Myxomatous mitral valve disease (MMVD) is the most common acquired heart disease in dogs and its occurrence in small-and medium-sized dogs has been extensively investigated. MMVD has been described in large breed dogs as well, but substantial knowledge gaps remain. The aim of this study was to provide characteristics, survival times, and prognostic variables in large breed dogs with MMVD. Medical records of dogs diagnosed with MMVD, between 2012 and 2021, were retrospectively reviewed and 202 dogs were analyzed. Median survival time (MST) for all-cause mortality was 800 days for stage B1 dogs, 274 days for stage B2 dogs, and 184 days for stage C dogs. The MST for cardiac-related death for B1 dogs could not be calculated (because survival was greater than 50% at the last timepoint) and for stage B2 and C dogs the MST were 484 and 252 days, respectively. These findings suggest that the frequency of cardiac-related death is low in large breed dogs with stage B1 MMVD. In addition, increased left atrial and ventricular size, evidence of systolic dysfunction, a thrilling murmur, and increased early trans-mitral peak velocity are predictors of cardiac-related death. Data also suggest that the risk of a negative outcome increases profoundly when large breed dogs advance from ACVIM stage B1 into stage B2 or C.

Background/Objectives: Histological assessment of the response to neoadjuvant immunotherapy in stage IIIB/C cutaneous melanoma is commonly performed using the INMC recommendations, which advocate embedding the entire tumour bed. However, this approach is highly resource-intensive. The original Swedish National Clinical Cancer Care Guidelines for Melanoma recommend a reduced embedding strategy, but its diagnostic performance in comparison with full embedding has not been systematically evaluated. We aimed to assess whether a reduced sampling approach based on selecting representative tumour bed slices provides comparable response classification to comprehensive embedding according to the INMC protocol. Methods: Ten consecutive patients with stage IIIB/C melanoma treated with neoadjuvant immunotherapy and subsequent lymph node dissection were included. All lymph node material was completely embedded, and the pathological response was evaluated using INMC criteria. Response classification based on the full embedding of the tumour bed was compared with reduced-sampling approaches that simulate the Swedish National Clinical Cancer Care Guidelines for Melanoma. Agreement between sampling methods was analyzed. Results: Targeted reduced sampling of two slices per lymph node demonstrated complete agreement with the full embedding for the INMC response category. Conclusions: In our study, a targeted reduced-embedding strategy focusing on slices with the largest area of tumour bed enables accurate histological assessment of response to neoadjuvant immunotherapy in stage IIIB/C melanoma while substantially reducing workload. These findings support the feasibility of targeted reduced embedding of instructions in the Swedish National Clinical Cancer Care Guidelines for Melanoma as an efficient alternative to full embedding of the lymphadenectomy specimens.