Editorial for the Thematic Issue on Fish Health and Disease Management IIEditorial

M Faldyna

Vet Med - Czech, 2026, 71(7)  

Efficacy of five peroral therapeutics against Ichthyophthirius multifiliis infestation in salmonidsOriginal Paper

K Matejickova, J Motlova, H Novotna, Z Mikulkova, P Ginterova, M Jerabek, L Pojezdal

Vet Med - Czech, 2026, 71(7):255-262 | DOI: 10.17221/99/2025-VETMED  

Ichthyophthirius multifiliis is a widespread parasitic ciliate causing significant losses in intensive freshwater aquaculture. This study evaluated the efficacy of medicated feed containing amprolium hydrochloride (2 mg/kg b.w./day), clopidol (2 mg/kg b.w./day), praziquantel (20 mg/kg b.w./day), toltrazuril (50 mg/kg b.w./day), and doxycycline (40 mg/kg b.w./day) administered at different stages of infection in experimentally infected brook trout fingerlings. Doxycycline and praziquantel demonstrated high protective efficacy (0–5% mortality) when applied during parasite exposure or the preclinical stage of infection. In contrast,...

An experimental challenge model for infecting African catfish (Clarias gariepinus) with Edwardsiella tardaOriginal Paper

I Toulova, V Vaibarova, I Papezikova, K Matejickova, I Mikulikova, H Novotna, M Palikova

Vet Med - Czech, 2026, 71(7):263-270 | DOI: 10.17221/102/2025-VETMED  

Edwardsiella tarda is an important fish pathogen that causes outbreaks leading to significant losses in aquacultural species such as African catfish (Clarias gariepinus). In order to study host-pathogen interactions and design preventive strategies, it is essential to prepare a reliable experimental infection model. The aim of this study was to develop a reproducible immersion challenge model for E. tarda infection in C. gariepinus. The present study consisted of preliminary experiments and a main experiment evaluating the different routes of infection and the bacterial concentrations and exposure durations in an immersion...

Rearing system type affects baseline and post-vaccination immune gene expression in Atlantic salmon gills during smoltificationOriginal Paper

D Mudronova, A Lagesen, E Pilipcinec, N Chomova, M Ratvaj

Vet Med - Czech, 2026, 71(7):271-279 | DOI: 10.17221/93/2025-VETMED  

Atlantic salmon undergo critical development before sea transfer, and vaccination during this stage is routine to build protective immunity. This study compared immune responses to vaccination in smolt-stage salmon reared in flow-through (FT) versus recirculating (REC) aquaculture systems. Ten clinically healthy fish per facility were collected one week before and two weeks after intraperitoneal vaccination with commercial multivalent vaccines. Using qPCR, we compared immune gene expression in the fish gills. Before the vaccination, REC fish exhibited higher relative expression of genes coding cathelicidin-1 (cath-1), interleukin-1β...

The contribution of polymer additives to microplastic toxicity: A long-term study with Oncorhynchus mykiss exposed to polystyrene microparticles with different hexabromocyclododecane contentOriginal Paper

N Hodkovicova, J Blahova, K Stastny, M Charvatova, A Franc, F Tichy, L Sedlackova, J Mares, M Faldyna, Z Svobodova

Vet Med - Czech, 2026, 71(7):280-294 | DOI: 10.17221/95/2025-VETMED  

Although microplastic toxicity in fish has been extensively studied, the role of polymer additives remains insufficiently understood. This study investigated the combined effects of polystyrene (PS) microplastics and the brominated flame retardant hexabromocyclododecane (HBCD) on the health of rainbow trout (Oncorhynchus mykiss) following six weeks of dietary exposure. Fish were exposed to PS particles with varying HBCD content (0.0 mg/g – PS-HBCD_free, 0.2 mg/g – PS-HBCD_low, 1.0 mg/g – PS-HBCD_high) or to HBCD alone (HBCD_only). The combination of PS and HBCD induced the most...