Background: Canine cognitive dysfunction (CCD) is a neurodegenerative condition affecting geriatric dogs and sharing several characteristics with human Alzheimer's disease (AD). CCD manifests as alterations of behavioral patterns and daily routines. Clinical signs are associated with neurodegenerative changes (eg, cortical atrophy and amyloid-beta deposits). Objectives: To investigate clinical characteristics, survival, and risk factors with CCD. Vitamin E was investigated as a potential marker of CCD. Methods: Ninety-four dogs >8 years of age were investigated with a validated CCD questionnaire and allocated to CCD, borderline CCD (b-CCD) and non-CCD groups. The dogs were included in 2008-2009 and followed up in an observational study until follow-up in 2012. Results: Four key clinical signs dominated in dogs with CCD: sleeping during the day and restless at night, decreased interaction, disorientation at home, and anxiety. A number of borderline CCD cases developed into CCD over time indicating that a prodromal stage of CCD may exist. CCD did not influence survival negatively. Small breeds did not show better survival than large breeds (P = .055) and there was no difference between sexes (P = .99). Conclusions and Clinical Importance: A few key questions addressing sleep-wake cycle, interaction, and signs of confusion and anxiety can be used as a clinical marker of CCD. Special attention should be paid to anxiety in dogs with CCD because it may be especially stressful to both dog and owner. Dogs with CCD seem to have a good chance of living a full lifespan if supported by the veterinarian and the owner.