title: Cognitive Function, Progression of Age-related Behavioral Changes, Biomarkers, and Survival in Dogs More Than 8 Years Old.
abstract: BACKGROUND
  Canine cognitive dysfunction (CCD) is an age-dependent neurodegenerative condition dominated by changes in behavioral patterns. Cohort studies investigating cognitive status in dogs are lacking.
  
  
  OBJECTIVE
  To investigate cognitive function, progression of age-related behavioral changes, survival, and possible biomarkers of CCD in aged dogs.
  
  
  METHODS
  Fifty-one dogs >8 years old; 21 with no cognitive deficits, 17 with mild cognitive impairments (MCI) and 13 with CCD.
  
  
  METHODS
  Longitudinal study. Recruitment period of 12 months and an observational period of 24 months including a baseline and 3 planned subsequent assessments. Cognitive status was determined using validated questionnaires. Plasma Aβ-peptides were quantified using commercial ELISA assays and cytokines by a validated immunoassay.
  
  
  RESULTS
  Signs characterizing dogs with CCD were aimless wandering, staring into space, avoid getting patted, difficulty finding dropped food and anxiety. Thirty-three percent of dogs with a normal cognitive status progressed to MCI and 22% classified as MCI progressed to CCD during the study period. For 6 dogs diagnosed with CCD, signs of cognitive dysfunction increased with time. A diagnosis of CCD did not affect survival. The level of plasma Aβ42 was significantly increased (P < .05) in the CCD group (92.8 ± 24.0 pg/mL) compared to the MCI (77.0 ± 12.3 pg/mL) and normal group (74.9 ± 10.0 pg/mL), but no significant differences in concentrations of systemic inflammatory markers were detected.
  
  
  CONCLUSIONS
  Canine cognitive dysfunction is a progressive disorder with an individual variability in the rate of cognitive decline and clinical signs. Plasma Aβ42 seems to be an interesting plasma biomarker of CCD.
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Schütt
authors.affiliation: Section for Epidemiology, Technical University of Denmark, Frederiksberg C, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Toft
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Berendt
mesh_terms: D000375:Aging; D016229:Amyloid beta-Peptides / Q000097:blood; D000818:Animals; D001522:Behavior, Animal; D015415:Biomarkers; D002097:C-Reactive Protein / Q000378:metabolism; D003072:Cognition Disorders / Q000097:blood*; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D005260:Female; D008136:Longevity; D008137:Longitudinal Studies; D008297:Male; D010446:Peptide Fragments / Q000097:blood
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); D002097:C-Reactive Protein
keywords: Amyloid-beta; Canine; Dementia; Geriatric; Longitudinal