Canine eosinophilic pulmonary granulomatosis: case report and literature review

We describe and illustrate herein a case of eosinophilic pulmonary granulomatosis (EPG) in a 16-mo-old, castrated male, Great Pyrenees crossbred dog. EPG appears to differ from eosinophilic pneumonias and eosinophilic bronchopneumopathy in dogs by the presence of nodules and masses in the lungs composed of eosinophils, macrophages, and various combinations of lymphocytes, plasma cells, neutrophils, and mast cells within fibrous tissue. Specific information from this dog was added to the information from the limited number of other dogs diagnosed with EPG reported in the veterinary literature, and the information analyzed. EPG appears to have no breed or sex predilection and tends to be a disease of younger dogs, often ≤ 3 y of age. Antemortem imaging of nodules and masses in the lungs, combined with cytologic evidence of eosinophils in the lesions, is highly suggestive of EPG, and the diagnosis can be confirmed postmortem. Concurrent eosinophilia and basophilia can be features of EPG, but their diagnostic value requires further investigation, as does the possible causal association with Dirofilaria immitis infection.