title: Effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs.
abstract: OBJECTIVE
  To determine whether gonadectomy predisposes dogs to development of age-related behavioral changes linked to cognitive impairment.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  29 sexually intact male dogs, 63 spayed female dogs, and 47 castrated male dogs 11 to 14 years old.
  
  
  METHODS
  Information on possible impairments in 4 behavioral categories linked to cognitive impairment (orientation in the home and yard, social interactions, house training, and sleep-wake cycle) was obtained from owners of the dogs by use of a structured telephone interview format. A second interview was performed 12 to 18 months after the initial interview, and differences in responses were evaluated.
  
  
  RESULTS
  Sexually intact male dogs were significantly less likely than neutered dogs to progress from mild impairment (i.e., impairment in 1 category) to severe impairment (i.e., impairment in > or = 2 categories) during the time between the first and second interviews. This difference was not attributable to differences in ages of the dogs, duration of follow-up, or the owners' perceptions of the dogs' overall health.
  
  
  CONCLUSIONS
  Results suggest that the presence of circulating testosterone in aging sexually intact male dogs may slow the progression of cognitive impairment, at least among dogs that already have signs of mild impairment. Estrogens would be expected to have a similar protective role in sexually intact female dogs; unfortunately, too few sexually intact female dogs were available for inclusion in the study to test this hypothesis. There may be a need to evaluate possible methods for counteracting the effects of loss of sex hormones in gonadectomized dogs.
authors: Behavior Service, Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors: B L
authors: BL
authors: Hart
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal; D003072:Cognition Disorders / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004283:Dog Diseases / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D004285:Dogs / Q000601:surgery*; D005260:Female; D008137:Longitudinal Studies; D008297:Male; D009919:Orchiectomy / Q000009:adverse effects / Q000662:veterinary*; D010052:Ovariectomy / Q000009:adverse effects / Q000662:veterinary*; D015995:Prevalence; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone