A classical swine fever (CSF) outbreak was confirmed at a pig farm in Gifu Prefecture in September 2018, after 26 years without an outbreak in Japan. Vaccination of domestic pigs and antibody testing to confirm the immune status started in October the following year. Based on an assessment of the immune status, the need to adjust the inoculation age for each farm depending on the immune status of sows in the herds was suggested. Therefore, a simulation model for estimating the optimal age for vaccination for each farm was developed by analyzing the relationship between maternally derived antibodies (MDA) and the immune response to vaccines using data from a survey of antibodies of sows and their litters. The model predicted the transfer of MDA to the litters using the Sample to Positive ratios (S/P) of the results of ELISA tests of sows, the decline in MDA, and the immune response to vaccination. The predictive accuracy of this model was evaluated using actual farm data and was considered sufficiently accurate to be used for estimating the appropriate age for vaccination. This method might be useful in preventing CSF outbreaks as the model can easily estimate the optimal age for vaccination.

Investigating a rapid and easy method for detecting cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) is important to improve screening efficacy at livestock hygiene service centers. In this study, we conducted BVDV antigen-detection ELISA tests using cattle hair root material which can be easily sampled, and the effects of the number of hair roots and pretreatment conditions on the test results were examined. The results of the ELISA test examination showed all three samples from PI cattle were positive when five or more hair roots were used, and two out of three samples were positive when only one hair root was used. Regarding the incubation time for the antigen-extraction procedure, we found that, compared to the S-N values obtained after overnight incubation which was recommended in the manufacturer's instructions, an incubation period longer than 240 minutes was enough to obtain S-N values that are greater than 90％ of the values obtained after overnight incubation while 10-120 minutes of incubation resulted in approximately 60％ of the values obtained after overnight incubation. These results should provide useful information applicable when using cattle hair roots as materials for the ELISA BVDV antigen-detection test.

Selecting the proper antibiotics for treating dairy cattle with non-agalactiae Streptococcus species-mediated mastitis is extremely important. However, limited data have been reported on the antimicrobial susceptibility of the non-agalactiae Streptococcus species isolates from dairy cattle with mastitis in Japan. Therefore, we investigated the antimicrobial susceptibility and antimicrobial resistance gene profiles of 96 non-agalactiae Streptococcus species isolated from dairy cattle with mastitis in Tochigi Prefecture, Japan, between 2010-2012 (49 isolates) and 2016-2018 (47 isolates). Over 40% of isolates in both periods were identified as Streptococcus uberis. Tetracycline resistance rate (2010-2012, 9.5%; 2016-2018, 36.4%) and pirlimycin resistance rate (2010-2012, 14.3%; 2016-2018, 31.8%) increased gradually in the S. uberis isolates. Almost all tetracycline- and pirlimycin-resistant isolates carried tetracycline resistance (tet(O), tet(S), or tet(M)) and lincomycin resistance (linB) genes, respectively. Erythromycin-resistant S. uberis isolates carried the erm(B) gene, and the minimun inhibitory concentrations for both erythromycin and pirlimycin were high.

A 6 cm diameter stalked mass was seen on the right side of the dewlap of an 11-month-old Japanese Black cattle. The surgical excision of the mass was performed and a diagnosis of myxoma was made based on histopathological findings. Approximately 2 months later, the tumor recurred at the resection site, and several small tumors of 0.5 to 1 cm in size developed on the right shoulder, right and left neck, and mandible until reoperation. A total of five tumors were resected. Based on the clinical course and histopathological findings, a diagnosis of multiple myxomas was made. At 10 months post-operation, there was no recurrence at the site of resection, and no new tumors had developed at new sites. Myxoma is a rare tumor in cattle, and there are few reports on surgical treatments and also no reports of multiple cutaneous myxoma in cattle. Although some human diseases are caused by genetic abnormalities, we have not been able to investigate the cause of the multiple occurrences of cutaneous myxoma in this case. Therefore, it is necessary to continue to monitor the recurrence of tumors in this case in the future.

A 14-year and 10-month old castrated male English Cocker Spaniel was brought to a night emergency animal hospital suffering from vomiting and limb tremors. At the time of admission, he was somnolent and unable to stand. It was suspected that he had been poisoned by ginkgo nuts or ginkgo seeds based on the owner's comments and the contents of the vomit. Treatment under hospital management commenced. Administration of a vitamin-B₆ preparation and symptomatic treatments were carried out and nine hours after treatment had begun, the dog recovered to the point where he was fully conscious and able to walk unaided. He was discharged from the hospital 11 hours after admission. For a period of 11 months after treatment there were no relapses and the dog was clinically normal.

We performed a serological analysis using an indirect immunofluorescence test to identify IgM and IgG antibodies against Encephalitozoon cuniculi in 75 rabbits showing neurological or ocular symptoms/lesions at an exotic animal clinic in Tokyo. The analysis included repeated serological tests of 27 of the 75 rabbits. Of the 75 rabbits, 40.0% (30/75) were positive for IgM antibodies and 89.3% (67/75) positive for IgG antibodies. All IgM antibody-positive rabbits were also positive for IgG antibodies. In other words, no rabbits were positive for IgM antibodies while also being negative for IgG antibodies. Of the 27 rabbits that underwent repeat serological tests, 66.7% (18/27) showed a change in antibody titers and 37.0% (10/27) showed an improvement of their symptoms. These results suggest that the repeated measurement of E. cuniculi IgM and IgG antibodies may be useful in understanding the immune status of infected rabbits, but the change of the antibody titers was not associated with the change of clinical symptoms.