title: Evaluation of a circumferential femoral head osteophyte as an early indicator of osteoarthritis characteristic of canine hip dysplasia in dogs.
abstract: OBJECTIVE
  To determine the relationship between a circumferential femoral head osteophyte (CFHO) and osteoarthritis characteristic of canine hip dysplasia, and to ascertain whether CFHO, like osteoarthritis, varies between diet-restricted and control-fed dogs.
  
  
  METHODS
  Longitudinal cohort study.
  
  
  METHODS
  48 Labrador Retrievers.
  
  
  METHODS
  Dogs were paired by size, sex, and litter and assigned to 1 of 2 equal groups at 2 months of age. The control-fed group was fed ad libitum, and the diet-restricted group was fed 25% less on a pairwise basis of the same diet for life. The dogs' hip joints were radiographed yearly for life. Each radiograph was evaluated for radiographic signs of osteoarthritis characteristic of hip dysplasia and for the presence and severity of a CFHO.
  
  
  RESULTS
  41 of the 48 (85.4%) dogs had a CFHO, which was detected at a median age of 5.4 years, and 33 of those 41 (80.5%) developed radiographic evidence of osteoarthritis. Nineteen (79.2%) dogs in the diet-restricted group and 22 (91.7%) in the control-fed group had a CFHO at a median age of 9 and 3 years, respectively. Of the dogs with a CFHO, 12 (63.2%) in the diet-restricted group and 20 (90.0%) in the control-fed group developed radiographic evidence of osteoarthritis characteristic of hip dysplasia at a median age of 11 and 6.5 years, respectively.
  
  
  CONCLUSIONS
  Results indicated a relationship between the CFHO and subsequent development of radiographic signs of osteoarthritis. If a CFHO is present in Labrador Retrievers, it might be considered an early indicator of osteoarthritis.
authors.affiliation: Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104-6010, USA.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Szabo
authors.forename: Daryl N
authors.initials: DN
authors.lastname: Biery
authors.forename: Dennis F
authors.initials: DF
authors.lastname: Lawler
authors.forename: Frances S
authors.initials: FS
authors.lastname: Shofer
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Powers
authors.forename: Richard D
authors.initials: RD
authors.lastname: Kealy
authors.forename: Gail K
authors.initials: GK
authors.lastname: Smith
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D015331:Cohort Studies; D004038:Diet, Reducing / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000178:diet therapy* / Q000517:prevention & control*; D004285:Dogs; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000473:pathology; D006619:Hip Dysplasia, Canine / Q000178:diet therapy* / Q000517:prevention & control* / Q000532:radiotherapy; D008137:Longitudinal Studies; D008297:Male; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000178:diet therapy / Q000517:prevention & control / Q000662:veterinary*; D011859:Radiography; D012720:Severity of Illness Index