Tick-borne diseases are often encountered in canine clinical practice. In the present study, a molecular epidemiological survey of dogs in Japan was conducted to understand the prevalence and geographical distribution of Babesia spp., Hepatozoon spp., Ehrlichia spp. and Anaplasma spp. Pathogen-derived DNA in blood samples obtained from 722 dogs with a history of exposure to ticks and/or fleas was examined by PCR. The prevalence of Babesia gibsoni, Babesia odocoilei-like species, Hepatozoon canis and Ehrlichia spp./Anaplasma spp. was 2.4% (16/722), 0.1% (1/722), 2.5% (18/722) and 1.5% (11/722), respectively. While B. gibsoni and Ehrlichia spp./Anaplasma spp. were detected in the western part of Japan, H. canis was detected in Tohoku area in addition to western and central parts of Japan.

Sensitive detection methods for nitrite (NO2 –) and nitrate (NO3 –) ions are essential to understand the nitrogen cycle and for environmental protection and public health. Herein, we report a detection method that combines ion-chromatographic separation of NO2 – and NO3 –, on-line photochemical conversion of these ions to peroxynitrite (ONOO–) by irradiation with a 222 nm excimer lamp, and chemiluminescence from the reaction between luminol and ONOO–. The detection limits for NO2 – and NO3 – were 0.01 and 0.03 μM, respectively, with linear ranges of 0.010–2.0 and 0.10–3.0 μM, respectively, at an injection volume of 1 μL. The results obtained by the proposed method for seawater analysis corresponded with those of a reference method (AutoAnalyzer based on the Griess reaction). As luminol chemiluminescence can measure ONOO– at picomolar concentrations, our method is expected to be able to detect NO2 – and NO3 – at picomolar concentrations owing to the high conversion ratio to ONOO– (>60%), assuming that contamination and background chemiluminescence issues can be resolved. This method has the potential to emerge as an innovative technology for NO2 – and NO3 – detection in various samples.