The Complicated Pet Food Industry

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The Complicated Pet Food Industry

In general, the pet food industry operates in a fairly veiled manner – particularly the larger manufacturers in the kibble segment. Current primary concerns have focused microbial contamination and the presence of ingredients undeclared on the label. Indeed, a 2013 study of dry pet foods used for food elimination trials stated that 80% of selected pet food diets were contaminated with unidentified ingredients.

More recently in 2018, a study critically assessed published discrepancies between ingredients and labeling in commercial pet foods, including those with “novel” or “limited” ingredients and containing micronized hydrolysates. Unexpected added ingredients were more frequently detected than those missing from the label.

The authors searched 2 article databases on July 7, 2017, and January 12, 2018, for relevant studies, and screened abstracts from the leading international veterinary dermatology congresses for reports on pet food labeling and ingredients. The resulting data were extracted from 17 articles and 1 abstract. The studies varied both in the number of pet foods tested (median: 15; range: 1- 210) and that of ingredients specifically evaluated (median: 4; range: 1-11). Studies most often employed either PCR to detect DNA or ELISA to identify proteins from 1 or more vegetable or animal species. Two studies used mass spectrometry to increase the number of detectable proteins.

The various methods found ingredients that were not on the label in 0-83% (median: 45%) of tested diets; this percentage varied between 33-83% in pet foods with novel or limited ingredients that are typically proposed for elimination diets. Similarly, ingredients were found to be missing from the label in 0-38% (median: 1%) of tested foods. Finally, 6 studies included evaluations of several hydrolysate-containing pet foods: mislabeling with unlabeled or missing ingredients was found only in 1 of them.

These statements should give everyone pause, since food elimination trial diets literally are used to figure out which food ingredient is causing a medical condition. This would be like a product’s packaging saying a product is “nut free”, when it in fact contains nuts.

As this is apparently happening with pre-packaged pet food elimination diets, it is not surprising that it can also apply generally to commercial pet diets. Think about the number of steps from “farm to bowl” meat ingredients must go through: farm to slaughterhouse to processing plant to possibly another processing plant and another plant to the packaging plant. Then, you need to factor in the grains, fruits, vegetables, and the vitamin and mineral packs that are added. This scenario barely scratches the surface.

To highlight the huge marketing impact this issue has had on the multibillion dollar pet food industry since May 2014, litigation between two very large pet food manufacturers and their suppliers about the listed and actual ingredients in their diets is ongoing through the federal courts. The back-and-forth litigation and its attendant publicity has given the public and world a mere glimpse into the pet industry.

The federal government has been involved and the accusations and findings have lead to criminal indictments and verdicts, with more possibly yet to come.

W. Jean Dodds, DVM
Hemopet / NutriScan
11561 Salinaz Avenue
Garden Grove, CA 92843


Ricci, R., Granato, A., Vascellari, M., Boscarato, M., Palagiano, C., Andrighetto, I., Diez, M. and Mutinelli, F. (2013), Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials. Journal of Animal Physiology and Animal Nutrition, 97: 32–38. doi: 10.1111/jpn.12045.

Olivry T, Mueller RS. Critically appraised topic on adverse food reactions of companion animals (5): discrepancies between ingredients and labeling in commercial pet foods. BMC Vet Res 2018: 14:24-28.

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