. Feeding a diet with a nutrient profile closer to a species-appropriate gold standard diet, as well as feeding it raw, warrants further research.

Nutrition studies that are independent of funding from large pet food companies producing practical pet foods such as Hill’s, Royal Canin and Purina are rare. Undergraduate education, postgraduate education and continuing professional development of practising vets is funded by practical pet food companies.

The DogRisk Group is a group of Independent university-based researchers led by Professor Anna Hielm-Bjorkman based at the University of Helsinki. The primary aim of the DogRisk Group is to assess the impact of diet and other environmental factors on diseases in dogs [31].

The DogRisk Group utilises a validated questionnaire using a huge number of dogs (upwards of 8000) to assess the impact of diet and environment [32]. Professor Hielm-Bjorkman is a regular and well-received speaker at the RFVS’s annual conference. Professor Hielm-Bjorkman takes a One Health approach and would like to use the dog as a nutritional model for human disease.

An initial analysis of the DogRisk data has revealed a decrease in the incidence of atopy and allergy in dogs that eat RMBDs [33]. It appears that an RMBD fed at a young age has a positive influence on reducing the incidence of atopy in the population. Eating raw meat, raw bone and cartilage gave the strongest association of any the food items consumed in the study.

A poster presented at the Waltham Nutritional Symposium (2013) analysed the data collected from the DogRisk Questionnaire in relation to canine hip dysplasia (CHD) in German shepherd dogs. The results of the analysis indicated that raw food, fed at a young age, could protect German shepherd dogs from CHD [34]. To test these results, further clinical studies are needed. Professor Hielm-Bjorkman spends the majority of her time trying to secure funding. Her main areas of interest are why chronic diseases in dogs and humans occur, how these diseases progress and the role that nutrition plays in these processes. Professor Hielm-Bjorkman works as a senior researcher and teacher at the Department of Equine and Small Animal Medicine at the Veterinary Faculty of the University of Helsinki. Many posters have been presented at congresses globally but, owing to a lack of funding, the DogRisk Group has difficulty publishing its work.

The RFVS is always looking for ways to help raise much-needed funds for independent nutrition research relating to the feeding of RMBDs.

WSAVA Problem 2: The Perceived High Risk of Contamination from RMBD

Within the veterinary profession there is a very vocal lobby opposing the feeding of an RMBD. The anti-raw-food lobby is keen to point out that RMBDs are laden with bacteria and pose a risk for both the pet and the owner. In the words of one corporate director: ‘How many more innocent children will have to be harmed before the veterinary profession will unite to condemn the practice of feeding raw food to pets?’ [35]. This same corporate chain retails raw pet foods from a number of their veterinary clinics. This highlights the current chaotic approach of the profession to feeding pets a raw food diet.

‘Reducing the risk of zoonotic infection’, published in the Canadian Medical Association Journal (CMAJ) in 2015 [36], makes a number of key points about reducing the risk of pet-associated zoonotic infection. The paper states that in a controlled health care environment, and with responsible human behaviour, the potential benefits of sharing our lives with companion animals far outweigh the apparently insignificant risks.

Pets are a potential source of zoonotic infection, no matter what they are fed. People may acquire zoonotic infections through bites, scratches, contact with animal saliva, urine and other bodily fluids or secretions, ingestion of animal faecal material, inhalation of infectious aerosols and through the bites of arthropods and other invertebrate vectors. Companion animals are a source for more than seventy human diseases. However, patient surveys and epidemiological studies suggest that the occurrence of pet-associated disease is low.

The CMAJ paper identifies a vulnerable group of people – patients who are immune-compromised, pregnant women, young children and older adults – who are at greater risk of zoonotic infection. Given a One Health approach, physicians and other healthcare providers, with the guidance of existing resources, can counsel patients on safe pet ownership and safe pet contact to reduce pet-associated disease.

When a disease is transmitted from animal to human involving any type of pet food, the cause is likely to be poor hygiene resulting from failing to appreciate just how dangerous pet foods can be. Illness among infants is significantly associated with feeding practical pet foods to pets in the kitchen [37]. This study in the journal Pediatrics concludes that dry dog foods were linked to human cases of salmonella over a three-year period. Toddlers are frequently infected by handling dry kibble left out in the kitchen. This paper highlights the importance of the proper handling and storage of dry pet foods in the home to prevent illness, especially among young children.

In 2017, Public Health England investigated an outbreak of Shiga toxin producing Escherichia coli (STEC). The investigation highlighted the necessity of a One Health approach to the control of STEC, owing to the complex interplay of pathogens between animals, the environment and humans [38]. The study identified the growing popularity of feeding pets on RMBDs and concluded that further work is needed to assess the risk and to improve infection control. The number of raw pet food manufacturers has increased from five in 2013 to ninety in 2018. In response to this growth, the Advisory Committee on Animal Feedingstuffs (ACAF) published a discussion paper, ‘Raw Pet Food’ [39], noting that the size of the UK raw pet food market has grown significantly over recent years, and is estimated to be worth in excess of £100 million annually. The discussion paper from ACAF concludes that improving awareness of risk is a priority, noting that in one case, in the STEC investigation carried out by Public Health England, an owner had close contact with a raw fed dog, including sharing their own toothbrush to brush the dog’s teeth.

The Veterinary Public Health Association (VPHA) website has posted the conclusion of the Incident Management Team from Public Health England in their zoonoses newsletter [40]. The Incident Management Team concluded that the best approach to reducing the risk of infection from raw pet foods is to improve the awareness of risk, and to promote good hygiene practices when handling raw pet food.

Public Health England has developed a number of infographics for pet owners with the introductory graphic ‘Handling Pet Foods Can Make People Unwell’ [41]. That’s all pet foods, not just raw pet foods, and these infographics have been welcomed and utilised by the RFVS.

The RFVS also acknowledges that those veterinary professionals with widespread experience of feeding raw food diets to pets know that resultant disease is very rare if owners are educated in the potential risks. Owners are experts at adhering to the proper handling and storage of these foods. The RFVS also acknowledges that salmonella, campylobacter and listeriosis are being carried by clinically healthy animals, raw fed or not, making the understanding of the canine and feline intestinal microbiota a very hot topic. Pathogenic species of bacteria including E. coli, Clostridium perfringens and Salmonella are regularly identified in healthy dog’s intestines [42].

All dogs lick their anal/genital area, lick other dogs’ orifices, eat faeces, eat dead animals, and drink from contaminated puddles and waterways. Equally all cats will lick their anal/genital area and many cats will hunt prey. Basic hygiene precautions ensure that we humans can all safely coexist with our pets.

Antibiotic resistance and RMBD are often linked in discussions about multi-drug-resistant bacteria (MDRB). Current research by the Royal Veterinary College in a three-year joint initiative with the UK Medical Research Council is investigating the critical control points at which interventions could substantially affect the spread of resistance [43]. The often close contact between pets and humans provides opportunities for the transmission of MDRB and resistance genes in either direction. The dog’s nose being a frequent carriage site for MDRB. We currently do not know the critical control points at which we need to intervene to reduce the spread of MDRB.

If the same concern for public health and the recommendation for banning raw food were applied to the zoo world, this would be a wholly impractical position. Several thousand keepers (including pregnant women) are feeding an RMBD every day to their captive carnivores (big and small cats, hyenas, bears, birds and reptiles) including raw meat and carcasses. If the feeding of RMBD were as dangerous as implied in some veterinary circles, we would have to close all of our zoos.

In 2017, the Pet Food Manufacturers’ Association (PFMA) Raw Pet Food Group developed in conjunction with Defra, the APHA, Public Health England and the Food Standards Agency published the Guidelines for the Manufacture of Raw Pet Food in the UK. An excellent example of the workings of a One Health approach. The guidelines will ensure the safety, hygiene and nutritional adequacy of raw pet food manufactured in the UK [44].

By default – it is often thought that feeding a Practical Pet Food must be safe. An increasingly global and complex pet food supply chain complicates the already substantial challenge of assuring pet food safety and nutritional adequacy [45]. Common sourcing of ingredients from a global supply chain and increased size of production lots leads to escalating problems. Pet owners who choose to raw feed are often suspicious of large pet food companies. Freeman et al in their 2013 review of the Risks and Benefits of raw meat based diets state that recalls of commercial pet foods for bacterial contamination, mycotoxicosis, thiamine deficiency, and Vitamin D toxicosis are evidence that feeding commercial dry extruded and moist pet foods is not completely without risk [4].

WSAVA Problem 3: Nutritional Deficiency and Excess

A recently published study from the University of Nottingham highlights the non-compliance of a range of popular cooked pet foods sold in the UK under FEDIAF Guidelines - 94% of wet foods and 61% of dry foods were non-compliant with EU guidelines [46]. The study concludes that if fed exclusively and over an extended period of time a number of these pet foods could impact negatively on the health of companion animals.

In July 2018, the FDA warned about a possible relationship between dilated cardiomyopathy (DCM) in dogs and the consumption of dog food formulated with potatoes and pulse ingredients. The Journal of Animal Science recently published a review article stating that adequate supply of taurine and/or precursors for taurine synthesis play an important role in preventing DCM [47]. The review states that bioavailability and digestibility are important considerations when formulating pet foods. The review concludes that dog food formulators should have a deep knowledge of processing methodologies and nutrient interactions, beyond meeting AAFCO nutrient profiles and should not carelessly follow unsubstantiated market trends.

The recent Hills Pet Food recall for excessive levels of Vitamin D in a range of their foods, highlights the challenge of assuring pet food quality in a global food environment. Given the recent Hills recall, the Nottingham University study and the concern over novel ingredients relating to DCM in dogs, it is time as a profession to acknowledge the limitations of our current pet food model. Increasingly, research has emphasized that the prior treatment of food before consumption may have a marked effect on the bioavailability of nutrients. Host related factors are also recognized as important. The efficiency of luminal and mucosal digestion influences nutrient bioavailability and is impacted by prior processing of food [48]. It is time to define a ‘gold standard’ species appropriate diet by which all manufactured pet foods can be compared.

The RFVS definition of ‘the gold standard diet’ for pets is as close to the dog and cats evolutionary diet as is practically possible. Manufactured from fresh frozen raw meaty bones, meats, organ meats, fruits and vegetables, minimally processed by mincing and freezing. With no added synthetic supplements, additives or preservatives.

The majority of raw pet food companies in the UK are using high quality raw meaty bones, and organ meats, sourced from the human food chain, of known provenance. There are currently nine raw pet food companies listed on the PFMA website. These companies are following the Guidelines for the Manufacture of Raw Pet Food in the UK. As raw pet food has become more popular with dog and cat owners, so too has demand for hard evidence as to its nutritional adequacy and safety. Veterinary professionals, in particular, seek reassurance. Naturally, they do not wish to recommend anything that could have adverse health implications.

A raw food manufacturer in the UK has recently invested in a research project to demonstrate that it is possible to formulate a species-appropriate raw food diet for dogs, without the need for additional synthetic supplementation. The study, Raw Proof [49], enrolled twenty-six dogs over a two-year period and fed them a range of RMBDs. The diets fed met the FEDIAF’s nutritional guidelines for complete and balanced nutrition. The FEDIAF recognises that its guidelines were developed in order to assess the nutritional adequacy of highly processed, manufactured cooked food that incorporates artificial supplementation. The FEDIAF acknowledges that its guidelines are not applicable to a species-appropriate diet of raw meaty bones and as such FEDIAF states that ‘pet foods can be adequate and safe when nutrient levels are outside the recommendations in this guide based on the manufacturer’s substantiation of nutritional adequacy and safety’. In Raw Proof the raw pet food manufacturer gives detailed substantiation of the nutritional adequacy and safety [49]. The study has been peer reviewed by a number of veterinary professionals and concludes that a properly formulated raw food diet will meet an adult dog’s nutritional requirements with no adverse health effects.

In the context of nutritional excess, companion animal obesity has been identified as a challenge for the veterinary profession. Obesity is seen as a multifactorial problem including excessive consumption of food, genetics, sex status, exercise and behaviour around food. Anecdotally, raw feeding vets can easily manage overweight pets. Given that high-protein, low-carbohydrate diets enhance weight loss in dogs [50], further research is warranted to consider the macronutrient profile of a species-appropriate RMBD in successful weight management. The positive influence of an RMBD in meeting many of the natural feeding behaviours of cats and dogs requires further investigation in the context of preventing obesity [51]. Cats are obligate carnivores with no requirement for carbohydrates [52]. As obligate carnivores they are metabolically programmed to utilise amino acids and fat rather than starch to produce energy. Additional starch in a cat’s diet is stored as fat [53]. We knew this in 2002 – sixteen years later we are facing an obesity epidemic. The current obesity issue has led to an awareness of the need for further understanding of the energy available from practical pet foods [54].

In terms of nutritional excess, the only reports for excessive nutrients from an RMBD is nutritional hyperthyroidism. Caused by the excessive feeding of thyroid gland to dogs in the form of necks from ruminant animals fed to dogs with the thyroid gland attached. This is easily resolved by only sourcing necks with the thyroid gland removed [55].

There are many perceived issues with nutritional excess and deficiency when feeding an RMBD. Home-prepared pet foods, raw or cooked, can be unbalanced. The RFVS believes that raw pet food manufacturers and the pet owning public need the knowledge and guidance of vets who endorse RMBDs.

WSAVA Problem 4: The Risk from Ingested Bones

The RFVS acknowledges that the feeding of inappropriately chosen raw meaty bones can be dangerous to dogs and cats. The RFVS is committed to educating owners about the safe feeding of raw meaty bones to improve dental health and mental health. The RFVS believes that the benefits of feeding appropriate sized raw meaty bones to dogs and cats outweighs the risks. The RFVS does not advocate the feeding of cooked bones.

The masticatory apparatus of carnivores has evolved to chew raw meaty bones [56]. Raw meaty bones are a natural component of the diet of our pet carnivores, and pets show a strong desire to chew on raw meaty bones when offered them. Long periods spent feeding and exercising the jaw, neck and shoulder muscles lead to psychological contentment [57]. Consumption of whole prey or raw meaty bones provides a relatively high intake of raw animal-derived fermentative substances such as minerals, cartilage and tendons which enhance gut health, stimulate microbial commensals and optimise immune function, as discussed in the DogRisk Studies [31, 32]. The RFVS does not advocate the chewing of large limb bones, owing to the development of massive shearing forces and the possibility of slab fractures.

Freeman et al. in their 2013 review, published in the Journal of the American Veterinary Medical Association [4], of the risks and benefits of raw food diets states that further research is needed to better understand the frequency of obstruction or perforation with raw versus cooked bones. The most common canine oesophageal foreign bodies are bones, various dental chews, rawhides, rubber balls and bottle caps [58]. There are no references to whether these bone foreign bodies are raw or cooked. Based on clinical experience, the RFVS believes that appropriately sized raw meaty bones rarely cause a problem.

In a retrospective case series of thirty-one dogs presenting for obstruction with a dental chew, the study states that the dental chews were difficult to remove orally via endoscopy, resulted in severe oesophageal damage, were associated with stricture formation and were associated with a high mortality rate [59]. Dental chews continue to be highly recommended by veterinarians in practice. Dental treats and chews also differ greatly in their effectiveness on the reduction of plaque, gingivitis, calculus and halitosis, making recommendation by a vet very difficult. Chewing raw bovine bones, however, was found to be an effective method of removing dental calculus in dogs [60]. In cats, a study comparing the dental calculus scores of domestic cats eating canned and dry foods with feral cats eating small mammals, birds, reptiles and insects found that dental calculus scores were significantly higher in domestic cats than in feral cats [61]. The current systematic scrutiny of our knowledge in relation to periodontal disease undertaken by RCVS Knowledge clearly highlights a gap in the evidence [62], and is a strong justification for further research into a species-appropriate RMBD.

Summary Statement

We, the Raw Feeding Veterinary Society (RFVS), refute the four major WSAVA criticisms. We challenge the supposed lack of evidence of the health benefits of raw food feeding, the apparent risk of infection posed by feeding cats and dogs a raw meaty bone diet, the lack of evidence of the nutritional adequacy of feeding cats and dogs a complete and balanced raw diet and the suggestion of the relative risk of feeding raw bony material to pets.

As practising veterinary professionals, the RFVS insists it is important we give pet owners clear, practical feeding strategies that can be easily followed. In a biologically ideal world every captive carnivore would be fed on live prey. Clearly, this is socially unacceptable, morally questionable and impractical. It is, however, the gold standard diet to which all manufactured pet food must be compared.

As owners continue to seek RMBDs for their pets, it is critical that the veterinary profession engages with the current research and science to support these owners in their choice of diet. The RFVS recognises that feeding an RMBD is a positive proactive choice made by highly motivated and intelligent pet owners.

The RFVS will continue to promote the extensive nutritional science available in relation to the documented health benefits of RMBDs.

The RFVS believes that ensuring pet owners are fully aware of the potential for zoonotic infection from their dogs and cats to their families and the extended community that these pets come into contact with will greatly reduce its risk. Also, we believe that zoonotic infection is a wider veterinary issue and not just a raw pet food issue.

The RFVS supports the PFMA’s Guidelines for the Manufacture of Raw Pet Food in the UK [44]. These guidelines ensure that pet food manufacturers are preparing high-quality raw pet foods with appropriate microbiological controls in place. These manufacturers understand the importance of a complete and balanced nutrient profile.

The safe feeding of RMBDs is a priority for the RFVS and we will continue to advise on the safe feeding of raw meaty bones to dogs and cats to provide improved dental and mental health.

The clinical experience of veterinary professionals and hundreds of thousands of pet owners around the world, together with current scientific literature, demonstrates that a carefully planned RMBD significantly and measurably improves pet health.

The RFVS will continue to support vets, vet nurses, allied professionals, academics, pet food manufacturers and pet owners to positively and safely feed as close to a gold standard species-appropriate RMBD as possible. The RFVS is committed to promoting current and future evidence-based research worldwide.

The RFVS is deeply committed to the health and welfare of pets, pet owners and the veterinary profession.

  1. Morelli, G., Bastianello, S., Catellani, P., and Ricci, R. (2019). Raw meat-based diets for dogs: Survey of owners’ motivations, attitudes and practices. BMC Veterinary Research, 15(1): 74.
  2. Morris, Z.S., Wooding, S., and Grant, J. (2011). The answer is 17 years, what is the question? Understanding time lags in translational research. Journal of the Royal Society of Medicine, 104(12): 510–520.
  3. WSAVA Global Nutritional Committee. (2013). The savvy cat owner’s guide: Nutrition on the internet. https://www.wsava.org/sites/default/files/nutrition%20on%20the%20iernet%20cats.pdf.
  4. Freeman, L.M., Chandler, M.L., Hamper, B.A, and Weeth, L.P. (2013). Current knowledge about the risks and benefits of raw meat-based diets for dogs and cats. Journal of the American Veterinary Medical Association, 243(11): 1549–1558.
  5. Gibbs, E.P.J. (2014). The evolution of One Health: A decade of progress and challenges for the future. Veterinary Record, 174(4): 85–91.
  6. Pet Food Industry. (2018). Raw pet food sales growing despite warnings. Pet Food Industry (March): 25. http://www.petfoodindustry-digital.com/201803/index.php#/32 March 2018.
  7. Herron, M.E., and Buffington, C.T. (2010). Environmental enrichment for indoor cats. Compendium (Yardley, PA), 32(12): E4.
  8. Ellis, S.L.H., Rodan, I., Carney, H.C., et al. (2013). AAFP and ISFM Feline Environmental Needs Guidelines. Journal of Feline Medicine and Surgery, 15(3): 219–230. doi: 10.1177/1098612X13477537.
  9. Glasgow, A.G., Cave, N.J., Marks, S.L., and Pedersen, N.C. (2002). Role of diet in the health of the feline intestinal tract and in inflammatory bowel disease. Cat Fanciers Almanac, 19: 78–80.
  10. Subcommittee on Dog and Cat Nutrition, Committee on Animal Nutrition, and National Research Council. (2006). Comparative physiology of dogs and cats. In: Nutrient Requirements of Dogs and Cats (revised edition). Washington, DC: National Academies Press: 5–21.
  11. Bosch, G., Hagen-Plantinga, E., and Hendriks, W. (2015). Dietary nutrient profiles of wild wolves: Insights for optimal dog nutrition? British Journal of Nutrition, 113(S1): S40–S54. doi: 10.1017/S0007114514002311.
  12. Simpson, S.J., and Raubenheimer, D. (2012). The nature of nutrition: A unifying framework. Australian Journal of Zoology, 59(6): 350–368.
  13. Freeman, L., Becvarova, I., Cave, N., et al. (2011). WSAVA Nutritional Assessment Guidelines. Journal of Feline Medicine and Surgery, 13(7): 516–525. doi: 10.1016/j.jfms.2011.05.009.
  14. The European Pet Food Industry. (2019). Nutritional Guidelines: Definition of Practical Pet Foods: 22. http://www.fediaf.org/self-regulation/nutrition/.
  15. WSAVA (2013). WSAVA Global Nutrition Committee Statement on Risks of Raw Meat-Based Diets. https://www.wsava.org/WSAVA/media/PDF_old/WSAVA-GNC-raw-diet-statement-12-3-14.pdf.
  16. Bermingham, E.N., Maclean, P., Thomas, D.G., et al. (2017). Key bacterial families (Clostridiaceae, Erysipelotrichaceae and Bacteroidaceae) are related to the digestion of protein and energy in dogs. PeerJ, 5: e3019.
  17. Crissey, S.D., Swanson, J.A., Lintzenich, B.A., et al. (1997). Use of a raw meat-based diet or a dry kibble diet for sand cats (Felis margarita). Journal of Animal Science, 75(8): 2154–2160.
  18. Kerr, K.R., Vester Boler, B.M., Morris, C.L., et al. (2012). Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets. Journal of Animal Science, 90(2): 515–522.
  19. Sandri, M., Dal Monego, S., Conte, G., et al. (2016). Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs. BMC Veterinary Research, 13(1): 65.
  20. Honneffer, J.B., Minamoto, Y., and Suchodolski, J.S. (2014). Microbiota alterations in acute and chronic gastrointestinal inflammation of cats and dogs. World Journal of Gastroenterology, 20(44): 16489–16497.
  21. Tizard, I.R., and Jones, S.W. (2018). The microbiota regulates immunity and immunologic diseases in dogs and cats. Veterinary Clinics: Small Animal Practice, 48(2): 307–322.
  22. Kim, J., An, J.U., Kim, W., et al. (2017). Differences in the gut microbiota of dogs (Canis lupus familiaris) fed a natural diet or a commercial feed revealed by the Illumina MiSeq platform. Gut Pathogens, 9(1): 68.
  23. Algya, K.M., Cross, T.W.L., Leuck, K.N., et al. (2018). Apparent total-tract macronutrient digestibility, serum chemistry, urinalysis, and fecal characteristics, metabolites and microbiota of adult dogs fed extruded, mildly cooked, and raw diets. Journal of Animal Science, 96(9): 3670–3683.
  24. Iennarella-Servantez, C.A. (2017). Evaluation of raw meat diets on macronutrient digestibility, fecal output, microbial presence, and general health status in domestic dogs. Graduate Theses and Dissertations, 15537.
  25. Arendt, M., Fall, T., Lindblad‐Toh, K., and Axelsson, E. (2014). Amylase activity is associated with AMY 2B copy numbers in dog: Implications for dog domestication, diet and diabetes. Animal Genetics, 45(5): 716–722.
  26. Craig, J.M. (2016). Atopic dermatitis and the intestinal microbiota in humans and dogs. Veterinary Medicine and Science, 2(2): 95–105.
  27. Anderson, R.C., Armstrong, K.M., Young, W., et al. (2018). Effect of kibble and raw meat diets on peripheral blood mononuclear cell gene expression profile in dogs. Veterinary Journal, 234: 7–10.
  28. Allen, B.G., Bhatia, S.K., Anderson, C.M., et al. (2014). Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism. Redox Biology, 2: 963–970.
  29. Packer, R.M., Law, T.H., Davies, E., et al. (2016). Effects of a ketogenic diet on ADHD-like behavior in dogs with idiopathic epilepsy. Epilepsy & Behavior, 55: 62–68.
  30. Dijcker, J.C., Hagen-Plantinga, E.A., Everts, H., et al. (2012). Dietary and animal-related factors associated with the rate of urinary oxalate and calcium excretion in dogs and cats. Veterinary Record, 171(2): 46.
  31. DogRisk. (2019). Independent university based research on dog nutrition and diseases. https://www.dogrisk.com.
  32. Roine, J., Uusitalo, L., and Hielm-Björkman, A. (2016). Validating and reliability testing the descriptive data and three different disease diagnoses of the Internet-based DOGRISK questionnaire. BMC Veterinary Research, 12(1): 30.
  33. Anturaniemi, J. (2018). The relationships between environment, diet, transcriptome and atopic dermatitis in dogs. https://helda.helsinki.fi/handle/10138/231737.
  34. Grundström, S., Baesley, S., and Hielm-Björkman, A. (2013). Influence of nutrition at young age on canine hip dysplasia in German Shepherd dogs: A case-control study from Finland. The WALTHAM International Nutritional Sciences Symposium (WINSS) 1–4 October 2013, Oregon, USA: 93.
  35. Letter to the Editor. (2019). Study commendable but must be more robust. Vet Times (7 January).
  36. Stull, J.W., Brophy, J., and Weese, J.S. (2015). Reducing the risk of pet-associated zoonotic infections. Canadian Medical Association Journal, 187(10): 736–743.
  37. Behravesh, C.B., Ferraro, A., Deasy, M., et al. (2010). Human salmonella infections linked to contaminated dry dog and cat food: 2006–2008. Pediatrics, 126(3): 477–483.
  38. Public Health England. (2018). Investigation into an outbreak of Shiga toxin producing Escherichia coli A (STEC) O157 PT 21/28 Stx2 in England. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/765498/STEC_O157_PT21.28_Outbreak_Report.pdf.
  39. Bond, M. (2018). Advisory Committee on Animal Feedingstuffs: Raw Pet Food: 75th Meeting of ACAF on 15 February 2018. https://acaf.food.gov.uk/sites/default/files/acafrawpetfood1803.pdf.
  40. Byrne, L. (2018). STEC linked to raw pet food. Zoonoses Newsletter, 20 (November). https://www.vpha.co.uk/our-position.
  41. Public Health England. (2019). Handling pet foods can make people unwell. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/745049/Raw_pet_food_safety_poster.pdf.
  42. Schmitz, S., and Suchodolski, J. (2016). Understanding the canine intestinal microbiota and its modification by pro‐, pre‐ and synbiotics: What is the evidence? Veterinary Medicine and Science, 2(2): 71–94.
  43. Royal Veterinary College. (2017). PET-risk: Transmission of multi-drug resistant bacteria between pets and humans. https://www.rvc.ac.uk/research/news/general/pet-risk.
  44. Pet Food Manufacturers’ Association. (2017). Guidelines for the Manufacture of Raw Pet Food in the UK. https://www.pfma.org.uk/news/raw-food---safety-guidelines.
  45. Butterwick, R.F., Erdman, J.W., Hill, R.C., et al. (2011). Challenges in developing nutrient guidelines for companion animals. British Journal of Nutrition, 106(S1): S24–S31.
  46. Davies, M., Alborough, R., Jones, L., et al. (2017). Mineral analysis of complete dog and cat foods in the UK and compliance with European guidelines. Scientific Reports, 7(1): 17107.
  47. Mansilla, W.D., Marinangeli, C.P.F., Ekenstedt, K.J., et al. (2019). Special topic: The association between pulse ingredients and canine dilated cardiomyopathy: Addressing the knowledge gaps before establishing causation. Journal of Animal Science, 97(3): 983–997.
  48. Gibson, R.S. (2007). The role of diet and host related factors in nutrient bioavailability and thus in nutrient-based dietary requirement estimates. Food and Nutrition Bulletin, 28(1 suppl. int.): S77–S100.
  49. Marshall, V. (2017). Raw Proof. Pewsey: The Darling Experiment. https://honeysrealdogfood.com/raw-proof/.
  50. Bierer, T.L., and Bui, L.H. (2004). High-protein low-carbohydrate diets enhance weight loss in dogs. Journal of Nutrition Volume, 134(8): 2087S–2089S. doi: 10.1093/jn/134.8.2087S.
  51. Zoran D.L. (2011). Effects of nutrition choices and lifestyle changes on the well-being of cats: A carnivore that has moved indoors. JAVMA 239(5): 596–606.
  52. Zoran, D.L. (2002). The carnivore connection to nutrition in cats. Journal of the American Veterinary Medical Association, 221(11): 1559–1567.
  53. Zoran, D.L. (2010). Obesity in dogs and cats: A metabolic and endocrine disorder. Veterinary Clinics: Small Animal Practice, 40(2): 221–239.
  54. Asaro, N.J., Guevara, M.A., Berendt, K., et al. (2017). Digestibility is similar between commercial diets that provide ingredients with different perceived glycemic responses and the inaccuracy of using the modified Atwater calculation to calculate metabolizable energy. Veterinary Science 4(4): 54. doi: 10.3390/vetsci4040054.
  55. Zeugswetter, F.K., Vogelsinger, K., and Handl, S. (2013). Hyperthyroidism in dogs caused by consumption of thyroid-containing head meat. Schweizer Archiv fur Tierheilkunde, 155(2): 149–152.
  56. Watson, A.D.J. (1994). Diet and periodontal disease in dogs and cats. Australian Veterinary Journal, 71(10): 313–318.
  57. Bond, J.C., and Lindburg, D.G. (1990). Carcass feeding of captive cheetahs (Acinonyx jubatus): The effects of a naturalistic feeding program on oral health and psychological well-being. Applied Animal Behaviour Science, 26(4): 373–382.
  58. Rousseau, A., Prittie, J., Broussard, J.D., et al. (2007). Incidence and characterization of esophagitis following esophageal foreign body removal in dogs: 60 cases (1999–2003). Journal of Veterinary Emergency and Critical Care, 17(2): 159–163.
  59. Leib, M.S., and Sartor, L.L. (2008). Esophageal foreign body obstruction caused by a dental chew treat in 31 dogs (2000–2006). Journal of the American Veterinary Medical Association, 232(7): 1021–1025.
  60. Marx, F.R., Machado, G.S., Pezzali, J.G., et al. (2016). Raw beef bones as chewing items to reduce dental calculus in Beagle dogs. Australian Veterinary Journal, 94(1–2): 18–23.
  61. Clarke, D.E., and Cameron, A. (1998). Relationship between diet, dental calculus and periodontal disease in domestic and feral cats in Australia. Australian Veterinary Journal, 76(10): 690–693.
  62. Van Veggel, N. and Armstrong, M. (2017). In dogs with periodontal disease is feeding a complete raw meat diet more effective than a complete kibble dental diet at reducing periodontal disease? Veterinary Evidence, 2(2). doi: 10.18849/ve.v2i2.88.