<p dir="ltr">In the US, dogs are considered members of the family by many people. Dogs may be obtained from multiple sources, but many in the US originate from commercial breeding kennels (CBKs). Prioritizing adult dogs’ welfare while they are housed in these kennels is essential for their well-being not only while residing there, but throughout the rest of their lives in new environments for those who are rehomed after their breeding careers end. However, the research conducted in this population is scarce. Therefore, evaluating dogs’ overall welfare states and factors that may affect them in this population is crucial.</p><p dir="ltr">Maternal factors are one of many that may affect puppies’ welfare states. This topic has never been directly explored in US CBKs and has been understudied in all domestic dogs. Therefore, this dissertation sought to explore associations between maternal factors and puppy welfare indicators, and related topics.</p><p dir="ltr">Chapter 2 aimed to explore changes in indicators of dams’ welfare states (<i>n</i>= 74), such as behavioral responses to a mild stressor and stress-related physiology, throughout the peri-parturient period in 8 CBKs. The changes observed were most likely due to natural biological changes associated with the peri-parturient period, and no worrisome indicators of welfare were detected. Additionally, Chapter 3 sought to investigate the relationship between dams’ levels of fear and stress (<i>n</i>= 90), as indicated by behavior and stress-related physiology, and metrics indicative of their puppies’ welfare states (<i>n</i>= 390), such as behavior, stress-related physiology, and physical health, in 12 CBKs. Findings suggest some associations between dams’ fear and stress and their puppies’ behavioral responses to isolation, physiology, and physical health. To further explore these associations, Chapter 4 examined the relationships between dams’ (<i>n</i>= 79) and puppies’ (<i>n</i>= 291) behavioral responses to novel social and non-social stimuli in 11 CBKs. No significant associations between dams’ and puppies’ responses were discovered, and possible reasons such as kennel management practices, puppies’ mobility and hazard avoidance, and differences between dams’ and puppies’ early life experiences were discussed. Finally, as the type and level of maternal care dams provide may be indicative of their welfare and may also be related to puppy welfare, Chapter 5 aimed to characterize maternal behaviors in a CBK (<i>n</i>= 12) and working dog population focused on detection work (<i>n</i>= 8). This study uncovered common maternal behaviors in each population, such as nursing and licking puppies. It also revealed that the behaviors observed were consistent with those reported for other dog populations, and found that factors such as day, time of day, litter size, and whelping type may influence their expression.</p><p dir="ltr">Overall, results from these studies suggest that there were no worrisome changes in dams’ welfare states throughout the peri-parturient period. Additionally, dams’ levels of fear and stress may affect potential indicators of their puppies’ welfare states, such as stress-related physiology, behavioral responses to stressors, and physical health. Findings highlight the importance of closely monitoring dams throughout the peri-parturient period for consistent displays of fear and stress, and abnormal behaviors. Doing so may not only affect dams’ welfare but that of their puppies as well. Further, the characterization and exploration of factors that may affect maternal care in various populations provides the basis for future work to explore maternal care as a mechanism behind the significant associations between dam and puppy welfare. The results also provide a foundation for breeders and caretakers to monitor maternal care, and make breeding selection and management interventions as needed to best support dam and puppy welfare. Altogether, findings from this research may have salient implications for dam’s welfare states throughout the peri-parturient period, and puppies’ welfare states while housed with their dams and into adulthood.</p>