To describe the radiographic appearance of benign bone infarcts and bone infarcts associated with neoplasia in dogs and determine the utility of radiography in differentiating benign and malignancy-associated bone infarcts.
49 dogs with benign (n = 33) or malignancy-associated (16) infarcts involving the appendicular skeleton.
A retrospective cohort study was performed by searching a referral osteopathology database for cases involving dogs with a histologic diagnosis of bone infarction. Case radiographs were anonymized and reviewed by 2 board-certified veterinary radiologists blinded to the histologic classification. Radiographic features commonly used to differentiate aggressive from nonaggressive osseous lesions were recorded, and reviewers classified each case as likely benign infarct, likely malignancy-associated infarct, or undistinguishable.
Only 16 (48%) of the benign infarcts and 6 (38%) of the malignancy-associated infarcts were correctly classified by both reviewers. Medullary lysis pattern and periosteal proliferation pattern were significantly associated with histologic classification. Although all 16 (100%) malignancy-associated lesions had aggressive medullary lysis, 23 of the 33 (70%) benign lesions also did. Eight of the 16 (50%) malignancy-associated infarcts had aggressive periosteal proliferation, compared with 7 of the 33 (21%) benign infarcts.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested that radiography was not particularly helpful in distinguishing benign from malignancy-associated bone infarcts in dogs.
Three 17-day-old Labrador Retriever puppies were referred for evaluation because of acute, progressive respiratory distress. The puppies were from the same litter, still suckling, and behaving normally 12 hours earlier. Housing consisted of a whelping box lined with towels, which was cleaned with dilute chlorhexidine solution. Pine oil solution, disinfectant spray,a and bleach were used to clean adjacent areas. The breeding pair had been vaccinated with a core vaccination protocol for rabies, distemper, adenovirus, parainfluenza, and parvovirus and did not have any clinical signs of illness. Four remaining puppies from the litter were clinically normal. Three months