ORBITAL PLASMACYTOMA IN A CAT

An Abyssinian cat presented with epistaxis, melaena and retinal vascul ar changes. Plasma protein levels were markedly elevated and a monoclo nal gammopathy was present on serum protein electrophoresis. Based on these laboratory findings, hyperviscosity syndrome was assumed to be r esponsible for the clinical signs. The cat responded initially to flui d therapy, but relapsed and then developed unilateral exophthalmia. Th e animal was euthanased and an extramedullary plasmacytoma of the righ t orbit was diagnosed at postmortem examination.