Sleep-wake disturbance in canine cognitive dysfunction: Guardian-reported patterns and a practical screening tool

Sleep-wake disturbance is a commonly reported feature of canine cognitive dysfunction (CCD), yet its specific patterns and clinical significance remain poorly characterised. This study aimed to describe guardian-reported sleep disturbances in dogs with CCD, examine their associations with cognitive severity and sensory changes, and develop a practical screening tool to support veterinary consultations. Guardians of dogs aged ≥ 8 years (n = 205) completed an online survey capturing cognitive status, sleep quality, sleep duration and timing, night-time disturbances, management strategies, and observed vision and hearing changes. Poorer sleep quality, reflected by reduced ability to fall asleep and remain asleep and increased nocturnal elimination, was significantly associated with greater CCD severity (adjusted p < 0.00001). Guardian-reported sleep duration did not differ significantly by CCD level, although dogs with more severe impairment were reported to sleep less at night and more during the day. Over half of dogs were reported to be most unsettled between 02:00-05:00, with a trend toward increasing late-afternoon/early-evening restlessness observed as cognitive impairment progressed. Guardian-reported vision and hearing changes, particularly bumping into objects and reduced auditory responsiveness, were more frequently reported in dogs with severe CCD. Using sleep, sensory, and age-related variables, a decision tree model demonstrated moderate discrimination between mild and more severe cognitive impairment (AUC = 0.69). These findings highlight sleep-wake disruption as a clinically relevant, guardian-observable feature of CCD and support the use of structured, observable indicators to facilitate earlier recognition and discussion of cognitive decline in senior dogs.