Summary
Objective: Identify radiographic risk factors for development of elbow dysplasia in giant breed
dogs less than one year of age.
Methods: Twenty-five giant breed puppies (Bernese Mountain dogs, English Mastiff, and Newfoundland)
were studied. Both elbows of each dog were radiographed monthly from two to six months
of age, then every other month until radial and ulnar physeal closure, followed two
months later by bilateral elbow computed tomography. Radiographic parameters measured
included the presence or absence of a separate centre of ossification of the anconeal
process (SCOAP), medial coronoid disease (MCD), ununited anconeal process, humeral
osteochondrosis, elbow incongruity, as well as the length of the radius and ulna,
radius-to-ulna ratio, and date of closure of the radial and ulnar physes.
Results: Fifteen dogs completed the study. Two Bernese Mountain dogs were diagnosed with MCD.
Risk factors significantly associated with medial coronoid disease included dyssynchronous
physeal closure and a decreased radius-to-ulna ratio, both detected between eight
to 11 months of age. A separate centre of ossification of the anconeal process was
present in 60% of the dogs, and was not a risk factor for development of elbow dysplasia.
Clinical significance: Transient, dyssynchronous growth of the radius and ulna may be a risk factor for
development of MCD in Bernese Mountain dogs. Dyssynchronous physeal closure or decreased
radius-to-ulna ratio prior to radiographic closure of the distal ulnar and radial
physes warrants further study in Bernese Mountain dogs and other breeds subject to
MCD development.
Keywords
Radiography - computed tomography - elbow dysplasia - giant breed dog
