title: The effects of lifetime food restriction on the development of osteoarthritis in the canine shoulder.
abstract: OBJECTIVE
  To report effects of age and lifetime food restriction on development and progression of shoulder joint osteoarthritis (OA) in Labrador retriever dogs.
  
  
  METHODS
  Longitudinal life-span, cohort study.
  
  
  METHODS
  Labrador retriever dogs (n=48).
  
  
  METHODS
  Littermates were paired (gender, weight) to make 24 pairs of genetically similar dogs. Each diet-restricted (DR) pair-mate was fed daily 75% of the same diet consumed by its control-fed (CF) pair-mate for life. Shoulders were evaluated radiographically at years 6, 8, and end of life (EOL). At EOL shoulders were evaluated grossly and by histopathology for OA.
  
  
  RESULTS
  Radiographic evidence of shoulder OA was identified in 78% of dogs. Severity of radiographic shoulder OA at 6 (P<.03) and 8 years (P<.02) was significantly lower among DR dogs compared with CF dogs. Pooled gross evaluation results revealed 40 of 46 dogs had cartilage erosion on the caudal aspect of the humeral head. By EOL, 91% of dogs had histopathologic changes consistent with OA.
  
  
  CONCLUSIONS
  There was a high overall prevalence of radiographic, gross, and histologic OA among dogs. Substantial disparity was found between radiographic evidence of OA (at EOL) and characteristic changes visible by gross and histologic examination.
  
  
  CONCLUSIONS
  Radiographic evaluation correlates poorly with severity of shoulder joint pathology. The benefits of DR on shoulder OA are consistent with the demonstrated effect of DR in delaying species- and strain-specific diseases of aging.
authors.affiliation: Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6010, USA. jrunge@vet.upenn.edu
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Runge
authors.forename: Darryl N
authors.initials: DN
authors.lastname: Biery
authors.forename: Dennis F
authors.initials: DF
authors.lastname: Lawler
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Gregor
authors.forename: Richard H
authors.initials: RH
authors.lastname: Evans
authors.forename: Richard D
authors.initials: RD
authors.lastname: Kealy
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Szabo
authors.forename: Gail K
authors.initials: GK
authors.lastname: Smith
mesh_terms: D000367:Age Factors; D000375:Aging / Q000473:pathology / Q000502:physiology; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001175:Arthrography / Q000379:methods / Q000662:veterinary*; D015331:Cohort Studies; D004038:Diet, Reducing; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000517:prevention & control; D004285:Dogs; D005260:Female; D008137:Longitudinal Studies; D008297:Male; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D011788:Quality of Life; D011897:Random Allocation; D012720:Severity of Illness Index