If an owner is experiencing the inability to function normally due to sadness, what stage of grief are they in?

The scenario described reflects the characteristics of the depression stage of grief. During this stage, individuals often experience profound sadness and may struggle to carry out their daily activities, indicating a significant emotional burden. This inability to function normally is a hallmark sign of depression, where feelings of hopelessness and despair can overshadow one's daily life.

Grief, which relates more broadly to the overall internal experience of loss, does not specify the intense state of sadness that manifests as an inability to function. Guilt often arises from feelings of personal responsibility or regret regarding the loss, while acceptance denotes a stage where individuals come to terms with their loss and begin to move forward emotionally. Thus, the symptoms presented fit squarely within the context of depression, making it the most appropriate choice.