We’ve known for some time that there are human health risks from feeding pets raw meat-based diets. Most of the evidence of this has been anecdotal, as published reports have been sparse. A few better documented reports have started to appear, including the fatal E. coli O157 infection I wrote about recently.

A few days ago, the CDC released a report about an outbreak of Salmonella Infantis infections in the US. It involved 92 people from 29 US starts and was linked to raw chicken products. Raw chicken-based pet food was among the raw chicken products from which the outbreak strain was isolated, and one person got sick after their pets ate chicken-based raw food.

This isn’t particularly surprising since Salmonella contamination is an inherent risk with raw poultry. Human disease can occur when people ingest Salmonella from undercooked meat or from contamination of their hands or environmental surfaces (e.g. in the kitchen). When it comes to raw pet food, people can be exposed from handling the food, cross contamination of food or surfaces, contamination of the food bowl or exposure to Salmonella in in feces of the pet.

CDC’s recommendation is pretty straightforward: “CDC does not recommend feeding raw diets to pets. Germs like Salmonella in raw pet food can make your pets sick. Your family also can get sick by handling the raw food or by taking care of your pet”.

I have the same recommendation, but am realistic enough to know that it’s still going to be done by some people. It definitely shouldn’t be done in households with very young, very old, pregnant or immunocompromised people or animals.

If you are going to feed raw diets to your pet, do it wisely. More information about this is available on the Worms & Germs Resources – Pets page.

Human health risks from raw pet food (either from exposure to pathogens in the food or in the feces of pets eating the food) are known to exist but they’re not well characterized. We know that dogs fed raw meat-based diets clearly have increased risk of shedding various pathogens, particularly Salmonella and multidrug resistant E. coli. We know this results in some degree of disease risk in animals and in humans, but the scope of the problem is poorly understood. A recent report from Public Health England provides some more information about the risks associated with feeding raw pet food.

The report is about four people who were infected with E coli O157, a particularly nasty strain of E. coli that can cause serious disease in people.

  • One person developed hemolytic uremic syndrome (HUS), a particularly severe consequence of infection, and died.
  • The four cases involved the same strain of E. coli O157. Three individuals had been exposed to dogs fed a raw meat diet. Tripe was the specific ingredient that was implicated.
  • Samples of raw pet food were collected for testing. All samples from one raw pet food producer were positive for STEC (shiga toxigenic E. coli, the group to which E. coli O157 belongs). A positive test was also obtained from the freezer of one of the affected individuals, and from one sample of raw tripe. It strain isolated from the tripe was a different from the outbreak strain but supported the notion that tripe might have been the cause. It’s not surprising that they couldn’t isolate the outbreak strain from the food, given the lag from the time of exposure of people to the time of sampling of pet food. Contamination is probably sporadic, with different strains contaminating different batches.

Feeding raw meat-based diets is popular, but associated with risks to pets and people (have we said that enough times yet?). My preference is for it not to be done, but I’m realistic enough to know that people are going to do it anyway. So, I focus on two things:

  1. Who should definitely NOT feed raw meat to their pets?
    • Households where pets or people are at increased risk of severe disease, including those where young, old, pregnant or immunocompromised individuals (human or animal) are present.
  2. If raw meat is to be fed, how can the risk be reduced?

I think I’ve covered this before (probably a few times), but the question keeps coming up so it can’t hurt to talk about it again:

Is freeze-dried raw pet food any different than fresh or frozen raw diets, from a microbiological standpoint?

We don’t have much pet food-specific research, but there’s little reason to believe there would be much difference when it comes to the things we’re concerned about. When I want to preserve bacteria, I freeze them or freeze-dry them. Those are actually the preferred methods for long-term storage. Freezing or freeze-drying is a pretty hospitable process and state for most bacteria. Some, such as Campylobacter, don’t tolerate freezing (or especially fresh-thaw cycles) as well as others, so freezing or freeze-drying might have some impact on those specific bugs. For the higher profile pathogens like Salmonella and Listeria, it probably doesn’t make a difference.

The story is quite different for some parasites. Many parasites and parasite eggs don’t tolerate freezing (that’s why fish for sushi is typically frozen at some point). Some are hardier than others, though. Toxoplasma, a potentially important foodborne parasite, is susceptible to freezing, but only if the temperature is low enough and the time is long enough (e.g. -12C for 3 days will kill most Toxoplasma cysts).

So, the take home message is that for of the microbes that we’re worried about with raw meat,  freezing or freeze-drying is NOT a food safety practice. It’s food preservation, not bacterial control.

A recent report from the Netherlands in Emerging Infectious Diseases (van Dijk et al 2018) describes a new twist on raw feeding concerns, Brucella suis infection.  Here’s the short version of the story:

A dog in the Netherlands developed fever, ascites (fluid free in the abdomen) and inflammation of the testicles.  After failing to respond to antibiotics, it was taken to surgery to be neutered.  In the process, culture samples were collected from the epididymis (tissue adjacent to the testicle) and from the abdominal fluid. Brucella suis was identified in both samples, which presumably caused a bit stir in the lab and the clinic since this bacterium is a rarely identified, can also infect people and is federally notifiable in the Netherlands (i.e. the government has to be contacted when it’s found). Ultimately, the dog was euthanized after failing to respond to further treatment.

Because this is a notifiable disease, there was an investigation. The dog did not have any of the typical exposures that would increase the risk of Brucella infection, such as contact with wildlife or livestock, breeding, or travel to brucellosis-endemic areas.  The dog’s raw, rabbit-based diet that was imported from Argentina therefore became the leading suspected source. Brucella suis was ultimately identified in samples from a 30,000 kg batch of raw rabbit imported from Argentina, a country where B. suis is present.

It’s a single case report so we can’t get too worked up about it, but it’s noteworthy for a couple reasons:

  • Reason 1 is the disease – brucellosis is a nasty. It can be hard to treat, is potentially zoonotic, and sometimes results in public health-mandated euthanasia of the dog.
  • Reason 2 is the importation aspect. The dog wasn’t imported but the bacterium was, via food. We’re trying to increase awareness of the need to query travel and importation history in pets, as it can significantly impact disease risks. Querying diet origins is even tougher.  While most people know where their dog has been in the past few weeks, they may not know much about where their dog’s diet has been. With commercial processed food, it’s not a big deal, but with higher-risk food like raw meat, importing food can be similar to the dog visiting the country of origin, from a disease standpoint. With raw meat, knowing where the meat came from and the disease risks in those areas may be important, but often not easy to find out.

The incidence of disease in dogs and cats associated with raw meat feeding isn’t clear, and is probably low. Nevertheless, I recommend avoiding raw meat feeding, especially in  high risk households (e.g. with elderly individuals, kids less than 5 years of age, pregnant women or immunocompromised individuals). However, if raw meat is to be fed, some basic precautions can used to help reduce the risks.  For details, see the raw meat infosheet on the Worms & Germs Resources – Pets page.

I haven’t written much lately about recalls of raw pet food because of Salmonella contamination. In large part that’s because it’s essentially an expected event. There are very good reasons why we cook food – one is to kill things that can make us sick. We assume that raw meat intended for our consumption is contaminated with bacteria like Campylobacter and Salmonella (because it often is). Therefore, we similarly expect raw meat for pet consumption to be frequently contaminated. Various research studies have confirmed that.

Highlighting the issues and risks yet again is a recent recall involving Blue Ridge Beef of Eatontown, Georgia. They are recalling “kitten grind” (an unfortunate name, in my opinion, but that’s a different story) after consumer complaints of deaths of two kittens. One death was confirmed to have been the result of Salmonella. Salmonella and Listeria were identified in the food (although it’s not clear to me whether it was the same strain and the same lot). Regardless, it’s not too surprising. Salmonella contamination of raw meat is common, and while disease in animals is fortunately rare, it can happen, sometimes with fatal consequences.

This should be a reminder that handling and feeding raw meat is a risk for exposure to pathogens such as Salmonella. My main recommendation is “don’t feed raw” plain and simple. That’s particularly true in households where there are high-risk people (e.g. young kids, elderly individuals, pregnant women, immunocompromised individuals) or high-risk animals (same types as for people). If someone’s determined to feed raw, it’s important to reduce the risk as much as possible. More information about that can be found in our raw meat infosheet on the Worms & Germs Resources – Pets page.

As if another reason was needed, a recent study from Australia (Martinez-Anton et al. 2018 J Vet Internal Med) found a strong association between dogs that consume raw chicken meat and a serious neurological condition known as acute polyradiculoneuritis (APN).  APN is comparable to Guillain-Barré syndrome (GBS) in humans.  The main objective of the study was to look at the association between APN and Campylobacter spp. infection, but knowing that this bacterium is commonly found in raw chicken, they also looked at consumption of raw chicken as a risk factor.  Owners of dogs with APN were 71 times more likely to report feeding raw chicken to their dogs compared to controls.  Of the 27 dogs in the study with APN, 96% (all but 1) were fed raw chicken, compared to 26% of control dogs.

And of course, anytime we’re talking about feeding a raw diet to a dog, we also need to consider the risk to the people who handle the food as well.  According to the CDC, about 1 in every 1,000 reported Campylobacter illnesses in people leads to GBS, and as many as 40% of GBS cases in the United States are thought to be triggered by Campylobacter infection.

Just one more reason to avoid feeding raw chicken to pets, and some extra motivation to pay close attention to safe food handling practices at home.

When we have discussions about the risks of feeding raw meat to dogs and cats, a frequent refrain is “where are the published reports of people getting sick?” While we know some illnesses occur, they tend not to get investigated to the level that they are published, which is problematic when trying to demonstrate the risks. Often the cases aren’t published because of failure to follow up with food testing, disjointed testing of the food and samples from affected people, or issues coordinating the animal, food and human information (given various barriers, including privacy issues).

However, a recent investigation in the US shows yet again that this is a real concern. Salmonella Reading infection was identified in two kids in a household, and the same Salmonella strain was isolated from four samples of pet food, namely Raws for Paws Ground Turkey Food for Pets (which is now under a FDA recall). One child was hospitalized with septicemia (i.e. bloodstream infection, a potentially fatal disease) and osteomyelitis (bone infection).

Deciding whether to feed raw meat to pets requires consideration of the risks.

My approach is that I don’t think it’s a good idea for anyone, but if you’re considering it:

  • A) think about situations where it should never be done, and,
  • B) take measures to reduce the risk.

Check out our raw meat infosheet on the Worms & Germs Resources – Pets page for more information on how to reduce the risks if you’re going to feed raw.

Situations in which raw feeding should not be done include households with people or animals that are more likely to get sick or suffer serious illness, including those with young children, as was the case here.

Image source: CDC Public Health Image Library 21918

Raw meatAccording to an alert from the College of Veterinarians of British Columbia:

The BC Centre for Disease Control is collaborating with BC health authorities, the Public Health Agency of Canada, and Health Canada to investigate an outbreak of Salmonella infections in British Columbia likely related to raw pet food. Raw pet food is food served to pets that contains raw animal proteins like meat, bones, organs, and eggs.

Four British Columbians who feed their pets raw food diets have become infected with the same strain of Salmonella. The exact source of the Salmonella is unknown but investigations are ongoing. Infections can occur during handling of raw meat, including raw pet food, or from pets shedding the bacteria. Animals can carry Salmonella bacteria but show no signs of illness.

I haven’t seen any other details yet and hopefully contact tracing is narrowing it down to the food type. It would be good to know how widespread exposure might be, since foodborne disease is markedly under-reported and if 4 cases of salmonellosis were confirmed, it’s likely that many more have actually occurred. Diagnosed case numbers tend to be the minority because they miss people that had mild disease and didn’t go to the doctor, situations where fecal testing was not recommended by the physician, or where the requested fecal samples were not collected.

Raw meat feeding inherently poses some risk to pets and households. It’s of particular concern when there are high-risk individuals (old, young, pregnant, immunocompromised) or high risk pets (similar groups) in the household, as members of these groups are more likely to get sick and more likely to have serious illness.

More information about raw meat feeding, including recommendations to reduce the risk for those who still want to do it, is available on the Worms & Germs Resources – Pets page, under the infosheet for raw meat.

Dog foodI don’t usually write about recalls of raw pet foods because… well, finding Salmonella, E. coli or Listeria in raw meat is far from surprising (although certainly concerning). However, the recent recall of Stella & Chewy’s products because of Listeria contamination is noteworthy.


Because their food is treated with high pressure pasteurization (HPP). This process uses high pressure to destroy bacteria. I typically consider HPP-treated food to be similar to commercial cooked products in terms of the risk of bacterial contamination and public health concerns. Yet, I add in the disclaimer that actual evidence of effectiveness on pet food seems to be limited. It makes sense that it would work; however, a variety of factors impact the effectiveness of HPP, so companies should have data that show their specific process works.

The big question here isn’t “why were bacteria in the food?” It’s a raw animal-based diet, bacteria are common contaminants.  The real question is “why were live bacteria in the food?” Figuring out how Listeria made it through the HPP processing is critically important. Hopefully there’s a real investigation into this.

There are a few possible explanations that I can come up with, and they vary greatly in the level of concern they would cause.

Post-treatment contamination: Careful review of the manufacturing process and testing (culture) of various environmental surfaces would typically be part of in investigation of this issue. If this was the problem, things such as physical or procedural changes and more QC testing might be indicated.

Ineffective HPP: There could be two different scenarios:

  • One is a breakdown in the process, with equipment problems, human error or some similar issue preventing an effective method from working. This is a problem but would presumably be fixable.
  • The other (more concerning) scenario is that the procedure they use is not actually adequately effective for the pet food they’re manufacturing.

Figuring out the cause of the problem is important to reduce the risk and help people make informed decisions about buying raw products.

A group of flea (or flea and tick) collars have been removed from the market in France following a risk assessment. The review looked at these widely available, over-the-counter products that contain a variety of different chemicals. The determination was that the risks posed by contact with the collars (particularly to children) were unacceptable compared to the benefits.

As with most risk assessments, cost-benefit is the key. With flea collars, you have something containing a chemical that’s easily (and commonly) touched by people, and you also have the potential that young children could put them in their mouths. That’s the "cost" aspect. The beneficial side is two-pronged. One consideration is the importance of flea and tick control to human and/or animal health. That’s certainly significant, since fleas and ticks can be associated with various problems, including infectious diseases and flea allergies. However, the other consideration is whether there are safer and/or more effective alternatives. The answer to that is yes – there are now much better approaches for flea and tick control than flea collars in terms of effectiveness and safety. The disadvantage is that these alternatives are somewhat more expensive and not available over the counter, but the cost and logistics are far from cumbersome.

So, the withdrawal of the flea collars from the market in France is a very reasonable move, and one that needs to be accompanied by information to pet owners that emphasizes that:

  • yes, flea and tick control are still important.
  • there are much more effective options that are safer for the pet and the family.
  • people should work with their veterinarian to determine the approach that best fits their pet(s) and family.