The influence of maternal care on stress-related behaviors in domestic dogs: What can we learn from the rodent literature?

An estimated 40% of dogs living as companion dogs are believed to exhibit some form of anxiety or stress-related behavior. Although this represents a significant welfare issue, our understanding of the origins of anxiety in dogs remains limited. Genetics, environment, and training methods have all been investigated, yet little attention has been paid to the care provided by the mother. Research conducted with altricial species, that rely heavily on maternal care for survival, suggests that early maternal care behaviors play an important role in the development of the infant and thus, behavior and temperament later in life. The most critical maternal behaviors include contact, nursing, licking (particularly anogenital licking which stimulates urination and defecation), punishment, thermoregulation, and movement. In domestic dogs, rapid neurological development occurs between postnatal days 3 and 16, yet investigations fail to measure or acknowledge the role that maternal care has during this critical window, or how the experience of puppies during this time influences behavior later in life, including response to stressful events. Evidence from the rodent literature indicates profound effects of maternal care on neurological and behavioral development. Although there may be differences in maternal behavior between rats and dogs, the underlying physiological mechanisms underpinning the programming of stress-related behavior are likely to be similar. For instance, the hypothalamic-pituitary-adrenal axis or stress responsiveness pathways are profoundly altered by maternal behaviors, and these changes are conserved throughout adult life. In this review, we examine the literature related to maternal care in canids alongside the literature related to maternal care in rodents and provide evidence that maternal care is critical to the healthy development of domestic dogs. Emphasis is placed on methodologies for quantifying maternal care and on the physiological mechanisms that might underpin behavioral changes induced by different amounts and types of maternal care.