Food handling practices of dog owners

As part of the Clinical Nutrition team at North Carolina State University (NCSU) College of Veterinary Medicine, our studies typically examine what we feed our pets. During water cooler talk, how we fed our own pets, including dog bowl hygiene, became a topic of conversation. Once we realized the range of habits among professionals, we wanted to dig deeper into the best practices, the reality of dog-feeding habits and how discrepancies may impact our patients and their owners. So, we conducted a study to investigate.

Study design

Participants were divided into 3 groups:

• Group A was given guidelines from the US Food and Drug Administration (FDA) regarding pet food handling

• Group B was given the same guidelines along with specific instructions extrapolated from the FDA Food Code for humans

• Group C was given no guidelines at all.

Our study was composed of 2 parts. The first part was a survey for dog owners regarding their dog and pet food-handling habits. The second part involved an assessment of bacterial contamination of dog bowls before and after the institution of hygiene protocols.

Survey findings

A total of 417 surveys were returned. Less than 5% of respondents were aware of the FDA pet food handling guidelines. However, when asked where they expected to find this information, 8% replied the FDA, 41% the food label, 28% their veterinarian, 11% the store of purchase, 6% the United States Department of Agriculture (USDA) and 6% various websites.

The majority (over 75%) reported compliance regarding inspecting the packaging for visible damage, avoiding using the food bowl as a scooping utensil, tightly covering leftover petfood, discarding food safely and avoiding raw food.

The minority (under 25%) reported compliance regarding washing hands prior to handling pet food, washing the food dish after each use, and washing the food scoop after each use.

Washing the dog bowl weekly was most commonly reported (22%), whereas 18% of respondents reported that they washed their dish less than every 3 months – or not at all.

The majority of respondents (65%) removed dry dog food from the manufacturer’s bag for storage. Roughly two-thirds of respondents reported preparing their pet’s food on a surface used for human food preparation or in the same room.

Analysis of bacterial contamination

The bowls of 68 dogs were swabbed 8 days following protocol initiation on average. Instituting a hygiene protocol made a difference: Groups A and B both had significant decreases in bacterial contamination, while Group C had a small increase (although not significant). Washing the bowl according to FDA recommendations (hot water or dishwasher) proved to be more effective than washing using cold or lukewarm water.

The analysis found no significant difference in hygiene between Groups A and B. Bowl material and drying method did not show a significant difference. Additionally, the initial contamination level did not differ based on the presence of immunocompromised individuals or children in the household.

Poor compliance and associated risks

Unsurprisingly, most dog owners were not aware of, and did not follow FDA pet food handling and storage guidelines. Hygiene-related handling practices, such as washing hands or the bowl, showed low levels of compliance.

Although this study did not differentiate between pathogenic and non-pathogenic bacteria, the implication of poor hygiene practices should be considered. There have been outbreaks of both human and pet illnesses secondary to dog food, and the Centers for Disease Control and Prevention (CDC) has suggested pet food handling, including cross-contamination in the kitchen and irregular cleaning of dog food dishes, as a factor in previous outbreaks.

Examining the effects of a fresh or raw diet, or any diet that involves increased preparation in the kitchen, is warranted, as previous studies have found that raw food is more likely to have bacterial contamination.

However, the risks can be mitigated. Both hygiene protocols yielded a significant reduction in bacterial colony counts in our study. These counts are commonly used in the food industry; for example, the CDC’s sanitization guidelines for human dishes are based on achieving a 5-log reduction in bacterial counts.

Nevertheless, only 20% of Group A and B respondents reported that they were likely to follow their hygiene instructions long-term, and only 8% said they were likely to follow all instructions. Since the protocols had multiple steps, it is difficult to say which were the most effective. Recommendations are needed that are both feasible and effective. Future studies should address potential concerns such as the effects of biofilms, the influence of bowl degradation on contamination and the risk of cross-contamination in households. This is particularly true for pathogenic bacteria with high zoonotic potential.

Future directions

The majority of respondents reported storing their pet food against FDA and manufacturer recommendations, which may have implications as far as increased risk of microbial contamination, nutritional degradation and palatability. Therefore, it is recommended that manufacturers study food stability under household conditions.

Additionally, the expected sources of pet food handling information, including the pet food label, veterinarians and pet food retailers, should consider featuring these public health recommendations for their clients and/or customers. However, it was noted that Group C showed no significant difference despite this information. This suggests that education beyond awareness is needed to allow for effective changes to be made.