Natural History of Canine Cognitive Dysfunction

Project Outlines and Aims

A critical challenge for the development of novel dementia therapies, such as cell replacement therapy, has been a lack of an appropriate translational model between rodents and humans. Rodent AD models are transgenic, relying on a priori assumptions about AD pathogenesis, and to date have exhibited limited ecological validity. By contrast, Canine Cognitive Dysfunction (CCD) occurs naturally in older dogs, with increasing frequency with age, and has many behavioural and neuropathological parallels with human AD. A definitive longitudinal validation study of CCD, however, has yet to be completed. Our first step has therefore been the Senior Dog Survey in order to assess behavioural and physical changes related to ageing in dogs. If you have a dog older than 8 years old you can complete the survey here .

We have commenced such a CCD validation study. To date we have identified a cohort of older retired labradors from NSW Police, Correctional services, the Australian Quarantine service and the Seeing Eye Dogs Association. These dogs have a proven ability to ‘learn to learn’, and so offer a considerable practical advantage for behavioural testing. We have also developed the Canine Cognitive Dysfunction Rating scale (CCDR), and will be validating a CCDR diagnosis through cross-section and longitudinal behavioural testing, including domains of memory, executive function and procedural learning.

Behavioural testing will begin in late 2007 with follow-up in 2008. We predict that dogs with a CCDR diagnosis will have more profound working memory impairments at baseline and experience faster memory decline over follow-up than matched dogs without a CCDR diagnosis. A subsample of dogs which die naturally within an extended follow-up period will also undergo neuropathological analysis. This project may therefore introduce a new ecologically valid animal model of dementia, underpinned by a formal diagnosis. This would clearly represent a major advance for the field.

Staff

Dr Michael Valenzuela (chief investigator)
Hannah Salvin (PhD candidate)
Professor Perminder Sachdev

Collaborators

Associate Professor Paul McGreevy, Faculty of Veterinary Science, University of Sydney