A 7-year-old male Yorkshire terrier was examined for multiple plaques
and nodules on the skin. The clinical, cytological and histopathologic
al features indicated a malignant histiocytosis. Cytoreductive chemoth
erapy produced moderate clinical improvement, but died at day 90 after
the first admission. Pathological examination revealed the neoplastic
histiocytes in the skin as well as in the myocardium and skeletal mus
cles.