ANIMAL MODELS

ELEVATED PAI-I AS A POSSIBLE ETIOLOGY OF PANOSTEITIS IN YOUNG GERMAN SHEPHERD DOGS

Ralph H. Lewis DVM, AVORE* Study Group, and John P. Jones, Jr. MD
*Association for Veterinary Research and Education
Diagnostic Osteonecrosis Center and Research Foundation
308 Dixon Drive, Lakeport, CA 95453

Canine panosteitis is an aseptic, idiopathic condition affecting the long bones of young dogs. It is initially manifested by limping and localized tenderness. Radiographs indicate endosteal and periosteal new bone formation. Bone scans reveal increased scintigraphic uptake. MRI studies demonstrate increased signal intensity on T2-weighting in periosteal and intramedullary regions, suggesting the bone marrow edema syndrome. We have found that the limping in affected dogs is rapidly relieved by unicortical fenestration (core decompression).

An ELISA human monoclonal antibody test was used as an antigenic assay for plasminogen activator inhibitor type I (PAI-I). Forty six German shepherd dogs were studied (25 males and 21 females). Fifteen of these 46 dogs were diagnosed with panosteitis. With Chi-square analysis, there was a significantly higher prevalence of panosteitis among younger dogs than among dogs over two years of age, but only for males (P=0.03). An analysis of variance indicated a significant interaction (P=0.03) between three factors, i.e. young age (dogs under two years), increased PAI-I, and panosteitis.