This paper reports the clinical findings and surgical treatment of feline right patent ductus arteriosus (RPDA) with a left aortic arch. A two-month-old female Maine Coon was referred for an investigation of regurgitation after weaning. RPDA with a left aortic arch was diagnosed based on the echocardiographic and computed tomography (CT) findings.A right-fourth intercostal thoracotomy was found to be an appropriate approach to the duct. Preoperative diagnosis is crucial and diagnostic imaging, including radiography, echocardiography, and cardiac CT examination, is essential for determining if the aortic arch is right or left.

Patent ductus arteriosus (PDA) is a rare congenital cardiovascular anomaly in cats. Due to their small body, intercostal thoracotomy is the most common option to close the PDA.However, few reports detail the surgical technique for ligating PDA in kittens. In this case report, three cats weighing 1.4 kg, 1.2 kg, and 2.9 kg were diagnosed PDA. Clip ligation via left fourth intercostal thoracotomy was performed and the cats were successfully treated.Postoperative echocardiography showed no residual flow in any of the cases. This case report highlights clip occlusion for small cats with PDA could be safe and effective.

Objective: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant B.1.1.529 (Omicron) was first detected in Japan in November 2021. In Osaka, public health centres subsequently increased active case finding and encouraged self-isolation. This study investigated the effectiveness of these countermeasures. Methods: Cases targeted for analysis were persons who had neither recently travelled abroad nor had contact with foreign tourists but tested positive for SARS-CoV-2 between 24 November 2021 and 4 January 2022 and were suspected or confirmed to have the Omicron variant. We performed a descriptive analysis and calculated the reproduction number (R) for each generation using the branching process method. Genomic sequencing data were analysed to plot a haplotype network. Results: A total of 251 cases were analysed. The median age was 30 years, and 46% (115/251) were in their 20s or younger. The first Omicron case in Osaka was detected on 21 December 2021. Local public health centres conducted health monitoring and contact tracing. We analysed R, using information from six clusters, including 42 pairs with a clear relationship between the case and the infected contact (infector–infectee pairs); the clusters had 19, 21 and 2 cases in each subsequent generation. The basic R (t = 0) was estimated to be 3.2, and subsequent generations (t = 1, 2) of R decreased to 1.1 and 0.1, respectively. The haplotype network showed that these cases constituted a monophyletic group with others detected around Osaka, indicating that these case-related clusters had been contained and were not involved in the nationwide Omicron waves. Discussion: Active case finding and self-isolation were found to be effective in limiting the spread of an emerging novel variant.