Two genogroups of Akabane virus, genogroup I (GI) and genogroup II (GII), often cause seasonal epidemics of Akabane disease in Japan. Therefore, a vaccine capable of eliciting neutralizing antibodies against both genogroups is crucial for disease prevention. While a GI vaccine could induce neutralizing antibodies against both GI and GII, a monovalent GI vaccine is not available yet. In this study, we evaluated the antibody responses in cattle to a monovalent inactivated vaccine containing the KN-06 strain classified as GI (KD-412, vaccination at 0 and 2 weeks, n=3), in comparison with a commercial trivalent inactivated vaccine containing the KN-06 strain (K3, vaccination at 0 and 2 weeks, n=4) and a commercial monovalent live vaccine containing the TS-C2 strain classified as GII (L, vaccination at 0 week, n=3). Then, one year after the first vaccination, we administered KD-412 to cattle vaccinated with KD-412 or L, and K3 to cattle vaccinated with K3, respectively. The neutralizing antibody titers against GI and GII elicited by second dose of KD-412 were equivalent to those elicited by second dose of K3. These titers persisted for one year. All cattle vaccinated with L showed sufficient immune responses to both GII and GI following KD-412 vaccination. In conclusion, the KD-412 monovalent vaccine is able to induce neutralizing antibodies against both GI and GII, and could be effective for vaccination against Akabane disease.

We conducted a seasonal study to investigate the duration of slaked lime decomposition in the field. The percentages of calcium hydroxide and calcium carbonate in the slaked lime were measured over time and a reagent was added to the slaked lime to assess color changes. The results showed that most of the calcium hydroxide was converted to calcium carbonate after about one week in every season. The reagent used in this study showed that the change in the color of the drops on the slaked lime surface coincided with the change in the percentage of calcium hydroxide. The reagent was shown to be useful as a simple test of slaked lime decomposition in the field. Additionally, a survey was conducted on the use of slaked lime in livestock farms. Many farms have a slaked lime application interval of more than two weeks, which may be after it has lost its disinfectant effect. The reagent can contribute to the efficient application of slaked lime while retaining its disinfectant effect. The results of this study indicated that the disinfection effect of slaked lime was significantly weakened by precipitation. We recommend that slaked lime be applied about once a week, even in the absence of precipitation.

A dog with a history of cardiac arrest under general anesthesia exhibited bradyarrhythmia refractory to treatment with atropine and isoproterenol during anesthesia for imaging. Although it was necessary to perform a total ear canal ablation on the dog, the possibility of unstable hemodynamics due to bradyarrhythmia and secondary hypotension developing intraoperatively was considered. Therefore, a temporary pacemaker was used to maintain the heart rate and thus stabilize hemodynamics. The temporary pacemaker was placed on the right ventricle after the introduction of anesthesia and the heart rate of the dog was set between 80 and 110 bpm. The invasive blood pressure during anesthesia was stabilized by using dopamine together with the pacemaker. Intraoperative or postoperative complications due to the temporary pacemaker were not observed. Thus, a temporary pacemaker is considered to be useful in the stabilization of the heart rate resulting in the stability of hemodynamics when a dog with a history of cardiac arrest due to anesthesia or hypotension due to bradyarrhythmia not stabilized by medicine has to undergo anesthesia for a long time.