The 17th Annual Meeting of the French Branch of the European Association of Fish Pathologists (EAFP) was held on 2 July 2025 Ploufragan-Plouzané-Niort Laboratory of French Agency for Food, Environmental and Occupational Health & Safety (Anses) in Ploufragan, Brittany, France. The meeting was organized by Pierre-Marie Boitard, Secretary of the French Branch of the EAFP, and Sandrine Baron (Mycoplasmology-Bacteriology-Antimicrobial Resistance Unit, Anses). The event was opened by Pierre-Marie Boitard and Nicolas Eterradossi, Director of the Anses Ploufragan-Plouzané-Niort Laboratory.

The meeting brought together around thirty participants from the aquatic animal health community, including researchers, doctoral students, veterinarians, and representatives of the aquaculture sector from several French research and higher education institutions, including Anses, Ifremer, Oniris, and Inrae.

A total of eleven oral presentations highlighted recent advances in fish and shellfish pathology. The keynote lecture, delivered by Steve Charette (Université Laval, Québec, Canada), addressed antimicrobial resistance in Aeromonas salmonicida salmonicida, the causative agent of furunculosis, and discussed current challenges and alternative approaches to disease control in aquaculture.

Antimicrobial resistance was further explored through two additional contributions. The first presented preliminary findings from a recent national study of the antimicrobial susceptibility of bacterial pathogens isolated from farmed fish in France. The second focused on resistance plasmids in Aeromonas salmonicida subsp. salmonicida, providing new insights into the genetic mechanisms.

Five presentations addressed the detection and characterization of bacterial (Vibrio spp., Flavobacterium spp.), viral (OsHV-1), and parasitic (Bonamia ostreae) pathogens. Collectively, these studies illustrated the growing importance of sequencing technologies for pathogen identification, epidemiological investigations, and disease surveillance in aquatic environments.

The meeting also covered broader aspects of aquatic animal health. Presentations examined the complementary value of macroscopic and microscopic approaches in the diagnosis of nodular lesions, the modelling of OsHV-4 epidemiological dynamics, and advances in vaccination strategies against furunculosis in rainbow trout.

The diversity of topics presented during this meeting reflects the vitality of the French fish pathology community and highlights the importance of multidisciplinary approaches for addressing current and emerging challenges in aquaculture health. The eleven abstracts presented in this issue provide an overview of these contributions and underscore the continued commitment of the EAFP French Branch to promoting scientific exchange and fostering collaboration among researchers, diagnosticians, and aquatic animal health professionals.

The book of abstract is available for download.