Quantification of measurement of femoral head coverage and Norberg angle within and among four breeds of dogs.
OBJECTIVE
To report values for percentage coverage of the femoral head (PC) and Norberg angle (NA) in 4 common breeds of dogs and to determine values for each that distinguish between normal and dysplastic hip status on the basis of Orthopedic Foundation for Animals (OFA) hip evaluation.


METHODS
1,841 dogs 24 to 48 months of age that were Labrador Retrievers (455), Golden Retrievers (423), Rottweilers (545), or German Shepherd Dogs (418).


METHODS
Retrospective analysis of NA and PC measured from standard OFA ventrodorsal pelvic radiographs from 4 breeds of dog.


RESULTS
Norberg angle ranged from 67.4 to 124.4 degrees for Labrador Retrievers, 59.7 to 128.6 degrees for Rottweilers, 70.2 to 119.4 degrees for Golden Retrievers, and 55.3 to 121.3 degrees for German Shepherd Dogs. The PC ranged from 6.5 to 79.9% for Labrador Retrievers, 5.7 to 79.5% for Rottweilers, 8.3 to 79.3% for Golden Retrievers, and 5.4 to 83.7% for German Shepherd Dogs. On the basis of logistic regression modeling for determining normal versus abnormal hip status for all 4 breeds, cutoff points for NA were <105 degrees and PC were <50%.


CONCLUSIONS
Results of our study indicate that cutoff points of NA of 105 degrees and PC of 50% do not differentiate normal versus dysplastic hip status. Each of the 4 breeds had different values for NA and PC that distinguished normal from dysplastic hip status.
Tomlinson
J L
JL
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
Johnson
J C
JC
D000818:Animals; D004285:Dogs / Q000033:anatomy & histology*; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006621:Hip Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011859:Radiography; D012044:Regression Analysis; D012189:Retrospective Studies; D013045:Species Specificity