ABSTRACT. DNA from 111 ticks collected by flagging in Tokachi district, Eastern Hokkaido, Japan were examined for infection with Rickettsia and Ehrlichia, by PCR and sequencing methodology. For Rickettsia, analysis of the partial sequence of the citrate synthase gene was successfully performed on 11 DNA samples from I. persulcatus, and 7 of them showed 99.8% identical with Rickettsia helvetica while the other 4 showed 99.8% identical with 'Candidatus Rickettsia tarasevichiae'. For Ehrlichia, a partial sequence of the 16S rRNA gene detected from I. persulcatus was 100% identical with that from Ehrlichia muris, and another DNA sample from I. ovatus showed 99.8% identical with Ehrlichia species detected from I. ovatus. The results suggest that the pathogens detected here might be distributed in this area.

Double-chambered right ventricle was diagnosed in two dogs, one of them a pup and the other full grown. Both dogs underwent surgery using the novel approach of right ventricular outflow chamber ventriculotomy via left intercostal thoracotomy with moderate hypothermia and moderate pump flow cardiopulmonary bypass under beating heart. No major complication occurred during and after the operation. On continuous wave Doppler echocardiography, the pressure gradient across the stenosis in the right ventricle decreased from 130 mmHg pre-operatively to 40 mmHg post-operatively at 1 year 5 months in the adult dog, and from 209 mmHg pre-operatively to 47 mmHg post-operatively at 1 year in the pup. Both dogs are active without clinical signs.