High levels of harmful bacteria found in many raw meat dog foods may be dangerous for more than just Fido, a new study suggests.
Not only can these foods put a dog at risk, but people who live with that dog, particularly the elderly, young and immunocompromised, are vulnerable, scientists say.
Harmful pathogens in raw food
"This research offers further compelling evidence to support vets' concerns about the potential animal and public health risks associated with feeding pets a raw meat-based diet," said veterinarian Dr Daniella Dos Santos. She is junior vice president of the British Veterinary Association.
"Bacteria such as E. coli and salmonella can cause significant gastrointestinal disease in animals," Dos Santos explained.
"Pets can also shed potentially harmful pathogens present in raw food into their environment, so there is a risk to owners both in handling the food and coming into contact with the animal. Pet owners who choose to feed a raw food diet should be aware of the potential health risks and take full precautions while storing and handling the food," she warned.
Raw meat-based diets have become popular for dogs in recent years. Unlike commercial dog foods, raw meat products are not heat-treated or freeze-dried to pasteurise their contents.
Researchers led by Dr Ingrid Hansson, from the Swedish University of Agricultural Sciences in Uppsala, Sweden, analysed samples from 60 packs of raw meat products for dogs. The food came from 10 different manufacturers in Sweden, Norway, Finland, Germany or England. The products contained either uncooked meat and/or edible bones and/or organs from cattle, chicken, lamb, turkeys, pigs, ducks, reindeer or salmon.
Dangers of E. coli
The samples were checked for bacteria that could potentially pose a health risk to animals and people: Enterobacteriaceae species; Clostridium perfringens, salmonella and campylobacter species.
All 60 samples contained Enterobacteriaceae species, which are indicators of faecal contamination. Levels varied, but 31 (52%) of the samples had levels above the European Union (EU) maximum of 5 000 bacteria per gram.
Most of the species detected in the samples are not known to cause infection, but E. coli – found in a third of the samples – does produce infection.
Another marker of faecal contamination and hygiene standards, C. perfringens, was found in 18 samples (30%). Two of the samples exceeded the maximum limits set by Swedish guidelines.
Salmonella and campylobacter bacteria can be passed from animals to people and cause infection. EU regulations don't permit salmonella in any animal food.
But the researchers found salmonella in four (7%) of the samples, and campylobacter species were found in three samples from three different manufacturers.
Risk of antibiotic resistance
The study was published online in the journal Vet Record.
Raw meat dog food should be: kept frozen until use, and thawed at 50 degrees Fahrenheit (10 degrees Celsius); kept separate from other food; and handled with separate kitchen equipment or with equipment that is washed thoroughly after use, the researchers advised.
Never let dogs lick people's faces immediately after they eat raw meat dog food. Also, don't give dogs raw meat products it they're being given antibiotics, because this could increase the risk of antibiotic resistance.
"Dogs in families with infants, elderly people or immunocompromised individuals should also not be fed [raw meat products], as these groups are more susceptible to infections," Hansson's team wrote.
The British Veterinary Association also does not recommend making a raw food diet at home without veterinary guidance due to the potential for nutritional deficiencies in homemade diets, Dos Santos said.
"We would advise any owner wanting to try a raw meat-based diet for their pet to first consult a veterinary surgeon," she said in a journal news release.
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