<p>  </p> <p>A large portion of the demand for purebred dogs in the United States is met by commercial breeding (CB). CB is a contentious issue, and concern exists surrounding the quality and quantity of human-animal interactions in CB kennels. Quality of caretaker interactions has been demonstrated to affect welfare in livestock and laboratory animals, yet is widely understudied in kenneled dogs, especially those kept for CB. It therefore warrants investigation. Thus, the aim of this study was to determine the effect of a short, regular, positive caretaker interaction on physiological and behavioral metrics of dog welfare in CB kennels. Adult bitches (n = 47) from two CB kennels received a daily interaction with a familiar caretaker for two weeks. Half of the dogs (n = 24) received a 2-minute caretaker interaction with treats (CI), and the other half (n = 23) received treats only (TO). All other human interactions were limited to routine husbandry. Fecal secretory immunoglobulin A (sIgA), hair cortisol concentration (HCC), and behavior in response to human approach were measured at baseline (Day 0), after two weeks of treatment (Day 14), and two weeks after treatment ended (Day 28). Behavior during treatment delivery was scored from video on days 1, 2, 8, 9, 13, and 14. General linear mixed models were used with treatment type and timepoint as fixed effects, dog nested within pen as random effects, and welfare metrics as dependent variables. Data from both facilities were analyzed and presented separately. In Facility 1 (n = 25), treatment type did not affect hair cortisol concentration (HCC) or fecal secretory immunoglobulin A (sIgA). However, HCC increased significantly from Day 0 to Day 28 (X2 = 5.83, <em>p </em>= 0.016) and fecal sIgA decreased significantly (X2 = 21.52, <em>p </em>< 0.001) over all three timepoints. Affiliative behavior in response to human approach increased over time with no significant effect of treatment type or tester (X2=10.549, <em>p</em>=0.001). Additionally, time spent in proximity to the caretaker significantly increased in both treatment groups during the daily interaction (CI: X2=14.047, <em>p</em><0.001, and TO: X2=5.121, <em>p</em>=0.024). In Facility 2 (n = 22), there was no effect of treatment type on physiological metrics, however, HCC decreased in time (X2 = 6.66, <em>p </em>= 0.009) in both treatment groups combined. Affiliative response to human approach increased over time in Facility 2 (X2=13.5782, <em>p</em>=0.001). During daily interactions, dogs from the TO group displayed increased affiliative (X2 = 8.58, <em>p </em>= 0.003) and decreased ambivalent (X2 = 10.42, <em>p </em>= 0.001) behaviors over time, while dogs from the CI group showed increasing latency to approach the caretaker (X2 = 4.38, <em>p </em>= 0.033). Changes in physiological and behavioral metrics differed by facility and treatment group. Factors such as variation in treatment quality and prior caretaker-animal relationship may play a role in dogs’ responses to the treatment. These results suggest that a caretaker interaction has the potential to improve welfare in dogs residing in CB kennels. However, careful consideration must be taken when implementing new protocols to avoid unintended increases in stress. For some adult dogs unaccustomed to extended, structured interactions with their caretakers, a 2-minute session may have resulted in increased physiological and behavioral stress, suggesting that a longer interaction might have jeopardized rather than improved their welfare. For these dogs, a more gradual introduction to human interactions may be more beneficial. This study offers new insight on the implementation of socialization, counterconditioning, and caretaker-dog interaction practices to maximize positive welfare in CB kennels. Future research is needed to further validate and expand upon these findings.</p>