Canine Panosteitis
Canine Panosteitis, also referred to as eosinophilic panosteitis, enostosis, endosteal proliferation of new bone, is an acquired self-limiting inflammatory developmental orthopedic disease of undetermined cause that affects the diaphyseal and metaphyseal regions of the long bones of rapidly growing large- and giant-breed dogs, typically between 5 and 18 months of age.
Among the overrepresented breeds affected with Panosteitis are German Shepherds, Doberman Pinschers, Golden Retrievers, Saint Bernards, Labrador Retrievers, and Basset Hounds, although it may occur in other breeds. Males are more commonly affected than females.
Panosteitis is a disease of the medullary bone characterized by bone marrow adipocyte degeneration, intramembranous ossification, and bony remodeling that results in medullary fibrosis and in some cases results in periosteal/endosteal new bone formation.
Clinical signs:
Pain-related lameness is the main clinical sign, and it should be considered as a differential diagnosis for any lameness in a young dog. Pain on direct palpation of the diaphysis of long bones is characteristic of panosteitis, most commonly affected are ulna, radius and humerus.
Diagnosis:
Patient history, signalment and clinical presentation are the first steps in forming a presumptive diagnosis, followed by a physical and orthopedic examination.
Orthopedic Radiographs should be performed as a way to confirm diagnosis and rule out other orthopedic diseases with similar clinical signs such as Hypertrophic Osteodystrophy and Osteochondrosis Dissecans.
Radiographic signs of panosteitis are frequently not compatible with clinical signs and will appear days or weeks later. The earliest radiographic sign of panosteitis is a decrease in opacity around the nutrient foramen. Later signs include an increase in mineral opacity within the medullary canal of long bones and loss of the normal trabecular bone pattern. Smooth periosteal and endosteal new bone may also be seen in more severe cases. Radiographs of the affected limb may be compared with those of the contralateral limb to assist in diagnosis.
Treatment:
Panosteitis is a self-limiting disease and resolves on its own. Episodes of pain and lameness from panosteitis last a few weeks in each affected bone. It may recur until the patient is about 18-24 months of age, after which there are typically no long-term consequences for the patient’s health.
Treatment consists of reduce pain and inflammation with the use of analgesics and anti-inflammatory drugs, in addition to controlled physical activity.
Sources:
Nina R Kieves, , Juvenile Disease Processes Affecting the Forelimb in Canines, Vet Clin North Am Small Anim Pract. 2021 Mar;51(2):365-382.
Demko J, McLaughlin R (2005). "Developmental orthopaedic disease". Vet Clin North Am Small Anim Pract. 35 (5): 1111–35,
Biery, D.N.; Lenehan, T.M.; Van Sickle, D.C. (1985). "Canine Panosteitis". Textbook of Small Animal Orthopaedics. Retrieved 2006-08-19.
Barrett RB, Schall WD, Lewis RE. Clinical and radiographic features of canine eosinophilic panosteitis. JAAHA. 1968;4:94-104.
