BDNF and dementia: Canine cognitive dysfunction (CCD) is an analog of human dementia because the conditions may share similar neuropathologies such as cerebral atrophy, ventricular dilation, reduced vascularity, decreased levels of brain‐derived neurotrophic factor (BDNF) and accumulation of β‐amyloid (Aβ) plaques (Cotman et al., 2002; Dewey et al., 2019; Head et al., 2000).