I am asked more frequently about the raw diet than anything else, especially on the internet. It is a hot potato with many passionate opinions online, however I believe it’s vital that clients can make an informed decision before deciding to feed this incredibly complex and risky diet to their pets. The FDA, WSAVA, AAHA, AVMA, CVMA have all written position statements recommending against these types of diets with good reason, many of which I will cover here.
Firstly, let me set a few things straight, I do not personally recommend feeding a raw diet to your pets. I don’t judge people who wish to feed this way, but I do recommend they seek the assistance of a Board Certified Veterinary Nutritionist to ensure they are preparing it safely, and it is nutritionally adequate or use a pre-made product from a reputable and accountable manufacturer who conducts strict quality control or better yet processes the food in some way to reduce the bacterial load. Formulating a diet is no simple task, and laypeople should not undertake this without the guidance of a qualified professional – see my blog here on who you should be looking for.
So, why don’t I recommend raw feeding?
1. Nutritional inadequacies
As with any home-prepared diet, ensuring it is complete and balanced is no easy task. The raw diet, is no different. I often see clients using a ratio of meat, organs and bones to “balance” the diet, however this is not a good way of ensuring the diet is actually complete, which Veterinary Nutrition Group show in their recent blog post here when running this type of diet through BalanceIT.com. My concern with the nutritional adequacy of raw diets comes from non-professionals dabbling in formulating in this way, especially when the diet is promoted by other non-professionals to new pet owners with very young animals who have strict nutritional requirements and underdeveloped immune systems. A number of issues can arise from raw diets that are inappropriately balanced or inadequately supplemented; a recent study showed cats eating a raw diet developed hypervitaminosis A due to the raw diet being rich in pork liver, while another study showed German Shepherd puppies raised on a raw diet developed osteodystrophy (see references at the bottom of this post). The other concern is the inclusion of bones in the diet which are both a risk to dental health in the way of fracturing teeth, and a foreign body obstruction risk of the bones becoming lodged in the throat or perforating the gut if ingested.
2. Bacterial load and contamination
Did you know that meat in the supermarket or butcher is allowed to contain Salmonella? This is due to the fact that it is designed to be cooked before it is eaten, which significantly reduces the bacterial load and makes it safe for consumption. The claim that domestic pets are able to handle the extra bacterial load due to a very low (highly acidic) stomach pH is inaccurate – the stomach pH of a dog is 2 (acidic), which rises to 6 (close to neutral 7) when consuming food, and drops back down to 2. Similarly, our stomach pH normally sits around 3, which also rises when we eat, and drops again after gastric emptying. A recent study was conducted showing kibble fed dogs had an average stomach pH of 2 – the claim that raw fed pets have a more acidic stomach pH in comparison to kibble fed pets is yet to be studied so cannot be proven. Stomach pH fluctuates in response to a variety of factors and stimuli however diet does not permanently change the stomach’s normal fasting pH. So the argument that raw diets increase stomach pH making it “safe” to overcome the bacterial content in the diet is inaccurate, and given the average pH of a human stomach is 3.0, it goes to show pets are no more able to handle consuming raw meat than we are. In addition to this, the risk of handling raw meat to the owner preparing it is significant and often a factor that isn’t taken into account when deciding to feed this diet; dogs being fed a raw diet had faeces that were positive for Salmonella (compared to pets on traditional kibble diets that were negative) which clients then handle when picking up faeces thus exposing them to Salmonella again. Immunocompromised individuals such as children, the elderly, pregnant women or clients undergoing chemotherapy or immunosuppressive treatments could become severely ill around pets that are raw fed and should never feed a raw diet. In addition to this, pets can also become ill from food borne pathogens, they are not immune as many proponents try to claim. I personally have seen a number of dogs hospitalised due to a raw meat diet, and a recent study from the University of Melbourne showed dogs fed raw chicken necks developed paralysis as a result of Camplyobacter infections.
3. Zoonotic disease
Following on from number 2, the risk for zoonotic disease is my third reason I don’t recommend raw feeding. With the global struggle against COVID-19, we should all be well acquainted with zoonotic diseases and how incredibly dangerous they can be. Pet owners are handling their pet’s faeces, their pets lick their face or pets lick their coat which we then stroke which provides a easy path of transmission of pathogens to the owner. As a veterinary professional with an autoimmune disease, this is a deep concern for me and my colleagues who handle patients daily; clients don’t always consider they are not the only people handling their pets! The groomer, the person on the street, the pet sitter, visitors to your home, children, etc are all handling your pets and when you feed a raw diet, you are putting their lives at risk. Yes, I said it. Their lives. Zoonotic diseases can be incredibly dangerous and life threatening – in the UK there were 13 cases of cats that become sick with tuberculosis recently, due to being fed a raw diet. Thankfully the owners did not catch it or develop symptoms, however this disease is very contagious and was thought to be eliminated in the Western world thanks to antibiotics. Due to the potential for human disease, as veterinary professionals we need to remember our obligations to protect human health through our work with animals and unfortunately due to raw diets, we are seeing a resurgence of these deadly pathogens, which leads to my next point…
4. Antibiotic resistance
When you are infected with a bacterial pathogen, typically your doctor will place you on antibiotics to help you fight off the disease. The problem is that some bacteria can develop a resistance to antibiotics (sometimes multiple types of antibiotics) meaning it can be incredibly difficult to fight off a disease and have life threatening consequences. Pets that are eating a raw diet have been found to carry resistant strains of certain bugs meaning if the owner was to become infected with it, antibiotics that are normally used to easily treat these infections will not work and the owner could rapidly become severely ill or die, and if owners are already immunocompromised or have family members that may be, the consequences of this could be absolutely dire.
5. Anecdotal benefits
Yes, there are some benefits of raw feeding – however these benefits are largely anecdotal and over-inflated. A study by Kerr et al (2012) suggested that the raw diet reported a marginally higher digestibility than kibble diets – however, this was for protein only. The fat, energy and dry matter digestibility showed no difference to a kibble diet. Heating up a raw diet in the microwave then provided the exact same digestibility to that of a kibble diet, so the idea that raw food is more easily digestible because it is raw is not necessarily the case – cooking actually improved the digestibility of ALL nutrients thus showing that a cooked diet doesn’t actually cause a reduction in digestibility, but can improve the digestibility of all nutrients in the diet even if it is marginal and would reduce the bacterial load aswell. Therefore, a gently cooked or high quality kibble diet could provide the same benefit as a raw diet if digestibility is a concern. As for other benefits that are often reported from raw diets such as improvements in skin and coat, better dental health, reduction in allergies, etc these unfortunately are not supported by scientific evidence; improved skin and coat can be due to a number of factors such as the elimination of an allergen or the addition of an essential fatty acid source, improved dental health may be due to chewing meaty bones however could also be achieved with a VOHC approved dental chew, and reduction in allergies or weight can also be achieved with a targeted diet to tackle those issues.
So there’s my five reasons why I don’t recommend feeding a raw diet to your pet. I feel it is my moral obligation to provide clients and veterinary professionals all the information when it comes to raw diets so they can make an educated choice and be aware of the risks to your pets and family when choosing a pet food, and have all the facts to hold a respectful conversation when it comes to raw feeding.
In my opinion, I just don’t believe it’s worth the risks. Kibble has its issues, and not all kibble diets are created equal – believe me, I know. Yes, there are problems with both types of diets when it comes to contamination. However, we need to weigh the good with the bad and make a educated choice before flatly claiming every food under the same category is “good” or “bad”. Nutrition is not black and white, we are learning more everyday and I hope we can all at least agree that we don’t know everything – but what we do know is concerning.
My final word:
As I mentioned above, if you still wish to feed a raw diet, power to you. I strongly recommend using a pre-made raw diet or a diet that has either been gently cooked or freeze dried to reduce the bacterial load. A diet that is strictly quality controlled and balanced is always a must and if you wish to home-prepare, seek a recipe or formulation from a Board Certified Veterinary Nutritionist.
DeLay J, Laing J. Nutritional osteodystrophy in puppies fed a BARF diet. AHL Newsletter. 2002;6:23
Hypervitaminosis A in the cat: a case report and review of the literature. Polizopoulou ZS, Kazakos G, Patsikas MN, Roubies NJ Feline Med Surg. 2005 Dec; 7(6):363-8
Kerr KR, Vester Boler BM, Morris CL, et al. 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. J Anim Sci 2012; 90: 515–522.
Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Joffe DJ, Schlesinger DP Can Vet J. 2002 Jun; 43(6):441-2
The occurrence and antimicrobial susceptibility of salmonellae isolated from commercially available canine raw food diets in three Canadian cities. Finley R, Reid-Smith R, Ribble C, Popa M, Vandermeer M, Aramini J. Zoonoses Public Health. 2008 Oct; 55(8-10):462-9
Nüesch-Inderbinen Magdalena,Treier Andrea, Zurfluh Katrin, Stephan Roger, 2019. Raw meat-based diets for companion animals: a potential source of transmission of pathogenic and antimicrobial-resistant EnterobacteriaceaeR. Soc. open sci.6191170191170http://doi.org/10.1098/rsos.191170
Vester BM, Burke SL, Liu KJ, et al. Influence of feeding raw or extruded feline diets on nutrient digestibility and nitrogen metabolism of African wildcats (Felis lybica). Zoo Biol 2010; 29: 676–686