title: Associations among exercise duration, lameness severity, and hip joint range of motion in Labrador Retrievers with hip dysplasia.
abstract: OBJECTIVE
  To evaluate factors associated with lameness severity and hip joint range of motion in dogs with hip dysplasia and to assess the association between hip joint range of motion and degree of lameness.
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  60 client-owned Labrador Retrievers with hip dysplasia.
  
  
  METHODS
  Owners completed a questionnaire regarding their dogs' daily exercise duration and type (i.e., low impact vs high impact) and lifestyle. Range of motion of affected hip joints was measured with a transparent plastic goniometer. The presence of subluxation or luxation of hip joints as a consequence of hip dysplasia and the size of the largest osteophytes or enthesophytes of hip joints on ventrodorsal radiographic images of the pelvis were recorded. Multivariate analyses were performed to identify factors associated with lameness, loss of hip joint flexion, and loss of hip joint extension and to identify factors associated with the presence of large osteophytes.
  
  
  RESULTS
  Exercise was associated with a decrease in the severity of lameness in dogs with hip dysplasia. The strength of this inverse relationship increased with longer exercise duration. Lameness was more severe in dogs with hip joint luxation than in dogs without luxation. Hip joint extension was 1° lower for each year of age, and osteophyte or enthesophyte size was 1 mm larger with each 3-year increase in age.
  
  
  CONCLUSIONS
  Longer daily exercise duration was associated with lower lameness scores in dogs with hip dysplasia. Dogs with hip joint luxation secondary to hip dysplasia had higher lameness scores than did dogs without hip joint luxation.
authors.affiliation: Department of Clinical Sciences and the Comparative Pain and Orthopedic Research Laboratories, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Greene
authors.forename: Denis J
authors.initials: DJ
authors.lastname: Marcellin-Little
authors.forename: B Duncan X
authors.initials: BD
authors.lastname: Lascelles
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D006619:Hip Dysplasia, Canine / Q000150:complications* / Q000473:pathology; D006621:Hip Joint / Q000473:pathology*; D007794:Lameness, Animal; D008297:Male; D010805:Physical Conditioning, Animal; D016059:Range of Motion, Articular; D013997:Time Factors