Relationship between hearing, cognitive function, and quality of life in aging companion dogs

Abstract

Background: Elderly people with presbycusis are at higher risk for dementia and depression than the general population. There is no information regarding consequences of presbycusis in dogs. Objective: Evaluate the relationship between cognitive function, quality of life, and hearing loss in aging companion dogs. Animals: Thirty-nine elderly companion dogs. Methods: Prospective study. Hearing was evaluated using brainstem auditory evoked response (BAER) testing. Dogs were grouped by hearing ability. Owners completed the canine dementia scale (CADES) and canine owner-reported quality of life (CORQ) questionnaire. Cognitive testing was performed, and cognitive testing outcomes, CADES and CORQ scores and age were compared between hearing groups. Results: Nineteen dogs could hear at 50 dB, 12 at 70 dB, and 8 at 90 dB with mean ages (months) of 141 ± 14, 160 ± 16, and 172 ± 15 for each group respectively (P =.0002). Vitality and companionship CORQ scores were significantly lower as hearing deteriorated (6.6-5.4, 50-90 dB group, P =.03 and 6.9-6.2, 50-90 dB group, P =.02, respectively). Cognitive classification by CADES was abnormal in all 90 dB group dogs and normal in 3/12 70 dB group and 11/19 50 dB group dogs (P =.0004). Performance on inhibitory control, detour and sustained gaze tasks decreased significantly with hearing loss (P =.001, P =.008, P =.002, respectively). In multivariate analysis, higher CADES score was associated with worse hearing (P =.01). Conclusions and Clinical Importance: Presbycusis negatively alters owner-pet interactions and is associated with poor executive performance and owner-assessed dementia severity.