Thrombocytopathia and light-chain proteinuria in a dog naturally infected with Ehrlichia canis

A 6–year‐old dog was presented for evaluation of recurrent epistaxis. Platelet counts, biochemical tests, and coagulation tests were within the normal range, but a mucosal bleeding time was prolonged; there was hyperproteinemia and a monoclonal gammopathy. Heterogeneity of light chains appeared in urine, however, thus suggesting that the gammopathy was polyclonal. Platelet aggregation tests showed decreased responsiveness to collagen. An Ehrlichia canis indirect fluorescent‐antibody titer was positive (1:40). Treatment with tetracycline, melphalan, and prednisone resulted in a rapid clinical improvement that persisted for at least 3 years.