This dissertation describes a series of four studies on cognitive aging, working memory, and cognitive flexibility in dogs (Canis lupus familiaris) and their wild relatives. In Chapters 2 and 3, I designed assessments for age-related cognitive deficits in pet dogs which can be deployed rapidly using inexpensive and accessible materials. These novel tests can be easily implemented by owners, veterinarians, and clinicians and therefore, may improve care for elderly dogs by aiding in the diagnosis of dementia. In addition, these widely deployable tests may facilitate the use of dementia in pet dogs as a naturally occurring model of Alzheimer’s Disease in humans.In Chapters 4 and 5, I modified one of these tests to demonstrate for the first time that coyotes (Canis latrans) and wolves (Canis lupus lupus) develop age-related deficits in cognitive flexibility. This was an important first step towards differentiating between the genetic and environmental components of dementia in dogs and in turn, humans. Unexpectedly, I also detected cognitive deficits in young, adult dogs and wolves but not coyotes. These finding add to a recent shift in understanding cognitive development in dogs which may improve cognitive aging tests as well as training, care, and use of working and pet dogs. These findings also suggest that the ecology of coyotes may select for flexibility earlier in development. In Chapter 5, I piloted the use of the same cognitive flexibility test for red and gray foxes so that future studies may test for lifespan changes in the cognition of small-bodied captive canids. More broadly, this paradigm may accommodate physical and behavioral differences between diverse pet and captive animals. In Chapters 4 and 5, I examined which ecological traits drive the evolution of behavioral flexibility and in turn, species resilience. I found that wolves displayed less flexibility than dogs and coyotes suggesting that species which do not rely heavily on unstable resources may be ill-equipped to cope with human habitat modification. Ultimately, this comparative work may help conservation practitioners to identify and protect species that cannot cope with rapid and unnatural environmental change.

Personality testing in dogs has become a controversial topic in the dog community in the last few years. These assessments have been used among owners, shelters, working dog trainers, breeders, and researchers to identify patterns of behavior that may lead to insight about a dog’s personality. Due to inconsistencies in terminology and validity testing, these personality tests have lost a notable amount of credibility. Focusing on questionnaire and behavioral based testing, this literature review aims to evaluate the significance of personality testing within the dog community. Each assessment will be analyzed for measurements and validity, as well as potential drawbacks and benefits. Four prominent personality assessments will be discussed in depth. These assessments include C-BARQ, DPQ, SAFER, and VIDOPET. I advocate for a mixed assessment model approach and highlight the benefits of expanding personality testing into genetic research.

Previous research pertaining to dog memory and cognition has been confined mainly to samples of colony dogs and therefore can be hard to generalize to a larger population of pet dogs and varying breeds. The present study focused entirely on pet dogs of many different breeds, rather than colony or laboratory animals for the purposes of accessibility, affordability, and novelty. Methods: We presented the dogs with a memory task in the form of a game in which the dogs chose to search for food at one of two locations at varying delay intervals, with a maximum time limit of one hour per dog. We expected our data to show a significant decrease in memory capacity and an increase in error rates among older dogs as compared to younger dogs; these results would allow us to conclude that it is likely many dogs, much like humans, experience various cognitive deficits as a function of increasing age. Results: Using one-factor ANOVA and linear and curvilinear regression analyses, we examined the relationship between the independent variable, age (individual dog ages as well as three generalized age categories), and three dependent variables. The dependent variables were: (a) percentage of correct choices at a 60 second delay interval, (b) maximum delay interval attempted (MDIA), and (c) the maximum delay interval that was completed above chance level (50%) (MDAC). We found significant results to support our hypotheses that aged dogs show spatial memory and cognitive deficits in comparison with young and middle-aged dogs, and that age can be considered a marginally significant predictor of spatial memory capacity.