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The Daily Vet by petMD

The Daily Vet is a blog featuring veterinarians from all walks of life. Every week they will tackle entertaining, interesting, and sometimes difficult topics in the world of animal medicine – all in the hopes that their unique insights and personal experiences will help you to understand your pets.

Chemicals May Mask Salmonella Risk

This co-packaging business model is common in the pet food industry and many of the hundreds of brands are actually manufactured by a small number of companies. Therefore, contamination at one plant, or ingredient sources from one supplier would affect many brand names. But the USDA (United States Department of Agriculture) has found another potential reason that salmonella contamination may be missed. The findings were reported in a Washington Post article on published on August 2nd of this year.



Disinfecting Chemicals in Slaughterhouses


The USDA is reviewing studies that suggest that the chemicals used to reduce bacterial contamination in poultry slaughterhouses may mask the presence of salmonella. The average chicken carcass is dipped or sprayed with chemicals four times as it progresses through processing. The chemicals are intended to reduce surface bacterial in order to meet USDA standards to reduce bacterial contamination in slaughterhouses.



Testing for Salmonella in Meat


Randomly chosen chickens are selected from the processing line and put in a plastic bag with a special solution to collect body surface contamination. The bird is then returned to the processing line and the solution is sent off for testing the following day. Apparently the newer and stronger chemicals used in the dips and sprays are not neutralized by the special solution and continue killing bacteria in the test solution during the period from collection to testing. Although the test result might be negative, the bird could actually be positive for salmonella. Researchers are concerned that this antiquated testing system is inadequate for present poultry processing methods.



USDA Salmonella Data


USDA inspection data over the last few years have shown that salmonella detection has been halved. The question is whether the rate is less because of a true decrease in contamination or if it has decreased due to a lack of detection. Jon Howarth, a scientist and technical director of one of the disinfecting chemical manufacturers, was present at a USDA briefing where this information was released. Howarth said of the data, “Food is safer; just not as safe as the tests are showing.” He also observed that despite improved testing results, the numbers of humans afflicted with salmonella from poultry had not changed in the same time period.


In addition to masking salmonella contamination, these disinfecting chemicals are suspected of causing medical problems to humans. In an article in The Washington Post, USDA plant inspectors reported a belief that these newer chemicals are contributing to many of the medical problems this group is experiencing. OSHA (Occupational Safety and Health Administration) is investigating the death of an inspector in a New York poultry plant that was featured in the Post article.



Non-Virtuous Cycle of Meat Production


People expect safe food but mass producing it in processing plants makes this difficult. As this post points out, attempts to maximize that safety have their own inherent problems and may even decrease safety. Other methods of disinfection have their side effects and detractors (i.e., radiation).


I don’t have any answers and it looks as if recalls are going to co-exist with the mass production of food, for both human and pet. My research for this post is not any more positive for homemade food.


Organically raised or free-range poultry are also required to be dipped or sprayed during processing. Although these chemicals differ from those used on regular birds, they still contain chemicals that consumers are unaware of when they buy organic. Seeking a reduced chemical exposure of food is harder than imagined. And paying a premium for an organic product that contains unknown chemicals should leave a bad taste in the mouths of consumers. The alternative is going back to raising our own livestock or buying live animals at farmers’ markets to slaughter and butcher ourselves. That is obviously unworkable for the majority of pet owners and really not much safer than the present solution. Home slaughter and processing is hardly germ free.



What is Left?


We have to pick our poison. Unfortunately, it is not a Burger King world and we can’t always have it our way. If you have a solution, please let us know.



Dr. Ken Tudor



Image: Susan Schmitz / Shutterstock



Last reviewed on July 26, 2015.

Comments  3

Leave Comment
  • Source of contamination
    08/29/2013 06:47pm

    As far as I am concerned, they should be doing a better job of gutting the meat sources at the slaughterhouses before they even think about using chemicals to clean up the mess they create with poor practices. What happens is that the entrails with all the natural gut bacteria in them are allowed to contact the meat we intend to consume. That is why there are so many different types of bacteria needing different methods of control. On top of that each bug has several different subspecies, such as with salmonella as an example. Most of them are relatively harmless, and the percentage of the "SE" is apparently small. All this is explained on page 7 of this URL: http://www.agf.gov.bc.ca/lhmr/pubs/se_control_programs0910.pdf under the title, "Salmonella Information." The problem is the complication of differentiating between harmless and harmful bacteria, for each species in the gut. Therefore the need for blanket control.

    As there are so many thousands of bugs in the gut, I guess we are going to have to put up with total sterilization until we come up with better means of gutting a chicken without nicking the intestines and spreading the gut bacteria where it shouldn't be. When you couple that with workers who are expected to work with a specific volume per hour, there has to be danger of contamination with present day practices. And then, of course, each meat inspection department is having to cut costs, so reducing the staff load to deal with this. We have to be heading toward more contamination with all these issues compounding.

  • Cposts
    08/29/2013 11:03pm

    It sure seems to me that it would be much less expensive for a company to catch problems before the product leaves the factory than it is to issue recalls. Not to mention, the consumer's negative view of the company that had to issue a recall.

  • Wait a second...
    09/10/2013 05:46pm

    If the disinfectants continue to kill bacteria in the sample solution, wouldn't it continue to kill bacteria on the carcass surface as well? Isn't the end product contamination the most important factor concerning the safety of the product?

    Not to mention, proper handling and cooking will destroy any end product contamination and plays a far bigger role in food safety. Why do we continue to think that all food should be sterile at point of sale?

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