Striped catfish (Pangasianodon hypophthalmus) farmers' perspectives on challenges and health management practices in the Mekong Delta, Vietnam: A qualitative study

Striped catfish (Pangasianodon hypophthalmus) farming in the Mekong Delta of Vietnam holds global significance with over a million tonnes produced annually at substantial export value. However, geographic concentration and farming intensity has led to substantial disease-related losses, with underreported concerns and disease control from farmers. This study employs a qualitative methodology to gain insightful perspectives from Vietnamese striped catfish farmers on industry challenges and health management practices. Thematic saturation was sought through qualitative interviews with 44 participants (19 nursery, 21 grow-out, and 4 vertically integrated farms), operating at private- or company-scales across six major production provinces (Dong Thap, An Giang, Can Tho, Vinh Long, Ben Tre, and Long An). Data were thematically analysed using the Framework method, focusing on the intricate interplay between host, environmental factors, and pathogen that contributes to rising disease prevalence and impacts profitability. Farmers articulated distress over escalating disease severity and low survival rates, exacerbated by declining water quality and major technical barriers such as seedstock and broodstock quality. Historically reported diseases, including Bacillary Necrosis in Pangasius (BNP) and Motile Aeromonas Septicaemia (MAS), remained prevalent. However, recent escalation of jaundice and swollen swim-bladder disease in grow-outs, as well as tail-rot disease (Flavobacterium columnare infection) in nurseries, have caused significant economic losses. Larger company-scale farms employed more standardised health management plans and educated staff compared to smaller, experience-based private farms. Antibiotics were perceived as less effective with infrequent antibiotic sensitivity testing, particularly among private farmers, due to inaccuracy. A trend towards reduced usage of antimicrobials and increased preference for dietary solutions was observed, with many farmers describing efforts to avoid antimicrobials, especially near harvest. Common preventive measures include regular environmental treatments and supplementary diets. However, the sector lacks advanced preventative measures, such as vaccination and early detection methods, highlighting the need for improved access to veterinary support to sustain striped catfish farming in Vietnam.