The aim of the present study was to investigate the oxidative stress occurrence during canine distemper (CD) virus infection in dog. For that, plasma concentrations of markers for oxidative stress (malondialdehyde (MDA), nitrates and nitrites, and ceruloplasmin at a lesser extend) and of antioxidant compounds (glutathione (GSH), ascorbate. retinol and P-carotene) were measured and compared in 11 naturally CD infected dogs (4 with a predominant neurological form, 3 with 1 pulmonary form, 3 with in intestinal form and 1 with only general signs) and in 6 healthy controls. All infected dogs exhibited significantly elevated plasma concentrations of oxidant markers (MDA, nitrates and nitrites) and of ceruplasmin compared to controls (p < 0.01) whereas antioxidant concentrations were significantly lowered in the diseased group (p < 0.05 for ascorbate and p < 0.01 for the others). Nevertheless, although nitrite concentrations were significantly decreased in (logs with neurological signs compared to the other infected clogs, the intensity of the variations of markers for oxidant and antioxidant status was independent of a specific clinical form of the disease. These results demonstrated the accumulation of reactive oxygen species leading to lipid peroxidation and to consumption of antioxidant system during acute CD in dogs.