Predicting behavioral changes associated with age-related cognitive impairment in dogs

Objective - To monitor the progression of age-related behavioral changes in dogs during a period of 6 to 18 months and to determine whether signs of dysfunction in any of 4 behavioral categories can be used to predict further impairment. Design - Age-stratified cohort study. Animals - 63 spayed female and 47 castrated male dogs 11 to 14 years of age. Procedure - Data were collected from randomly selected dog owners who were interviewed by telephone twice at a 12- to 18-month interval; data were included if the dog had lived ≥ 6 months between interviews. The interview focused on signs of impairment in the following behavioral categories: orientation in the home and yard, social interactions with human family members, house training, and the sleep-wake cycle. Dogs were determined to have impairment in 0 behavioral categories (on the basis of ≤ 1 sign for each category), impairment in 1 category (≥ 2 signs of dysfunction in that category), or impairment in ≥> 2 categories. Results - Between interviews, 22% (16/73) of dogs that did not have impairment in a category at the time of the first interview developed impairment in that category by the time of the second interview. Forty-eight percent (13/27) of dogs that had impairment in 1 category at the time of the first interview developed impairment in ≥ 2 categories by the time of the second interview and were significantly more likely to develop impairment in ≥ 2 categories, compared with dogs that initially had impairment in 0 categories. Dogs with 1 sign of dysfunction in orientation were significantly more likely to develop impairment in that category, compared with dogs that had 0 signs of dysfunction in orientation. Conclusions and Clinical Relevance - Age related behavioral changes in dogs are progressive. Clinicians should consider trying to predict which dogs are most likely to become progressively impaired during the subsequent 6 to 18 months.