Template-Type: ReDIF-Article 1.0 Author-Name: M Ondrackova Author-Workplace-Name: Institute of Vertebrate Biology of the Czech Academy of Sciences, Brno, Czech Republic Author-Name: J Kolarova Author-Workplace-Name: South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Vodňany, Czech Republic Author-Name: K Skocovska Author-Workplace-Name: Institute of Vertebrate Biology of the Czech Academy of Sciences, Brno, Czech Republic Title: In vitro comparison of anthelmintic efficacy across Gyrodactylus species Abstract: Gyrodactylosis, caused by monogenean parasites of the genus Gyrodactylus, poses a significant threat to aquaculture, particularly under intensive farming conditions. This study evaluated the in vitro effectiveness of three veterinary anthelmintics - fenbendazole (FBZ), levamisole hydrochloride (LHC), and ivermectin (IVM) - against four Gyrodactylus species collected from wild cyprinid hosts. Parasite survival was monitored over 48 h at 6-7 °C. LHC showed the highest efficacy at both tested concentrations (30 and 50 mg/l), achieving near-complete mortality within 8 hours. FBZ and IVM were significantly less effective, with 23% and 33% of parasites surviving, respectively. Species-specific differences in drug susceptibility were observed, particularly with FBZ and IVM, with G. carassii showing consistently higher sensitivity than G. laevis, G. rutilensis, and G. vimbi. Lower water temperatures probably contributed to reduced drug efficacy and prolonged parasite survival. These findings highlight the importance of species-level evaluation and temperature considerations when selecting anthelmintic treatments for gyrodactylosis. In vitro testing under controlled conditions offers valuable insights into parasite susceptibility and complements in vivo approaches. Further research incorporating broader parasite diversity, temperature ranges, and pharmacological profiles is recommended to optimise treatment strategies in aquaculture. Keywords: fenbendazole, gyrodactylids, ivermectin, levamisole, survival Journal: Veterinární medicína Pages: 129-138 Volume: 71 Issue: 4 Year: 2026 DOI: 10.17221/79/2025-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/79/2025-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-202604-0001.txt Handle: RePEc:caa:jnlvet:v:71:y:2026:i:4:id:79-2025-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: R Dobsikova Author-Workplace-Name: Department of Animal Breeding, Animal Nutrition and Biochemistry, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: P Marsalek Author-Workplace-Name: Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: J Velisek Author-Workplace-Name: Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia, České Budějovice, Czech Republic Author-Name: J Blahova Author-Workplace-Name: Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, Brno, Czech Republic Title: Effect of a 24-hour praziquantel bath on the haematological and biochemical profile and selected parameters of oxidative stress in grass carp (Ctenopharyngodon idella) Abstract: This study assessed the effect of a 24-hour bath with praziquantel (2 and 4 mg/l) on grass carp (Ctenopharyngodon idella) by monitoring the haematological parameters, plasma biochemical profile, and oxidative stress indices. Fish were sampled at 24-, 48-, 72-, and 96-hours post-exposure (hpe). The haematological analysis revealed a significant increase (P < 0.05) in the white blood cell count immediately after treatment at both concentrations, with no subsequent changes. Within the plasma biochemical profile, a significant decrease (P < 0.05) was observed only in chloride (24 hpe at 2 mg/l; 72 hpe at both concentrations) and in magnesium (48 hpe at 2 mg/l). The oxidative stress responses indicated that the gill was the most responsive tissue. In the gill, the catalase and glutathione-S-transferase activities increased significantly (P < 0.05) at 48 hpe at 4 mg/l. Lipid peroxidation in the gill decreased at 48 hpe but increased at 72 hpe following exposure to 4 mg/l. In the hepatopancreas, the glutathione peroxidase activity significantly decreased at 48 hpe at 2 mg/l. In the plasma, significant changes (P < 0.05) were detected only in the ceruloplasmin activity, which decreased at 72 hpe in the 2 mg/l group. These findings provide essential baseline data supporting the potential future application of praziquantel in aquaculture. Keywords: antioxidant enzymes, blood, lipid peroxidation, quinoline antiparasitic Journal: Veterinární medicína Pages: 147-155 Volume: 71 Issue: 4 Year: 2026 DOI: 10.17221/89/2025-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/89/2025-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-202604-0002.txt Handle: RePEc:caa:jnlvet:v:71:y:2026:i:4:id:89-2025-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: I Mikulikova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: Z Lepkova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: H Bandouchova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: J Blahova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: I Papezikova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: H Novotna Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Workplace-Name: Veterinary Research Institute, Brno, Czech Republic Author-Name: I Toulova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: K Kobelkova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Name: K Odehnalova Author-Workplace-Name: Czech Academy of Sciences, Brno, Czech Republic Author-Name: E Postulkova Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: M Radojicic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: J Mares Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Author-Name: D Mudronova Author-Workplace-Name: University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovak Republic Author-Name: M Palikova Author-Workplace-Name: University of Veterinary Sciences Brno, Brno, Czech Republic Author-Workplace-Name: Mendel University in Brno, Brno, Czech Republic Title: The effect of Lactiplantibacillus plantarum probiotic supplement on rainbow trout challenged with Aeromonas salmonicida Abstract: Two probiotic (Lactiplantibacillus plantarum) supplementation strategies (continuous and cyclic) were evaluated for their ability to enhance resistance of rainbow trout (Oncorhynchus mykiss) to Aeromonas salmonicida infection. Neither of these strategies improved post-challenge survival. Instead, cyclic administration resulted in a significantly higher mortality rate (73%) compared with continuous supplementation (52%) and the control group (46%). One week post-challenge, most haematological, plasma biochemical, and immune parameters showed no significant difference between treatments, though fish receiving cyclic supplementation did exhibit a reduced lymphocyte count. However, three weeks post-challenge, this same group showed a significant decrease in total phagocyte number and in the proportion of phagocytes within white blood cells. IgM concentrations were significantly lower in both probiotic-supplemented groups than in the control group. In the cyclic group, reductions in interleukin-10 and elevations in total protein levels were also observed. Microbiome analysis of gut content three weeks post-challenge revealed a marked decline in microbial diversity in both probiotic-treated groups. These findings indicate that, under the experimental conditions, probiotic supplementation did not provide protection against A. salmonicida infection and that cyclic administration may disrupt immune homeostasis and intestinal microbial stability, ultimately compromising host resilience. Keywords: furunculosis, gut microbiota, lactobacilli, Oncorhynchus mykiss Journal: Veterinární medicína Pages: 156-168 Volume: 71 Issue: 4 Year: 2026 DOI: 10.17221/101/2025-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/101/2025-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-202604-0003.txt Handle: RePEc:caa:jnlvet:v:71:y:2026:i:4:id:101-2025-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: Z Mikulkova Author-Workplace-Name: Tekro, spol. s r.o., Prague, Czech Republic Author-Name: K Matejickova Author-Workplace-Name: Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czech Republic Author-Name: J Motlova Author-Workplace-Name: Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czech Republic Author-Name: P Ginterova Author-Workplace-Name: Tekro, spol. s r.o., Prague, Czech Republic Author-Name: M Jerabek Author-Workplace-Name: Tekro, spol. s r.o., Prague, Czech Republic Author-Name: L Pojezdal Author-Workplace-Name: Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czech Republic Title: Oral efficacy of controlled-release doxycycline against Ichthyophthirius multifiliis infestation in salmonids Abstract: Ichthyophthiriosis, caused by Ichthyophthirius multifiliis, is a major threat in salmonid aquaculture. This study evaluated the efficacy of orally administered standard doxycycline and controlled-release doxycycline formulations in experimentally infected brook trout (Salvelinus fontinalis). Fish received medicated feed for 10 days starting seven days post-infection. Controlled-release doxycycline achieved the highest survival rate (84.2%), followed by standard doxycycline (73.7%), while no control fish survived after day 25 post-infection. Both drug formulations eliminated trophonts from the skin and gills by 20 days post-treatment. Despite a 2.5-fold lower dietary dose, the controlled-release doxycycline achieved a tissue concentration equivalent to ~32% of that of standard doxycycline, with similar retention rates. Levels of doxycycline residues in water declined over time for both groups, indicating limited environmental release. These results demonstrate the effective mitigation of ichthyophthiriosis with orally administered doxycycline and the enhancement of antiparasitic efficacy and reduction of drug load in tissues and the environment via controlled-release technology, supporting its potential as a sustainable medicated feed strategy in salmonid aquaculture. Keywords: brook trout, controlled release drug, medicated diet, rainbow trout Journal: Veterinární medicína Pages: 139-146 Volume: 71 Issue: 4 Year: 2026 DOI: 10.17221/104/2025-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/104/2025-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-202604-0004.txt Handle: RePEc:caa:jnlvet:v:71:y:2026:i:4:id:104-2025-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: M Faldyna Author-Workplace-Name: Department of Infectious diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czech Republic Title: Editorial for the Thematic Issue on Fish Health and Disease Management Journal: Veterinární medicína Number: 0 Volume: 71 Issue: 4 Year: 2026 File-URL: http://vetmed.agriculturejournals.cz/artkey/vet-202604-0005_editorial-for-the-thematic-issue-on-fish-health-and-disease-management.php File-Format: text/html File-URL: http://vetmed.agriculturejournals.cz/pdfs/vet/2026/04/05.pdf File-Format: Application/pdf Handle: RePEc:caa:jnlvet:v:71:y:2026:i:4:id:vet-202604-0005