Bovine Borna disease causes mobility abnormalities due to Borna disease virus 1 (BoDV‐1) infection. Subclinical infections among livestock are well known. Both vertical as well as horizontal transmission has been reported. The purpose of this report was to clarify the relative risk (RR) of vertical viral transmission in dairy cattle herds on a farm that previously reported Borna disease. The antibody prevalence within the herd was 35.5% using the BoDV‐1 antibody test. The RR of vertical transmission in this group was insignificant; however, within one family line, there was a significant RR of 3.03 (90% CI 1.08‐8.49). There was no association between reproductive performance and the presence or absence of BoDV‐1 infection in the herd. BoDV‐1 antibody prevalence within this herd was elevated compared to previous reports. The RR of vertical transmission of BoDV‐1 within certain strains indicates the need for active prevention of vertical transmission.

An 8-month-old Japanese black calf died on the 12th day after the initial consultation for pneumonia. Necropsy revealed verrucous endocarditis in the mitral valve, a hepatic abscess and a pulmonary abscess. Bacteriological examination isolated Fusobacterium necrophorum subsp. necrophorum from these lesions. Histopathological examination revealed gram-negative rod bacilli in valvular endocarditis encapsulated in the liver, and pulmonary abscesses. F. necrophorum is a common pathogen for suppurative disease in fattening beef cattle, however, only one case of bovine endocarditis was reported during meat inspection in the slaughterhouse. This case features valvular endocarditis due to F. necrophorum subsp. necrophorum in the left atrium and mitral valve.

Multiple cysts and mass lesions were detected adjacent to the prostate of a 14-year-old, male, mixed breed dog with a history of perineal hernia. Histologically, the cysts were lined by epithelial cells with microvilli. The masses were mainly composed of thin walled venous and/or lymphatic structures, and partially thickened wall artery-like structures. The epithelial cells of cysts were positive for antibodies against cytokeratin AE1/AE3, CAM5.2, vimentin and Wilms' tumor protein, and the endothelial cells of masses were positive for antibodies against CD31 and factor VIII by immunohistochemical analysis. By Elastica van Gieson staining, elastic fibers were seldom observed in the thickened vascular walls, which mainly consisted of collagen fibers and muscle tissue. Based on these findings, the diagnosis was made of serosal inclusion cysts and arteriovenous fistulas in the paraprostatic area of a dog.

To investigate the possibility of tick-borne disease (TBD) occurrence in Yamagata, Japan, we attempted to detect the specific gene of TBD causative pathogens in 158 host-seeking adult ticks and 112 adult ticks biting wild animals in Yamagata from 2016 to 2018. Results revealed that all tick specimens were negative for the pathogens' gene of Japanese spotted fever, Lyme disease, tick-borne relapsing fever, tick-borne encephalitis, and severe fever with thrombocytopenia syndrome, all of which have been reported in Japan. In contrast, the specific gene sequence of Rickettsia helvetica was detected from 30 Ixodes monospinosus and a Haemaphysalis japonica. That of Rickettsia monacensis was detected from an Ixodes nipponensis. Results show that TBD known in Japan might not constitute a serious human health threat in Yamagata, but special attention is required to monitor the occurrence of TBD, including ones that have not been reported in Japan.