Growing old gracefully—Behavioral changes associated with “successful aging” in the dog, Canis familiaris

Aging is associated with behavioral and cognitive changes in all mammals. Unlike most clinical presentations, changes associated with aging do not always reflect an underlying pathology and therefore baselines for normality can be difficult to establish. Using data from a large cross-sectional survey of older dog owners, we aimed to identify normative behavioral changes associated with “successful aging” in dogs, and the rate of deterioration that could be expected over a 6-month period. Binary logistic regression identified significant age group effects from 18 items (difference in reported item incidence across age group: 4.5%-30.3%, P < 0.001-0.038). Significant age group effects on the percentage of dogs deteriorating over the preceding 6 months were evident in 21 items (difference in item deterioration across age group: 3.5%-25.7%, P < 0.001-0.033). The modal frequency of problem behaviors and abnormal ingestive or locomotory items was found to be low and the effect on memory and learning was minimal. Despite this, more than half of the items were reported to have shown a greater than 10% incidence of deterioration. In particular, activity and play levels, response to commands, and fears and phobias showed considerable deterioration. These findings represent the first steps toward the development of baseline values for normal behavioral changes in “successfully aging” dogs.