title: Quantification of the association between intervertebral disk calcification and disk herniation in Dachshunds.
abstract: OBJECTIVE
  To quantify the association between intervertebral disk calcification and disk herniation in Dachshunds.
  
  
  METHODS
  Longitudinal study.
  
  
  METHODS
  61 Dachshunds that had been radiographically screened for calcification of intervertebral disks at 2 years of age in other studies. Thirty-seven of the dogs had survived to the time of the present study and were > or = 8 years of age; 24 others had not survived.
  
  
  METHODS
  Radiographic examination of 36 surviving dogs was performed, and information on occurrence of disk calcification at 2 years of age were obtained from records of all 61 Dachshunds. Information on occurrence of disk herniation between 2 and 8 years of age was obtained from owners via questionnaire. Associations between numbers of calcified disks and disk herniation were analyzed via maximum likelihood logistic regression.
  
  
  RESULTS
  Disk calcification at 2 years of age was a significant predictor of clinical disk herniation (odds ratio per calcified disk, 1.42; 95% confidence interval, 1.19 to 1.81). Number of calcified disks in the full vertebral column was a better predictor than number of calcified disks between vertebrae T10 and L3. Numbers of calcified disks at > or = 8 years of age and at 2 years of age were significantly correlated.
  
  
  CONCLUSIONS
  Number of calcified disks at 2 years of age was a good predictor of clinical disk herniation in Dachshunds. Because of the high heritability of disk calcification, it is possible that an effective reduction in occurrence of severe disk herniation in Dachshunds could be obtained by selective breeding against high numbers of calcified disks at 2 years of age.
authors.affiliation: Department of Microbiology and Risk Assessment, The National Food Institute, Technological University of Denmark, 2860 Søborg, Denmark.
authors.forename: Vibeke F
authors.initials: VF
authors.lastname: Jensen
authors.forename: Sarah
authors.initials: S
authors.lastname: Beck
authors.forename: Knud A
authors.initials: KA
authors.lastname: Christensen
authors.forename: Jens
authors.initials: J
authors.lastname: Arnbjerg
mesh_terms: D000367:Age Factors; D000818:Animals; D001947:Breeding; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000235:genetics / Q000473:pathology*; D004285:Dogs; D005260:Female; D020022:Genetic Predisposition to Disease; D015994:Incidence; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D011237:Predictive Value of Tests; D011859:Radiography; D012720:Severity of Illness Index; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*