Search results for: Raw diet

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Issues with raw diets and H5N1 influenza risk in cats (and dogs) have gotten a lot of attention in the last week or two. Like most emerging disease situations, it’s still fluid, and we’re learning more as time goes on, but we know enough at this point to at least make some basic assessments and recommendations. Here’s my current take on it.

What are the concerns with H5N1 influenza and raw diets for pets?

The unprecedented pandemic of H5N1 highly pathogenic avian influenza (HPAI) has ongoing for more than 2 years. Massive numbers of wild birds have been affected around the world. Spillover into domestic animals is an ever-present risk where this virus is circulating in wild birds, with domestic poultry being the most severely affected. Millions of domestic poultry have died or been depopulated due to infection, and spillover infections have also occurred in mammals, including many cats and at least one dog.

Recently, H5N1 influenza infection has been linked to consumption of contaminated raw meat diets in at least two cats. It’s been well established for some time that ingestion of infected birds can lead to H5N1 influenza infection in cats, based on earlier studies and field observations. It is therefore unsurprising that infections could occur if infected poultry makes its way into raw diets fed to cats, and unfortunately the infection in cats is often fatal.  The risk to dogs is less clear, but infection was reported in one dog that died shortly after close contact (chewing on) an infected bird. Dogs may be less susceptible to H5N1 influenza than cats, but they are still susceptible and infection can have dire consequences, so the same concepts apply to both species.

What types of raw diets for pets pose a risk of H5N1 influenza infection?

Poultry-based diets are the main concern, including chicken, turkey and duck, as all poultry are highly susceptible to H5N1 influenza. However, the virus is now also widespread in dairy cattle in the US, particularly in certain states (like California at the moment). Work done by the Food Safety and Inspection Service (FSIS) in the US has found no evidence of virus in retail beef samples and only very low levels of virus in samples from 1 of 185 cull dairy cows tested (the positive cow did not enter the food chain). More investigation is needed, but it is likely that viral loads in muscle of infected cattle are far less than those in poultry. Risks from beef are presumably low, but the potential for the virus to be present in meat from infected dairy cattle cannot be dismissed.

Does use of “human grade” meat in raw diets eliminate the risk?

Human grade meat does not mean pathogen-free – it only means that the meat would have been allowed for sale for human consumption based on more rigourous requirements for the animals, facilities, processing and handling. These presumably reduce, but do not eliminate,  the risk of H5N1 infected animals entering the pet food chain.  

Does high-pressure pasteurization of raw diets eliminate H5N1 influenza virus?

High pressure pasteurization (HPP) of food products uses high pressure (rather than high heat, as in cooking) to reduce contamination with bacteria and viruses. Many commercial raw diets for pets are high pressure pasteurized (which is good). The pressures achieved during this process should inactivate influenza virus, but there are no standard methods for HPP. The effectiveness of HPP depends on the pressure, temperature, and composition of the food matrix. It is unclear whether manufacturers have developed and validated the method for their wide range of diets and pathogen risks. Recalls of high-pressure pasteurized raw diets because of Salmonella contamination have been regular occurrences, and a recent infection in a cat was linked to such a diet. High pressure pasteurization should be considered a risk reduction step, not a risk elimination step.

Are frozen or freeze-dried raw diets lower risk for H5N1 influenza?

Freezing and freeze drying are effective preservation methods for viruses, so its unlikely that these methods substantially reduce the risk of viral contamination in raw diets. Ultralow freezing is used for longterm preservation of viruses, but shorter-term survival is also possible at temperatures achieved using normal freezers (-20C). A study of the survivability of H7N9 influenza on raw chicken meat (Dai et al. Lancet 2022) reported that viral infectivity was maintained for 9 days at -20C, 4 days at 4C and 4 days at 25C. This was a rather small study, so it is possible that somewhat longer survival could occur in some situations. In nature, long term (e.g. overwintering) survival of influenza virus in ice has been suspected.

While the survival kinetics of this virus with freezing are not clear, it should be assumed that the virus could survive frozen for at least a week, and possibly much longer. Freezing should not be assumed to be a risk mitigation measure for viral contamination of raw diets.

Freeze drying is a highly effective virus preservation method. Survival of virus in freeze dried food has not been assessed, but in the absence of specific evidence, it is reasonable to assume that influenza virus would survive for long periods of time in such diets.

My cat is doing well on a raw diet and I don’t want to change. What can I do?

Raw diets can be cooked so that the cat receives a diet with the same ingredients but without the risk from H5N1 influenza (and other pathogens). There is no evidence that cooking reduces the health benefits of a diet. Cooking the food to an internal temperature of 165F/74C will inactivate influenza virus and other pathogens such as Salmonella.  

My cat has eaten a raw diet that’s been recalled diet. What should I do?

You should observe your cat closely and contact your veterinarian in you are concerned or your cat develops any signs of illness. Antiviral prophylaxis could be considered in particularly high-risk situations where it is likely that the cat has eaten contaminated food. This may not be the case for all recalled diets and would depend on the nature of the recall. Early signs of H5N1 influenza in cats are not well established, but often seem to be vague signs such as lethargy, malaise and decreased appetite. Rapid progression to severe disease can occur so veterinary care should be sought as soon as possible.

My cat has eaten a raw diet that’s not been recalled. What should I do?

Unless there is evidence that the diet has been implicated in disease, the odds of a problem developing are low. However, it would still be ideal to transition the cat to a cooked diet, whether that’s a commercial wet or dry diet, a home-cooked diet or cooking the cat’s current raw diet. Monitoring of your cat for illness, as above, is still indicated, as always.

What are risks to people from contact with contaminated raw diets?

The risk to people from H5N1 influenza from handling contaminated raw diets is likely quite low but not zero. Exposure could happen from inadvertent ingestion of the virus from contaminated surfaces (e.g. food prep surfaces, refrigerator, food bowls). That would likely be low level exposure, but the infectious dose of the virus is not known so it could still be relevant. There are similar risks with these diets from pathogens such as Salmonella, so good food handling practices are always warranted. These include avoiding cross-contamination with human foods and kitchen surfaces, careful cleaning and disinfection of in contact surfaces, dishes and utensils, and thorough handwashing (or use of an alcohol-based hand sanitizer) after contact with the raw diet or food bowls.

The greatest risk to people would be from exposure to a cat (or less likely a dog) infected with H5N1 influenza. An infected animal might be shedding enough virus to infect people, although the risk of this is still unclear. Any cat or dog with suspected influenza should be handled sparingly, and with use of good infection control measures, including a mask (ideally an N95 respirator) and eye protection.  

Closing thoughts

My opinions on raw diets have been pretty clear all along. I don’t think there’s any evidence that raw diets have any health benefits over an appropriate cooked diet, but raw diets come with numerous infectious disease risks. I’ve seen enough dogs and cats (and sometimes owners) sickened from raw diets to be confident in that. At the same time, I’m a realist and know that some people will continue to feed pets raw diets regardless. That’s why we have a infosheet about raw diets that includes ways to reduce the infectious disease risks for those who choose to feed them to their pets.

The current situation doesn’t really change anything for me. I’m still opposed to raw diets for pets, and this simply adds yet another layer of risk to pets and people that consume/feed them.

If someone is adamant that they are going to feed their pet a raw diet, here’s what I currently recommend:

  • Avoid diets that contain poultry (including duck)
  • Use a diet treated with high pressure pasteurization (realizing it reduces risk, but does not eliminate it)
  • Take care to avoid cross contamination of human food, and use good food handling and hygiene practices (always)
  • If your pet has been fed raw meat and gets sick, make sure your veterinarian knows about the diet so they can consider whether that might be relevant
  • Pay attention to the news and recalls so that you can stop feeding a diet if there are any known issues (but realize that we don’t typically know about any issues until one or more animals gets really sick or dies from the diet)
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Hot on the heels of the recent death of a cat in Oregon due to H5N1 influenza infection linked to a raw diet (that some raw diet proponents are trying to deflect or downplay), we have confirmation of a very similar case in California. Los Angeles County Public Health has issued a notice to avoid feeding Monarch Raw Pet Food “due to detection of H5 bird flu in product samples.” (note the plural). H5N1 was confirmed in one cat that was fed this diet and is suspected in four other cats from the same household.

The diet type was not reported, but the company’s website indicates “Our pet food is made of human grade USDA free-range poultry that is raised in the San Joaquin Valley.” Free range poultry are at increased risk of H5N1 infection from wild birds. Nonetheless, it would be interesting to know how infected poultry made it into the food chain (even the pet food chain), since H5N1 influenza usually causes widespread illness and death in domestic poultry, so it’s pretty obvious when it hits a poultry farm (and sick birds cannot be sent to slaughter).

The status of the infected cat wasn’t reported, but H5N1 infection in cats is often fatal based on what we know to date. Hopefully the cat had a milder infection, but I assume it was at least worse than a routine upper respiratory tract infection, since testing is usually limited to pets that are pretty sick.

The good news is that food-associated H5N1 influenza risks are totally avoidable… just don’t feed pets raw diets. The cost:benefit calculus is pretty easy since this virus kills cats and there are no health benefits of raw diets. More information about raw meat-based diets for pets (beyond the risk of H5N1 flu) can be found in the Worms & Germs / OAHN Raw Meat Diets infosheet, available on the Worms & Germs Resources – Pets page.

People can get pretty fired up when I talk about raw diets for pets. I’ll start off with my personal bias: I’d rather not see pets fed raw meat and raw animal-based products (e.g. pig ears and various bits-o-cow you can find in pet stores). There are clear risks to pets and owners from raw diets, including infectious and non-infectious issues. I’ll stay in my lane and focus on the infectious disease topics here.

We, and others, have shown that pets fed raw diets have high rates of shedding of certain bacteria that can cause disease.  I’ve been involved in various investigations of disease in dogs and cats (and some in owners) linked to raw diets for pets. At the same time, I’m a realist and recognize that the risk isn’t overwhelming for most people and pets, and not everyone is going to change their pet’s diet as a result of said risk.

So, I approach raw diets from the standpoint of “I’d rather not see them used, and there are almost always acceptable, lower risk commercial cooked diets available” but at the same time “The risk is probably low for most dogs and owners, but some situations are clearly higher risk.” I’d rather spend my energy focusing on situations where I think it’s a really bad idea, and try to give some guidance to people that insist on doing it. That way I can still engage people, rather than push them away with a more dogmatic approach.  That’s why we created a factsheet for pet owners about raw diets (to be honest it needs an update, but it’s still useful as many of the risks themselves haven’t changed… but more on that below).

We have to keep our eye on this issue and be alert for new information that changes the story in any direction.  Initial work on raw diets focused on Salmonella, and that’s still an issue.  However, in the past few years, my bigger concern has been antibiotic-resistant bacteria like E. coli. Dogs fed raw diets have much higher rates of shedding of multidrug-resistant Gram negative bacteria like E. coli in feces. Eating a raw diet seems to be as much of a risk factor as the dog being treated with antibiotics (probably because antibiotic treatments are short term while feeding is much longer term exposure). What this means for human or animal health isn’t clear, but raw pet food-associated infections have been identified in people and a dog carrying a resistant bacterium in its gut is likely at increased risk of developing an infection with that bacterium. For E. coli and related bugs, urinary tract infections would be among the most common issues, but a wide range of disease can potentially occur.

That’s a long introduction to the paper that prompted this post. The study in question (Mounsey et al, One Health 2022) doesn’t change the story at all, but adds more pieces of evidence.

In this study, they collected history and fecal samples from puppies at 16 weeks of age. Those samples were tested for antimicrobial-resistant E coli.

  • They ended up recruiting 223 puppies, 43 of which were being fed a raw diet.
  • 32 (74%!) of the raw-fed puppies were shedding E. coli resistant to at least one antibiotic, compared to 76/180 (42%) of the other puppies.
  • They looked at a number of other potentially contributing factors, such as where the dogs were walked, and didn’t find anything else that was associated with resistant E. coli shedding.
  • When they looked at resistance to individual antibiotics, raw diet feeding was associated with resistance to many drugs, with the strongest effect for fluoroquinolones, a drug class classified in the highest priority critically important antimicrobial group for humans.
  • When they looked more at the fluoroquinolone-resistant isolates, they found that many were strains that were found in urinary tract infections in people in the same area.

So, I’ll stick with my “I’d rather not have people feed their pets raw diets” line, with the added “I  REALLY don’t want to see those diets fed to very young pets, old pets or pets with immunodeficiencies, OR in households where someone is very young, elderly, pregnant or immunocompromised.”

If someone’s intent on feeding a raw diet, risk reduction is the key (risk elimination being impossible).

Diet selection is part of that. Some diets are treated to reduce (not eliminate) microbial contaminants, usually using high pressure pasteurization, which applies pressure to kill bacteria and parasites in the product. It’s not perfect by any means, but it’s useful in decreasing the microbial load. Sticking with companies that provide information about their quality control and risk reduction plan is good too. Some raw diet companies do a good job. Others… well, not so much.

Beyond that, it’s a lot of good ol’ common sense, hygiene and hand washing. Our raw diet factsheet has some information, and any good food safety infosheet will have a lot of tips that apply equally to handling raw diets for pets as they do to handling raw products during food preparation for people.

A recent study looked at human illness associated with raw pet food and has led to headlines such as “It is safe to feed raw pet foods.”

Did the study say that?  No, it did not.

If you asked 100 people if they had a foodborne disease in the past year, I assume few would say “yes,” despite the widespread estimate that about 30% of people get a foodborne illness every year. If you ask people if they got a foodborne disease from a specific food, the numbers would be even weaker / lower. People generally don’t have good recall for things like that, since we don’t usually recognize a cause when we get intestinal disease. The odds of someone linking their vomiting or diarrhea to their pet’s food are low, especially if they have no awareness that their pet’s food is a risk. Even if someone thinks about the source of their disease (which probably isn’t overly common), would they think about their pet’s food as the source, versus other foods in the house, versus a restaurant, versus anywhere else they ate? I suspect the average pet owner would not.

The problem isn’t the study, it’s how the study has been interpreted. It didn’t (and couldn’t) get a good estimate of the burden of disease associated with raw pet diets. The title of the study is Owners’ perception of acquiring infections through raw pet food: a comprehensive internet-based survey (Anturaniemi et al, Vet Rec, 2019). It looked at perceptions, which is useful, but has a lot of limitations.

The study was an internet survey of pet owners who fed raw diets. Internet surveys are easy to do, but are problematic for a few reasons. When you ask 1000 people to complete a survey and 990 respond, you know you captured your population well. If 10 respond, you know you haven’t and maybe you have a biased group of respondents (e.g. people that were more motivated / biased one way or another might be more likely to respond). With an internet survey, you generally have no idea how many people got the survey, and therefore no idea what percentage of people responded. The survey was disseminated through the research group’s Facebook page and through the researchers’ own academic, private and industrial contacts, so the people invited may not reflect the typical pet owning population. That doesn’t mean the results are useless (I’ve done internet surveys myself), it just means we need to be careful interpreting results. I tend to approach surveys as tools to get some basic information to figure out what questions to address more thoroughly, rather than tools to  answer specific questions.

The main question that was asked in this study was “Are there/have there been people in your household that have become sick from handling raw pet food or that have become sick from contact with a raw pet food eating pet?”

That’s a question we want to answer. However, it’s not a question the general public is well equipped to answer themselves.

  • The sample size was large (16,475 households), which is good, but there’s not much information about the households to determine how reflective they are of the broader population.
  • Most had been feeding raw diets for years, but some were pretty recent (e.g. 0.1 years, which is not much time for someone to get sick as a result).
  • Overall, 0.2% of households reported a “confirmed” transmission from the pet or food. That’s a relatively small number, but 0.2% per year means a lot of sick people. I’m actually surprised that people reported getting sick from their pet’s food at all. I’d expect massive under-recognition and under-reporting, so seeing any reports is interesting. If you consider that in most foodborne disease, reported cases usually account for less than 10% of the real number (and probably less than that here), the true burden of disease based on these numbers is quite a bit higher, to a level I’d certainly be concerned about.
  • Salmonella and Campylobacter were most the commonly reported infections. However, most of the time, there was no effort to confirm the pet food as the source, so it’s hard to say what the numbers really mean.
  • In situations where there was “confirmed” transmission, 31% of the time the pet was sick at the same time. That maybe strengthens the association between human and animal disease, but also maybe shows potential bias. Are people more likely to blame the pet/food if both they and their pet are sick at the same time, and blame human food or not consider pet food if the pet isn’t sick? I have no idea, but that could greatly influence self-reported data.
  • Interestingly, raw foods were handled in the same place as human food and with human food utensils significantly more often in the negative households. That’s the opposite of what I’d expect. The counter argument might be that people who handle raw pet food poorly are not tuned into the risks and are therefore less likely to identify or blame the pet food if they get sick.

The authors sum things up in a more balanced manner than internet headline writers:

“As a conclusion, this large study population from all over the world shows that the transmission of zoonotic pathogens might happen, but it seems to be sporadic. It is clear that the precise source of the pathogen is often challenging to find, which makes the interpretation of the result difficult. However, studies using different kind of approaches should be conducted in the future to be able to get a better understanding of the true risks or possible health benefits of feeding raw food diets to pets. This way the true pros and cons can be accurately analysed, before asking pet owners not to feed their pets with a nutritionally balanced raw diet.”

That’s a good conclusion. This study provides some baseline information and can help tailor future studies. It helps us figure out how to get a good answer rather than giving us a good answer now.

More information about ways to reduce the risk from feeding raw diets is available on the Worms & Germs Resources – Pets page.

Back in 2008, we reported an association between feeding raw diets to dogs and shedding of cephalosporin-resistant bacteria in dogs (that makes me feel old… one of many things that does these days, I guess). It didn’t get too much attention at the time, since the main focus of the study was on Salmonella, the most commonly discussed concern with raw diet feeding. We also didn’t pay as much attention to those other bacteria 11 years ago.

I was speaking about antibiotic resistance at the 2019 ACVIM Forum in Phoenix AZ last week, and extended-spectrum beta-lactamase (ESBL)-producing bacteria kept coming up – not just from me, but also in lots of questions from the audience. ESBLs are enzymes that bacteria produce to break down some commonly used (and important) antibiotics, including 3rd generation cephalosporins. These bacteria also tend to acquire various other resistance genes, making some strains highly drug-resistant. ESBLs can be produced by a range of Gram negative bacteria, most notably E. coli, and these bacteria are causing more and more problems. Bacteria can also be resistant to 3rd generation cephalosporins via a different resistance mechanism that’s also of concern. Sometimes, studies focus just on ESBLs while others cover cephalosporin resistance by other mechanisms as well. Resistance by either mechanism is a problem.

One thing that got a lot of people talking at the conference was discussion of things that increase a dog’s risk of shedding ESBLs (or, more broadly, antibiotic-resistant bacteria). One risk factor is previous antibiotic treatment. That’s not surprising. The other big risk factor that’s come up in a few recent studies happens to be feeding raw diets.

  • Our study from 2008 reported dogs that ate raw meat were 15X more likely to shed cephalosporin-resistant E. coli.
  • A UK study reported an 11X higher risk of shedding 3rd generation cephalosporin-resistant E. coli by raw fed dogs. (Schmidt et al. 2015)
  • Another study from the UK reported that dogs that ate raw poultry were 48X as likely to shed ESBL E. coli compared to dogs that didn’t. (They were also 104X (!!) as likely to shed E. coli resistant to fluoroquinolones, another important drug class). (Wedley et al. 2017)
  • In a Dutch study, dogs that were fed raw meat were twice as likely to shed ESBL producing E. coli. (Baede et al. 2015)
  • The same Dutch group also looked at cats, and found that raw feeding was the only factor associated with shedding ESBL-producing bacteria, with a 32X increased risk. (Baede et al. 2017)

These results are actually not surprising.  Resistant bugs can be present in food animals, and those bugs can then contaminate the meat from those animals at slaughter or a subsequent step in the production chain. Measures are taken to reduce the risk, but whether it’s an “ultra-premium” raw diet product or meat from the local grocery store, there’s always some risk of bacterial contamination. That’s why we cook meat, and why we should always use basic hygiene practices to reduce cross-contamination and inadvertent exposure to harmful bacteria in the kitchen and elsewhere.

I won’t get into the whole raw diet discussion here but will hit on some of my highlights:

  • Raw feeding is associated with risk to the pet and owners, and should be avoided whenever possible.
  • In some situations, raw diets should never be fed to pets, including households with young kids, elderly individuals, pregnant women or immunocompromised individuals, or with animals that fit into similar risk groups.
  • High-pressure pasteurization likely reduces contaminant levels but doesn’t sterilize the food. If someone is going to feed a raw diet, they should use one of these diets but still consider the food contaminated.

More information about raw diets and how to reduce the risk when feeding a raw diet is available on the Worms & Germs Resources – Pets page.

CTV has a consumer reports segment and a recent topic involved feeding pets “natural” diets (although no one ever defined what that really means). In the report on the CTV Consumer Alert website (it’s currently about the third story into the video if you just press play, or you can shortcut to it using the link below the main video window), a 26 year old cat is held up as a poster child for the health benefits of raw food. Making it to 26 is a noteworthy accomplishment for a cat, but it’s far from rare, and you can’t know whether the cat survived because of its diet or despite its diet. At the end of the clip, they mention he cat has kidney disease, not an uncommon problem in older cats but one that is often blamed by raw proponents on commercial foods. It’s also not a condition that I’d want to see someone try to manage with a raw diet.

Anyway, the story has the typical statements (including one from a veterinarian) about how raw and “natural” diets produce a healthier animal, stronger immune system and shinier haircoat, but without citing any proof (because there is none) and with no discussion whatsoever about the potential animal and public health impacts of raw meat feeding.

Good investigations are good. Quick reports put together with little thought or consideration of the issues are just time filler. The host, Pat Foran, said in his conclusion that “natural” pet foods have less filler so there’s less to come out the back end of the dog. Well, news reports comprised of filler produce the same kind of by-product.

If you are going to feed raw, at least take the time to research how to do it safely, both for your pet and your household. Raw feeding can be done in a nutritionally sound manner, but it takes time, effort and money. Some people are willing and able to do that, but if you’re not, don’t feed raw. Raw feeding also carries some risk of gastrointestinal disease like salmonellosis in the animal as well as exposure of people in the household to those same bugs. Certain households, particularly those with high risk individuals (e.g. elderly, infants, pregnant women, immunocompromised persons) should avoid raw feeding or only use products that have been high pressure pasteurized. There are a few commercial raw diets that are treated in this manner and these are preferable as the process should kill most relevant bacteria, reducing or eliminating the infectious disease risks to pets and people.

Like many other things in life, the key is being informed so you understand the risks and benefits, and whether recommendations made by people have any substance behind them. Too often, people make a major change like feeding raw based on a comment on a website or from another dog owner, with no clue about the issues and no effort to figure out how to do it right. That’s just asking for problems.

More information about raw diets can be found on the Worms & Germs Resources page.

Delta Society has recently announced a policy prohibiting animals fed raw meat or raw animal products from participating in their Pet Partners program. This policy was established because of research indicating dogs fed raw meat are much more likely to be shedding harmful bacteria like Salmonella and drug resistant E. coli in their feces compared to dogs fed commercial or home cooked diets, and the fact that these dogs come into close and frequent contact with people that are more susceptible to infections and at increased risk having severe infections.

Not surprisingly, internet chat sites are abuzz, and there’s much condemnation and consternation from some. Some of the more vocal minority are stating that they’ll just lie and say that they’re not feeding raw.  I guess such dishonest actions would be based on a combination of ignorance and arrogance – feeding raw is your own decision, but blatantly flouting a policy that was put in place to reduce risks to those most susceptible is stupid and irresponsible.

One of the problems with peoples’ reactions is the fact that they are confusing two separate issues. One debate is whether raw feeding is more healthy or more harmful to the pet. That’s a controversial area, but this policy has nothing to do with that. This policy deals with the increased likelihood that raw-fed pets are shedding harmful bacteria. That’s been very well proven in scientific studies. Do raw-fed pets cause disease in people in hospitals? We don’t know. However, we have enough evidence to indicate there is the potential for increased risk to patients, and that added risk can be eliminated by not feeding raw meat products.

Hopefully, people will realize that this policy has been put in place for a good reason, and that it’s focused on protection of people at high risk of serious illness. It’s not a broad condemnation of raw diets, it’s just a statement that it is not considered appropriate for dogs that will have contact with high risk populations – a recommendation that’s far from new.

Details about this policy can be found here.

Disclosure: I’m a member of Delta Society’s Medical Advisory Board. However, the opinions expressed here are mine and do not necessarily reflect the views of Delta Society.

PetProductNews.com reports that Nature’s Variety, a raw pet food company, has unveiled results of a recent "research study" on their products. Whenever you see "research," especially on the web, you need to consider whether it’s really valid scientific information or a marketing ploy. This particular case certainly doesn’t seem like anything approaching real research.

Apparently the study, commissioned by Nature’s Variety, involved the feeding of six adult dogs variations of different diets over a 4.5 month period. They looked at stool quality, volume and odor, blood chemistry, quality of their skin and coat and body weight.

  • In research, we worry about sample size. You need to have enough animals to detect any real differences. With 6 dogs, 4.5 months of feeding and different diets, you don’t have much of a chance to detect a problem (or a benefit, usually). You could have a diet that kills 10% of the dogs that eat it every year and not detect it in study of that size!
  • The number of dogs and time don’t even fulfill AAFCO feeding trial requirements, so this doesn’t provide any information that would be accepted using standard requirements.

Nature’s Variety director of research stated “It’s kind of a sigh of relief.”

  • It’s pretty concerning that the head of research would be relieved that there were no obvious health problems in such a small study. If they don’t have real confidence in the quality of the food, why are they selling it? If you have confidence in your diet, you say "Of course, as expected, our diet was shown to be nutritious and safe…" not "Wow, we’re really happy no dogs died!" Research to indicate safety and nutritional value should be done before you sell, not well after.

Duclos said she expects the study to be published in a peer-reviewed journal in about one year.

  • Not likely. For one thing, from what they are releasing, it’s very weak and not defensible scientifically. For another, they’ve already released the results. It’s inappropriate for people to release results before they’ve undergone peer review, and releasing data in a press release will probably prevent any reasonable journal from even considering the study.

It’s good that Nature’s Variety is trying to do some research. It’s also good that they’re addressing Salmonella contamination following their recent recall. The fact that they are doing something progressive is an encouraging sign. However, they need to do proper research, and make sure it undergoes appropriate scrutiny, instead of using small and relatively useless studies to generate press releases.

Raw feeding has inherent risks of exposure for people and pets to potentially harmful bacteria like Salmonella. Raw feeding can probably be done safely for both the pet and people in some, but not all, situations. More information about raw meat feeding can be found on the Worms & Germs Resources page. 

Click image for source.

Meat QuestionFeeding raw meat diets to dogs is a very controversial issue. Some proponents passionately advocate these diets (e.g. the BARF diet) based on vague and unproven recommendations. Opponents cite various studies showing that pets fed raw meat (not surprisingly) have high carriage rates of potentially harmful bacteria such as Salmonella, and reports of diarrhea or nutritional imbalances in these animals. However, there have been only a few good studies looking at the true health benefits and risks of feeding these diets to dogs.

A recent study in the journal Zoonoses and Public Health described the risks of therapy dogs shedding Salmonella and other potentially harmful bacteria. The authors tested 200 dogs over a 1 year period, 20% of which were fed raw meat as part of their normal diet. Dogs fed raw meat were 23 times more likely to shed Salmonella compared to other dogs. They were also 17 times as likely to be shedding extended spectrum beta-lactamase (ESBL) Escherichia coli (a highly drug-resistant form of E. coli).

The study concluded that, because of the risk of Salmonella shedding and the high-risk nature of the patients and other people that therapy dogs interact with, dogs that are involved with hospital/patient visitation programs should not be fed raw meat.

What does this tell us about feeding raw meat to pets?

Although this study doesn’t answer all of the questions about the risks of raw meat diets, it reinforces the fact that pets fed raw meat have significantly higher rates of shedding of potentially harmful bacterial such as Salmonella and antibiotic-resistant E. coli. Eating pig ear treats has also been associated with Salmonella shedding. However, there was no association between a dog being fed raw meat and the animal itself developing diarrhea. In fact, raw-fed dogs had a lower incidence of extra-intestinal infections (combination of eye, ear, skin and urinary tract infections).

In general, raw meat diets should be avoided. While adverse health effects were not reported in this study, disease (including deaths) from Salmonella has been reported in dogs in other studies. While the overall risk may be low, feeding raw meat is an avoidable risk. However, it would be inappropriate to completely ignore the finding that raw-fed dogs had lower rates of certain infections. It is possible that there can be health benefits from feeding raw meat in certain dogs, but the potential benefits must be weighed against the potential risks to the animals and people with which the has contact. Raw meat diets should never be fed to pets that have contact with immunocompromised people (in the household or as part of visitation program), infants or the elderly.

If you are going to feed raw meat to your pet, make sure you take precautions to reduce the risk of infecting yourself or someone else. We’ll post more on that aspect soon.

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Blue Ridge Beef has (again) recalled a diet because of Salmonella contamination – this time a kitten diet. As is often the case, the issue was identified after a pet that was fed the diet got sick. This follows a recall of a puppy diet from the same company in December for Salmonella contamination was identified after a litter of puppies got sick that was identified after a litter of puppies got sick. (It seems like a bit of a “stealthy” recall too, as I see no information on the company’s website about it.) Of note, the company states on its website that its diets are high pressure-pasteurized.

A recall of raw pet food for Salmonella isn’t surprising. Bacterial contamination rates in these diets are high, and recalls are only the tip of that iceberg. Recalls of high pressure-pasteurized diets are more noteworthy but unfortunately are also far from rare.

High pressure pasteurization (HPP) is a process used to reduce pathogen burdens in raw food. It should markedly reduce (or perhaps sometimes even eliminate) bacteria like Salmonella and viruses like influenza. However, as we repeatedly see in situations like this, contamination can still occur. Whether that’s because of an inadequate method for HPP or post-processing contamination is unclear, but it probably relates to using methods that are not adequately tested and validated for the specific food matrix.

These repeated recalls raise a number of issues. One is the standard concern about contamination of these diets with bacteria like Salmonella, that cause disease in dogs and cats, and sometimes owners who have contact with the diets or animals. More recently, we now also have important concerns about H5N1 avian influenza virus contamination of raw meat diets for pets, as multiple cat deaths have been linked to consumption of such raw diets (including diets that were high pressure-pasteurized).

I recommend not feeding raw diets to pets. We cook food for people to kill things that can hurt us, and the same concept applies to pet food. If someone insists on feeding a raw diet, I recommend a high pressure-pasteurized diet to help reduce the risks, but this certainly does not eliminate the risks. Pet owners need to be aware that (despite all the claims on various companies’ websites) there are still infectious disease risks to pets and people with these diets, and safe food handling practices in the home are critical to reduce the risks to people in particular.

Since there’s no health benefit from raw diets beyond equivalent cooked diets, it’s best to go with a cooked diet. Post-cooking cross-contamination of food can also still occur, so while they still aren’t zero risk, they are much lower risk than raw diets.