Research links raw meat diets to higher presence of bacteria

A study has found Salmonella and antibiotic‑resistant forms of Escherichia coli are more commonly present in dogs fed raw meat diets, compared to those that are not.

Scientists from the University of Liverpool analysed nearly 200 faecal samples for the study, which has been published in the Journal of Small Animal Practice.

And the authors believe their findings should be used to advise owners of the potential risks of raw feeding, despite fierce debate about the merits of the approach within the veterinary sector.

Samples and findings

A total of 190 samples were collected from around 140 dogs for the study. Of those, 114 were from raw-fed dogs, with 76 from non-raw-fed animals.

A dog was considered to eat a raw diet if any element of it that was fed at least once a week was not cooked.

The researchers found 62 of the samples from raw-fed dogs (54.4%) contained an antimicrobial-resistant form of E coli, compared to 13 (17.1%) of their non‑raw counterparts.

A total of 53 raw samples (46.5%) contained a tetracycline‑resistant form of the bacteria, against 10 (13.2%) of the non-raw group.

Additionally, third‑generation cephalosporin‑resistant and multidrug‑resistant forms were found in 35 (30.7%) and 28 (24.6%) of the raw samples, with only three each (3.95%) in the non‑raw cohort. A total of 8 (7%) of the raw samples were also found to contain Salmonella, compared to none of the non‑raw samples.

Adverts and advice

The researchers found advertising (28.1%) and advice from friends (26.3%) were the most common reasons given by owners for their choice of a raw-based diet.

Among the owners of the raw‑fed dogs, 95 (83.3%) highlighted stool consistency as a benefit of the diet, with 74 (64.9%) stating oral hygiene and/or breath.

In total, 44 (38.6%) also cited their dog’s demeanour or behaviour as a benefit, compared to 9 (11.8%) of the non-raw sample.

Friends’ advice was also the most frequent reason given for the choice of a non-raw diet (28.9%), followed by advice from vets (23.7%) and breeders (22.6%).

Coat quality

But coat quality (39; 51.3%) was the most common benefit cited by owners for choosing a non-raw diet, ahead of stool consistency (31; 40.8%).

Nick Thompson, founding president of the Raw Feeding Veterinary Society, suggested the paper itself had highlighted improved oral hygiene, stool consistency and behaviour associated with a raw diet, through the responses given by participating owners.

However, the researchers said the answers given by owners should be treated cautiously, because of potential variation between their interpretations and those of professionals.

‘Negligible’ threat

Dr Thompson, who was commenting in a personal capacity, added: “Antimicrobial resistance is a global concern. I feel the risk to owners who do not routinely pick up stools with their bare hands and neglect to wash their hands afterwards is very low indeed.”

He argued the threat posed by raw-fed dogs was “negligible” compared to the risks posed by meat produced under concentrated animal feeding operation conditions.

Dr Thompson further questioned the university’s stated links with pet food company Royal Canin, which include a professorship bearing the manufacturer’s name.

However, the researchers said they had no links that could inappropriately influence the study.

They acknowledged the research may not be representative of the wider canine population and could be limited by the lack of a standard raw diet.

Potential dangers

But they maintain the study should be used to educate owners of the potential dangers.

The paper concluded: “Strategies should be implemented to increase pet owners’ awareness of the risks involved with feeding raw meat to their dogs and hence reduce any potential risk to themselves, their family and their pets.”

Guidance published by veterinary charity PDSA also argues: “A lot of the apparent benefits of raw diets can be easily achieved by making sure you’re feeding your pet any balanced, age‑appropriate diet.”

The study is available to view online.