Summary of Purina Pet Food Adverse Event Reports (November 22, 2023 - April 15, 2024), FDA Actions and Findings
Adverse Events
In late November 2023, the FDA began to receive an increased frequency of adverse event reports about a variety of companion animal illnesses (largely dogs, a few cats) that pet owners attributed to pet food. Initially, the reports were mostly about products made by Nestle Purina Pet Care (Purina), but as publicity and social media discussion increased, so did the array of brands and products mentioned in reports submitted to the FDA.
Most of the clinical signs (symptoms) described in dogs and cats included gastrointestinal (e.g., diarrhea, vomiting), renal (kidney), hepatic (liver), and/or neurological (e.g., seizures) symptoms. Gastrointestinal symptoms were the most common type of report. Gastrointestinal symptoms can be associated with pet food, abrupt dietary changes, or many other factors, such as existing health issues, exposure to chemicals or contaminants, consumption of foods or substances without the pet owner’s knowledge, and certain medications.
As part of case follow-up, FDA veterinarians try to determine the potential causes of illness through owner interviews, diagnostic testing at the time of the illness, and testing of both opened and unopened food from the same lot as the suspect food.
FDA Response Activities
Adverse Event Report Follow-Up
The FDA received approximately 1,300 adverse event reports for a variety of Purina pet foods between November 22, 2023, and April 15, 2024.
After initial review of the adverse event reports, veterinarians from the FDA’s Office of Surveillance and Compliance and FDA’s Veterinary Laboratory Investigation and Response Network (Vet-LIRN) identified 107 reports that contained sufficient information for follow-up, and met the selection criteria below:
- Owner’s willingness to be contacted for additional information
- Type of symptoms reported (primarily gastrointestinal, hepatic and neurologic cases were selected)
- Time between the illness and submission of report (prioritizing recent illness)
- Availability of veterinary medical records
- Availability of product with lot number and best-by date
Next, the agency’s veterinarians reviewed veterinary medical records, interviewed the pet owners about their pets’ medical and diet histories and other potential exposures, and/or arranged for Vet-LIRN laboratory testing of pet food products still in the owners’ possession.
The FDA evaluates every report it receives; however, the agency does not have sufficient resources to follow up on every report. When the FDA does not follow up on a report, one of the main reasons is that the report does not contain sufficient information. Examples of limitations the FDA faced when following up on these Purina reports include lack of pet owner contact information, missing or incomplete product information (brand, flavor, formulation, best-by date), nonspecific descriptions of pet symptoms, and reports that were about events that occurred months or years earlier.
Testing
Vet-LIRN collected and tested samples of pet food (“open product”) from pet owners as part of their clinical case follow up. Initial Vet-LIRN testing was broad because there were no common factors in the pet food reports (product, lot, manufacturer, animal clinical signs) to help identify potential hazards. Using the findings from the initial Vet-LIRN labs, the FDA determined which products and analytes to target for regulatory testing. Then, the FDA collected unopened products from retail settings and conducted regulatory testing. Comparing the Vet-LIRN testing of open samples of food with the FDA’s regulatory testing of sealed packages can help identify when contamination or other problems (if detected) might have occurred.
Vet-LIRN Testing
The goal of Vet-LIRN’s testing was to see if anything in the open packages of food collected from pet owners might have caused the reported symptoms in their pet(s). Vet-LIRN tested based on the symptoms described in the adverse event reports:
- Gastrointestinal screen: bacteria (Salmonella, E. coli, Listeria, Staphylococcus, B. cereus), and general toxicology
- Hepatic/neurologic screen: general toxicology, metals (including heavy metals), nutrient imbalances, and mycotoxins
Vet-LIRN testing of open product was negative for:
- Mycotoxins (aflatoxin, fumonisin, deoxynivalenol)
- Excess vitamin D
- Bacteria (Salmonella, E. coli, Listeria, Staphylococcus aureus)
- Pesticides
- Phosphine (a fumigant used to control insects on grain and other commodities)
- Rancid fat
Findings for metals, including micronutrients, were not of clinical concern, meaning levels were likely too low to trigger animal illness in otherwise healthy pets. Vet-LIRN tested for all or combinations of the following: arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, phosphorus, potassium, selenium, sodium, sulfur, thallium and zinc.
Vet-LIRN did detect the bacterium Bacillus in 17 open product (pet owner-provided) samples. Bacillus is present in the environment and most strains are benign. Bacillus cereus (B. cereus) is a strain capable of producing a toxin known to make people sick. Little is known about B. cereus and how ingestion may affect animals, including pets. B. cereus was detected in 7 out of 29 open product samples provided by pet owners.
Regulatory Testing
Over the course of a 30-day period, the FDA’s Office of Regulatory Affairs collected 20 sealed product samples from retail settings, representing four brands of Purina pet food.
As with the Vet-LIRN testing of open product from pet owners’ homes, the testing of unopened pet food collected at retail was designed to identify bacterial (Salmonella, Shiga-toxin producing E. coli, Bacillus cereus) and toxicological hazards (mycotoxins, heavy metals, pesticides), as well as nutritional (vitamin D) imbalances.
The FDA’s regulatory testing of unopened product was negative for:
- Mycotoxins (aflatoxin, fumonisin, deoxynivalenol)
- Excess vitamin D
- Bacteria (Salmonella, Shiga-toxin producing E. coli)
- Pesticides
- Phosphine
- Bacillus cereus (testing on unopened samples was conducted by Vet-LIRN)
Findings for metals (arsenic, cadmium, chromium, copper, iron, lead, mercury, thallium and zinc) were not of clinical concern, meaning levels were likely too low to trigger animal illness in otherwise healthy pets.
Whole-genome sequencing revealed that the B. cereus strains identified through Vet-LIRN’s open-product testing were not related to one another. This ruled out a common source of the Bacillus because the unrelated strains were only found in open samples and not sealed packages collected at retail settings.
Inspection
The FDA conducted a comprehensive animal food inspection at the Purina manufacturing facility in Clinton, Iowa, the manufacturing site of the most frequently mentioned products in adverse event reports submitted to the FDA. The comprehensive inspection included a review of the firm’s hazard analysis, food safety plan, preventive controls, and an evaluation of adverse event reports submitted to Purina directly. For an in-depth explanation of comprehensive animal food inspections, please see: Compliance Program Guidance Manual 7371.00 Comprehensive Animal Food Inspections.
At the end of the inspection, the FDA issued the firm a single-item Form FDA 483 (Notice of Inspectional Observations) citing, “You did not conduct a reanalysis of your food safety plan as appropriate.” This observation was noted because, although Purina corporate headquarters was aware of the adverse event reports associated with pet food manufactured at the Clinton facility, at the time of the inspection, the facility had not reanalyzed its food safety plan to account for a potential hazard that could cause the reported animal illnesses. As detailed in the Food Safety Modernization Act's Final Rule for Preventive Controls in Animal Food, the FDA expects firms to perform this type of reanalysis and determine whether their food safety plans need to be modified.
Conclusion
After thoroughly analyzing pet food adverse event reports, testing opened products from pet owners and sealed products from retail settings, and conducting a facility inspection, the FDA has determined the existing evidence does not identify a public health concern that could explain the symptoms detailed in these adverse event reports about Purina pet foods.
The agency followed standard processes in evaluating the adverse event reports and identifying those most likely to yield additional information. However, this situation did present unique challenges in that there was a large volume of reports describing a wide array of reported symptoms, but relatively few met the criteria for follow up. The agency is aware of various media outlets and bloggers that have reported a high number of adverse events. Unfortunately, the FDA did not receive data to fully evaluate or substantiate most of these cases. As a science-based regulatory and public health agency, the FDA relies on data to be able to analyze adverse events and identify causes of illness.
Throughout its analysis, the FDA had a conscious commitment to notify the public if it uncovered information, such as laboratory results indicating contamination or a specific illness in pets that ate a particular lot, that could translate into actionable advice for veterinarians or pet owners. The agency has previously issued safety advisories in situations when there was a common link between the reports, such as findings of a pathogen, vitamin overdose, or disease agent that connected the food to the illnesses. In the recent situation regarding the adverse event reports mentioning Purina pet food, there was no direct or consistent connection between the wide range of adverse events submitted to the FDA, and evidence does not conclusively link the reported adverse events to Purina pet food.
The FDA continues to monitor and evaluate pet food adverse event reports to identify potential follow-up actions. The agency encourages consumers and veterinarians to submit reports about issues with pet food electronically through the Safety Reporting Portal or by calling an FDA Consumer Complaint Coordinator. For additional support with using the online Safety Reporting Portal, the FDA now offers the SmartHub - Safety Intake Portal, where an electronic assistant helps walk individuals through the process of submitting their report. For an explanation of the information and level of detail that would be helpful to include in a report to the FDA, please see How to Report a Pet Food Complaint.