Signalment & History
A 13 month old FI German Shepherd Dog presents for a 3 week history of intermittent lameness in her right thoracic limb. She is non-weight bearing on her right thoracic limb.
On physical examination, you detect pain in her right elbow.
Findings
There is a heterogenous region of sclerosis within the medullary cavity of the proximal ulnar diaphysis. The cartilage and joint space are normal; there is no evidence of cartilaginous abnormalities or abnormalities in the subchondral bone. The joint is congruent.
Diagnosis
This lesion is consistent with Panosteitis.
- Panosteitis causes bone marrow degeneration characterized by loss of the trabecular pattern in the medullary cavity and decreased contrast between the cortical bone and the medullary cavity.
- Panosteitis affects the diaphysis of long bones.
- Lesions may occur in one bone or in several, and may be solitary or multiple. Multiple lesions may coalesce.
- Lesions often originate around the nutrient foramen.
- As the disease resolves, the bone eventually remodels and returns to normal, although there may be some persistent cortical thickening.
- Panosteitis is a common cause of intermittent lameness in young, growing dogs, usually 5-12 months of age. Shifting leg lameness is common as it can develop in several limbs.
- Panosteitis is most common in large and giant breed dogs, of which German Shepherd dogs are most frequently affected. It is more common in males than females.
- Clinical signs include acute shifting lameness with or without a history of trauma, lethargy, anorexia and fever.
- Upon clinical examination, the bones are painful when squeezed.
- The disease causes inflammation and remodeling of the medullary cavity of the diaphysis of long bones.
- The humerus, proximal ulna and femur are commonly affected.
- Radiographic signs often do not correlate well with clinical signs of lameness.
References
(Trostel et al.) Canine lameness caused by developmental orthopedic diseases: Panosteitis, Legg-Calve-Perthes disease and hypertrophic osteodytrophy. Compendium (2003); 25(4), 282-287)
