Computed Tomographic Features and Prevalence of Orbital Ligament Mineralization in Dogs

Mineralization within the orbital ligament (OL) is occasionally observed on canine head computed tomography (CT) examinations, typically without associated clinical signs. This feature has been only briefly mentioned in the veterinary literature. The present retrospective descriptive study evaluated 402 dogs to determine the prevalence and CT characteristics of OL mineralization, including its location, morphology, margins, symmetry, size, and attenuation. Associations with signalment, medical history and concurrent mineralization were also assessed. Orbital ligament mineralization was identified in 157 of 402 dogs (39.1%). The lesion was consistently located dorsally (100%), and was most often symmetrical, triangular, well-defined and heterogenous. The presence of OL mineralization was significantly associated with increasing age and body weight, as well as with concurrent mineralization in other sites, such as lungs and ears. The lesion was significantly less frequent in brachycephalic dogs. No associations were found with facial trauma, orbital disease or other pathological conditions. Orbital ligament mineralization appears to be a common incidental finding in canine head CT studies, most likely representing a benign, age-related, and non-pathological change.